ReShape Lifesciences 10-K 27 Mar 14 2013 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2013	Feb. 28, 2014	Jun. 30, 2013
Document Information [Line Items]	'	'	'
Document Type	'10-K	'	'
Amendment Flag	'false	'	'
Document Period End Date	31-Dec-13	'	'
Document Fiscal Year Focus	'2013	'	'
Document Fiscal Period Focus	'FY	'	'
Trading Symbol	'ETRM	'	'
Entity Registrant Name	'EnteroMedics Inc	'	'
Entity Central Index Key	'0001371217	'	'
Current Fiscal Year End Date	'--12-31	'	'
Entity Well-known Seasoned Issuer	'No	'	'
Entity Current Reporting Status	'Yes	'	'
Entity Voluntary Filers	'No	'	'
Entity Filer Category	'Non-accelerated Filer	'	'
Entity Common Stock, Shares Outstanding	'	66,568,937	'
Entity Public Float	'	'	$45,186,980

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2013	Dec. 31, 2012
Current assets:	'	'
Cash and cash equivalents	$23,297,479	$22,308,781
Restricted cash	'	200,000
Accounts receivable	17,742	52,406
Inventory	1,127,941	1,271,207
Prepaid expenses and other current assets	546,744	571,654
Total current assets	24,989,906	24,404,048
Property and equipment, net	577,095	609,672
Other assets	820,767	1,082,765
Total assets	26,387,768	26,096,485
Current liabilities:	'	'
Current portion of notes payable	4,000,000	3,000,000
Accounts payable	127,329	340,555
Accrued expenses	4,186,060	3,673,609
Accrued interest payable	526,672	523,678
Total current liabilities	8,840,061	7,537,842
Notes payable, less current portion (net of discounts of $131,670 and $316,028 at December 31, 2013 and 2012, respectively)	2,868,330	6,683,972
Total liabilities	11,708,391	14,221,814
Commitments and contingencies (note 14)	'	'
Stockholders' equity:	'	'
Common stock, $0.01 par value; 125,000,000 shares authorized; 63,551,350 and 41,843,270 shares issued and outstanding at December 31, 2013 and 2012, respectively	635,514	418,433
Additional paid-in capital	239,996,934	211,628,650
Deficit accumulated during development stage	-225,953,071	-200,172,412
Total stockholders' equity	14,679,377	11,874,671
Total liabilities and stockholders' equity	$26,387,768	$26,096,485

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Notes payable, less current portion, discounts	$131,670	$316,028
Common stock, par value	$0.01	$0.01
Common stock, shares authorized	125,000,000	125,000,000
Common stock, shares issued	63,551,350	41,843,270
Common stock, shares outstanding	63,551,350	41,843,270

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	12 Months Ended			132 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013
Sales	'	$311,493	'	$311,493
Cost of goods sold	'	231,520	'	231,520
Gross profit	'	79,973	'	79,973
Operating expenses:	'	'	'	'
Research and development	11,075,493	10,668,044	16,673,238	138,525,111
Selling, general and administrative	13,658,824	11,960,893	8,583,347	73,788,687
Total operating expenses	24,734,317	22,628,937	25,256,585	212,313,798
Operating loss	-24,734,317	-22,548,964	-25,256,585	-212,233,825
Other income (expense):	'	'	'	'
Interest income	5,717	9,877	12,241	4,051,857
Interest expense	-932,364	-901,835	-722,859	-13,396,969
Change in value of warrant liability	'	'	'	-3,840,622
Other, net	-119,695	-19,181	-30,119	-402,544
Net loss	($25,780,659)	($23,460,103)	($25,997,322)	($225,822,103)
Net loss per share-basic and diluted	($0.47)	($0.59)	($0.86)	'
Shares used to compute basic and diluted net loss per share	55,009,916	39,536,500	30,205,447	'

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Loss (USD $)	12 Months Ended			132 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013
Net loss	($25,780,659)	($23,460,103)	($25,997,322)	($225,822,103)
Change in unrealized gain (loss) on available for sale investments	'	-692	692	'
Comprehensive loss	($25,780,659)	($23,460,795)	($25,996,630)	($225,822,103)

Consolidated_Statements_of_Sto

Consolidated Statements of Stockholders' Equity (Deficit) (USD $)

Total

Series A Convertible Preferred Stock

Series B Convertible Preferred Stock

Common Stock

Series C Convertible Preferred Stock

November 13, 2003 Convertible Bridge Notes

April 23, 2004 Convertible Bridge Notes

June 30, 2004 Convertible Bridge Notes

Aug-07

Oct-07

Sep-10

Dec-10

Alpha Medical, Inc.

Alpha Medical, Inc.

Beta Medical, Inc.

Beta Medical, Inc.

Series C Preferred Stock

Series C Preferred Stock

Series B Preferred Stock

Series B Preferred Stock

Series A Preferred Stock

Series A Preferred Stock

Series A Preferred Stock

Series A Preferred Stock

Series A Preferred Stock

Common Stock

Common Stock

Common Stock

Common Stock

Common Stock

Additional Paid-in Capital

Additional Paid-in Capital

Additional Paid-in Capital

Additional Paid-in Capital

Additional Paid-in Capital

Additional Paid-in Capital

Additional Paid-in Capital

Additional Paid-in Capital

Additional Paid-in Capital

Additional Paid-in Capital

Additional Paid-in Capital

Additional Paid-in Capital

Additional Paid-in Capital

Additional Paid-in Capital

Additional Paid-in Capital

Additional Paid-in Capital

Deferred Compensation

Deferred Compensation

Accumulated Other Comprehensive Income

Accumulated During the Development Stage

Series B Convertible Preferred Stock

Series B Convertible Preferred Stock

Series B Convertible Preferred Stock

Series A Convertible Preferred Stock

Series A Convertible Preferred Stock

Series C Convertible Preferred Stock

Series B Convertible Preferred Stock

Series A Convertible Preferred Stock

Common Stock

Alpha Medical, Inc.

Beta Medical, Inc.

Series A Convertible Preferred Stock

Alpha Medical, Inc.

Beta Medical, Inc.

Series A Convertible Preferred Stock

Series B Convertible Preferred Stock

Common Stock

Series C Convertible Preferred Stock

November 13, 2003 Convertible Bridge Notes

April 23, 2004 Convertible Bridge Notes

June 30, 2004 Convertible Bridge Notes

Aug-07

Oct-07

Sep-10

Dec-10

Alpha Medical, Inc.

Alpha Medical, Inc.

Beta Medical, Inc.

Beta Medical, Inc.

Common Stock

Series A Convertible Preferred Stock

Series A Convertible Preferred Stock

Series B Convertible Preferred Stock

Series B Convertible Preferred Stock

Series B Convertible Preferred Stock

Series A Convertible Preferred Stock

Series A Convertible Preferred Stock

Beginning Balance at Dec. 18, 2002

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of Series A convertible preferred stock

'

'

'

'

'

'

'

'

'

'

'

'

'

$301,674

'

$301,674

'

'

'

'

'

'

'

$55

$55

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$301,619

'

$301,619

'

'

'

'

Issuance of Series A convertible preferred stock (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

5,525

5,525

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock Issued (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

18,315

18,315

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock issued

'

'

'

'

'

'

'

'

'

'

'

'

10,000

'

10,000

'

'

'

'

'

'

'

'

'

'

'

'

'

183

183

'

'

'

'

'

'

'

'

'

'

'

'

9,817

'

9,817

'

'

'

'

'

Net loss

-603,348

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-603,348

Ending Balance at Dec. 31, 2002

20,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

110

'

'

'

'

366

'

'

'

'

622,872

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-603,348

Ending Balance (in shares) at Dec. 31, 2002

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

11,050

'

'

'

'

36,630

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of Series A convertible preferred stock

'

-661,674

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-119

'

'

'

'

-183

'

'

'

'

-661,372

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of Series A convertible preferred stock (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-11,936

'

'

'

'

-18,315

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Warrants issued for the purchase of shares of convertible preferred stock for cash

'

'

'

'

'

107

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

107

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of Series A convertible preferred stock

'

661,674

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

110

'

'

'

'

'

'

'

'

'

661,564

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of Series A convertible preferred stock (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

10,989

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock Issued (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

6,410

15,568

19,229

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock issued

10,500

'

'

'

'

'

'

'

'

'

'

'

'

350,000

'

850,000

'

'

'

'

'

'

'

64

156

192

'

'

'

'

10,308

'

'

'

'

'

'

'

'

'

'

'

'

349,936

'

849,844

'

'

'

'

Net loss

-1,900,288

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-1,900,288

Ending Balance at Dec. 31, 2003

-669,681

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

321

'

'

'

'

375

'

'

'

'

1,833,259

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-2,503,636

Ending Balance (in shares) at Dec. 31, 2003

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

32,081

'

'

'

'

37,544

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Convertible preferred stock issued upon conversion of debt

'

'

1,599,652

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

676

'

'

'

'

'

'

'

'

'

'

'

'

1,598,976

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Convertible preferred stock issued upon conversion of debt (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

67,615

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Warrants issued for the purchase of shares of convertible preferred stock for cash

'

'

48,720

'

'

'

30

20

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

48,720

'

'

'

30

20

'

'

'

'

'

'

'

'

'

'

'

'

Fair value of warrants related to convertible bridge notes

153,722

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

153,722

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock Issued (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

319,128

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock issued

'

'

7,455,225

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3,191

'

'

'

'

'

'

'

'

'

'

'

'

7,452,034

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of common stock options to nonemployees

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3,610

'

'

'

'

'

'

'

'

'

'

'

'

'

-3,610

'

'

Amortization of deferred compensation

830

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

830

'

'

'

Exercise of stock warrants

'

187,652

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

209

'

'

'

'

'

'

'

'

'

187,443

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net loss

-3,448,752

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-3,448,752

Exercise of stock warrants (in shares)

'

20,963

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

20,963

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Ending Balance at Dec. 31, 2004

5,327,418

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3,867

'

530

'

'

'

'

375

'

'

'

'

11,277,814

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-2,780

'

'

-5,952,388

Ending Balance (in shares) at Dec. 31, 2004

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

386,743

'

53,044

'

'

'

'

37,544

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Warrants issued for the purchase of shares of convertible preferred stock for cash

'

'

74,636

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

74,636

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock Issued (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

200,776

126,806

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock issued

4,738,916

'

2,994,782

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2,008

1,268

'

'

'

'

'

'

'

'

'

'

4,736,908

'

2,993,514

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of common stock options to nonemployees

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

7,288

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-7,288

'

'

'

Common stock issued to nonemployees

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

376

'

'

'

'

'

102,124

'

'

'

'

'

'

'

'

'

'

'

'

'

-102,500

'

'

Common stock issued to nonemployees (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

37,546

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Warrants issued for the purchase of shares of common stock

'

'

'

15,500

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

15,500

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Exercise of common stock options

13,450

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

49

'

'

'

'

13,401

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Exercise of common stock options (in shares)

4,927

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

4,927

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amortization of deferred compensation

25,041

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

25,041

'

'

'

Net loss

-11,215,191

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-11,215,191

Ending Balance at Dec. 31, 2005

1,974,552

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

7,143

'

530

'

'

'

'

800

'

'

'

'

19,221,185

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-87,527

'

'

-17,167,579

Ending Balance (in shares) at Dec. 31, 2005

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

714,325

'

53,044

'

'

'

'

80,017

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Convertible preferred stock issued upon conversion of debt

'

'

'

'

5,381,016

'

'

'

'

'

'

'

'

'

'

'

'

1,108

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

5,379,908

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Convertible preferred stock issued upon conversion of debt (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

110,820

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Employee stock-based compensation expense

47,479

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

47,479

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Warrants issued for the purchase of shares of convertible preferred stock for cash

735,438

'

102,022

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

735,438

'

102,022

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Nonemployee stock-based compensation expense

86,125

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

86,125

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock Issued (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

20,595

820,190

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock issued

1,000,000

'

'

'

37,602,661

'

'

'

'

'

'

'

'

'

'

'

206

8,202

'

'

'

'

'

'

'

'

'

'

'

'

999,794

'

'

'

37,594,459

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock warrants reclassified to convertible preferred stock warrant liability

'

'

'

'

-735,438

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-735,438

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common stock issued to nonemployees

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

5

'

16

'

'

5,245

'

'

4,484

'

'

'

'

'

'

'

'

'

'

'

'

-5,250

-4,500

'

'

Common stock issued to nonemployees (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

458

'

1,648

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Exercise of common stock options

39,596

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

145

'

'

'

'

39,451

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Exercise of common stock options (in shares)

14,504

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

14,504

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amortization of deferred compensation

30,798

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

30,798

'

'

'

Net loss

-17,690,477

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-17,690,477

Ending Balance at Dec. 31, 2006

28,573,772

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

9,516

'

7,143

'

530

'

'

'

'

966

'

'

'

'

63,480,152

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-66,479

'

'

-34,858,056

Ending Balance (in shares) at Dec. 31, 2006

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

951,605

'

714,325

'

53,044

'

'

'

'

96,627

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Employee stock-based compensation expense

883,310

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

883,310

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Nonemployee stock-based compensation expense

1,289,349

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,289,349

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Warrants issued for the purchase of shares of series C convertible preferred stock in valued at per warrant for debt facility commitment

'

'

'

'

550,212

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

550,212

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Warrants issued for the purchase of shares of series C convertible preferred stock in valued at per warrant for debt funding

'

'

'

'

281,321

'

'

'

197,731

194,716

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

281,321

'

'

'

197,731

194,716

'

'

'

'

'

'

'

'

'

'

Stock warrants reclassified from convertible preferred stock warrant liability

'

'

'

'

1,090,345

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,090,345

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock Issued (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

833,333

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock issued

35,447,337

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

8,333

'

'

'

'

35,439,004

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Reclassification of amounts due to shareholders for fractional shares upon reverse stock split

-355

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-355

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common stock issued to Mayo Foundation upon closing the IPO in November 2007 with a fair value of $48.30 per share

1,658,654

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

343

'

'

'

'

1,658,311

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common stock issued to Mayo Foundation upon closing the IPO in November 2007 with a fair value of $48.30 per share (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

34,341

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Conversion of preferred stock to common stock

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-9,516

'

-7,143

'

-530

'

'

'

'

17,480

'

'

'

'

-291

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Exercise of over-allotment option by underwriters in connection with the IPO for cash

3,644,477

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

817

'

'

'

'

3,643,660

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Conversion of preferred stock to common stock (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-951,605

'

-714,325

'

-53,044

'

'

'

'

1,748,030

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Exercise of over-allotment option by underwriters in connection with the IPO for cash (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

81,642

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Exercise of common stock options

21,187

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

59

'

'

'

'

21,128

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Exercise of common stock options (in shares)

5,854

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

5,854

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amortization of deferred compensation

24,812

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

24,812

'

'

'

Net loss

-28,575,348

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-28,575,348

Ending Balance at Dec. 31, 2007

45,281,520

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

27,998

'

'

'

'

108,728,593

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-41,667

'

'

-63,433,404

Ending Balance (in shares) at Dec. 31, 2007

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2,799,827

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Employee stock-based compensation expense

2,648,410

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2,648,410

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Nonemployee stock-based compensation expense

-147,855

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-147,855

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Change in unrealized gain (loss) on available for sale investments

12,988

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

12,988

'

Warrants issued for the purchase of shares of common stock

1,398,702

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,398,702

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Exercise of common stock options

65,407

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

169

'

'

'

'

65,238

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Exercise of common stock options (in shares)

16,829

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

16,829

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amortization of deferred compensation

20,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

20,000

'

'

'

Net loss

-37,874,028

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-37,874,028

Ending Balance at Dec. 31, 2008

11,405,144

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

28,167

'

'

'

'

112,693,088

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-21,667

'

12,988

-101,307,432

Ending Balance (in shares) at Dec. 31, 2008

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2,816,656

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Employee stock-based compensation expense

2,209,216

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2,209,216

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Nonemployee stock-based compensation expense

210,075

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

210,075

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Change in unrealized gain (loss) on available for sale investments

-12,988

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-12,988

'

Issuance of common stock in private investment public equity offering

15,089,853

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

21,851

'

'

'

'

15,068,002

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of common stock in private investment public equity offering (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2,185,066

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of common stock in registered direct offering

4,836,385

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

10,268

'

'

'

'

4,826,117

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of common stock in registered direct offering (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,026,845

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common stock warrants reclassified to common stock warrant liability

-1,529,670

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-1,398,702

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-130,968

Cashless exercise of warrants with an exercise price of per share in exchange for shares of common stock

494,652

'

'

4,750,126

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

622

'

1,255

'

'

494,030

'

'

4,748,871

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Cashless exercise of warrants with an exercise price of per share in exchange for shares of common stock (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

62,244

'

125,470

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Exercise of common stock options

37,517

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

134

'

'

'

'

37,383

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Exercise of common stock options (in shares)

13,450

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

13,450

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amortization of deferred compensation

20,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

20,000

'

'

'

Net loss

-31,929,200

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-31,929,200

Ending Balance at Dec. 31, 2009

5,581,110

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

62,297

'

'

'

'

138,888,080

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-1,667

'

'

-133,367,600

Ending Balance (in shares) at Dec. 31, 2009

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

6,229,731

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Employee stock-based compensation expense

2,529,355

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2,529,355

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Nonemployee stock-based compensation expense

33,204

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

33,204

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock Issued (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3,394,309

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock issued

'

5,777,532

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

33,943

'

'

'

'

'

'

'

'

'

5,743,589

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Conversion of preferred stock to common stock

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-33,943

'

'

'

'

33,943

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Conversion of preferred stock to common stock (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-3,394,309

'

'

'

'

3,394,309

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of common stock in registered direct offering

4,495,347

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

12,398

'

'

'

'

4,482,949

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of common stock in registered direct offering (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,239,717

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Warrants issued for the purchase of shares of common stock

'

'

'

289,257

'

'

'

'

'

'

424,289

100

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

289,257

'

'

'

'

'

'

424,289

100

'

'

'

'

'

'

'

'

Common stock warrants reclassified to equity from common stock warrant liability

312,751

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

312,751

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Adjustment for fractional shares upon reverse stock split

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

45

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of common stock in public equity offering

27,586,135

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

170,200

'

'

'

'

27,415,935

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Exercise of common stock options

23,697

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

86

'

'

'

'

23,611

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of common stock in public equity offering (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

17,020,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Exercise of common stock options (in shares)

8,586

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

8,586

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amortization of deferred compensation

1,667

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,667

'

'

'

Net loss

-17,347,387

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-17,347,387

Ending Balance at Dec. 31, 2010

29,707,057

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

278,924

'

'

'

'

180,143,120

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-150,714,987

Ending Balance (in shares) at Dec. 31, 2010

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

27,892,388

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Employee stock-based compensation expense

2,817,082

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2,817,082

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Nonemployee stock-based compensation expense

75,614

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

75,614

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Change in unrealized gain (loss) on available for sale investments

692

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

692

'

Additional financing costs for registered public offering

-45,745

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-45,745

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Exercise of common stock options

2,164

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

11

'

'

'

'

2,153

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Exercise of common stock options (in shares)

1,139

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,139

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Exercise of stock warrants

129,689

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

592

'

'

'

'

129,097

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of common stock in registered public offering

13,351,674

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

88,000

'

'

'

'

13,263,674

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net loss

-25,997,322

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-25,997,322

Exercise of stock warrants (in shares)

59,219

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

59,219

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of common stock in registered public offering (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

8,800,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Ending Balance at Dec. 31, 2011

20,040,905

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

367,527

'

'

'

'

196,384,995

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

692

-176,712,309

Ending Balance (in shares) at Dec. 31, 2011

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

36,752,746

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Employee stock-based compensation expense

4,173,132

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

4,173,132

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Nonemployee stock-based compensation expense

52,190

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

52,190

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Change in unrealized gain (loss) on available for sale investments

-692

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-692

'

Issuance of common stock in registered direct offering

4,682,129

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

22,717

'

'

'

'

4,659,412

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of common stock in registered direct offering (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2,271,705

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Warrants issued for the purchase of shares of common stock

237,349

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

237,349

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Exercise of common stock options

12,666

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

53

'

'

'

'

12,613

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Exercise of common stock options (in shares)

5,219

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

5,219

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Exercise of stock warrants

6,137,095

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

28,136

'

'

'

'

6,108,959

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net loss

-23,460,103

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-23,460,103

Exercise of stock warrants (in shares)

2,813,600

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2,813,600

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Ending Balance at Dec. 31, 2012

11,874,671

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

418,433

'

'

'

'

211,628,650

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-200,172,412

Ending Balance (in shares) at Dec. 31, 2012

41,843,270

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

41,843,270

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Employee stock-based compensation expense

5,788,249

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

5,788,249

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Nonemployee stock-based compensation expense

166,679

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

166,679

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock Issued (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

7,917,755

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock issued

10,587,117

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

79,178

'

'

'

'

10,507,939

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Exercise of stock warrants

28,020

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

203

'

'

'

'

27,817

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of common stock in registered public offering

12,015,300

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

137,700

'

'

'

'

11,877,600

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net loss

-25,780,659

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-25,780,659

Exercise of stock warrants (in shares)

20,325

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

20,325

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of common stock in registered public offering (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

13,770,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Ending Balance at Dec. 31, 2013

$14,679,377

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$635,514

'

'

'

'

$239,996,934

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

($225,953,071)

Ending Balance (in shares) at Dec. 31, 2013

63,551,350

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

63,551,350

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Consolidated_Statements_of_Sto1

Consolidated Statements of Stockholders' Equity (Deficit) (Parenthetical) (USD $)

12 Months Ended

0 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

0 Months Ended

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2010

Dec. 31, 2009

Dec. 31, 2008

Dec. 31, 2007

Dec. 31, 2005

Dec. 31, 2004

Dec. 31, 2007

Dec. 31, 2007

Dec. 31, 2007

Dec. 31, 2013

Dec. 31, 2010

Dec. 31, 2006

Dec. 31, 2005

Dec. 31, 2004

Dec. 31, 2010

Dec. 31, 2009

Dec. 31, 2005

Dec. 31, 2007

Dec. 31, 2006

Dec. 31, 2004

Dec. 31, 2004

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2009

Dec. 31, 2008

Dec. 31, 2006

Dec. 31, 2013

Dec. 31, 2009

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2009

Dec. 31, 2008

Dec. 31, 2006

Dec. 31, 2013

Dec. 31, 2003

Dec. 31, 2003

Dec. 31, 2002

Dec. 31, 2003

Dec. 31, 2002

Dec. 31, 2002

Dec. 31, 2003

Dec. 31, 2002

Aug-07

Oct-07

IPO

At-The-Market

Series A Convertible Preferred Stock

Series B Convertible Preferred Stock

Series B Convertible Preferred Stock

Series B Convertible Preferred Stock

Common Stock

Common Stock

Common Stock

Series C Convertible Preferred Stock

Series C Convertible Preferred Stock

April 23, 2004 Convertible Bridge Notes

June 30, 2004 Convertible Bridge Notes

Minimum

Minimum

Minimum

Minimum

Minimum

Minimum

Minimum

Maximum

Maximum

Maximum

Maximum

Maximum

Maximum

Series B Preferred Stock

Common Stock

Alpha Medical, Inc.

