Hansen Medical (HNSN) 10-K 13 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. 28, 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	'HNSN	'	'
Entity Registrant Name	'HANSEN MEDICAL INC	'	'
Entity Central Index Key	'0001276591	'	'
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	'Accelerated Filer	'	'
Entity Common Stock, Shares Outstanding	'	110,755,536	'
Entity Public Float	'	'	$84,600,000

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$27,995	$32,749
Short-term investments	1,945	8,424
Accounts receivable, net of allowance of $554 at December 31, 2013 and 2012	5,114	5,235
Inventories	12,203	9,134
Prepaids and other current assets	1,914	1,932
Total current assets	49,171	57,474
Property and equipment, net	3,641	6,040
Restricted cash	5,394	'
Other assets	2,953	578
Total assets	61,159	64,092
Current liabilities:	'	'
Accounts payable	3,337	3,056
Accrued liabilities	3,934	3,322
Current portion of deferred revenue	2,912	2,702
Current portion of long-term debt	'	5,156
Total current liabilities	10,183	14,236
Deferred rent, net of current portion	310	354
Deferred revenue, net of current portion	203	68
Long-term debt, net of current portion	33,358	24,261
Other long-term liabilities	229	434
Total liabilities	44,283	39,353
Commitments and contingencies (Note 7)	'	'
Stockholders' equity:	'	'
Preferred stock, par value $0.0001: Authorized: 10,000 shares Issued and outstanding: none	'	'
Common stock, par value $0.0001: Authorized: 200,000 shares Issued and outstanding: 99,014 and 67,078 at December 31, 2013 and 2012, respectively	10	7
Additional paid-in capital	369,170	322,252
Accumulated other comprehensive (loss) income	360	-578
Accumulated deficit	-352,664	-296,942
Total stockholders' equity	16,876	24,739
Total liabilities and stockholders' equity	$61,159	$64,092

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, except Per Share data, unless otherwise specified
Accounts receivable, allowance	$554	$554
Preferred stock, par value	$0.00	$0.00
Preferred stock, shares authorized	10,000	10,000
Preferred stock, shares issued	'	'
Preferred stock, shares outstanding	'	'
Common stock, par value	$0.00	$0.00
Common stock, shares authorized	200,000	200,000
Common stock, shares issued	99,014	67,078
Common stock, shares outstanding	99,014	67,078

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenues:	'	'	'
Product	$11,790	$12,303	$16,720
Service	5,192	5,333	5,409
Total revenues	16,982	17,636	22,129
Cost of revenues:	'	'	'
Product	11,150	11,990	14,600
Service	2,331	2,036	2,611
Total cost of revenues	13,481	14,026	17,211
Gross profit	3,501	3,610	4,918
Operating expenses:	'	'	'
Research and development	16,139	16,126	12,156
Selling, general and administrative	31,765	25,987	31,428
Loss on settlement of litigation (Note 7)	4,500	'	'
Total operating expenses	52,404	42,113	43,584
Gain on licensing of intellectual property (Note 5)	'	20,000	'
Gain on sale of intellectual property (Note 6)	'	'	23,000
Loss from operations	-48,903	-18,503	-15,666
Interest income	25	78	150
Loss on extinguishment of debt	-1,935	'	'
Interest expense	-3,952	-3,511	-573
Other expense, net	-842	-95	-623
Loss before income taxes	-55,607	-22,031	-16,712
Income tax expense	-115	-114	'
Net loss	($55,722)	($22,145)	($16,712)
Basic and diluted net loss per share	($0.70)	($0.35)	($0.30)
Shares used to compute basic and diluted net loss per share	79,052	62,472	55,362

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Loss (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Net loss	($55,722)	($22,145)	($16,712)
Other comprehensive income (loss), net:	'	'	'
Change in unrealized gains and losses on investments	276	-716	491
Amounts reclassified to other income (expense)	627	'	'
Foreign currency translation adjustment	35	19	-5
Change in other comprehensive income (loss)	938	-697	486
Comprehensive loss	($54,784)	($22,842)	($16,226)