Alpha Medical, Inc.

Alpha Medical, Inc.

Beta Medical, Inc.

Beta Medical, Inc.

Beta Medical, Inc.

Series B Convertible Preferred Stock

Series B Convertible Preferred Stock

At-The-Market

Common Stock

At-The-Market

November 13, 2003 Convertible Bridge Notes

Series A Preferred Stock

Series A Preferred Stock

Common Stock

Series A Preferred Stock

Series A Preferred Stock

Common Stock

Series A Convertible Preferred Stock

Series A Convertible Preferred Stock

Series A Convertible Preferred Stock

Series A Convertible Preferred Stock

Issuance of common stock in registered direct offering

'

'

'

$3.90

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock issued upon conversion of convertible bridge notes, value of convertible bridge notes

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$1,564,843

'

'

'

'

$5,250,003

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Convertible preferred stock warrants, exercise price

'

'

'

'

'

'

'

'

$8.95

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Warrants issued for debt modification (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

150,642

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Accrued interest portion of the convertible bridge notes

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

34,809

'

'

'

'

131,013

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Warrants issued for debt modification value, per share

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$1.92

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of common stock in public offering for cash per share

$0.95

'

$1.65

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Exercise of common stock options (in shares)

'

5,219

1,139

8,586

13,450

16,829

5,854

4,927

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Exercise of common stock options, per share

'

'

$1.90

$2.76

'

'

$3.60

$2.76

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$1.90

$2.76

$2.76

'

'

'

'

$2.58

$22.20

$11.46

'

'

'

'

'

'

'

'

'

'

Stock issued, per share

'

$2.22

'

'

$7.28

'

$48

'

'

'

'

$48

'

$1.72

'

$23.66

$23.66

$1.75

$4.80

'

'

$48.56

'

'

'

'

'

'

'

$1.10

'

'

'

'

'

'

$2.10

'

$0.54

$54.60

$54.60

$0.54

$54.60

$54.60

$0.54

Exercise of over-allotment option by underwriters in connection with the IPO for cash, financing costs

'

'

'

'

'

'

274,315

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of common stock in public offering, financing costs

'

'

'

'

806,499

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Cashless exercise of warrants, per share

'

'

'

'

$6.90

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Cashless exercise of warrants (in shares)

'

'

'

'

159,420

'

'

'

'

'

'

'

'

'

'

'

'

'

104,700

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Cashless exercise of warrants with an exercise price in exchange for shares of common stock (in shares)

'

'

'

'

125,470

'

'

'

'

'

'

'

'

'

'

'

'

'

62,244

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Payments of stock issuance costs public offering

1,066,200

'

1,168,326

2,198,865

'

'

'

'

'

'

'

'

381,981

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of common stock in registered direct offering for cash per share, financing costs

'

367,871

'

339,547

92,470

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Exercise of stock warrants, per share

'

$1.90

$2.19

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$1.14

'

'

'

'

'

'

$1.90

$2.19

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of common stock and warrants to purchase number of shares of common stock

5,508,000

'

1,760,000

17,020,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Exercise of stock warrants (in shares)

20,325

2,813,600

59,219

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common or preferred stock financing costs

'

'

'

'

'

'

4,552,663

11,085

94,776

'

'

'

'

60,679

'

5,218

'

'

'

'

'

2,222,342

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common stock issued to Mayo Foundation upon closing the IPO, fair value of per share

'

'

'

'

'

'

$48.30

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common stock issued to non employees, per share

'

'

'

'

'

'

'

$2.76

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$2.76

'

'

'

'

'

'

$11.46

'

'

'

'

'

'

'

'

'

Warrants issued, per share

'

$2.22

'

'

'

$7.80

'

$6.42

'

'

'

'

'

'

$17.55

'

'

'

'

'

$49.67

$29.89

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Warrants issued for the purchase of stock, purchase price

'

'

'

$100

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Warrants Issued for Series C Convertible Preferred Stock, per share

'

'

'

'

'

'

'

'

'

$69.83

$68.76

'

'

'

'

'

'

'

'

'

$48.56

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Warrants issued for the purchase of shares of series C convertible preferred stock Valued per warrant for debt funding (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

5,664

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance of common stock options to nonemployees, common stock options

'

'

'

'

'

'

'

7,757

3,819

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Share-based goods and nonemployee services transaction, per option

'

'

'

'

'

'

'

$0.94

$0.94

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Warrants issued for the purchase of stock (in shares)

'

106,746

'

340,400

1,092,533

233,117

'

'

7,556

2,832

2,832

'

'

'

5,812

11,624

1,081

3,394,309

'

28,389

11,327

24,606

'

733

'

'

'

'

'

'

'

'

'

'

'

'

'

3,919

'

'

'

'

'

'

'

Stock issued, per share

'

$2.22

'

'

$7.28

'

$48

'

'

'

'

$48

'

$1.72

'

$23.66

$23.66

$1.75

$4.80

'

'

$48.56

'

'

'

'

'

'

'

$1.10

'

'

'

'

'

'

$2.10

'

$0.54

$54.60

$54.60

$0.54

$54.60

$54.60

$0.54

Series B convertible preferred stock issued, per share

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$23.66

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock issued, per share

'

$2.22

'

'

$7.28

'

$48

'

'

'

'

$48

'

$1.72

'

$23.66

$23.66

$1.75

$4.80

'

'

$48.56

'

'

'

'

'

'

'

$1.10

'

'

'

'

'

'

$2.10

'

$0.54

$54.60

$54.60

$0.54

$54.60

$54.60

$0.54

Warrants issued for purchase of stock

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$6.45

$0.13

'

$0.54

'

'

$0.03

$0.03

'

'

'

'

'

'

'

'

'

'

'

'

'

$0.03

'

'

'

'

'

'

'

Cashless exercise of warrants, per share minimum

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$6.90

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Cashless exercise of warrants, per share maximum

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$23.64

'

'

'

'

'

'

'

'

'

'

'

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended			132 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013
Cash flows from operating activities:	'	'	'	'
Net loss	($25,780,659)	($23,460,103)	($25,997,322)	($225,822,103)
Adjustments to reconcile net loss to net cash used in operating activities:	'	'	'	'
Depreciation	174,629	226,990	303,972	2,661,657
Loss on sale of equipment	'	767	1,269	74,894
Stock-based compensation	5,954,928	4,225,322	2,892,696	24,643,416
Amortization of commitment fees, debt issuance costs and original issue discount	199,592	207,310	234,740	4,293,525
Amortization of short-term investment premium or discount	'	4,719	3,261	-300,071
Change in value of warrant liability	'	'	'	3,840,622
Other, net	8,030	'	'	8,030
Change in operating assets and liabilities:	'	'	'	'
Accounts receivable	26,634	-52,406	'	-25,772
Inventory	143,266	-202,584	-1,068,623	-1,127,941
Prepaid expenses and other current assets	24,910	233,145	-368,261	-546,744
Other assets	246,764	-813,063	-176,985	-803,632
Accounts payable	60,732	-224,562	367,491	137,310
Accrued expenses	512,451	-2,699,761	3,834,999	4,186,060
Accrued interest payable	2,994	74,857	37,329	692,494
Net cash used in operating activities	-18,425,729	-22,479,369	-19,935,434	-188,088,255
Cash flows from investing activities:	'	'	'	'
Decrease in restricted cash	200,000	'	6,327,031	'
Purchases of short-term investments available for sale	'	'	-5,007,980	-19,890,213
Maturities of short-term investments available for sale	'	1,000,000	4,000,000	19,854,414
Purchases of short-term investments held to maturity	'	'	'	-22,414,130
Maturities of short-term investments held to maturity	'	'	'	22,750,000
Purchases of property and equipment	-416,010	-76,394	-252,274	-3,323,626
Net cash (used in) provided by investing activities	-216,010	923,606	5,066,777	-3,023,555
Cash flows from financing activities:	'	'	'	'
Proceeds from stock options exercised	'	12,666	2,164	215,684
Proceeds from warrants exercised	28,020	6,137,095	129,689	6,482,456
Proceeds from sale of common stock and warrants for purchase of common stock	24,050,598	5,050,000	14,520,000	143,455,037
Common stock financing costs	-1,448,181	-367,871	-1,214,071	-11,294,482
Payment to shareholders for fractional shares upon reverse stock split	'	'	'	-355
Proceeds from sale of Series A, B and C convertible preferred stock	'	'	'	63,766,564
Series A, B and C convertible preferred stock financing costs	'	'	'	-1,658,662
Proceeds from notes payable and convertible notes payable	'	5,347,807	'	47,993,774
Repayments on notes payable	-3,000,000	-752,841	-921,997	-34,178,928
Debt issuance costs	'	-50,000	'	-371,799
Net cash provided by financing activities	19,630,437	15,376,856	12,515,785	214,409,289
Net increase (decrease) in cash and cash equivalents	988,698	-6,178,907	-2,352,872	23,297,479
Cash and cash equivalents:	'	'	'	'
Beginning of period	22,308,781	28,487,688	30,840,560	'
End of period	23,297,479	22,308,781	28,487,688	23,297,479
Supplemental disclosure:	'	'	'	'
Interest paid	729,778	619,668	450,751	8,402,346
Noncash investing and financing activities:	'	'	'	'
Cancellation of Alpha Medical, Inc. Series A convertible preferred stock and common stock	'	'	'	-661,674
Issuance of Beta Medical, Inc. Series A convertible preferred stock in exchange for Alpha Medical, Inc. Series A convertible preferred stock and common stock	'	'	'	661,674
Value of warrants issued with debt and for debt commitment	'	237,349	'	4,070,532
Value of warrants issued with sale of common and preferred stock offerings	'	'	'	1,684,832
Cashless exercise of warrants	'	'	'	5,244,778
Conversion of notes and interest payable to Series B and C convertible preferred shares	'	'	'	6,980,668
Options issued for deferred compensation	'	'	'	10,898
Common stock issued to Mayo Foundation and for deferred compensation	'	'	'	1,770,904
Reclassification of warrant liability	'	'	'	2,932,766
Conversion of convertible preferred stock to common stock	'	'	'	$51,132

Formation_and_Business_of_the_

Formation and Business of the Company	12 Months Ended
	Dec. 31, 2013
Formation and Business of the Company	'
	-1	Formation and Business of the Company
	EnteroMedics Inc. (EnteroMedics or the Company) is developing implantable systems to treat obesity, metabolic diseases and other gastrointestinal disorders. The Company was incorporated in the state of Minnesota on December 19, 2002, originally as two separate legal entities, Alpha Medical, Inc. and Beta Medical, Inc., both of which were owned 100% by a common stockholder. Effective October 1, 2003, the two entities were combined and the combined entity changed its name to EnteroMedics Inc. The Company reincorporated in Delaware on July 22, 2004. The Company is in the development stage, as defined by the Accounting Standards Codification. Since inception the Company has devoted substantially all of its resources to recruiting personnel, developing its product technology, obtaining patents to protect its intellectual property and raising capital, and thus far has only derived revenues from its primary business activity in 2012. The Company is headquartered in St. Paul, Minnesota.
	EnteroMedics Europe Sárl (EnteroMedics Europe), a wholly owned subsidiary of the Company, was formed in January 2006. EnteroMedics Europe is a Swiss entity established as a means to conduct clinical trials in Switzerland. Upon establishment there were 20 shares of EnteroMedics Europe issued and outstanding with a par value of 1,000 Swiss Francs. EnteroMedics purchased 100% of the shares and then issued one share to a fiduciary agent. The one share is the property of EnteroMedics and is held by the fiduciary in a fiduciary capacity under terms of the Fiduciary Agreement. The functional currency of EnteroMedics Europe has been determined to be the U.S. Dollar.
	In November 2007, the Company completed its initial public offering of common stock (IPO), issuing a total of 914,975 shares for net proceeds of approximately $39.1 million after expenses and underwriters’ discounts and commissions, and including the exercise of the underwriters’ over-allotment option.
	Since inception, EnteroMedics has incurred losses through December 31, 2013 totaling approximately $225.8 million and has not generated positive cash flows from operations. The Company expects such losses to continue into the foreseeable future as it continues to develop and commercialize its technologies. The Company may need to obtain additional financing and there can be no assurance that the Company will be successful in obtaining additional financing on favorable terms, or at all. If adequate funds are not available, the Company may have to delay development or commercialization of products or license to third parties the rights to commercialize products or technologies that the Company would otherwise seek to commercialize. See Notes 7 and 8 for additional discussion of financing activities.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2013
Summary of Significant Accounting Policies	'
	-2	Summary of Significant Accounting Policies
	Basis of Presentation
	The Company has prepared the accompanying consolidated financial statements in conformity with accounting principles generally accepted in the United States of America. The Company’s fiscal year ends on December 31.
	Use of Estimates
	The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates.
	Principles of Consolidation
	The consolidated financial statements include the accounts of the Company and its wholly owned subsidiary. All intercompany transactions and accounts have been eliminated in consolidation.
	Concentration of Credit Risk and Other Risks and Uncertainties
	Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash and cash equivalents. Cash and cash equivalents are primarily deposited in demand and money market accounts. At times, such deposits may be in excess of insured limits. Investments in money market funds are not considered to be bank deposits and are not insured or guaranteed by the federal deposit insurance company or other government agency. These money market funds seek to preserve the value of the investment at $1.00 per share; however, it is possible to lose money investing in these funds. The Company has not experienced any losses on its deposits of cash and cash equivalents.
	Most of the products developed by the Company will require approval from the U.S. Food and Drug Administration (FDA) or corresponding foreign regulatory agencies prior to commercial sales. There can be no assurance the Company’s products will receive the necessary approvals. If the Company is denied approval or approval is delayed, it will have a material adverse impact on the Company.
	The medical device industry is characterized by frequent and extensive litigation and administrative proceedings over patent and other intellectual property rights. Whether a product infringes a patent involves complex legal and factual issues, the determination of which is often difficult to predict, and the outcome may be uncertain until the court has entered final judgment and all appeals are exhausted. The Company’s competitors may assert that its products or the use of the Company’s products are covered by U.S. or foreign patents held by them.
	Fair Value of Financial Instruments
	Carrying amounts of certain of the Company’s financial instruments, including cash and cash equivalents, restricted cash, accounts receivable, prepaid expenses and other current assets, accounts payable and accrued liabilities approximate fair value due to their short maturities. The fair values of investments in debt and equity securities, if any, are disclosed in Note 3. The fair value of the Company’s long-term debt is approximately $7.3 million as of December 31, 2013 based on the present value of estimated future cash flows using a discount rate commensurate with borrowing rates available to the Company. If measured at fair value in the consolidated financial statements, long-term debt (including the current portion) would be classified as Level 2 in the fair value hierarchy.
	Cash and Cash Equivalents
	The Company considers highly liquid investments generally with maturities of 90 days or less when purchased to be cash equivalents. Cash equivalents are stated at cost, which approximates market value. The Company’s cash equivalents are primarily in money market funds and certificates of deposit. The Company deposits its cash and cash equivalents in high-quality credit institutions. Under terms of the Company’s notes payable agreements (see Note 7), in the event of default, the lender has the right to enforce account control agreements and restrict the Company’s access to their cash and investment accounts.
	Restricted Cash
	The Company had $200,000 in a cash collateral money market account as of December 31, 2012. Pursuant to the Lease Agreement the Company entered into with Roseville Properties Management Company in July 2008, the Company was required to deliver to Roseville Properties an irrevocable, unconditional, standby letter of credit in the amount of $200,000 on the second anniversary of the commencement of lease payments. The irrevocable standby letter of credit was issued by Silicon Valley Bank, who required the Company to set up a restricted cash collateral money market account to fully secure the standby letter of credit. The fully secured standby letter of credit was maintained through October 1, 2013, per the terms of the lease agreement.
	Short-Term Investments
	The Company considers all investments with maturities greater than three months and less than one year at the time of purchase as short-term investments and classifies them as either available for sale or held to maturity. The Company also considers certain investments with maturities greater than one year but which are also held for liquidity purposes and are available for sale as short-term investments.
	Available-for-sale securities are carried at fair value based on quoted market prices, with the unrealized gains and losses included in other comprehensive income within stockholders’ equity (deficit) in the consolidated balance sheets. Realized gains and losses and declines in value judged to be other than temporary on available-for-sale securities are included in interest and other income. Interest and dividends on securities classified as available for sale are included in interest income. The cost of securities sold is based on the specific identification method.
	Short-term investments in debt securities which the Company has the positive intent and ability to hold to maturity are reported at cost, adjusted for premiums and discounts that are recognized in interest income, using the interest method, over the period to maturity. Unrealized losses on held-to-maturity securities reflecting a decline in value determined to be other than temporary are charged to income.
	Inventory
	The Company accounts for inventory at the lower of cost or market and records any long-term inventory as other assets in the consolidated balance sheets.
	Property and Equipment, Net
	Property and equipment are stated at cost less accumulated depreciation and amortization. Depreciation of property and equipment is computed using the straight-line method over their estimated useful lives of three to seven years. Leasehold improvements are amortized on a straight-line basis over the lesser of their useful life or the term of the lease. Upon retirement or sale, the cost and related accumulated depreciation are removed from the consolidated balance sheets and the resulting gain or loss is reflected in the consolidated statements of operations. Repairs and maintenance are expensed as incurred.
	Impairment of Long-Lived Assets
	The Company evaluates its long-lived assets for impairment by comparison of the carrying amounts to future net undiscounted cash flows expected to be generated by such assets when events or changes in circumstances indicate the carrying amount of an asset may not be recoverable. Should an impairment exist, the impairment loss would be measured based on the excess carrying value of the asset over the asset’s fair value or estimates of future discounted cash flows. The Company has not identified any such impairment losses to date.
	Income Taxes
	Income taxes are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carry-forwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. A valuation allowance for deferred income tax assets is recorded when it is more likely than not that some portion or all of the deferred income tax assets will not be realized. The Company has provided a full valuation allowance against the gross deferred tax assets as of December 31, 2013 and 2012 (see Note 10). The Company’s policy is to classify interest and penalties related to income taxes as income tax expense in the consolidated statements of operations.
	Comprehensive Loss
	Comprehensive loss is defined as the change in equity of a company during a period from transactions and other events and circumstances excluding transactions resulting from investment owners and distributions to owners. There was no difference from reported net loss for the year ended December 31, 2013. The difference from reported net loss for the years ended December 31, 2012 and 2011 related entirely to changes in unrealized gains (losses) on available-for-sale investments.
	Revenue Recognition
	The Company recognizes revenue when persuasive evidence of an arrangement exists, title or risk of loss has passed, the selling price is fixed or determinable and collection is reasonably assured. The Company sells products internationally through distributors and recognizes revenue upon sale to the distributor as these sales are considered to be final and no right of return or price protection exists. Terms of sales to international distributors are generally EXW, reflecting that goods are shipped “ex works,” in which risk of loss is assumed by the distributor at the shipping point. The Company does not provide for rights of return to customers on product sales and therefore does not record a provision for returns.
	Research and Development Expenses
	Research and development expenses are charged to expense as incurred. Research and development expenses include, but are not limited to, product development, clinical trial expenses, including supplies, devices, explants and revisions, regulatory expenses, payroll and other personnel expenses, materials and consulting costs.
	Patent Costs
	Costs associated with the submission of a patent application are expensed as incurred given the uncertainty of the patents resulting in probable future economic benefits to the Company. Patent-related legal expenses included in general and administrative costs were $296,575, $278,987 and $271,105 for the years ended December 31, 2013, 2012 and 2011, respectively, and $2,739,844 for the period from December 19, 2002 (inception) to December 31, 2013.
	Derivative Instruments
	The Company accounts for outstanding warrants that are not indexed to the Company’s stock or warrants issued when the Company has insufficient authorized and unissued stock available to share settle the outstanding warrants as derivative instruments, which require that the warrants be classified as a liability and measured at fair value with changes in fair value recognized currently in earnings and recorded separately in the consolidated statements of operations.
	Effective January 1, 2009, the Company adopted new authoritative accounting guidance regarding the financial reporting for outstanding equity-linked financial instruments. As a result of this change in accounting guidance, the Company assessed any outstanding equity-linked financial instruments and concluded that warrants issued in November 2008 with a recorded value of $1.4 million on December 31, 2008 were to be reclassified from equity to a liability. The cumulative effect of the change in accounting principle on January 1, 2009 was a $130,968 increase to the deficit accumulated during development stage. See Note 7 for details.
	Stock-Based Compensation
	Prior to January 1, 2006, the Company accounted for stock-based employee compensation using the intrinsic value method and recognized the expense over the option vesting period. The intrinsic value method is calculated as the difference, if any, between the fair value of the Company’s stock and the exercise price on the date of the grant. The Company also followed the minimum value disclosure provisions.
	Effective January 1, 2006, the Company adopted the fair value method of accounting for share-based payments, which superseded the previous accounting method, and requires compensation expense to be recognized using a fair-value-based method for costs related to all share-based payments including stock options. Companies are required to estimate the fair value of share-based payment awards on the date of grant using an option-pricing model. The Company adopted the new provisions using the prospective transition method, which requires that for nonpublic entities that used the minimum value method for either pro forma or financial statement recognition purposes, to apply the new accounting provisions only to option grants or modifications to existing options that occur after the required effective date. For options granted prior to January 1, 2006, the Company applied the intrinsic value provisions on unvested awards. All options granted prior to January 1, 2006, have fully vested. All option grants valued after January 1, 2006 are expensed on a straight-line basis over the vesting period.
	The fair value method is applied to all share-based payment awards issued to employees and where appropriate, nonemployees, unless another source of literature applies. When determining the measurement date of a nonemployee’s share-based payment award, the Company measures the stock options at fair value and remeasures such stock options to the current fair value until the performance date has been reached.
	Net Loss Per Share
	Basic net loss per share is computed by dividing net loss by the weighted-average number of common shares outstanding during the period. Diluted net loss per share is based on the weighted-average common shares outstanding during the period plus dilutive potential common shares calculated using the treasury stock method. Such potentially dilutive shares are excluded when the effect would be to reduce a net loss per share. The Company’s potential dilutive shares, which include outstanding common stock options and warrants, have not been included in the computation of diluted net loss per share for all periods as the result would be anti-dilutive.
	The following table sets forth the computation of basic and diluted net loss per share for the years ended December 31, 2013, 2012 and 2011:
			Years ended
			December 31,
			2013			2012			2011
	Numerator:
	Net loss		$	(25,780,659	)	$	(23,460,103	)	$	(25,997,322	)
	Denominator for basic and diluted net loss per share:
	Weighted-average common shares outstanding			55,009,916			39,536,500			30,205,447
	Net loss per share—basic and diluted		$	(0.47	)	$	(0.59	)	$	(0.86	)
	The following table sets forth the potential shares of common stock that are not included in the calculation of diluted net loss per share because to do so would be anti-dilutive as of the end of each period presented:
			December 31,
			2013			2012			2011
	Stock options outstanding			11,687,300			7,835,533			3,470,908
	Warrants to purchase common stock			25,550,625			21,216,447			23,923,301
	Recently Issued Accounting Standards
	Various accounting standards and interpretations have been issued with 2013 effective dates and effective dates subsequent to December 31, 2013. The Company has evaluated the recently issued accounting pronouncements that are currently effective or will be effective in 2014 and believe that none of them have had or will have a material effect on the Company’s financial position, results of operations or cash flows.