Consolidated_Statements_of_Sto

Consolidated Statements of Stockholders' Equity (USD $)	Total	Private Placemen	Common Stock	Common Stock	Additional Paid- In Capital	Additional Paid- In Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
In Thousands, except Share data				Private Placemen		Private Placemen
Beginning Balances at Dec. 31, 2010	$30,772	'	$5	'	$289,219	'	($367)	($258,085)
Beginning Balances (in shares) at Dec. 31, 2010	'	'	53,901,000	'	'	'	'	'
Exercise of stock options and issuance of common stock pursuant to the employee equity incentive plan (in shares)	'	'	886,000	'	'	'	'	'
Exercise of stock options and issuance of common stock pursuant to the employee equity incentive plan	831	'	'	'	831	'	'	'
Withholding taxes paid on vested restricted stock units	-303	'	'	'	-303	'	'	'
Issuance of common stock pursuant to the employee stock purchase plans (in shares)	'	'	334,000	'	'	'	'	'
Issuance of common stock pursuant to the employee stock purchase plans	536	'	'	'	536	'	'	'
Issuance of common stock for technology acquired, shares	'	'	75,000	'	'	'	'	'
Issuance of common stock and warrants pursuant to private placement (in shares)	'	'	'	4,785,000	'	'	'	'
Issuance of common stock and warrants pursuant to private placement	'	9,960	'	1	'	9,959	'	'
Issuance of common stock for technology acquired	367	'	'	'	367	'	'	'
Issuance of warrants in connection with debt	868	'	'	'	868	'	'	'
Employee share-based compensation expense	6,676	'	'	'	6,676	'	'	'
Net loss	-16,712	'	'	'	'	'	'	-16,712
Change in unrealized loss on investments	491	'	'	'	'	'	491	'
Translation adjustment	-5	'	'	'	'	'	-5	'
Ending Balances at Dec. 31, 2011	33,481	'	6	'	308,153	'	119	-274,797
Ending Balances (in shares) at Dec. 31, 2011	'	'	59,981,000	'	'	'	'	'
Exercise of stock options and issuance of common stock pursuant to the employee equity incentive plan (in shares)	'	'	1,449,000	'	'	'	'	'
Exercise of stock options and issuance of common stock pursuant to the employee equity incentive plan	548	'	'	'	548	'	'	'
Withholding taxes paid on vested restricted stock units	-14	'	'	'	-14	'	'	'
Issuance of common stock pursuant to the employee stock purchase plans (in shares)	'	'	357,000	'	'	'	'	'
Issuance of common stock pursuant to the employee stock purchase plans	684	'	'	'	684	'	'	'
Issuance of common stock and warrants pursuant to private placement (in shares)	'	'	'	5,291,000	'	'	'	'
Issuance of common stock and warrants pursuant to private placement	'	10,000	'	1	'	9,999	'	'
Non-employee stock-based compensation	9	'	'	'	9	'	'	'
Employee share-based compensation expense	2,873	'	'	'	2,873	'	'	'
Net loss	-22,145	'	'	'	'	'	'	-22,145
Change in unrealized loss on investments	-716	'	'	'	'	'	-716	'
Translation adjustment	19	'	'	'	'	'	19	'
Ending Balances at Dec. 31, 2012	24,739	'	7	'	322,252	'	-578	-296,942
Ending Balances (in shares) at Dec. 31, 2012	'	'	67,078,000	'	'	'	'	'
Exercise of stock options and issuance of common stock pursuant to the employee equity incentive plan (in shares)	53,000	'	788,000	'	'	'	'	'
Exercise of stock options and issuance of common stock pursuant to the employee equity incentive plan	114	'	'	'	114	'	'	'
Withholding taxes paid on vested restricted stock units	-18	'	'	'	-18	'	'	'
Issuance of common stock pursuant to the employee stock purchase plans (in shares)	'	'	394,000	'	'	'	'	'
Issuance of common stock pursuant to the employee stock purchase plans	560	'	'	'	560	'	'	'
Issuance of common stock and warrants pursuant to private placement (in shares)	'	'	'	28,455,000	'	'	'	'
Issuance of common stock and warrants pursuant to private placement	'	37,126	'	3	'	37,123	'	'
Issuance of common shares in connection with the litigation settlement, shares	2,298,539	'	2,299,000	'	'	'	'	'
Issuance of common shares in connection with the litigation settlement	4,250	'	'	'	4,250	'	'	'
Employee share-based compensation expense	4,889	'	'	'	4,889	'	'	'
Net loss	-55,722	'	'	'	'	'	'	-55,722
Change in unrealized loss on investments	276	'	'	'	'	'	276	'
Amounts reclassified to other income (expense)	627	'	'	'	'	'	627	'
Translation adjustment	35	'	'	'	'	'	35	'
Ending Balances at Dec. 31, 2013	$16,876	'	$10	'	$369,170	'	$360	($352,664)
Ending Balances (in shares) at Dec. 31, 2013	'	'	99,014,000	'	'	'	'	'