Shortterm_Investments_and_Fair

Short-term Investments and Fair Value Measurements	12 Months Ended
	Dec. 31, 2013
Short-term Investments and Fair Value Measurements	'
	-3	Short-term Investments and Fair Value Measurements
	Fair value of financial assets and liabilities is defined as the price that would be received to sell an asset or transfer a liability in an orderly transaction between market participants at the measurement date. A fair value hierarchy has been established that prioritizes the inputs to valuation techniques used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements). The three levels of the fair value hierarchy are described below:
		•	Level 1—Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities.
		•	Level 2—Quoted prices for similar assets and liabilities, quoted prices for identical or similar assets or liabilities in markets that are not active or model-derived valuations for which all significant inputs are observable, either directly or indirectly.
		•	Level 3—Prices or valuation techniques that require inputs that are both significant to the fair value measurement and unobservable.
	The Company’s assets that are measured at fair value on a recurring basis are classified within Level 1 or Level 2 of the fair value hierarchy. The Company does not hold any assets that are measured at fair value using Level 3 inputs. The types of instruments the Company invests in that are valued based on quoted market prices in active markets include U.S. treasury securities. Such instruments are classified by the company within Level 1 of the fair value hierarchy. U.S. treasuries are valued using unadjusted quoted prices for identical assets in active markets that the Company can access.
	The types of instruments the Company invests in that are valued based on quoted prices in less active markets, broker or dealer quotations, or alternative pricing sources with reasonable levels of price transparency include the Company’s U.S. agency securities, commercial paper, U.S. corporate bonds and municipal obligations. Such instruments are classified by the Company within Level 2 of the fair value hierarchy. The Company values these types of assets using consensus pricing or a weighted average price, which is based on multiple pricing sources received from a variety of industry standard data providers (e.g. Bloomberg), security master files from large financial institutions, and other third-party sources. The multiple prices obtained are then used as inputs into a distribution-curve-based algorithm to determine the daily market price.
	The Company did not hold any short-term investments classified as available for sale or held to maturity as of December 31, 2013 and 2012.

Inventory

Inventory	12 Months Ended
	Dec. 31, 2013
Inventory	'
	-4	Inventory
	From inception, inventory related purchases had been used for research and development related activities and had accordingly been expensed as incurred. In December 2011, the Company began receiving Australian Register of Therapeutic Goods (ARTG) listings for components of the Maestro Rechargeable System from the Australian Therapeutic Goods Administration (TGA), with the final components being listed on the ARTG in January 2012. As a result, the Company determined certain assets were recoverable as inventory beginning in December 2011. The Company accounts for inventory at the lower of cost or market and records any long-term inventory as other assets in the consolidated balance sheets. There was approximately $794,000 and $862,000 of long-term inventory, primarily consisting of raw materials, as of December 31, 2013 and 2012, respectively.
	Current inventory consists of the following as of:
			December 31,
			2013		2012
	Raw materials		$	385,565	$	198,647
	Work-in-process			624,530		1,051,286
	Finished goods			117,846		21,274
	Inventory		$	1,127,941	$	1,271,207

Property_and_Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2013
Property and Equipment	'
	-5	Property and Equipment
	Property and equipment consists of the following as of:
			December 31,
			2013			2012
	Furniture and equipment		$	2,274,633		$	2,143,025
	Computer hardware and software			499,922			489,478
	Leasehold improvements			46,754			46,754
				2,821,309			2,679,257
	Less accumulated depreciation and amortization			(2,244,214	)		(2,069,585	)
	Property and equipment, net		$	577,095		$	609,672

Accrued_Expenses

Accrued Expenses	12 Months Ended
	Dec. 31, 2013
Accrued Expenses	'
	-6	Accrued Expenses
	Accrued expenses consists of the following as of:
			December 31,
			2013		2012
	Professional service related expenses		$	2,650,163	$	2,229,057
	Payroll related expenses			1,043,028		1,099,713
	Other expenses			492,869		344,839
	Accrued expenses		$	4,186,060	$	3,673,609

Notes_Payable

Notes Payable	12 Months Ended
	Dec. 31, 2013
Notes Payable	'
	-7	Notes Payable
	Notes payable consists of the following as of:
			December 31,
			2013			2012
	Growth capital loan dated April 16, 2012 (net of discounts of $131,670 and $316,028 at December 31, 2013 and 2012, respectively)		$	6,868,330		$	9,683,972
	Less current portion			(4,000,000	)		(3,000,000	)
	Total long-term debt		$	2,868,330		$	6,683,972
	November 18, 2008 Debt Facility with Silicon Valley Bank, Venture Lending & Leasing V, Inc. and Compass Horizon Funding Company LLC
	On November 18, 2008, the Company entered into a Loan and Security Agreement (the Prior Loan Agreement) with Silicon Valley Bank (SVB), Venture Lending & Leasing V, Inc. (a private equity fund under the management of Western Technology Investment (WTI)) and Compass Horizon Funding Company LLC (Horizon and, collectively with SVB and WTI, the Lenders), in an aggregate principal amount of up to $20.0 million. On November 21, 2008, SVB and WTI each funded a term loan in the aggregate principal amount of $10.0 million and $5.0 million, respectively. The additional $5.0 million term loan was automatically funded by Horizon on April 28, 2009 when the trading price of the Company’s common stock on the NASDAQ Global Market exceeded a target amount specified in the Prior Loan Agreement.
	Interest-only payments were required on the term loans during a period beginning on the term loan funding date and continuing through June 30, 2009, followed thereafter by equal monthly payments of principal and interest over the remaining term of the term loan. Amounts borrowed under the Prior Loan Agreement had an annual interest rate equal to 12.0% during the period of interest-only payments, and thereafter, at a rate of 11.0% per annum for the remainder of the term. Per the Prior Loan Agreement, the Company was also required to make a final payment in an aggregate amount equal to 5.0% of the term loans funded by the Lenders (the Final Payment Fee).
	The debt financing was collateralized by a first security priority lien on all of the Company’s assets, excluding intellectual property. The Company entered into account control agreements in order to perfect the Lenders’ first security interest in the Company’s cash and investment accounts.
	On December 1, 2009, the Company voluntarily prepaid both the WTI and Horizon term loans in full. Both WTI and Horizon released their right to future interest when the term loans were paid in full.
	During 2010 and 2011, the Company and SVB entered into four amendments to the Prior Loan Agreement, which modified the payment terms, annual interest rate and financial covenants. A brief summary of the four amendments is provided below.
	On February 8, 2010, the Company and SVB entered into the First Amendment to the Prior Loan Agreement, which reduced the annual interest rate from 11.0% to a fixed annual rate of 10.0%, payable monthly, revised the liquidity financial covenant and added a New Capital Transaction covenant.
	On July 8, 2010, the Company and SVB entered into a Second Amendment (the Second Amendment) to the Prior Loan Agreement, which modified the repayment terms of the loan such that interest only payments were required through December 31, 2010 followed by 30 equal payments of principal and interest, increased the annual interest rate from 10.0% to a fixed annual rate of 11.0%, payable monthly, revised the liquidity financial covenant and added additional New Capital Transaction requirements.
	On November 4, 2010, the Company and SVB entered into a Third Amendment (the Third Amendment) to the Prior Loan Agreement, which modified the New Capital Transaction covenant, suspended the liquidity financial covenant and required the Company to maintain a blocked cash collateral account with funds equal to the principal balance outstanding.
	On March 3, 2011, the Company entered into a Fourth Amendment (the Fourth Amendment) to the Prior Loan Agreement with SVB. The Fourth Amendment modified the repayment terms of the term loan such that beginning April 1, 2011 through September 30, 2011, the Company was required to make interest only monthly payments on the term loan. Then, beginning on October 1, 2011, the remaining balance due on the term loan started to amortize over 30 equal payments of principal and interest, payable monthly. In addition, the Fourth Amendment amended the interest rate due effective March 1, 2011 on the remaining principal amount of the term loan from 11.0% to a fixed annual rate of 6.25%, payable monthly. The Fourth Amendment reinstated the liquidity financial covenant and eliminated SVB’s springing lien on the Company’s intellectual property, the New Capital Transactions requirement and the requirement of the Third Amendment to maintain a blocked cash collateral account with funds equal to the principal balance outstanding.
	Warrants Issued
	The Prior Loan Agreement required the issuance of warrants to the Lenders with an aggregate exercise price equal to 11.0% of the loan commitment. The warrants gave the Lenders the option to purchase either (i) shares of the Company’s common stock with a per share exercise price equal to $9.51, or (ii) shares of the Company’s stock (including common stock) issued in an equity financing that occurred within 18 months after November 18, 2008 at the per share price of the stock sold in the financing. On November 18, 2008 (i) SVB was issued a warrant to purchase an aggregate number of shares equal to $1,100,000 divided by the per share exercise price of the warrant, (ii) WTI was issued a warrant to purchase an aggregate number of shares equal to $550,000 divided by the per share exercise price of the warrant, and (iii) Horizon received a warrant to purchase an aggregate number of shares equal to $55,000 divided by the per share exercise price of the warrant. On April 28, 2009 Horizon was issued an additional warrant to purchase an aggregate number of shares equal to $495,000 divided by the per share exercise price of the warrant in connection with the additional $5.0 million term loan that was automatically funded by Horizon pursuant to the Prior Loan Agreement.
	On November 18, 2008, the Company issued a total of 179,328 common stock warrants with an exercise price of $9.51 per share and a ten year life to the Lenders, or a calculated fair value of $1.4 million. This fair value was calculated using a Black-Scholes valuation model and the following assumptions: volatility of 78.9%, dividend rate of 0%, risk-free interest rate of 3.54% and a ten year life. The exercise price of the common stock warrants issued on November 18, 2008 was adjusted to $6.90, the price per share sold in an equity financing that closed on February 24, 2009, resulting in an additional 67,773 common stock warrants for the Lenders. On April 28, 2009, the Company issued a total of 49,460 common stock warrants with an exercise price of $10.01 per share and a ten year life to Horizon, or a calculated fair value of $542,144. This fair value was calculated using a Black-Scholes valuation model and the following assumptions: volatility of 99.1%, dividend rate of 0%, risk-free interest rate of 3.00% and a ten year life. The exercise price of the common stock warrants issued to Horizon on both November 18, 2008 and April 28, 2009 was further adjusted to $4.80, the price per share sold in an equity financing that closed October 7, 2009, resulting in an additional 57,152 common stock warrants for Horizon. The exercise price of Horizon’s outstanding common stock warrants was further adjusted to $3.90, the price per share sold in an equity financing that closed January 20, 2010, resulting in an additional 26,442 common stock warrants for Horizon.
	As discussed in Note 2, effective January 1, 2009, as a result of a change in accounting guidance, the Company revalued the warrants issued in November 2008 and reclassified them from equity to a liability. The fair value of the warrant liability on January 1, 2009 was $1.5 million and the change in fair value was recorded as an increase to the deficit accumulated during development stage. This fair value was calculated using a weighted-average Black-Scholes valuation model and the following assumptions: volatility of 79.6%, dividend rate of 0%, risk-free interest rate of 2.24% and a remaining life of 9.88 years.
	As of December 31, 2009, Horizon had outstanding 114,583 common stock warrants with an exercise price of $4.80 per share. The fair value of the warrant liability associated with these warrants was $471,585 as of December 31, 2009. This fair value was calculated using a weighted-average Black-Scholes valuation model and the following assumptions: volatility between 103.9% and 104.8%, dividend rate of 0%, risk-free interest rate of 3.84% and a remaining life between 8.89 and 9.33 years. The Company recorded a decrease of $119,904 in the change in value of the warrant liability for the year ended December 31, 2009 for this portion of the warrant liability.
	As of December 31, 2010, Horizon had outstanding 141,025 common stock warrants with an exercise price of $3.90 per share. The fair value of the warrant liability associated with these warrants was $312,751 as of May 18, 2010, the date on which the warrants’ down round protection expired. This Level 3 fair value was calculated using a weighted-average Black-Scholes valuation model and the following assumptions: volatility between 113.25% and 113.33%, dividend rate of 0%, risk-free interest rate of 3.38% and a remaining life between 8.51 and 8.95 years. As a result of the down round protection expiring, on May 18, 2010 the Company recorded a decrease of $158,834 in the change in value of the warrant liability for the year ended December 31, 2010 and reclassified the warrant liability to equity.
	On July 8, 2010, per the terms of the Second Amendment to the Prior Loan Agreement, SVB was issued a warrant to purchase 150,642 shares of the Company’s common stock with an exercise price of $2.10 per share.
	Warrants Exercised
	On September 29, 2009, SVB completed a cashless exercise of the warrants issued to them as part of the Prior Loan Agreement. SVB held a total of 159,420 common stock warrants with an exercise price of $6.90 per share. The cashless exercise of the warrants resulted in the Company issuing 125,470 shares of its common stock. The fair value of the warrant liability on the date of exercise was $4.8 million. This fair value was calculated using a weighted-average Black-Scholes valuation model and the following assumptions: volatility of 108.0%, dividend rate of 0%, risk-free interest rate of 3.29% and a remaining life of 9.14 years. As a result of the warrants being exercised, the warrant liability was reclassified to equity with $3.8 million being recorded as a change in value of the warrant liability for the year ended December 31, 2009.
	On October 2, 2009, WTI completed a cashless exercise of the warrants issued to them as part of the Prior Loan Agreement entered into on November 18, 2008. WTI held a total of 79,710 common stock warrants with an exercise price of $6.90 per share. The cashless exercise of the warrants resulted in the Company issuing 59,248 shares of its common stock. The fair value of the warrant liability on the date of exercise was $494,652. This fair value was calculated using a weighted-average Black-Scholes valuation model and the following assumptions: volatility of 108.0%, dividend rate of 0%, risk-free interest rate of 3.22% and a remaining life of 9.13 years. As a result of the warrants being exercised, the warrant liability was reclassified to equity with $1,210 being recorded as a change in value of the warrant liability for the year ended December 31, 2009. WTI also completed a cashless exercise of an additional 24,990 common stock warrants with an exercise price of $23.64 per share. The cashless exercise of the warrants resulted in the Company issuing 2,996 shares of its common stock. These warrants were not included as part of the warrant liability.
	April 16, 2012 Debt Facility with Silicon Valley Bank
	On April 16, 2012, the Company entered into a new Loan and Security Agreement (the Loan Agreement) with SVB, pursuant to which SVB agreed to make term loans to the Company in an aggregate principal amount of up to $20.0 million ($10.0 million of which is not available as the Company did not meet the predefined primary efficacy measures of the ReCharge trial as well as certain financial objectives for 2012), on the terms and conditions set forth in the Loan Agreement. The Loan Agreement amends and restates the Prior Loan Agreement, as amended.
	Pursuant to the Loan Agreement, a term loan was funded in the aggregate principal amount of $10.0 million on April 23, 2012, a portion of which was used to repay in full the outstanding debt of approximately $4.7 million. The term loan required interest only payments monthly through March 31, 2013 followed by 30 equal payments of principal in the amount of $333,333 plus accrued interest beginning on April 1, 2013 and ending on September 1, 2015, payable monthly. Amounts borrowed under the Loan Agreement bear interest at a fixed annual rate equal to 8.0%. A 5.0% final payment fee from the Prior Loan Agreement will be due on September 1, 2015. The Company may voluntarily prepay the term loan in full, but not in part, and any voluntary or mandatory prepayment is subject to applicable prepayment premiums and will also include the final payment fee. The Company was required to comply with certain financial covenants that require the Company to generate certain minimum amounts of revenue from the sale of its Maestro System and to implant certain minimum numbers of Maestro Systems during cumulative quarterly measurement periods beginning with the period ended March 31, 2013 and ending with the period ending June 30, 2015. The Company did not meet the financial covenants for the period ended March 31, 2013 and therefore entered into a First Amendment (the First Amendment) to the Loan Agreement on May 9, 2013 pursuant to which the Company and SVB agreed to new financial covenants.
	The First Amendment eliminated the financial covenants that required the Company to generate certain minimum amounts of revenue from the sale of its Maestro System and to implant certain minimum numbers of Maestro Systems during cumulative quarterly measurement periods beginning with the period ended March 31, 2013 and ending with the period ending June 30, 2015. It also removed SVB’s ability to require the Company to maintain a restricted cash balance of $7.5 million in an SVB account as a result of the Company not meeting the predefined primary efficacy measures of the ReCharge trial.
	The First Amendment added two new financial covenants, one of which requires the Company to receive cumulative aggregate net proceeds of at least $5.0 million by November 15, 2013, which has been fulfilled through the use of the equity distribution agreement with Canaccord Genuity Inc. (see Note 8), and $10.0 million by April 15, 2014 from new capital transactions. The amount required will adjust up or down based on the Company’s actual cash position compared to its financial plan. The second financial covenant requires the Company to maintain a liquidity ratio (unrestricted cash divided by outstanding debt) of at least 1.25:1.00 until it receives FDA approval for the Maestro Rechargeable System at which point it will be reduced to 0.75:1.00. The First Amendment did not change the interest rate or the amortization structure. The Company will pay SVB a $187,000 success fee in the event the Company receives FDA approval for the Maestro Rechargeable System.
	The Company has granted SVB a security interest in all of the Company’s assets, excluding intellectual property except with respect to all license, royalty fees and other revenues and income arising out of or relating to any of the intellectual property and all proceeds of the intellectual property. The Company also has entered into a negative pledge arrangement with SVB pursuant to which it has agreed not to encumber any of its intellectual property without SVB’s prior written consent.
	Pursuant to the Loan Agreement, on April 16, 2012, the Company issued SVB a warrant to purchase 106,746 shares of common stock, exercisable for ten years from the date of grant, at an exercise price of $2.34 per share.
	Scheduled debt principal payments are as follows as of December 31, 2013:
	Years Ending December 31:
	2014		$	4,000,000
	2015			3,000,000
				7,000,000
	Less original issue discount			(131,670	)
	Notes payable, net		$	6,868,330

Stock_Sales

Stock Sales	12 Months Ended
	Dec. 31, 2013
Stock Sales	'
	-8	Stock Sales
	Public Offering—September 2011
	On September 28, 2011, the Company closed a public offering, selling 8,800,000 shares of common stock, together with warrants to purchase approximately 1,760,000 shares of common stock at an aggregate price of $1.65 per share and corresponding warrant, for gross proceeds of $14.5 million before deducting offering expenses. Certain directors of the Company participated in the public offering (see Note 13).
	The warrants have an exercise price of $1.90 per share of common stock and are exercisable for a period of five years from September 28, 2011. Holders of the warrants are not permitted to exercise those warrants for an amount of common stock that would result in the holder owning more than 19.99% of the Company’s common stock. The warrants may be redeemed in whole or in part at the option of the Company, at a redemption price of $0.01 per warrant at any time after any date on which the closing sale price of the common stock, as reported on the principal exchange or trading facility on which it is then traded, has equaled or exceeded $1.00 more than the exercise price of the warrants for 10 consecutive trading days. The Company is required to provide 30 days’ prior written notice to the warrantholder of the Company’s intention to redeem the warrant; provided, that the Company may not provide this notice until the earlier of (i) 30 days following the date the Company initially releases the results of the blinded portion of the ReCharge trial or (ii) June 30, 2013. The Company may not redeem any portion of a warrant if, had the holder exercised that portion of the warrant in lieu of redemption, it would have resulted in such holder owning more than 19.99% of the common stock outstanding after such exercise.
	Registered Direct Offering—April 2012
	On April 16, 2012, the Company entered into a securities purchase agreement with a current investor for the sale of 2,271,705 shares of its common stock in a registered direct offering, at a purchase price of $2.223 per share. On April 20, 2012, the offering closed and the Company received gross proceeds of $5.0 million before deducting estimated offering expenses.
	Public Offering—February 2013
	On February 27, 2013, the Company closed a public offering, selling 13,770,000 shares of common stock, together with warrants to purchase approximately 5,508,000 shares of common stock at an aggregate price of $0.95 per share and corresponding warrant, for gross proceeds of $13.1 million before deducting offering expenses. Certain directors of the Company participated in the public offering (see Note 13).
	The warrants have an exercise price of $1.14 per share of common stock and are exercisable for a period of five years from February 27, 2013. Holders of the warrants are not permitted to exercise those warrants for an amount of common stock that would result in the holder owning more than 19.99% of the Company’s common stock.
	Equity Distribution Agreement—July 2013
	On July 31, 2013, the Company entered into an equity distribution agreement with Canaccord Genuity Inc. (Canaccord) to sell shares of the Company’s common stock having aggregate gross sales proceeds of up to $20.0 million, from time to time, through an “at-the-market” equity offering program (ATM) under which Canaccord will act as the Company’s sales agent. The Company will determine, at its sole discretion, the timing and number of shares to be sold under this ATM. The Company will pay Canaccord a commission for its services in acting as agent in the sale of common stock equal to 2.0% of the gross sales price per share of all shares sold through it as agent under the equity distribution agreement. As of December 31, 2013, the Company had sold 7,917,755 shares under the ATM at a weighted-average selling price of $1.39 per share for gross proceeds of approximately $11.0 million before deducting offering expenses. Subsequent to December 31, 2013 through March 27, 2014, the Company has sold an additional 2,506,222 shares under the ATM at a weighted-average selling price of $2.33 per share for gross proceeds of approximately $5.8 million before deducting offering expenses.

Convertible_Preferred_Stock

Convertible Preferred Stock	12 Months Ended
	Dec. 31, 2013
Convertible Preferred Stock	'
	-9	Convertible Preferred Stock
	The Company’s Amended and Restated Certificate of Incorporation, currently authorizes 5,000,000 shares of $0.01 par value convertible preferred stock. As of December 31, 2013 and 2012, there were no shares of convertible preferred stock issued or outstanding as all shares of Series A, Series B and Series C convertible preferred stock converted into shares of common stock upon completion of the Company’s IPO utilizing the quotient obtained by dividing the original purchase price per share of $6.5593, $3.9430 and $8.0926 by $4.2379, $3.9430 and $8.0926 per share, respectively, and all shares of Series A convertible preferred stock issued with the September 29, 2010 private placement converted to common stock on a 1:1 basis upon the December 14, 2010 closing of the Company’s public offering.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2013
Income Taxes	'
	-10	Income Taxes
	The Company has incurred net operating losses (NOLs) since inception. The Company has not reflected any benefit of such net operating loss carryforwards in the accompanying consolidated financial statements.
	The income tax expense benefit differed from the amount computed by applying the U.S. federal income tax rate of 34% to income before income taxes as a result of the following:
			2013			2012			2011
	Computed ‘expected’ tax benefit			34	%		34	%		34	%
	Other permanent adjustments			-2.3	%		-2.2	%		-1.8	%
	Research and development credit			3.5	%		0	%		1.6	%
	Federal valuation allowance			-35.2	%		-31.8	%		-33.8	%
				0	%		0	%		0	%
	The tax effect of temporary differences that give rise to significant portions of the deferred tax assets as of December 31 is presented below:
			2013			2012
	Deferred tax assets (liabilities):
	Start-up costs		$	8,851,000		$	10,367,000
	Capitalized research and development costs			24,844,000			23,658,000
	Reserves and accruals			4,530,000			3,447,000
	Property and equipment			105,000			143,000
	Research and development credit			1,508,000			486,000
	Net operating loss carryforwards			12,198,000			9,185,000
	Total gross deferred tax assets			52,036,000			47,286,000
	Valuation allowance			(52,036,000	)		(47,286,000	)
	Net deferred tax assets		$	—		$	—
	In assessing the realization of deferred tax assets, management considers whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during periods in which those temporary differences become deductible. In addition, certain limitations imposed under the Internal Revenue Code (IRC) could further limit the Company’s realization of these deferred tax assets in the event of changes in ownership of the Company (as described below).
	Based on the level of historical taxable losses and projections of future taxable income (losses) over the periods in which the deferred tax assets can be realized, management currently believes that it is more likely than not that the Company will not realize the benefits of these deductible differences. Accordingly, the Company has provided a valuation allowance against the gross deferred tax assets as of December 31, 2013 and 2012.
	As of December 31, 2013, the Company has generated U.S. federal net operating loss carryforwards of approximately $81.2 million. Of this amount, approximately $33.1 million is available after the application of Section 382 limitations described below. Of the total federal net operating loss, $221,000 would result in tax benefits recorded to additional paid-in capital. The federal net operating loss carryforwards expire in the years 2022 through 2033.
	The IRC imposes restrictions on the utilization of various carryforward tax attributes in the event of a change in ownership of the Company, as defined by IRC Section 382. In addition, IRC Section 382 may limit the Company’s built-in items of deduction, including capitalized start-up costs and research and development costs. During 2011, the Company completed an IRC Section 382 review and the results of this review indicate ownership changes have occurred which would cause a limitation on the utilization of carryforward attributes. The Company’s gross net operating loss carryforwards, start-up costs and research and development credits are all subject to limitation. Under these tax provisions, the limitation is applied first to any built-in losses, then to any net operating losses and then to any general business credits. The Section 382 limitation and accompanying recognized built-in loss limitation is currently estimated to result in the expiration of $48.1 million of the Company’s gross federal net operating loss carryforward, as well as a write-off of $5.9 million of capitalized start-up costs, $11.1 million of capitalized research and development costs, $1.5 million of property and equipment and $2.4 million of research and development credits. Any ownership changes since we completed the IRC Section 382 review in 2011 could result in further limitations on the utilization of carryforward attributes.
	As of December 31, 2013 and 2012, there were no unrecognized tax benefits. Accordingly, a tabular reconciliation from beginning to ending periods is not provided. The Company will classify any future interest and penalties as a component of income tax expense if incurred. To date, there have been no interest or penalties charged or accrued in relation to unrecognized tax benefits.
	The Company does not anticipate that the total amount of unrecognized tax benefits will change significantly in the next twelve months.
	The Company is subject to federal examinations for the years 2010 forward. There are no tax examinations currently in progress.

Stock_Options

Stock Options	12 Months Ended
	Dec. 31, 2013
Stock Options	'
	-11	Stock Options
	The Company has adopted the Amended and Restated 2003 Stock Incentive Plan (the Plan) that includes both incentive stock options and nonqualified stock options to be granted to employees, officers, consultants, independent contractors, directors and affiliates of the Company. At December 31, 2013 and 2012, according to the Plan, 12,300,000 shares have been authorized and reserved. The board of directors establishes the terms and conditions of all stock option grants, subject to the Plan and applicable provisions of the IRC. Incentive stock options must be granted at an exercise price not less than the fair market value of the common stock on the grant date. The options granted to participants owning more than 10% of the Company’s outstanding voting stock must be granted at an exercise price not less than 110% of fair market value of the common stock on the grant date. The options expire on the date determined by the board of directors, but may not extend more than 10 years from the grant date, while incentive stock options granted to participants owning more than 10% of the Company’s outstanding voting stock expire five years from the grant date. The vesting period for employees is generally over four years. The vesting period for nonemployees is determined based on the services being provided.
	On September 27, 2012, a special meeting of stockholders was held and the stockholders approved the Amended and Restated 2003 Stock Incentive Plan which (i) authorized an additional 8,000,000 shares for issuance under the Plan, (ii) extended the term of the Plan to September 27, 2022, (iii) gave the Compensation Committee the flexibility to cash out outstanding awards without participant consent in connection with a corporate transaction, (iv) modernized the provisions of the Plan with respect to Section 162(m) and Section 409A of the IRC of 1986, as amended and (v) made certain other clarification and administrative changes.
	Stock option activity is as follows:
			Shares			Outstanding Options					Aggregate
			Available For								Intrinsic
			Grant			Number of			Weighted-Average		Value
						Shares			Exercise Price
	Shares reserved at Plan inception			7,143			—		$	—
	Balance, December 31, 2003			7,143			—			—
	Shares reserved			73,260			—			—
	Options granted			(57,466	)		57,466			2.76
	Options exercised			—			—			—
	Options cancelled			641			(641	)		2.76
	Balance, December 31, 2004			23,578			56,825			2.76
	Shares reserved			113,148			—			—
	Options granted			(84,028	)		84,028			2.76
	Options exercised			—			(4,926	)		2.76
	Options cancelled			7,209			(7,209	)		2.76
	Balance, December 31, 2005			59,907			128,718			2.76
	Shares reserved			94,449			—			—
	Options granted			(113,277	)		113,277			6.9
	Options exercised			—			(14,498	)		2.76
	Options cancelled			17,237			(17,237	)		2.76
	Balance, December 31, 2006			58,316			210,260			5
	Shares reserved			362,183			—			—
	Options granted			(176,098	)		176,098			45.78
	Options exercised			—			(5,851	)		3.65
	Options cancelled			30,416			(30,416	)		74.71
	Balance, December 31, 2007			274,817			350,091			19.48
	Shares reserved			—			—			—
	Options granted			(221,838	)		221,838			45.56
	Options exercised			—			(16,820	)		3.89
	Options cancelled			89,019			(89,019	)		38.69
	Balance, December 31, 2008			141,998			466,090			28.79
	Shares reserved			500,000			—			—
	Options granted			(692,645	)		692,645			14.68
	Options exercised			—			(13,437	)		2.79
	Options cancelled			149,736			(149,736	)		31.2
	Balance, December 31, 2009			99,089			995,562			18.96
	Shares reserved			1,149,817			—			—
	Options granted			(423,789	)		423,789			1.96
	Options exercised			—			(8,592	)		2.76
	Options cancelled			598,244			(598,244	)		25.29
	Balance, December 31, 2010			1,423,361			812,515			5.6
	Shares reserved			2,000,000			—			—
	Options granted			(2,716,464	)		2,716,464			2.44
	Options exercised			—			(1,139	)		1.9
	Options cancelled			56,932			(56,932	)		3.21
	Balance, December 31, 2011			763,829			3,470,908			3.17
	Shares reserved			8,000,000			—			—
	Options granted			(4,462,873	)		4,462,873			3.35
	Options exercised			—			(5,219	)		2.43
	Options cancelled			93,029			(93,029	)		2.79
	Balance, December 31, 2012			4,393,985			7,835,533			3.28	$	1,359,840
	Shares reserved			—			—			—
	Options granted			(4,346,000	)		4,346,000			1.32
	Options exercised			—			—			—
	Options cancelled			494,233			(494,233	)		3
	Balance, December 31, 2013			542,218			11,687,300		$	2.56	$	3,284,696
	The options outstanding, vested and currently exercisable by exercise price at December 31, 2013:
	Outstanding Options and Expected to Vest										Options Exercisable and Vested
	Exercise		Number of			Weighted-Average			Aggregate		Number of		Weighted-Average		Aggregate
Price	Shares		Remaining			Intrinsic			Options		Exercise Price		Intrinsic
	Outstanding		Contractual Life			Value							Value
			(Years)
$0.01 to $2.00			5,274,326			8.7		$	3,284,696		1,339,740	$	1.61	$	573,861
$2.01 to $3.00			2,208,857			6.8			—		1,508,012		2.63		—
$3.01 to $5.00			4,086,635			8.4			—		1,551,542		3.43		—
$5.01 to $10.00			4,166			5.1			—		4,166		8.4		—
> $10.00			113,316			4.3			—		113,316		23.97		—
			11,687,300					$	3,284,696		4,516,776	$	3.14	$	573,861
Stock-Based Compensation for Nonemployees
Stock-based compensation expenses related to stock options granted to nonemployees is recognized as the stock options are earned. The Company believes that the fair value of the stock options is more reliably measurable than the fair value of the services received. The fair value of the stock options granted is calculated at each reporting date, using the Black-Scholes option-pricing model, until the award vests or there is a substantial disincentive for the nonemployee not to perform the required services. The fair value for the years ended December 31, 2013, 2012 and 2011 was calculated using the following assumptions, defined below:
		Years Ended December 31,
		2013		2012	2011
Risk-free interest rates		0.26%–2.98%		0.24%–2.05%	0.26%–3.45%
Expected life		1.50 years–9.76 years		2.00 years–9.25 years	2.04 years–9.95 years
Expected dividends		0%		0%	0%
Expected volatility		80.00%–143.00%		63.48%–142.25%	79.50%–123.80%
Stock-based compensation expense charged to operations on options granted to nonemployees for the years ended December 31, 2013, 2012 and 2011 was $166,679, $52,190 and $75,614, respectively, and $1,776,280 for the period from December 19, 2002 (inception) to December 31, 2013.
Employee Stock-Based Awards Granted on or Subsequent to January 1, 2006
On January 1, 2006, the Company adopted the fair value method of accounting for the issuance of stock-based payments, using the prospective transition method. Under this transition method, beginning January 1, 2006, compensation cost recognized includes: (a) compensation cost for all stock-based awards granted prior to, but not yet vested as of December 31, 2005, based on the intrinsic value method, and (b) compensation cost for all stock-based payments granted or modified subsequent to December 31, 2005, based on the estimated grant-date fair value.
Compensation cost for employee stock-based awards is based on the estimated grant-date fair value and is recognized over the vesting period of the applicable award on a straight-line basis. The weighted average estimated fair value of the employee stock options granted for the years ended December 31, 2013, 2012 and 2011 was $1.22, $3.19 and $2.13 per share, respectively.
The Company uses the Black-Scholes pricing model to determine the fair value of stock options. The determination of the fair value of stock-based payment awards on the date of grant is affected by the Company’s stock price as well as assumptions regarding a number of complex and subjective variables. These variables include the Company’s expected stock price volatility over the term of the awards, actual and projected employee stock option exercise behaviors, risk-free interest rates and expected dividends. The estimated grant-date fair values of the employee stock options were calculated using the Black-Scholes valuation model, based on the following assumptions for the years ended December 31, 2013, 2012 and 2011:
		Years Ended December 31,
		2013		2012	2011
Risk-free interest rates		0.94%–1.33%		0.90%–1.09%	1.13%–2.68%
Expected life		6.00 years–6.25 years		6.00 years–6.25 years	5.42 years–6.25 years
Expected dividends		0%		0%	0%
Expected volatility		148.00%–149.00%		137.58%–143.98%	114.80%–124.40%
Expected Life.    The expected life is based on the “simplified” method described in the SEC Staff Accounting Bulletin, Topic 14: Share-Based Payment.
Volatility.    Since the Company was a private entity for most of 2007 and a limited amount of historical data regarding the volatility of its common stock was available, the expected volatility used for 2012 and 2011 was based on both the volatility of similar entities, referred to as “guideline” companies, and the Company’s historical volatility. In evaluating similarity, the Company considered factors such as industry, stage of life cycle and size. Effective with the year ended December 31, 2013, the expected volatility was based solely on the Company’s historical volatility.
Risk-Free Interest Rate.    The risk-free rate is based on the daily yield curve rate from the U.S. Treasury with remaining terms similar to the expected term on the options.
Dividend Yield.    The Company has never declared or paid any cash dividends and does not plan to pay cash dividends in the foreseeable future, and, therefore, used an expected dividend yield of zero in the valuation model.
Forfeitures.    The Company is required to estimate forfeitures at the time of grant, and revise those estimates in subsequent periods if actual forfeitures differ from those estimates. The Company uses historical data to estimate pre-vesting option forfeitures and record stock-based compensation expense only for those awards that are expected to vest. All stock-based payment awards are amortized on a straight-line basis over the requisite service periods of the awards, which are generally the vesting periods. If the Company’s actual forfeiture rate is materially different from its estimate, the stock-based compensation expense could be significantly different from what the Company has recorded in the current period.
As of December 31, 2013 there was approximately $13.9 million of total unrecognized compensation costs, net of estimated forfeitures, related to employee unvested stock option awards granted after January 1, 2006, which are expected to be recognized over a weighted-average period of 3.66 years.
The aggregate intrinsic value of stock options (the amount by which the market price of the stock on the date of exercise exceeded the exercise price of the option) exercised during the years ended December 31, 2012 and 2011, was $3,044 and $588, respectively. There were no stock option exercises for the year ended December 31, 2013.