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash flows from operating activities	'	'	'
Net loss	($55,722)	($22,145)	($16,712)
Adjustments to reconcile net loss to net cash used in operating activities:	'	'	'
Loss on settlement of litigation	4,500	'	'
Gain on licensing of intellectual property	'	-20,000	'
Gain on sale of intellectual property	'	'	-23,000
Depreciation and amortization	2,949	3,265	3,359
Stock-based compensation	4,889	2,882	6,676
Issuance of common stock for technology acquired	'	'	367
Amortization of common stock warrants	195	270	15
(Gain) loss on disposal of fixed assets	'	-15	9
Net realized gains and losses on investments	677	40	370
Loss on extinguishment of debt	1,935	'	'
Provision (benefit) for doubtful accounts	'	554	-3
Loss on settlement of note receivable	'	'	190
Changes in operating assets and liabilities:	'	'	'
Accounts receivable	120	-296	-1,283
Inventories	-3,069	-2,735	-1,398
Deferred cost of revenues	18	1,406	1,704
Prepaids and other current assets	297	116	215
Other assets	-1,280	68	-137
Accounts payable	226	112	-213
Accrued liabilities	568	-886	-712
Deferred revenue	345	-3,668	-5,199
Other long-term liabilities	597	247	-639
Net cash used in operating activities	-42,755	-40,785	-36,391
Cash flows from investing activities	'	'	'
Purchase of property and equipment	-550	-772	-550
Proceeds from sales and maturities of short-term investments	6,704	17,363	13,216
Purchase of investments	'	-10,860	-26,633
Proceeds from licensing of intellectual property	'	20,000	'
Proceeds from sale of intellectual property	'	'	23,000
Collection of note receivable	'	'	3,628
Changes in restricted cash	-5,394	65	'
Net cash provided by investing activities	760	25,796	12,661
Cash flows from financing activities	'	'	'
Proceeds from issuance of common stock and warrants	39,268	10,000	10,000
Costs related to issuance of common stock and warrants	-2,087	'	-40
Proceeds from loans	33,000	'	30,000
Costs related to issuance of loans	-1,538	'	-305
Repayments of loan principal	-30,000	'	-6,238
Final loan repayment fees	-2,058	'	'
Proceeds from exercise of common stock options	114	548	831
Proceeds from employee stock purchase plan	560	684	536
Withholding taxes paid on vested restricted stock units	-18	-14	-303
Net cash provided by financing activities	37,241	11,218	34,481
Net increase (decrease) in cash and cash equivalents	-4,754	-3,771	10,751
Cash and cash equivalents at beginning of year	32,749	36,520	25,769
Cash and cash equivalents at end of year	27,995	32,749	36,520
Supplemental disclosures of cash flow information	'	'	'
Cash paid during the period for interest	5,207	2,599	1,199
Supplemental schedule of non-cash investing and financing activities	'	'	'
Equity issuance costs not yet paid	$55	'	'
Issuance of common stock warrants	'	'	868

The_Company

The Company	12 Months Ended
	Dec. 31, 2013
The Company	'
	1	The Company
	Nature of Operations
	Hansen Medical, Inc. (the “Company”) develops, manufactures and markets a new generation of medical robotics designed for accurate positioning, manipulation and stable control of catheters and catheter-based technologies. The Company was incorporated in the state of Delaware on September 23, 2002. The Company is headquartered in Mountain View, California. In March 2007, the Company established Hansen Medical UK Ltd., a wholly-owned subsidiary located in the United Kingdom and, in May 2007, the Company established Hansen Medical, GmbH, a wholly-owned subsidiary located in Germany. Both subsidiaries are engaged in marketing the Company’s products in Europe.
	Need to Raise Additional Capital
	From inception to December 31, 2013, the Company has incurred losses totaling approximately $352.7 million and has not generated positive cash flows from operations. The Company expects such losses to continue through at least the year ended December 31, 2014 as it continues to commercialize its technologies and develop new applications and products. The Company anticipates its existing cash, cash equivalents and short-term investment balances along with interest income earned in addition to estimated amounts that are expected to be received through the sale of its products and services will be sufficient to meet its anticipated cash requirements for the next twelve months. As of December 31, 2013, the Company’s cash, cash equivalents, short-term investments and restricted cash were $35.3 million. In accordance with terms of the private placement financing completed in the third quarter of 2013, as of February 28, 2014, 11.4 million Series A warrants were exercised for total proceeds of $14.0 million, and the Company had remaining outstanding warrants exercisable for up to 22.8 million shares of common stock, which if exercised in full would yield gross proceeds of up to approximately $39.8 million. The Company may need to raise additional funding and may attempt to do so at any time by selling equity or debt securities, licensing core or non-core intellectual property assets, entering into future research and development funding arrangements or entering into a credit facility in order to meet its continuing cash needs. Failure to meet projected revenue levels, raise additional funding or manage spending may adversely impact the Company’s ability to achieve its long term intended business objectives. The Company will continue to evaluate its financial condition based upon changing future economic conditions and the achievement of estimated revenue and will consider the implementation of additional cost reductions if and as circumstances warrant.