Warrants

Warrants	12 Months Ended
	Dec. 31, 2013
Warrants	'
	-12	Warrants
	Stock warrant activity is as follows:
			Common			Price(1)		Series A			Price(1)		Series B			Price(1)		Series C			Price(1)
			Shares					Preferred					Preferred					Preferred
								Shares					Shares					Shares
	Balance as of:
	December 31, 2002			—					—					—					—
	Granted			—					20,963		$	5.46		3,916		$	23.68		—
	Exercised			—					—					—					—
	Cancelled			—					—					—					—
	December 31, 2003			—					20,963		$	5.46		3,916		$	23.68		—
	Granted			—					—					16,859		$	23.68		—
	Exercised			—					(20,963	)	$	8.95		—					—
	Cancelled			—					—					—					—
	December 31, 2004			—					—					20,775		$	23.68		—
	Granted			28,385		$	2.76		—					11,624		$	23.68		—
	Exercised			—					—					—					—
	Cancelled			—					—					—					—
	December 31, 2005			28,385		$	2.76		—					32,399		$	23.68		—
	Granted			—					—					5,811		$	23.68		24,605		$	48.56
	Exercised			—					—					—					—
	Cancelled			—					—					—					—
	December 31, 2006			28,385		$	2.76		—					38,210		$	23.68		24,605		$	48.56
	Granted			—					—					—					22,650		$	48.56
	Exercised			—					—					—					—
	Cancelled			—					—					—					—
	Converted upon close of IPO			85,465		$	37.44		—					(38,210	)	$	23.68		(47,255	)	$	48.56
	December 31, 2007			113,850		$	28.79		—					—					—
	Granted(2)			179,328		$	9.51		—					—					—
	Exercised			—					—					—					—
	Cancelled			—					—					—					—
	December 31, 2008			293,178		$	17		—					—					—
	Granted(2)(3)			1,540,036		$	7.86		—					—					—
	Exercised(3)			(264,120	)	$	8.49		—					—					—
	Cancelled(3)			(236,759	)	$	9.53		—					—					—
	December 31, 2009			1,332,335		$	9.44		—					—					—
	Granted(2)(3)			21,046,376		$	2.19		—					—					—
	Exercised			—					—					—					—
	Cancelled(3)			(153,993	)	$	5.78		—					—					—
	December 31, 2010			22,224,718		$	2.6		—					—					—
	Granted(2)			1,759,997		$	1.9		—					—					—
	Exercised			(59,219	)	$	2.19		—					—					—
	Cancelled			(2,195	)	$	23.68		—					—					—
	December 31, 2011			23,923,301		$	2.55		—					—					—
	Granted(2)			106,746		$	2.34		—					—					—
	Exercised			(2,813,600	)	$	2.18		—					—					—
	Cancelled			—					—					—					—
	December 31, 2012			21,216,447		$	2.6		—					—					—
	Granted(2)			5,508,000		$	1.14		—					—					—
	Exercised			(20,325	)	$	1.38		—					—					—
	Cancelled			(1,153,497	)	$	9.14		—					—					—
	December 31, 2013			25,550,625		$	1.99		—					—					—
	-1	Represents weighted-average exercise price per share.
	-2	See Notes 7 and 8 for discussions relating to the issuance of warrants in 2013, 2012, 2011, 2010, 2009 and 2008.
	-3	See Note 7 for discussions relating to both the cashless exercises of warrants in 2009 and the cancellation and reissuance of warrants following down round equity financings.
	At December 31, 2013 and 2012, the weighted-average remaining contractual life of outstanding warrants was 2.87 and 3.33 years, respectively. All of the warrants outstanding are currently exercisable at the option of the holder into the equivalent number of shares of common stock.

Related_Party_Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2013
Related Party Transactions	'
	-13	Related Party Transactions
	Public Offerings
	As discussed in Note 8, on September 28, 2011, the Company closed a public offering, selling 8,800,000 shares of common stock, together with warrants to purchase approximately 1,760,000 shares of common stock at an aggregate price of $1.65 per share and corresponding warrant. The following principal stockholder, purchased shares of common stock and warrants at a price of $1.65 per share and corresponding warrant. The shares purchased, together with the proceeds, before expenses, to the Company, are shown in the table below:
	Beneficial Owner		Shares		Warrants		Proceeds, before
			Purchased		Purchased		expenses, to the Company
	Bay City Capital			840,000		167,999	$	1,386,000
	Carl Goldfischer, M.D. is a director of the Company and is a managing director of Bay City Capital LLC.
	As discussed in Note 8, on February 27, 2013, the Company closed a public offering, selling 13,770,000 shares of common stock, together with warrants to purchase approximately 5,508,000 shares of common stock at an aggregate price of $0.95 per share and corresponding warrant. The following principal stockholder, purchased shares of common stock and warrants at a price of $0.95 per share and corresponding warrant. The shares purchased, together with the proceeds, before expenses, to the Company, are shown in the table below:
	Beneficial Owner		Shares		Warrants		Proceeds, before
			Purchased		Purchased		expenses, to the Company
	Anthony Jansz			150,000		60,000	$	142,500
	Anthony Jansz is a director of the Company.
	Consulting Agreement—Anthony Jansz
	Effective June 1, 2011, the Company entered into a four year consulting agreement with Anthony Jansz, who is a member of the board of directors. Pursuant to the agreement, in exchange for consulting services provided, Mr. Jansz is entitled to receive a consulting fee of $96,000 AUD (approximately $86,000 USD as of December 31, 2013) per year and the reimbursement of reasonable expenses. Mr. Jansz also received an option to purchase 50,000 shares of common stock at $2.76 per share that vest in 48 equal monthly installments beginning on July 1, 2011. The full grant date fair value of the option grant was approximately $108,000.
	On December 20, 2012, the Company entered into an amendment, effective October 1, 2012, to the consulting agreement with Mr. Jansz. Pursuant to the amendment, during the period from October 1, 2012 until June 30, 2013, Mr. Jansz agreed to commit additional time to performing consulting services for the Company. In exchange for these additional services, Mr. Jansz is entitled to receive a consulting fee of $12,000 AUD (approximately $11,000 USD as of December 31, 2013) per month from October 1, 2012 until June 30, 2013. Mr. Jansz also received an option to purchase 75,000 shares of the Company’s common stock on January 22, 2013 at $2.65 per share, which vests as follows: (A) 16,667 of such 75,000 shares vested on January 22, 2013, the date of grant; (B) 16,667 of such 75,000 shares vested on January 22, 2014; (C) 16,666 of such 75,000 shares will vest on January 22, 2015; and (D) the remaining 25,000 of such 75,000 shares will vest upon the occurrence of both (i) the Company successfully obtaining full Australian reimbursement approval for both surgeon’s fees and hospital fees for the VBLOC vagal blocking therapy and the Maestro Rechargeable System from the Australian Medical Services Advisory Committee prior to June 30, 2014 and (ii) the Company successfully obtaining device listing for the Maestro Rechargeable System on the Australian Prostheses List prior to June 30, 2014. The full grant date fair value of the option grant was approximately $153,000.
	The Company has continued to pay Mr. Jansz a consulting fee of $12,000 AUD per month subsequent to June 30, 2013 as a result of the additional time he continues to spend providing consulting services to the Company. Mr. Jansz also received an additional option to purchase 100,000 shares of the Company’s common stock on May 31, 2013 at $1.31 per share, which vests as follows: (A) 16,667 of such 100,000 shares vested on May 31, 2013, the date of the grant; (B) 16,667 of such 100,000 shares will vest on May 31, 2014; (C) 16,666 of such 100,000 shares will vest on May 31, 2015; (D) 25,000 of such 100,000 shares would have vested upon the implementation of the Australian Specialty Clinic Commercial Validation Project as evidenced by the implantation of 10 or more Maestro Rechargeable Systems in an Australian Clinic prior to December 31, 2013; and (E) the remaining 25,000 of such 100,000 shares will vest upon the Company successfully obtaining an Item Listing for Maestro Rechargeable System implantation by December 31, 2014. The Australian Specialty Clinic Commercial Validation Project was not implemented prior to December 31, 2013 resulting in 25,000 shares not vesting. The full grant date fair value of the option grant was approximately $103,000.
	Total stock-based compensation expense recorded was approximately $126,000, $23,000 and $10,000 for the years ended December 31, 2013, 2012 and 2011, respectively. In addition to the option grant, the Company paid Mr. Jansz approximately $154,000, $195,000 and $67,000 in fees and expenses for consulting services provided during the years ended December 31, 2013, 2012 and 2011, respectively.
	Other
	The Company has entered into an agreement with an advisory firm to provide various consulting services. The advisory firm is partially owned by a company with whom a member of our board of directors is a partner. The Company recognized $146,000 in selling, general and administrative expense for the year ended December 31, 2013 for consulting services provided by the advisory firm.

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2013
Commitments and Contingencies	'
	-14	Commitments and Contingencies
	Effective October 1, 2008 the Company entered into a seven-year non-cancelable operating lease agreement for office/warehouse space. The lease expires on September 30, 2015 with monthly base rent ranging from $19,570 to $24,643. Total rent expense recognized for the years ended December 31, 2013, 2012 and 2011 was $270,872, $270,872 and $270,872 respectively, and $1,894,800 for the period from December 19, 2002 (inception) to December 31, 2013. Facility related expenses are included as general and administrative costs on the consolidated statements of operations.
	The following is a schedule of total future minimum lease payments due as of December 31, 2013:
	Years ending December 31:
	2014		$	291,369
	2015			221,789
			$	513,158
	The Company is exposed to product liability claims that are inherent in the testing, production, marketing and sale of medical devices. Management believes any losses that may occur from these matters are adequately covered by insurance, and the ultimate outcome of these matters will not have a material effect on the Company’s financial position or results of operations. The Company is not currently a party to any litigation and is not aware of any pending or threatened litigation that could have a material adverse effect on the Company’s business, operating results or financial condition.
	The Company is evaluating its product, the Maestro System, in human clinical trials, including the EMPOWER trial and ReCharge trial. Both of these clinical trials require patients to be followed out to 60 months. The Company is required to pay for patient follow up visits only to the extent they occur. In the event a patient does not attend a follow up visit, the Company has no financial obligation. The Company is also required to pay for explants or revisions, including potential conversions of ReCharge control devices to active devices, should a patient request or be required to have one during the course of the clinical trials. The Company has no financial obligation unless an explant, revision or conversion is requested or required. Clinical trial costs are expensed as incurred.
	In 2005, EnteroMedics entered into an exclusive collaborative obesity device research and development agreement with the Mayo Foundation for Medical Education and Research (Mayo Foundation), Rochester, Minnesota. Through this agreement, EnteroMedics collaborated with a group of physicians and researchers at Mayo Clinic in the field of obesity. Under the terms of this five-year agreement, EnteroMedics and this group of Mayo specialists collectively worked toward the development of new and innovative medical devices for the treatment of obesity. The agreement also includes a similar collaboration for the development of products to address a wide variety of disorders susceptible to treatment by electrically blocking neural impulses on the vagus nerve.
	Under this agreement, the Company issued 36,630 shares of common stock to the Mayo Foundation in 2005 and recorded $100,000 as deferred compensation, which was amortized over the term of the five-year agreement and was fully amortized in 2010. In accordance with the agreement, upon the closing of the IPO in November 2007, the Company was also obligated to issue 34,341 shares of common stock as consideration to the Mayo Foundation and recorded a one-time stock-based compensation expense of $1.7 million. The stock-based compensation expense is recorded on the consolidated statements of operations as research and development expense.
	The Mayo Foundation received an annual $250,000 retainer fee which commenced in 2005 and continued through January 2009. The annual retainer fee paid to the Mayo Foundation is recorded on the consolidated statements of operations as research and development expense.
	On March 11, 2010, the Company entered into Amendment No. 1 to the agreement with the Mayo Foundation extending the Company’s collaboration with the Mayo Foundation for a period of two years. Pursuant to the amendment, the Mayo Foundation granted the Company certain royalty-bearing, worldwide exclusive and non-exclusive licenses and committed to the joint collaboration between the Company and a designated group of physicians and researchers at the Mayo Clinic for the development and testing of products for the treatment of obesity, including devices that use electrical signaling to block the vagal nerve, and for the treatment of other gastrointestinal diseases, solely using devices that use electrical signaling to block the vagal nerve. The Mayo Foundation received an annual retainer of $100,000 in 2010 and 2011. The agreement was further amended on January 15, 2011 with Amendment No. 2. Under the terms of Amendment No. 2, the annual retainer the Mayo Foundation received for 2011 was reduced to $75,000. The agreement was further amended on February 3, 2012 with Amendment No. 3. Under the terms of Amendment No. 3, beginning in 2012 the Mayo Foundation will be reimbursed for services provided at an hourly rate only. Amendment No. 3 does not provide for additional annual retainer payments. No other terms were changed by Amendment Nos. 2 or 3. The agreement was further amended on February 3, 2013 and on February 3, 2014 with Amendment Nos. 4 and 5, respectively, extending the joint collaboration between the company and a designated group of physicians and researchers at the Mayo Clinic. No other terms were changed by Amendment Nos. 4 or 5.
	The Company may also be obligated to pay the Mayo Foundation, contingent upon the occurrence of certain future events, earned royalty payments, including a minimum annual royalty as defined by the agreement, as amended, for the commercial sale of products developed and patented by the Mayo Foundation, jointly patented by the Company and the Mayo Foundation, or a product where the Mayo Foundation provided know-how as defined by the agreement, as amended. If no products are patented, the minimum royalty is not due.

Retirement_Plan

Retirement Plan	12 Months Ended
	Dec. 31, 2013
Retirement Plan	'
	-15	Retirement Plan
	The Company has a 401(k) profit-sharing plan that provides retirement benefits to employees. Eligible employees may contribute a percentage of their annual compensation, subject to Internal Revenue Service limitations. The Company’s matching is at the discretion of the Company’s board of directors. For the years ended December 31, 2013, 2012 and 2011 and for the period from December 19, 2002 (inception) to December 31, 2013, the Company did not provide any matching of employees’ contributions.

Quarterly_Data

Quarterly Data	12 Months Ended
	Dec. 31, 2013
Quarterly Data	'
	-16	Quarterly Data (unaudited)
	The following table represents certain unaudited quarterly information for each of the eight quarters in the period ended December 31, 2013. In management’s opinion, this information has been prepared on the same basis as the audited consolidated financial statements and includes all the adjustments necessary to fairly state the unaudited quarterly results of operations (in thousands, except per share data).
			First			Second			Third			Fourth
			Quarter			Quarter			Quarter			Quarter
	2013:00:00
	Net loss		$	(6,581	)	$	(6,323	)	$	(6,303	)	$	(6,573	)
	Basic and diluted net loss per share		$	(0.14	)	$	(0.11	)	$	(0.11	)	$	(0.11	)
	2012:00:00
	Net loss		$	(5,633	)	$	(4,954	)	$	(5,847	)	$	(7,027	)
	Basic and diluted net loss per share		$	(0.15	)	$	(0.13	)	$	(0.14	)	$	(0.17	)

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2013
Basis of Presentation	'
	Basis of Presentation
	The Company has prepared the accompanying consolidated financial statements in conformity with accounting principles generally accepted in the United States of America. The Company’s fiscal year ends on December 31.
Use of Estimates	'
	Use of Estimates
	The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates.
Principles of Consolidation	'
	Principles of Consolidation
	The consolidated financial statements include the accounts of the Company and its wholly owned subsidiary. All intercompany transactions and accounts have been eliminated in consolidation.
Concentration of Credit Risk and Other Risks and Uncertainties	'
	Concentration of Credit Risk and Other Risks and Uncertainties
	Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash and cash equivalents. Cash and cash equivalents are primarily deposited in demand and money market accounts. At times, such deposits may be in excess of insured limits. Investments in money market funds are not considered to be bank deposits and are not insured or guaranteed by the federal deposit insurance company or other government agency. These money market funds seek to preserve the value of the investment at $1.00 per share; however, it is possible to lose money investing in these funds. The Company has not experienced any losses on its deposits of cash and cash equivalents.
	Most of the products developed by the Company will require approval from the U.S. Food and Drug Administration (FDA) or corresponding foreign regulatory agencies prior to commercial sales. There can be no assurance the Company’s products will receive the necessary approvals. If the Company is denied approval or approval is delayed, it will have a material adverse impact on the Company.
	The medical device industry is characterized by frequent and extensive litigation and administrative proceedings over patent and other intellectual property rights. Whether a product infringes a patent involves complex legal and factual issues, the determination of which is often difficult to predict, and the outcome may be uncertain until the court has entered final judgment and all appeals are exhausted. The Company’s competitors may assert that its products or the use of the Company’s products are covered by U.S. or foreign patents held by them.
Fair Value of Financial Instruments	'
	Fair Value of Financial Instruments
	Carrying amounts of certain of the Company’s financial instruments, including cash and cash equivalents, restricted cash, accounts receivable, prepaid expenses and other current assets, accounts payable and accrued liabilities approximate fair value due to their short maturities. The fair values of investments in debt and equity securities, if any, are disclosed in Note 3. The fair value of the Company’s long-term debt is approximately $7.3 million as of December 31, 2013 based on the present value of estimated future cash flows using a discount rate commensurate with borrowing rates available to the Company. If measured at fair value in the consolidated financial statements, long-term debt (including the current portion) would be classified as Level 2 in the fair value hierarchy.
Cash and Cash Equivalents	'
	Cash and Cash Equivalents
	The Company considers highly liquid investments generally with maturities of 90 days or less when purchased to be cash equivalents. Cash equivalents are stated at cost, which approximates market value. The Company’s cash equivalents are primarily in money market funds and certificates of deposit. The Company deposits its cash and cash equivalents in high-quality credit institutions. Under terms of the Company’s notes payable agreements (see Note 7), in the event of default, the lender has the right to enforce account control agreements and restrict the Company’s access to their cash and investment accounts.
Restricted Cash	'
	Restricted Cash
	The Company had $200,000 in a cash collateral money market account as of December 31, 2012. Pursuant to the Lease Agreement the Company entered into with Roseville Properties Management Company in July 2008, the Company was required to deliver to Roseville Properties an irrevocable, unconditional, standby letter of credit in the amount of $200,000 on the second anniversary of the commencement of lease payments. The irrevocable standby letter of credit was issued by Silicon Valley Bank, who required the Company to set up a restricted cash collateral money market account to fully secure the standby letter of credit. The fully secured standby letter of credit was maintained through October 1, 2013, per the terms of the lease agreement.
Short-Term Investments	'
	Short-Term Investments
	The Company considers all investments with maturities greater than three months and less than one year at the time of purchase as short-term investments and classifies them as either available for sale or held to maturity. The Company also considers certain investments with maturities greater than one year but which are also held for liquidity purposes and are available for sale as short-term investments.
	Available-for-sale securities are carried at fair value based on quoted market prices, with the unrealized gains and losses included in other comprehensive income within stockholders’ equity (deficit) in the consolidated balance sheets. Realized gains and losses and declines in value judged to be other than temporary on available-for-sale securities are included in interest and other income. Interest and dividends on securities classified as available for sale are included in interest income. The cost of securities sold is based on the specific identification method.
	Short-term investments in debt securities which the Company has the positive intent and ability to hold to maturity are reported at cost, adjusted for premiums and discounts that are recognized in interest income, using the interest method, over the period to maturity. Unrealized losses on held-to-maturity securities reflecting a decline in value determined to be other than temporary are charged to income.
Inventory	'
	Inventory
	The Company accounts for inventory at the lower of cost or market and records any long-term inventory as other assets in the consolidated balance sheets.
Property and Equipment, Net	'
	Property and Equipment, Net
	Property and equipment are stated at cost less accumulated depreciation and amortization. Depreciation of property and equipment is computed using the straight-line method over their estimated useful lives of three to seven years. Leasehold improvements are amortized on a straight-line basis over the lesser of their useful life or the term of the lease. Upon retirement or sale, the cost and related accumulated depreciation are removed from the consolidated balance sheets and the resulting gain or loss is reflected in the consolidated statements of operations. Repairs and maintenance are expensed as incurred.
Impairment of Long-Lived Assets	'
	Impairment of Long-Lived Assets
	The Company evaluates its long-lived assets for impairment by comparison of the carrying amounts to future net undiscounted cash flows expected to be generated by such assets when events or changes in circumstances indicate the carrying amount of an asset may not be recoverable. Should an impairment exist, the impairment loss would be measured based on the excess carrying value of the asset over the asset’s fair value or estimates of future discounted cash flows. The Company has not identified any such impairment losses to date.
Income Taxes	'
	Income Taxes
	Income taxes are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carry-forwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. A valuation allowance for deferred income tax assets is recorded when it is more likely than not that some portion or all of the deferred income tax assets will not be realized. The Company has provided a full valuation allowance against the gross deferred tax assets as of December 31, 2013 and 2012 (see Note 10). The Company’s policy is to classify interest and penalties related to income taxes as income tax expense in the consolidated statements of operations.
Comprehensive Loss	'
	Comprehensive Loss
	Comprehensive loss is defined as the change in equity of a company during a period from transactions and other events and circumstances excluding transactions resulting from investment owners and distributions to owners. There was no difference from reported net loss for the year ended December 31, 2013. The difference from reported net loss for the years ended December 31, 2012 and 2011 related entirely to changes in unrealized gains (losses) on available-for-sale investments.
Revenue Recognition	'
	Revenue Recognition
	The Company recognizes revenue when persuasive evidence of an arrangement exists, title or risk of loss has passed, the selling price is fixed or determinable and collection is reasonably assured. The Company sells products internationally through distributors and recognizes revenue upon sale to the distributor as these sales are considered to be final and no right of return or price protection exists. Terms of sales to international distributors are generally EXW, reflecting that goods are shipped “ex works,” in which risk of loss is assumed by the distributor at the shipping point. The Company does not provide for rights of return to customers on product sales and therefore does not record a provision for returns.
Research and Development Expenses	'
	Research and Development Expenses
	Research and development expenses are charged to expense as incurred. Research and development expenses include, but are not limited to, product development, clinical trial expenses, including supplies, devices, explants and revisions, regulatory expenses, payroll and other personnel expenses, materials and consulting costs.
Patent Costs	'
	Patent Costs
	Costs associated with the submission of a patent application are expensed as incurred given the uncertainty of the patents resulting in probable future economic benefits to the Company. Patent-related legal expenses included in general and administrative costs were $296,575, $278,987 and $271,105 for the years ended December 31, 2013, 2012 and 2011, respectively, and $2,739,844 for the period from December 19, 2002 (inception) to December 31, 2013.
Derivative Instruments	'
	Derivative Instruments
	The Company accounts for outstanding warrants that are not indexed to the Company’s stock or warrants issued when the Company has insufficient authorized and unissued stock available to share settle the outstanding warrants as derivative instruments, which require that the warrants be classified as a liability and measured at fair value with changes in fair value recognized currently in earnings and recorded separately in the consolidated statements of operations.
	Effective January 1, 2009, the Company adopted new authoritative accounting guidance regarding the financial reporting for outstanding equity-linked financial instruments. As a result of this change in accounting guidance, the Company assessed any outstanding equity-linked financial instruments and concluded that warrants issued in November 2008 with a recorded value of $1.4 million on December 31, 2008 were to be reclassified from equity to a liability. The cumulative effect of the change in accounting principle on January 1, 2009 was a $130,968 increase to the deficit accumulated during development stage. See Note 7 for details.
Stock-Based Compensation	'
	Stock-Based Compensation
	Prior to January 1, 2006, the Company accounted for stock-based employee compensation using the intrinsic value method and recognized the expense over the option vesting period. The intrinsic value method is calculated as the difference, if any, between the fair value of the Company’s stock and the exercise price on the date of the grant. The Company also followed the minimum value disclosure provisions.
	Effective January 1, 2006, the Company adopted the fair value method of accounting for share-based payments, which superseded the previous accounting method, and requires compensation expense to be recognized using a fair-value-based method for costs related to all share-based payments including stock options. Companies are required to estimate the fair value of share-based payment awards on the date of grant using an option-pricing model. The Company adopted the new provisions using the prospective transition method, which requires that for nonpublic entities that used the minimum value method for either pro forma or financial statement recognition purposes, to apply the new accounting provisions only to option grants or modifications to existing options that occur after the required effective date. For options granted prior to January 1, 2006, the Company applied the intrinsic value provisions on unvested awards. All options granted prior to January 1, 2006, have fully vested. All option grants valued after January 1, 2006 are expensed on a straight-line basis over the vesting period.
	The fair value method is applied to all share-based payment awards issued to employees and where appropriate, nonemployees, unless another source of literature applies. When determining the measurement date of a nonemployee’s share-based payment award, the Company measures the stock options at fair value and remeasures such stock options to the current fair value until the performance date has been reached.
Net Loss Per Share	'
	Net Loss Per Share
	Basic net loss per share is computed by dividing net loss by the weighted-average number of common shares outstanding during the period. Diluted net loss per share is based on the weighted-average common shares outstanding during the period plus dilutive potential common shares calculated using the treasury stock method. Such potentially dilutive shares are excluded when the effect would be to reduce a net loss per share. The Company’s potential dilutive shares, which include outstanding common stock options and warrants, have not been included in the computation of diluted net loss per share for all periods as the result would be anti-dilutive.
	The following table sets forth the computation of basic and diluted net loss per share for the years ended December 31, 2013, 2012 and 2011:
		Years ended
		December 31,
		2013			2012			2011
	Numerator:
	Net loss	$	(25,780,659	)	$	(23,460,103	)	$	(25,997,322	)
	Denominator for basic and diluted net loss per share:
	Weighted-average common shares outstanding		55,009,916			39,536,500			30,205,447
	Net loss per share—basic and diluted	$	(0.47	)	$	(0.59	)	$	(0.86	)
Recently Issued Accounting Standards	'
	Recently Issued Accounting Standards
	Various accounting standards and interpretations have been issued with 2013 effective dates and effective dates subsequent to December 31, 2013. The Company has evaluated the recently issued accounting pronouncements that are currently effective or will be effective in 2014 and believe that none of them have had or will have a material effect on the Company’s financial position, results of operations or cash flows.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2013
Computation of Basic and Diluted Net Loss per Share	'
	The following table sets forth the computation of basic and diluted net loss per share for the years ended December 31, 2013, 2012 and 2011:
		Years ended
		December 31,
		2013			2012			2011
	Numerator:
	Net loss	$	(25,780,659	)	$	(23,460,103	)	$	(25,997,322	)
	Denominator for basic and diluted net loss per share:
	Weighted-average common shares outstanding		55,009,916			39,536,500			30,205,447
	Net loss per share—basic and diluted	$	(0.47	)	$	(0.59	)	$	(0.86	)
Antidilutive Securities	'
	The following table sets forth the potential shares of common stock that are not included in the calculation of diluted net loss per share because to do so would be anti-dilutive as of the end of each period presented:
		December 31,
		2013			2012			2011
	Stock options outstanding		11,687,300			7,835,533			3,470,908
	Warrants to purchase common stock		25,550,625			21,216,447			23,923,301

Inventory_Tables

Inventory (Tables)	12 Months Ended
	Dec. 31, 2013
Current Inventory	'
	Current inventory consists of the following as of:
		December 31,
		2013		2012
	Raw materials	$	385,565	$	198,647
	Work-in-process		624,530		1,051,286
	Finished goods		117,846		21,274
	Inventory	$	1,127,941	$	1,271,207

Property_and_Equipment_Tables

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2013
Property and Equipment	'
	Property and equipment consists of the following as of:
		December 31,
		2013			2012
	Furniture and equipment	$	2,274,633		$	2,143,025
	Computer hardware and software		499,922			489,478
	Leasehold improvements		46,754			46,754
			2,821,309			2,679,257
	Less accumulated depreciation and amortization		(2,244,214	)		(2,069,585	)
	Property and equipment, net	$	577,095		$	609,672

Accrued_Expenses_Tables

Accrued Expenses (Tables)	12 Months Ended
	Dec. 31, 2013
Accrued Expenses	'
	Accrued expenses consists of the following as of:
		December 31,
		2013		2012
	Professional service related expenses	$	2,650,163	$	2,229,057
	Payroll related expenses		1,043,028		1,099,713
	Other expenses		492,869		344,839
	Accrued expenses	$	4,186,060	$	3,673,609

Notes_Payable_Tables

Notes Payable (Tables)	12 Months Ended
	Dec. 31, 2013
Notes Payable	'
	Notes payable consists of the following as of:
		December 31,
		2013			2012
	Growth capital loan dated April 16, 2012 (net of discounts of $131,670 and $316,028 at December 31, 2013 and 2012, respectively)	$	6,868,330		$	9,683,972
	Less current portion		(4,000,000	)		(3,000,000	)
	Total long-term debt	$	2,868,330		$	6,683,972
Scheduled of Debt Principal Payments	'
	Scheduled debt principal payments are as follows as of December 31, 2013:
	Years Ending December 31:
	2014	$	4,000,000
	2015		3,000,000
			7,000,000
	Less original issue discount		(131,670	)
	Notes payable, net	$	6,868,330

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2013
Tax Rate Reconciliation	'
	The income tax expense benefit differed from the amount computed by applying the U.S. federal income tax rate of 34% to income before income taxes as a result of the following:
		2013			2012			2011
	Computed ‘expected’ tax benefit		34	%		34	%		34	%
	Other permanent adjustments		-2.3	%		-2.2	%		-1.8	%
	Research and development credit		3.5	%		0	%		1.6	%
	Federal valuation allowance		-35.2	%		-31.8	%		-33.8	%
			0	%		0	%		0	%
Deferred Tax Assets	'
	The tax effect of temporary differences that give rise to significant portions of the deferred tax assets as of December 31 is presented below:
		2013			2012
	Deferred tax assets (liabilities):
	Start-up costs	$	8,851,000		$	10,367,000
	Capitalized research and development costs		24,844,000			23,658,000
	Reserves and accruals		4,530,000			3,447,000
	Property and equipment		105,000			143,000
	Research and development credit		1,508,000			486,000
	Net operating loss carryforwards		12,198,000			9,185,000
	Total gross deferred tax assets		52,036,000			47,286,000
	Valuation allowance		(52,036,000	)		(47,286,000	)
	Net deferred tax assets	$	—		$	—

Stock_Options_Tables

Stock Options (Tables)	12 Months Ended
	Dec. 31, 2013
Summary of Stock Option Activity	'
	Stock option activity is as follows:
		Shares			Outstanding Options					Aggregate
		Available For								Intrinsic
		Grant			Number of			Weighted-Average		Value
					Shares			Exercise Price
	Shares reserved at Plan inception		7,143			—		$	—
	Balance, December 31, 2003		7,143			—			—
	Shares reserved		73,260			—			—
	Options granted		(57,466	)		57,466			2.76
	Options exercised		—			—			—
	Options cancelled		641			(641	)		2.76
	Balance, December 31, 2004		23,578			56,825			2.76
	Shares reserved		113,148			—			—
	Options granted		(84,028	)		84,028			2.76
	Options exercised		—			(4,926	)		2.76
	Options cancelled		7,209			(7,209	)		2.76
	Balance, December 31, 2005		59,907			128,718			2.76
	Shares reserved		94,449			—			—
	Options granted		(113,277	)		113,277			6.9
	Options exercised		—			(14,498	)		2.76
	Options cancelled		17,237			(17,237	)		2.76
	Balance, December 31, 2006		58,316			210,260			5
	Shares reserved		362,183			—			—
	Options granted		(176,098	)		176,098			45.78
	Options exercised		—			(5,851	)		3.65
	Options cancelled		30,416			(30,416	)		74.71
	Balance, December 31, 2007		274,817			350,091			19.48
	Shares reserved		—			—			—
	Options granted		(221,838	)		221,838			45.56
	Options exercised		—			(16,820	)		3.89
	Options cancelled		89,019			(89,019	)		38.69
	Balance, December 31, 2008		141,998			466,090			28.79
	Shares reserved		500,000			—			—
	Options granted		(692,645	)		692,645			14.68
	Options exercised		—			(13,437	)		2.79
	Options cancelled		149,736			(149,736	)		31.2
	Balance, December 31, 2009		99,089			995,562			18.96
	Shares reserved		1,149,817			—			—
	Options granted		(423,789	)		423,789			1.96
	Options exercised		—			(8,592	)		2.76
	Options cancelled		598,244			(598,244	)		25.29
	Balance, December 31, 2010		1,423,361			812,515			5.6
	Shares reserved		2,000,000			—			—
	Options granted		(2,716,464	)		2,716,464			2.44
	Options exercised		—			(1,139	)		1.9
	Options cancelled		56,932			(56,932	)		3.21
	Balance, December 31, 2011		763,829			3,470,908			3.17
	Shares reserved		8,000,000			—			—
	Options granted		(4,462,873	)		4,462,873			3.35
	Options exercised		—			(5,219	)		2.43
	Options cancelled		93,029			(93,029	)		2.79
	Balance, December 31, 2012		4,393,985			7,835,533			3.28	$	1,359,840
	Shares reserved		—			—			—
	Options granted		(4,346,000	)		4,346,000			1.32
	Options exercised		—			—			—
	Options cancelled		494,233			(494,233	)		3
	Balance, December 31, 2013		542,218			11,687,300		$	2.56	$	3,284,696
Options Outstanding Vested and Currently Exercisable by Exercise Price	'
	The options outstanding, vested and currently exercisable by exercise price at December 31, 2013:
	Outstanding Options and Expected to Vest									Options Exercisable and Vested
	Exercise	Number of			Weighted-Average			Aggregate		Number of		Weighted-Average		Aggregate
	Price	Shares			Remaining			Intrinsic		Options		Exercise Price		Intrinsic
		Outstanding			Contractual Life			Value						Value
					(Years)
	$0.01 to $2.00		5,274,326			8.7		$	3,284,696		1,339,740	$	1.61	$	573,861
	$2.01 to $3.00		2,208,857			6.8			—		1,508,012		2.63		—
	$3.01 to $5.00		4,086,635			8.4			—		1,551,542		3.43		—
	$5.01 to $10.00		4,166			5.1			—		4,166		8.4		—
	> $10.00		113,316			4.3			—		113,316		23.97		—
			11,687,300					$	3,284,696		4,516,776	$	3.14	$	573,861
Non employees	'
Stock Option Valuation Assumptions	'
	The fair value for the years ended December 31, 2013, 2012 and 2011 was calculated using the following assumptions, defined below:
		Years Ended December 31,
		2013		2012	2011
	Risk-free interest rates	0.26%–2.98%		0.24%–2.05%	0.26%–3.45%
	Expected life	1.50 years–9.76 years		2.00 years–9.25 years	2.04 years–9.95 years
	Expected dividends	0%		0%	0%
	Expected volatility	80.00%–143.00%		63.48%–142.25%	79.50%–123.80%
Employees Stock Option Plan	'
Stock Option Valuation Assumptions	'
	The estimated grant-date fair values of the employee stock options were calculated using the Black-Scholes valuation model, based on the following assumptions for the years ended December 31, 2013, 2012 and 2011:
		Years Ended December 31,
		2013		2012	2011
	Risk-free interest rates	0.94%–1.33%		0.90%–1.09%	1.13%–2.68%
	Expected life	6.00 years–6.25 years		6.00 years–6.25 years	5.42 years–6.25 years
	Expected dividends	0%		0%	0%
	Expected volatility	148.00%–149.00%		137.58%–143.98%	114.80%–124.40%

Warrants_Tables

Warrants (Tables)	12 Months Ended
	Dec. 31, 2013
Stock Warrants Activity	'
	Stock warrant activity is as follows:
			Common			Price(1)		Series A			Price(1)		Series B			Price(1)		Series C			Price(1)
			Shares					Preferred					Preferred					Preferred
								Shares					Shares					Shares
	Balance as of:
	December 31, 2002			—					—					—					—
	Granted			—					20,963		$	5.46		3,916		$	23.68		—
	Exercised			—					—					—					—
	Cancelled			—					—					—					—
	December 31, 2003			—					20,963		$	5.46		3,916		$	23.68		—
	Granted			—					—					16,859		$	23.68		—
	Exercised			—					(20,963	)	$	8.95		—					—
	Cancelled			—					—					—					—
	December 31, 2004			—					—					20,775		$	23.68		—
	Granted			28,385		$	2.76		—					11,624		$	23.68		—
	Exercised			—					—					—					—
	Cancelled			—					—					—					—
	December 31, 2005			28,385		$	2.76		—					32,399		$	23.68		—
	Granted			—					—					5,811		$	23.68		24,605		$	48.56
	Exercised			—					—					—					—
	Cancelled			—					—					—					—
	December 31, 2006			28,385		$	2.76		—					38,210		$	23.68		24,605		$	48.56
	Granted			—					—					—					22,650		$	48.56
	Exercised			—					—					—					—
	Cancelled			—					—					—					—
	Converted upon close of IPO			85,465		$	37.44		—					(38,210	)	$	23.68		(47,255	)	$	48.56
	December 31, 2007			113,850		$	28.79		—					—					—
	Granted(2)			179,328		$	9.51		—					—					—
	Exercised			—					—					—					—
	Cancelled			—					—					—					—
	December 31, 2008			293,178		$	17		—					—					—
	Granted(2)(3)			1,540,036		$	7.86		—					—					—
	Exercised(3)			(264,120	)	$	8.49		—					—					—
	Cancelled(3)			(236,759	)	$	9.53		—					—					—
	December 31, 2009			1,332,335		$	9.44		—					—					—
	Granted(2)(3)			21,046,376		$	2.19		—					—					—
	Exercised			—					—					—					—
	Cancelled(3)			(153,993	)	$	5.78		—					—					—
	December 31, 2010			22,224,718		$	2.6		—					—					—
	Granted(2)			1,759,997		$	1.9		—					—					—
	Exercised			(59,219	)	$	2.19		—					—					—
	Cancelled			(2,195	)	$	23.68		—					—					—
	December 31, 2011			23,923,301		$	2.55		—					—					—
	Granted(2)			106,746		$	2.34		—					—					—
	Exercised			(2,813,600	)	$	2.18		—					—					—
	Cancelled			—					—					—					—
	December 31, 2012			21,216,447		$	2.6		—					—					—
	Granted(2)			5,508,000		$	1.14		—					—					—
	Exercised			(20,325	)	$	1.38		—					—					—
	Cancelled			(1,153,497	)	$	9.14		—					—					—
	December 31, 2013			25,550,625		$	1.99		—					—					—
	-1	Represents weighted-average exercise price per share.
	-2	See Notes 7 and 8 for discussions relating to the issuance of warrants in 2013, 2012, 2011, 2010, 2009 and 2008.
	-3	See Note 7 for discussions relating to both the cashless exercises of warrants in 2009 and the cancellation and reissuance of warrants following down round equity financings.

Related_Party_Transactions_Tab

Related Party Transactions (Tables)	12 Months Ended
	Dec. 31, 2013
Bay City Capital	'
Shares Purchased by Related Parties	'
	The shares purchased, together with the proceeds, before expenses to the Company, are shown in the table below:
	Beneficial Owner	Shares		Warrants		Proceeds, before
		Purchased		Purchased		expenses, to the Company
	Bay City Capital		840,000		167,999	$	1,386,000
Anthony Jansz	'
Shares Purchased by Related Parties	'
	The shares purchased, together with the proceeds, before expenses to the Company, are shown in the table below:
	Beneficial Owner	Shares		Warrants		Proceeds, before
		Purchased		Purchased		expenses, to the Company
	Anthony Jansz		150,000		60,000	$	142,500

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2013
Future Minimum Lease Payment	'
	The following is a schedule of total future minimum lease payments due as of December 31, 2013:
	Years ending December 31:
	2014	$	291,369
	2015		221,789
		$	513,158

Quarterly_Data_Tables

Quarterly Data (Tables)	12 Months Ended
	Dec. 31, 2013
Quarterly Information	'
	The following table represents certain unaudited quarterly information for each of the eight quarters in the period ended December 31, 2013. In management’s opinion, this information has been prepared on the same basis as the audited consolidated financial statements and includes all the adjustments necessary to fairly state the unaudited quarterly results of operations (in thousands, except per share data).
		First			Second			Third			Fourth
		Quarter			Quarter			Quarter			Quarter
	2013:00:00
	Net loss	$	(6,581	)	$	(6,323	)	$	(6,303	)	$	(6,573	)
	Basic and diluted net loss per share	$	(0.14	)	$	(0.11	)	$	(0.11	)	$	(0.11	)
	2012:00:00
	Net loss	$	(5,633	)	$	(4,954	)	$	(5,847	)	$	(7,027	)
	Basic and diluted net loss per share	$	(0.15	)	$	(0.13	)	$	(0.14	)	$	(0.17	)

Formation_and_Business_of_the_1

Formation and Business of the Company - Additional Information (Detail)

0 Months Ended

1 Months Ended

3 Months Ended

12 Months Ended

132 Months Ended

1 Months Ended

Dec. 31, 2002

Apr. 16, 2012

Nov. 30, 2007

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2010

Dec. 31, 2009

Dec. 31, 2008

Dec. 31, 2007

Dec. 31, 2006

Dec. 31, 2005

Dec. 31, 2004

Dec. 31, 2003

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Jan. 31, 2006

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

Alpha Medical, Inc.

Beta Medical, Inc.

EnteroMedics Europe

CHF

Organization And Description Of Business [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Ownership percentage of an entity combined to form the Company

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

100.00%

100.00%

'

Common stock, shares outstanding

'

'

'

63,551,350

'

'

'

41,843,270

'

'

'

63,551,350

41,843,270

'

'

'

'

'

'

'

'

'

63,551,350

'

'

20

Common stock, par value

'

'

'

$0.01

'

'

'

$0.01

'

'

'

$0.01

$0.01

'

'

'

'

'

'

'

'

'

$0.01

'

'

1,000

Repurchased shares percentage

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

100.00%

Stock Issued (in shares)

'

2,271,705

914,975

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1

Net proceeds from initial public offering

'

'

$39,100,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net income(loss)

($603,348)

'

'

($6,573,000)

($6,303,000)

($6,323,000)

($6,581,000)

($7,027,000)

($5,847,000)

($4,954,000)

($5,633,000)

($25,780,659)

($23,460,103)

($25,997,322)

($17,347,387)

($31,929,200)

($37,874,028)

($28,575,348)

($17,690,477)

($11,215,191)

($3,448,752)

($1,900,288)

($225,822,103)

'

'

'

Summary_of_Significant_Account3

Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	1 Months Ended	12 Months Ended			132 Months Ended
	Dec. 31, 2008	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013
Schedule Of Significant Accounting Policies [Line Items]	'	'	'	'	'
Long-term debt	'	$7,300,000	'	'	$7,300,000
Cash equivalents maturity period	'	'90 days	'	'	'
Cash collateral money market	'	'	200,000	'	'
Standby letter of credit amount	'	200,000	'	'	'
Patent related legal expenses	'	296,575	278,987	271,105	2,739,844
Reclassification of warrant liability	1,400,000	'	'	'	2,932,766
Increase in accumulated deficit as a result of change in accounting principle	$130,968	'	'	'	'
Minimum	'	'	'	'	'
Schedule Of Significant Accounting Policies [Line Items]	'	'	'	'	'
Short term investment maturity period	'	'3 months	'	'	'
Property and equipment estimated useful lives	'	'3 years	'	'	'
Maximum	'	'	'	'	'
Schedule Of Significant Accounting Policies [Line Items]	'	'	'	'	'
Short term investment maturity period	'	'1 year	'	'	'
Property and equipment estimated useful lives	'	'7 years	'	'	'
Standby letters of credit	'	'	'	'	'
Schedule Of Significant Accounting Policies [Line Items]	'	'	'	'	'
Stand by letter of credit expiration date	'	1-Oct-13	'	'	'
Money Market Funds	'	'	'	'	'
Schedule Of Significant Accounting Policies [Line Items]	'	'	'	'	'
Money market funds preserve the value of investment per share	'	$1	'	'	'

Computation_of_Basic_and_Dilut

Computation of Basic and Diluted Net Loss Per Share (Detail) (USD $)

0 Months Ended

3 Months Ended

12 Months Ended

132 Months Ended

Dec. 31, 2002

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2010

Dec. 31, 2009

Dec. 31, 2008

Dec. 31, 2007

Dec. 31, 2006

Dec. 31, 2005

Dec. 31, 2004

Dec. 31, 2003

Dec. 31, 2013

Numerator:

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net loss

($603,348)

($6,573,000)

($6,303,000)

($6,323,000)

($6,581,000)

($7,027,000)

($5,847,000)

($4,954,000)

($5,633,000)

($25,780,659)

($23,460,103)

($25,997,322)

($17,347,387)

($31,929,200)

($37,874,028)

($28,575,348)

($17,690,477)

($11,215,191)

($3,448,752)

($1,900,288)

($225,822,103)

Denominator for basic and diluted net loss per share:

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Weighted-average common shares outstanding

'

'

'

'

'

'

'

'

'

55,009,916

39,536,500

30,205,447

'

'

'

'

'

'

'

'

'

Net loss per share-basic and diluted

'

($0.11)

($0.11)

($0.11)

($0.14)

($0.17)

($0.14)

($0.13)

($0.15)

($0.47)

($0.59)

($0.86)

'

'

'

'

'

'

'

'

'

Potential_Shares_of_Common_Sto

Potential Shares of Common Stock Not Included in Calculation of Diluted Net Loss per Share (Detail)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Stock options outstanding	'	'	'
Anti-dilutive Securities	'	'	'
Anti-dilutive as of end of each period	11,687,300	7,835,533	3,470,908
Warrants to purchase common stock	'	'	'
Anti-dilutive Securities	'	'	'
Anti-dilutive as of end of each period	25,550,625	21,216,447	23,923,301

Inventory_Additional_Informati

Inventory - Additional Information (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Inventory [Line Items]	'	'
Long-term inventory	$794,000	$862,000

Current_Inventory_Detail

Current Inventory (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Inventory [Line Items]	'	'
Raw materials	$385,565	$198,647
Work-in-process	624,530	1,051,286
Finished goods	117,846	21,274
Inventory	$1,127,941	$1,271,207

Property_and_Equipment_Detail

Property and Equipment (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Line Items]	'	'
Furniture and equipment	$2,274,633	$2,143,025
Computer hardware and software	499,922	489,478
Leasehold improvements	46,754	46,754
Property and Equipment, Gross	2,821,309	2,679,257
Less accumulated depreciation and amortization	-2,244,214	-2,069,585
Property and equipment, net	$577,095	$609,672

Accrued_Expenses_Detail

Accrued Expenses (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Accrued Expenses [Line Items]	'	'
Professional service related expenses	$2,650,163	$2,229,057
Payroll related expenses	1,043,028	1,099,713
Other expenses	492,869	344,839
Accrued expenses	$4,186,060	$3,673,609

Notes_Payable_Detail

Notes Payable (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Accounts Payable [Line Items]	'	'
Growth capital loan dated April 16, 2012 (net of discounts of $131,670 and $316,028 at December 31, 2013 and 2012, respectively)	$6,868,330	$9,683,972
Less current portion	-4,000,000	-3,000,000
Total long-term debt	$2,868,330	$6,683,972

Notes_Payable_Parenthetical_De

Notes Payable (Parenthetical) (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Accounts Payable [Line Items]	'	'
Notes payable, discounts	$131,670	$316,028

Notes_Payable_Additional_Infor

Notes Payable - Additional Information (Detail) (USD $)

1 Months Ended

12 Months Ended

132 Months Ended

12 Months Ended

1 Months Ended

1 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

12 Months Ended

Apr. 16, 2012

Jan. 31, 2009

Nov. 30, 2007

Dec. 31, 2013

Dec. 31, 2009

Dec. 31, 2013

Feb. 28, 2013

Apr. 23, 2012

Jul. 01, 2009

Jun. 30, 2009

Dec. 31, 2008

Nov. 18, 2008

Dec. 31, 2013

Dec. 31, 2007

Dec. 31, 2003

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2010

Dec. 31, 2009

Dec. 31, 2008

Dec. 31, 2006

Dec. 31, 2005

Nov. 30, 2008

Feb. 27, 2013

Sep. 28, 2011

Feb. 14, 2009

Nov. 18, 2008

Apr. 23, 2012

Apr. 16, 2012

Nov. 21, 2008

Nov. 18, 2008

Feb. 08, 2010

Jul. 08, 2010

Mar. 01, 2011

9-May-13

9-May-13

9-May-13

9-May-13

9-May-13

Sep. 30, 2009

Dec. 31, 2009

Sep. 29, 2009

Jul. 08, 2010

Sep. 30, 2009

Nov. 21, 2008

Nov. 18, 2008

Oct. 31, 2009

Dec. 31, 2013

Dec. 31, 2009

Oct. 02, 2009

Oct. 31, 2009

Dec. 31, 2013

Apr. 28, 2009

Nov. 18, 2008

Apr. 30, 2012

Dec. 31, 2010

Dec. 31, 2009

Jan. 20, 2010

Oct. 07, 2009

Apr. 28, 2009

Dec. 31, 2009

Dec. 31, 2009

Dec. 31, 2010

Dec. 31, 2010

Dec. 31, 2010

Common Stock

Common Stock

Common Stock

Common Stock

Common Stock

Common Stock

Common Stock

Common Stock

Common Stock

Common Stock

Warrants to purchase common stock

Warrants to purchase common stock

Warrants to purchase common stock

Warrants to purchase common stock

Warrants to purchase common stock

Silicon Valley Bank

Silicon Valley Bank

Silicon Valley Bank

Silicon Valley Bank

Silicon Valley Bank

Silicon Valley Bank

Silicon Valley Bank

Silicon Valley Bank

Silicon Valley Bank

Silicon Valley Bank

Silicon Valley Bank

Silicon Valley Bank

Silicon Valley Bank

Silicon Valley Bank

Silicon Valley Bank

Silicon Valley Bank

Silicon Valley Bank

Western Technology Investment

Western Technology Investment

Western Technology Investment

Western Technology Investment

Western Technology Investment

Western Technology Investment

Western Technology Investment

Western Technology Investment

Horizon Funding

Horizon Funding

Horizon Funding

Horizon Funding

Horizon Funding

Horizon Funding

Horizon Funding

Horizon Funding

Horizon Funding

Horizon Funding

Horizon Funding

Horizon Funding

Horizon Funding

Installment

First Amendment

Second Amendment

Fourth Amendment

15-Nov-13

15-Nov-13

15-Nov-13

15-Nov-13

15-Nov-13

Warrants to purchase common stock

Warrants to purchase common stock

Warrants to purchase common stock

Warrants to purchase common stock

Warrants to purchase common stock

Warrants to purchase common stock

Warrants to purchase common stock

Warrants to purchase common stock

Warrants to purchase common stock

Warrants to purchase common stock

Warrants to purchase common stock

Warrants to purchase common stock

Warrants to purchase common stock

Warrants to purchase common stock

Warrants to purchase common stock

Warrants to purchase common stock

Warrants to purchase common stock

Warrants to purchase common stock

Warrants to purchase common stock

Warrants to purchase common stock

Warrants to purchase common stock

Warrants to purchase common stock

Installment

Installment

15-Apr-14

Until it receives FDA approval for the Maestro Rechargeable System

After FDA approval for the Maestro Rechargeable System

Second Amendment

Common Stock

Common Stock

Common Stock

Minimum

Maximum

Fair Value, Inputs, Level 3

Fair Value, Inputs, Level 3

Fair Value, Inputs, Level 3

BasisPoint

BasisPoint

Minimum

Maximum

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Principal amount of loan

$10,000,000

'

'

'

'

'

'

$10,000,000

'

'

'

$20,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$10,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$5,000,000

'

'

'

'

'

'

'

$5,000,000

'

'

'

'

'

'

'

'

'

'

'

'

Loan agreement with annual rate

'

'

'

'

'

'

'

'

11.00%

12.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

11.00%

10.00%

11.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Final payment fee percentage

'

'

'

5.00%

'

5.00%

'

'

'

'

'

5.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Loan agreement with fixed annual rate

'

'

'

'

'

'

'

8.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

10.00%

11.00%

6.25%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of installments of repayment of debt

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

30

'

'

'

'

30

30

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Warrants exercise price

'

'

'

'

'

'

1.14

'

'

'

'

9.51

'

'

'

'

'

'

'

'

'

'

'

'

1.9

6.9

9.51

'

2.34

'

'

'

'

'

'

'

'

'

'

'

'

6.9

2.1

'

'

'

'

23.64

'

6.9

'

'

'

'

'

3.9

4.8

3.9

4.8

10.01

'

'

'

'

'

Warrants issued

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,100,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

550,000

'

'

'

'

'

'

495,000

55,000

'

'

'

'

'

'

'

'

'

'

'

Issued warrant

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

5,508,000

1,760,000

67,773

179,328

'

106,746

'

'

'

'

'

'

'

'

'

'

'

'

'

150,642

'

'

'

'

'

'

'

'

'

'

'

'

'

'

26,442

57,152

49,460

'

'

'

'

'

Warrants issued, term

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'10 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'10 years

'

'

'

'

'

Fair value of warrant liability

'

'

'

'

'

'

'

'

'

'

1,500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

4,800,000

'

'

'

'

'

'

'

494,652

'

'

'

'

'

312,751

471,585

'

'

542,144

'

'

'

'

'

Warrant fair value assumption, volatility rate

'

79.60%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

78.90%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

108.00%

'

'

'

'

'

'

108.00%

'

'

'

'

'

'

'

99.10%

'

'

'

'

'

103.90%

104.80%

'

113.25%

113.33%

Warrant fair value assumption, dividend rate

'

0.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0.00%

'

'

'

'

'

'

0.00%

'

'

'

'

'

'

'

0.00%

'

0.00%

'

'

'

'

'

0.00%

'

'

Warrant fair value assumption, risk free interest rate

'

2.24%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3.54%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3.29%

'

'

'

'

'

'

3.22%

'

'

'

'

'

'

'

3.00%

'

3.84%

'

'

'

'

'

3.38%

'

'

Warrant fair value assumption, remaining life

'

'9 years 10 months 17 days

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'10 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'9 years 1 month 21 days

'

'

'

'

'

'

'9 years 1 month 17 days

'

'

'

'

'

'

'

'10 years

'

'

'

'

'

'8 years 10 months 21 days

'9 years 3 months 29 days

'

'8 years 6 months 4 days

'8 years 11 months 12 days

Warrants outstanding

'

'

'

'

'

'

'

'

'

'

'

'

25,550,625

113,850

'

21,216,447

23,923,301

22,224,718

1,332,335

293,178

28,385

28,385

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

141,025

114,583

'

'

'

'

'

'

'

'

Change in value of warrant liability

'

'

'

'

'

-3,840,622

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3,800,000

'

'

'

'

'

'

'

1,210

'

'

'

'

'

'

158,834

119,904

'

'

'

'

'

'

'

'

Cashless exercise of warrants

'

'

'

'

159,420

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

159,420

'

'

'

'

'

'

79,710

24,990

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock Issued (in shares)

2,271,705

'

914,975

'

'

'

'

'

'

'

'

'

7,917,755

833,333

19,229

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

125,470

'

'

'

'

'

'

59,248

2,996

'

'

'

'

'

'

'

'

'

'

'

'

'

Term loans, agreed sum

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

20,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amount used to repay outstanding debt

'

'

'

'

'

'

'

4,700,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Repayment of principal amount

'

'

'

333,333

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Conditional amount to be placed in restricted account at SVB

'

'

'

7,500,000

'

7,500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Cumulative aggregate proceeds from new capital transactions

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

5,000,000

10,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Liquidity ratio (unrestricted cash divided by outstanding debt)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1.25

0.75

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Success fee percentage in the event the Company receives FDA approval for the Maestro Rechargeable System

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$187,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Time for exercising warrant

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'10 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Schedule_of_Debt_Principal_Pay

Schedule of Debt Principal Payments (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Debt Instrument [Line Items]	'	'
2014	$4,000,000	'
2015	3,000,000	'
Notes payable, gross	7,000,000	'
Less original issue discount	-131,670	-316,028
Notes payable, net	$6,868,330	$9,683,972

Stock_Sales_Additional_Informa

Stock Sales - Additional Information (Detail) (USD $)

1 Months Ended

12 Months Ended

3 Months Ended

1 Months Ended

1 Months Ended

Feb. 27, 2013

Feb. 28, 2013

Apr. 20, 2012

Apr. 16, 2012

Sep. 28, 2011

Nov. 30, 2007

Dec. 31, 2013

Jul. 31, 2013

Nov. 18, 2008

Mar. 27, 2014

Sep. 28, 2011

Feb. 27, 2013

Feb. 14, 2009

Nov. 18, 2008

Sep. 28, 2011

Jul. 31, 2013

Feb. 27, 2013

Sep. 28, 2011

Subsequent Event

Warrants to purchase common stock

Warrants to purchase common stock

Warrants to purchase common stock

Warrants to purchase common stock

Minimum

Maximum

Common Stock

Common Stock

Warrants to purchase common stock

Class of Stock [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock Issued (in shares)

'

'

'

2,271,705

'

914,975

'

'

'

'

'

'

'

'

'

'

13,770,000

8,800,000

Warrant issued

'

'

'

'

'

'

'

'

'

'

1,760,000

5,508,000

67,773

179,328

'

'

'

'

Purchase price per share

$0.95

'

'

'

$1.65

'

'

'

'

'

'

'

'

'

'

'

'

'

Gross proceeds before deducting estimate offering expenses

$13,100,000

'

$5,000,000

'

$14,500,000

'

$11,000,000

'

'

$5,800,000

'

'

'

'

'

$20,000,000

'

'

Warrants exercise price

'

1.14

'

'

'

'

'

'

9.51

'

1.9

'

6.9

9.51

'

'

'

'

Warrant, exercise period

'

'5 years

'

'

'

'

'

'

'

'

'5 years

'

'

'

'

'

'

'

Maximum percentage of ownership restriction on warrant exercises

'

19.99%

'

'

'

'

'

'

'

'

19.99%

'

'

'

'

'

'

'

Warrant redemption price

'

'

'

'

'

'

'

'

'

'

0.01

'

'

'

'

'

'

'

Closing sale price of common stock

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$1

'

'

'

Number of consecutive trading days

'

'

'

'

'

'

'

'

'

'

'10 days

'

'

'

'

'

'

'

Required prior notice period

'

'

'

'

'

'

'

'

'

'

'30 days

'

'

'

'

'

'

'

Purchase price per share

'

'

'

$2.22

'

'

$1.39

'

'

$2.33

'

'

'

'

'

'

'

'

Commission or discount percentage on issue of shares

'

'

'

'

'

'

'

2.00%

'

'

'

'

'

'

'

'

'

'

Number of shares sold

'

'

'

'

'

'

7,917,755

'

'

2,506,222

'

'

'

'

'

'

'

'

Convertible_Preferred_Stock_Ad

Convertible Preferred Stock - Additional Information (Detail) (USD $)	12 Months Ended				12 Months Ended
	Dec. 31, 2012	Dec. 31, 2009	Dec. 31, 2007	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2013
					Series A Preferred Stock	Series B Preferred Stock	Series C Preferred Stock
Common Stock, Preferred Stock, Treasury Stock, Stock-Based Compensation And Other Benefits [Line Items]	'	'	'	'	'	'	'
Convertible preferred stock authorized	'	'	'	5,000,000	'	'	'
Convertible preferred stock par value	'	'	'	$0.01	'	'	'
Convertible preferred stock issued	'	'	'	0	'	'	'
Convertible preferred stock outstanding	'	'	'	0	'	'	'
Equity issued, price per share	$2.22	$7.28	$48	'	$6.56	$3.94	$8.09
Preferred stock conversion, denominator	'	'	'	'	$4.24	$3.94	$8.09

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Taxes [Line Items]	'	'	'
U.S. federal income tax rate	34.00%	34.00%	34.00%
U.S. federal net operating loss carryforwards amount	$81,200,000	'	'
Net operating loss carryforwards amount available for utilization	33,100,000	'	'
Tax benefit recorded to additional paid-in capital	221,000	'	'
Gross federal net operating loss carryforward expired amount	48,100,000	'	'
Deferred tax asset, write-off of capitalized start-up costs	5,900,000	'	'
Deferred tax asset, write-off of capitalized research and development costs	11,100,000	'	'
Deferred tax asset, write-off of property and equipment	1,500,000	'	'
Deferred tax asset, write-off of research and development credits	2,400,000	'	'
Unrecognized tax	0	0	'
Interest or penalties charged or accrued related to unrecognized tax benefits	0	'	'
Tax examinations	$0	'	'
Federal examinations for the years	'2010	'	'
Minimum	'	'	'
Income Taxes [Line Items]	'	'	'
Federal net operating loss carryforwards expiration date	'2022	'	'
Maximum	'	'	'
Income Taxes [Line Items]	'	'	'
Federal net operating loss carryforwards expiration date	'2033	'	'

Tax_Rate_Reconciliation_Detail

Tax Rate Reconciliation (Detail)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Schedule of Effective Tax Rate Reconciliation [Line Items]	'	'	'
Computed 'expected' tax benefit	34.00%	34.00%	34.00%
Other permanent adjustments	-2.30%	-2.20%	-1.80%
Research and development credit	3.50%	0.00%	1.60%
Federal valuation allowance	-35.20%	-31.80%	-33.80%
Effective Income Tax Rate Reconciliation, Percent	0.00%	0.00%	0.00%

Deferred_Tax_Assets_Detail

Deferred Tax Assets (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Deferred tax assets (liabilities):	'	'
Start-up costs	$8,851,000	$10,367,000
Capitalized research and development costs	24,844,000	23,658,000
Reserves and accruals	4,530,000	3,447,000
Property and equipment	105,000	143,000
Research and development credit	1,508,000	486,000
Net operating loss carryforwards	12,198,000	9,185,000
Total gross deferred tax assets	52,036,000	47,286,000
Valuation allowance	-52,036,000	-47,286,000
Net deferred tax assets	'	'

Stock_Options_Additional_Infor

Stock Options - Additional Information (Detail) (USD $)	1 Months Ended	12 Months Ended			132 Months Ended
	Sep. 27, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013
Schedule Of Stock Options [Line Items]	'	'	'	'	'
Stock incentive plan, shares authorized	'	12,300,000	12,300,000	'	12,300,000
Options granted to participants	'	10.00%	'	'	'
Stock incentive plan, additional shares authorized	8,000,000	'	'	'	'
Stock-based compensation	'	$5,954,928	$4,225,322	$2,892,696	$24,643,416
Weighted average estimated fair value of stock options granted	'	$1.22	$3.19	$2.13	'
Total unrecognized compensation costs related to non-vested stock options	'	13,900,000	'	'	13,900,000
Total unrecognized compensation costs related to non-vested stock options, weighted-average period of recognition	'	'3 years 7 months 28 days	'	'	'
Aggregate intrinsic value of stock options	'	0	3,044	588	'
Incentive Stock Options	'	'	'	'	'
Schedule Of Stock Options [Line Items]	'	'	'	'	'
Options granted to participants	'	10.00%	'	'	'
Stock Option | Employee Awards	'	'	'	'	'
Schedule Of Stock Options [Line Items]	'	'	'	'	'
Award vesting period	'	'4 years	'	'	'
Nonemployees	'	'	'	'	'
Schedule Of Stock Options [Line Items]	'	'	'	'	'
Stock-based compensation	'	$166,679	$52,190	$75,614	$1,776,280
Minimum	'	'	'	'	'
Schedule Of Stock Options [Line Items]	'	'	'	'	'
Options granted to participants owning more than 10% of outstanding voting stock, exercise price percentage	'	110.00%	'	'	'
Minimum | Incentive Stock Options	'	'	'	'	'
Schedule Of Stock Options [Line Items]	'	'	'	'	'
Option expiration period	'	'5 years	'	'	'
Maximum	'	'	'	'	'
Schedule Of Stock Options [Line Items]	'	'	'	'	'
Option expiration period	'	'10 years	'	'	'

Summary_of_Stock_Option_Activi

Summary of Stock Option Activity (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008	Dec. 31, 2007	Dec. 31, 2006	Dec. 31, 2005	Dec. 31, 2004	Dec. 31, 2003
Schedule Of Stock Options [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Outstanding Options, Number of Shares, Options exercised	'	-5,219	-1,139	-8,586	-13,450	-16,829	-5,854	-14,504	-4,927	'	'
Outstanding Options, Weighted-Average Exercise Price, Options exercised	'	'	$1.90	$2.76	'	'	$3.60	$2.76	$2.76	'	'
Aggregate Intrinsic Value	$3,284,696	'	'	'	'	'	'	'	'	'	'
Stock Incentive Plan 2003	'	'	'	'	'	'	'	'	'	'	'
Schedule Of Stock Options [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Shares Available For Grant, Beginning Balance	4,393,985	763,829	1,423,361	99,089	141,998	274,817	58,316	59,907	23,578	7,143	'
Shares Available For Grant, Shares reserved	'	8,000,000	2,000,000	1,149,817	500,000	'	362,183	94,449	113,148	73,260	'
Shares Available For Grant, Options granted	-4,346,000	-4,462,873	-2,716,464	-423,789	-692,645	-221,838	-176,098	-113,277	-84,028	-57,466	'
Shares Available For Grant, Options exercised	'	'	'	'	'	'	'	'	'	'	'
Shares Available For Grant, Options cancelled	494,233	93,029	56,932	598,244	149,736	89,019	30,416	17,237	7,209	641	'
Shares Available For Grant, Ending Balance	542,218	4,393,985	763,829	1,423,361	99,089	141,998	274,817	58,316	59,907	23,578	7,143
Outstanding Options, Number of Shares, Beginning Balance	7,835,533	3,470,908	812,515	995,562	466,090	350,091	210,260	128,718	56,825	'	'
Outstanding Options, Number of Shares, Shares reserved	'	'	'	'	'	'	'	'	'	'	'
Outstanding Options, Number of Shares, Options granted	4,346,000	4,462,873	2,716,464	423,789	692,645	221,838	176,098	113,277	84,028	57,466	'
Outstanding Options, Number of Shares, Options exercised	'	-5,219	-1,139	-8,592	-13,437	-16,820	-5,851	-14,498	-4,926	'	'
Outstanding Options, Number of Shares, Options cancelled	-494,233	-93,029	-56,932	-598,244	-149,736	-89,019	-30,416	-17,237	-7,209	-641	'
Outstanding Options, Number of Shares, Ending Balance	11,687,300	7,835,533	3,470,908	812,515	995,562	466,090	350,091	210,260	128,718	56,825	'
Outstanding Options, Weighted-Average Exercise Price, Beginning Balance	$3.28	$3.17	$5.60	$18.96	$28.79	$19.48	$5	$2.76	$2.76	'	'
Outstanding Options, Weighted-Average Exercise Price, Shares reserved	'	'	'	'	'	'	'	'	'	'	'
Outstanding Options, Weighted-Average Exercise Price, Options granted	$1.32	$3.35	$2.44	$1.96	$14.68	$45.56	$45.78	$6.90	$2.76	$2.76	'
Outstanding Options, Weighted-Average Exercise Price, Options exercised	'	$2.43	$1.90	$2.76	$2.79	$3.89	$3.65	$2.76	$2.76	'	'
Outstanding Options, Weighted-Average Exercise Price, Options cancelled	$3	$2.79	$3.21	$25.29	$31.20	$38.69	$74.71	$2.76	$2.76	$2.76	'
Outstanding Options, Weighted-Average Exercise Price, Ending Balance	$2.56	$3.28	$3.17	$5.60	$18.96	$28.79	$19.48	$5	$2.76	$2.76	'
Aggregate Intrinsic Value	$3,284,696	$1,359,840	'	'	'	'	'	'	'	'	'
Stock Incentive Plan 2003 | Inception Date	'	'	'	'	'	'	'	'	'	'	'
Schedule Of Stock Options [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Shares Available For Grant, Shares reserved	7,143	'	'	'	'	'	'	'	'	'	'
Outstanding Options, Number of Shares, Shares reserved	'	'	'	'	'	'	'	'	'	'	'

Options_Outstanding_Vested_and

Options Outstanding Vested and Currently Exercisable by Exercise Price (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Number of shares outstanding	11,687,300
Aggregate Intrinsic Value	$3,284,696
Number of Options	4,516,776
Weighted-Average Exercise Price	$3.14
Aggregate Intrinsic Value	573,861
$0.01 to $2.00	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Exercise price, lower limit	$0.01
Exercise price, upper limit	$2
Number of shares outstanding	5,274,326
Weighted-Average remaining contractual life (Years)	'8 years 8 months 12 days
Aggregate Intrinsic Value	3,284,696
Number of Options	1,339,740
Weighted-Average Exercise Price	$1.61
Aggregate Intrinsic Value	$573,861
$2.01 to $3.00	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Exercise price, lower limit	$2.01
Exercise price, upper limit	$3
Number of shares outstanding	2,208,857
Weighted-Average remaining contractual life (Years)	'6 years 9 months 18 days
Number of Options	1,508,012
Weighted-Average Exercise Price	$2.63
$3.01 to $5.00	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Exercise price, lower limit	$3.01
Exercise price, upper limit	$5
Number of shares outstanding	4,086,635
Weighted-Average remaining contractual life (Years)	'8 years 4 months 24 days
Number of Options	1,551,542
Weighted-Average Exercise Price	$3.43
$5.01 to $10.00	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Exercise price, lower limit	$5.01
Exercise price, upper limit	$10
Number of shares outstanding	4,166
Weighted-Average remaining contractual life (Years)	'5 years 1 month 6 days
Number of Options	4,166
Weighted-Average Exercise Price	$8.40
> $10.00	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Exercise price, lower limit	$10
Exercise price, upper limit	'>$10
Number of shares outstanding	113,316
Weighted-Average remaining contractual life (Years)	'4 years 3 months 18 days
Number of Options	113,316
Weighted-Average Exercise Price	$23.97

StockBased_Compensation_for_No

Stock-Based Compensation for Non Employees (Detail)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Risk-free interest rates, minimum	0.94%	0.90%	1.13%
Risk-free interest rates, maximum	1.33%	1.09%	2.68%
Expected dividends	0.00%	0.00%	0.00%
Expected volatility, minimum	148.00%	137.58%	114.80%
Expected Volatility, maximum	149.00%	143.98%	124.40%
Minimum	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Expected life	'6 years	'6 years	'5 years 5 months 1 day
Maximum	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Expected life	'6 years 3 months	'6 years 3 months	'6 years 3 months
Non employees	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Risk-free interest rates, minimum	0.26%	0.24%	0.26%
Risk-free interest rates, maximum	2.98%	2.05%	3.45%
Expected dividends	0.00%	0.00%	0.00%
Expected volatility, minimum	80.00%	63.48%	79.50%
Expected Volatility, maximum	143.00%	142.25%	123.80%
Non employees | Minimum	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Expected life	'1 year 6 months	'2 years	'2 years 15 days
Non employees | Maximum	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Expected life	'9 years 9 months 4 days	'9 years 3 months	'9 years 11 months 12 days

Estimated_GrantDate_Fair_Value

Estimated Grant-Date Fair Values of Employee Stock Options (Detail)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Risk-free interest rates, minimum	0.94%	0.90%	1.13%
Risk-free interest rates, maximum	1.33%	1.09%	2.68%
Expected dividends	0.00%	0.00%	0.00%
Expected volatility, minimum	148.00%	137.58%	114.80%
Expected Volatility, maximum	149.00%	143.98%	124.40%
Minimum	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Expected life	'6 years	'6 years	'5 years 5 months 1 day
Maximum	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Expected life	'6 years 3 months	'6 years 3 months	'6 years 3 months

Stock_Warrant_Activity_Detail

Stock Warrant Activity (Detail)

12 Months Ended

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2010

Dec. 31, 2009

Dec. 31, 2008

Dec. 31, 2007

Dec. 31, 2005

Dec. 31, 2004

Dec. 31, 2003

Dec. 31, 2007

Dec. 31, 2006

Dec. 31, 2005

Dec. 31, 2004

Dec. 31, 2003

Dec. 31, 2007

Dec. 31, 2006

Common Stock

Common Stock

Common Stock

Common Stock

Common Stock

Common Stock

Common Stock

Common Stock

Series A Preferred Stock

Series A Preferred Stock

Series B Preferred Stock

Series B Preferred Stock

Series B Preferred Stock

Series B Preferred Stock

Series B Preferred Stock

Series C Preferred Stock

Series C Preferred Stock

Class of Warrant or Right [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Beginning Balance

21,216,447

23,923,301

22,224,718

1,332,335

293,178

113,850

28,385

'

20,963

'

38,210

32,399

20,775

3,916

'

24,605

'

Granted

5,508,000

[1]

106,746

[1]

1,759,997

[1]

21,046,376

[1],[2]

1,540,036

[1],[2]

179,328

[1]

'

28,385

'

20,963

'

5,811

11,624

16,859

3,916

22,650

24,605

Exercised

-20,325

-2,813,600

-59,219

'

-264,120

[2]

'

'

'

-20,963

'

'

'

'

'

'

'

'

Cancelled

-1,153,497

'

-2,195

-153,993

[2]

-236,759

[2]

'

'

'

'

'

'

'

'

'

'

'

'

Ending Balance

25,550,625

21,216,447

23,923,301

22,224,718

1,332,335

293,178

113,850

28,385

'

20,963

'

38,210

32,399

20,775

3,916

'

24,605

Converted upon close of IPO

'

'

'

'

'

'

85,465

'

'

'

-38,210

'

'

'

'

-47,255

'

Beginning Balance

2.6

[3]

2.55

[3]

2.6

[3]

9.44

[3]

17

[3]

28.79

[3]

2.76

[3]

'

5.46

[3]

'

23.68

[3]

23.68

[3]

23.68

[3]

23.68

[3]

'

48.56

[3]

'

Granted

1.14

[1],[3]

2.34

[1],[3]

1.9

[1],[3]

2.19

[1],[2],[3]

7.86

[1],[2],[3]

9.51

[1],[3]

'

2.76

[3]

'

5.46

[3]

'

23.68

[3]

23.68

[3]

23.68

[3]

23.68

[3]

48.56

[3]

48.56

[3]

Exercised

1.38

[3]

2.18

[3]

2.19

[3]

'

8.49

[2],[3]

'

'

'

8.95

[3]

'

'

'

'

'

'

'

'

Cancelled

9.14

[3]

'

23.68

[3]

5.78

[2],[3]

9.53

[2],[3]

'

'

'

'

'

'

'

'

'

'

'

'

Ending Balance

1.99

[3]

2.6

[3]

2.55

[3]

2.6

[3]

9.44

[3]

17

[3]

28.79

[3]

2.76

[3]

'

5.46

[3]

'

23.68

[3]

23.68

[3]

23.68

[3]

23.68

[3]

'

48.56

[3]

Converted upon close of IPO

'

'

'

'

'

'

37.44

[3]

'

'

'

23.68

[3]

'

'

'

'

48.56

[3]

'

[1]

See Notes 7 and 8 for discussions relating to the issuance of warrants in 2013, 2012, 2011, 2010, 2009 and 2008.

[2]

See Note 7 for discussions relating to both the cashless exercises of warrants in 2009 and the cancellation and reissuance of warrants following down round equity financings.

[3]

Represents weighted-average exercise price per share.

Warrants_Additional_Informatio

Warrants - Additional Information (Detail) (Warrants to purchase common stock)	Dec. 31, 2013	Dec. 31, 2012
Warrants to purchase common stock	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Warrant outstanding, weighted-average remaining contractual life	'2 years 10 months 13 days	'3 years 3 months 29 days

Related_Party_Transactions_Add

Related Party Transactions - Additional Information (Detail)

1 Months Ended

12 Months Ended

132 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

1 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

Apr. 16, 2012

Nov. 30, 2007

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2005

Dec. 31, 2004

Dec. 31, 2013

Feb. 27, 2013

Sep. 28, 2011

Feb. 27, 2013

Sep. 28, 2011

Feb. 14, 2009

Nov. 18, 2008

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Jun. 30, 2011

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

31-May-13

Jan. 22, 2013

Jan. 31, 2013

Jun. 30, 2011

Jan. 22, 2013

Jan. 22, 2013

Dec. 31, 2012

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Jan. 22, 2014

Dec. 31, 2013

Feb. 27, 2013

Sep. 28, 2011

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

Warrants to purchase common stock

Warrants to purchase common stock

Warrants to purchase common stock

Warrants to purchase common stock

Consulting Agreement - Anthony Jansz

Consulting Agreement - Anthony Jansz

Consulting Agreement - Anthony Jansz

Consulting Agreement - Anthony Jansz

Consulting Agreement - Anthony Jansz

Consulting Agreement - Anthony Jansz

Consulting Agreement - Anthony Jansz

Consulting Agreement - Anthony Jansz

Consulting Agreement - Anthony Jansz

Consulting Agreement - Anthony Jansz

Consulting Agreement - Anthony Jansz

Consulting Agreement - Anthony Jansz

Consulting Agreement - Anthony Jansz

Consulting Agreement - Anthony Jansz

Consulting Agreement - Anthony Jansz

Consulting Agreement - Anthony Jansz

Consulting Agreement - Anthony Jansz

Consulting Agreement - Anthony Jansz

Consulting Agreement - Anthony Jansz

Consulting Agreement - Anthony Jansz

Consulting Agreement - Anthony Jansz

Consulting Agreement - Anthony Jansz

Consulting Services

Common Stock

Common Stock

USD ($)

AUD

AUD

USD ($)

AUD

USD ($)

USD ($)

Stock Option

Stock Option

Stock Option

Stock Option

Stock Option

Stock Option

Stock Option

Stock Option

Stock Option

Stock Option

Stock Option

Stock Option

Stock Option

Subsequent Event

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

Vest on January 22, 2014

Vest on January 22, 2015

Vest on January 22, 2015

Prior to June 30, 2014

Vest on May 31, 2014

Vest on May 31, 2015

Vest upon implementation of Australian Specialty Clinic Commercial Validation Project prior to December 31, 2013

Vest upon Company successfully obtaining an Item Listing for Maestro Rechargeable System implantation by December 31, 2014

Stock Option

Vest on January 22, 2014

Related Party Transaction [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock Issued (in shares)

2,271,705

914,975

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

13,770,000

8,800,000

Warrant issued

'

'

'

'

'

'

'

'

'

'

5,508,000

1,760,000

67,773

179,328

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Purchase price per share

'

'

'

'

'

'

'

'

$0.95

$1.65

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Consulting agreement term

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'4 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Consulting fee

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$11,000

12,000

12,000

'

$86,000

96,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Award granted, shares

'

'

'

'

'

7,757

3,819

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

100,000

75,000

'

50,000

'

'

'

'

'

'

'

'

'

'

'

'

Award granted, price per share

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$1.31

$2.65

'

$2.76

'

'

'

'

'

'

'

'

'

'

'

'

Award vesting period

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'48 months

'

'

'

'

'

'

'

'

'

'

'

'

Grant date fair value of award grant

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

153,000

103,000

'

'

108,000

'

'

'

'

'

'

'

'

'

'

'

'

Award vested, shares

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

16,667

'

16,667

'

'

'

'

'

'

'

'

'

16,667

'

'

'

Award expected to vest, shares

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

16,666

25,000

16,667

16,666

25,000

25,000

'

'

'

'

Award vesting date

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

22-Jan-14

22-Jan-15

'

'

31-May-14

31-May-15

'

'

'

'

'

'

Latest date for approval of Australian reimbursement for the remaining options to vest

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

31-Dec-14

'

30-Jun-14

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of shares not vested

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

25,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock-based compensation

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

126,000

'

23,000

10,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Payment for consulting services

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

154,000

'

195,000

67,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Selling,general and administrative expenses

'

'

$13,658,824

$11,960,893

$8,583,347

'

'

$73,788,687

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$146,000

'

'

Shares_Purchased_by_Related_Pa

Shares Purchased by Related Parties (Detail) (USD $)

1 Months Ended

12 Months Ended

1 Months Ended

Feb. 27, 2013

Apr. 20, 2012

Apr. 16, 2012

Sep. 28, 2011

Nov. 30, 2007

Dec. 31, 2013

Feb. 27, 2013

Sep. 28, 2011

Sep. 28, 2011

Sep. 28, 2011

Feb. 27, 2013

Feb. 27, 2013

Feb. 27, 2013

Sep. 28, 2011

Feb. 14, 2009

Nov. 18, 2008

Sep. 28, 2011

Feb. 27, 2013

Common Stock

Common Stock

Bay City Capital

Bay City Capital

Anthony Jansz

Anthony Jansz

Warrants to purchase common stock

Warrants to purchase common stock

Warrants to purchase common stock

Warrants to purchase common stock

Warrants to purchase common stock

Warrants to purchase common stock

Common Stock

Common Stock

Bay City Capital

Anthony Jansz

Related Party Transaction [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock Issued (in shares)

'

'

2,271,705

'

914,975

'

13,770,000

8,800,000

'

840,000

'

150,000

'

'

'

'

'

'

Warrants Purchased

'

'

'

'

'

'

'

'

'

'

'

'

5,508,000

1,760,000

67,773

179,328

167,999

60,000

Proceeds, before expenses, to the Company

$13,100,000

$5,000,000

'

$14,500,000

'

$11,000,000

'

'

$1,386,000

'

$142,500

'

'

'

'

'

'

'

Commitments_and_Contingencies_1

Commitments and Contingencies - Additional Information (Detail) (USD $)

1 Months Ended

12 Months Ended

132 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

Oct. 31, 2008

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2005

Dec. 31, 2004

Dec. 31, 2013

Mar. 31, 2010

Dec. 31, 2005

Nov. 30, 2007

Nov. 30, 2007

Dec. 31, 2005

Dec. 31, 2009

Dec. 31, 2008

Dec. 31, 2007

Dec. 31, 2006

Dec. 31, 2005

Dec. 31, 2011

Dec. 31, 2010

Dec. 31, 2011

Oct. 31, 2008

Oct. 31, 2008

Amendment One

Collaborative Arrangement

Collaborative Arrangement

Collaborative Arrangement

Collaborative Arrangement

Retainer Fees

Retainer Fees

Retainer Fees

Retainer Fees

Retainer Fees

Retainer Fees

Retainer Fees

Retainer Fees

Minimum

Maximum

Research and development

Common Stock

Common Stock

Amendment One

Amendment One

Amendment Two

Loss Contingencies [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Operating lease agreement term

'7 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Operating lease agreement expiration date

30-Sep-15

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Operating lease, monthly base rent

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$19,570

$24,643

Total rent expense

'

270,872

270,872

270,872

'

'

1,894,800

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of months that require patients to be followed out in clinical trials

'

'60 months

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Collaborative obesity device research and development agreement, term

'

'

'

'

'5 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Securities issued, shares

'

'

'

'

7,757

3,819

'

'

'

'

34,341

36,630

'

'

'

'

'

'

'

'

'

'

Deferred compensation

'

'

'

'

'

'

'

'

100,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock-based compensation

'

'

'

'

'

'

'

'

'

1,700,000

'

'

'

'

'

'

'

'

'

'

'

'

Research and development expense

'

$11,075,493

$10,668,044

$16,673,238

'

'

$138,525,111

'

'

'

'

'

$250,000

$250,000

$250,000

$250,000

$250,000

$100,000

$100,000

$75,000

'

'

Collaborative obesity device research and development agreement, extension period

'

'

'

'

'

'

'

'2 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Future_Minimum_Lease_Payment_D

Future Minimum Lease Payment (Detail) (USD $)	Dec. 31, 2013
Leases Future Minimum Payments [Line Items]	'
2014	$291,369
2015	221,789
Operating Leases, Future Minimum Payments Due, Total	$513,158

Quarterly_Information_Detail

Quarterly Information (Detail) (USD $)

0 Months Ended

3 Months Ended

12 Months Ended

132 Months Ended

Dec. 31, 2002

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2010

Dec. 31, 2009

Dec. 31, 2008

Dec. 31, 2007

Dec. 31, 2006

Dec. 31, 2005

Dec. 31, 2004

Dec. 31, 2003

Dec. 31, 2013

Quarterly Financial Data [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net loss

($603,348)

($6,573,000)

($6,303,000)

($6,323,000)

($6,581,000)

($7,027,000)

($5,847,000)

($4,954,000)

($5,633,000)

($25,780,659)

($23,460,103)

($25,997,322)

($17,347,387)

($31,929,200)

($37,874,028)

($28,575,348)

($17,690,477)

($11,215,191)

($3,448,752)

($1,900,288)

($225,822,103)

Basic and diluted net loss per share

'

($0.11)

($0.11)

($0.11)

($0.14)

($0.17)

($0.14)

($0.13)

($0.15)

($0.47)

($0.59)

($0.86)

'

'

'

'

'

'

'

'

'