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 accordance with generally accepted accounting principles in the United States of America (“GAAP”). The Company’s fiscal year ends on December 31. The consolidated financial statements include the accounts of the Company and its subsidiaries. All significant intercompany accounts and transactions have been eliminated.
	Use of Estimates
	The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Significant estimates relate to the recognition of revenue, the evaluation of customer credit risk, the valuation of investments, inventory valuations, the determination of impairment of assets, stock-based compensation, loss contingencies and the valuation of our deferred tax assets, among others. Actual results could differ from those estimates.
	Revenue Recognition
	The Company’s revenues are primarily derived from the sale of the Sensei system and the Magellan Robotic System and the associated catheters as well as the sale of customer service contracts. Under the Company’s revenue recognition policy, revenues are recognized when persuasive evidence of an arrangement exists, delivery to the customer has occurred or the services have been fully rendered, the sales price is fixed or determinable and collectability is probable.
		•	Persuasive Evidence of an Arrangement. Persuasive evidence of an arrangement for sales of systems is generally determined by a sales contract signed and dated by both the customer and the Company, including approved terms and conditions and the receipt of an approved purchase order. Evidence of an arrangement for the sale of disposable products is determined through an approved purchase order from the customer. Evidence of an arrangement for the sale of customer service is determined through either a signed sales contract or an approved purchase order from the customer. Sales to customers are generally not subject to any performance, cancellation, termination or return rights.
		•	Delivery.
		•	Systems and Disposable Products. Typically, ownership of systems, catheters and other disposable products passes to customers upon shipment, at which time delivery is deemed to be complete.
		•	Customer Service Revenue. The Company recognizes customer service revenue from the sale of product maintenance plans. Revenue from customer services, whether sold individually or as a separate unit of accounting in a multi-element arrangement, is deferred and amortized over the service period, which is typically one year.
		•	Multiple-element Arrangements. It is common for the sale of Sensei and Magellan systems to include multiple elements which qualify as separate units of accounting. These elements commonly include the sale of the system and a product maintenance plan, in addition to installation of the system and initial training. Less commonly, these elements may include the sale of certain disposable products or other elements. Generally, under multiple-element arrangements, the systems are delivered at the beginning of the arrangement and the related revenue is recognized at that time. Installation and training is generally completed within 90 days at which time the revenue is recognized. Customer service revenue associated with the product maintenance plan is recognized ratably over the service period, which is typically one year. Other elements are recognized once delivered in accordance with contract terms. In arrangements that include multiple elements, the Company allocates revenue to the various elements based on vendor-specific objective evidence of fair value (“VSOE”) of the elements if VSOE exists. VSOE for each element is based on the price for which the item is sold separately, determined based on historical evidence of stand-alone sales of these elements or stated renewal rates for the element. If VSOE does not exist for an element, the Company allocates revenue based on third-party evidence (“TPE”) of selling price for the elements if TPE exists. TPE is the price of the Company’s or any competitor’s largely interchangeable products or services in standalone sales to similarly-situated customers. If neither VSOE nor TPE exist for a specific element, the Company allocates revenue to the various elements based on its best estimate of the selling price for that element or estimated selling price (“ESP”) using a top-down approach, which takes into account the Company’s target prices and overall pricing objectives. In situations where the Company has delivered certain elements but not delivered other elements, the Company, after it has allocated revenue to the various elements under the relative selling price method based on VSOE, TPE or ESP, defers revenue for the undelivered elements. Because the Company has neither VSOE nor TPE for its systems, the allocation of revenue is based on ESP for the systems sold. The Company determines ESP for its systems by considering multiple factors, including, but not limited to, features and functionality of the system, geographies, type of customer, and market conditions. The Company regularly reviews ESP and maintains internal controls over the establishment and updates of these estimates.
		•	Sales Price Fixed or Determinable. The Company assesses whether the sales price is fixed or determinable at the time of the transaction. Sales prices are documented in the executed sales contract or purchase order received prior to shipment The Company’s standard terms do not allow for contingencies, such as trial or evaluation periods, refundable orders, payments contingent upon the customer obtaining financing or other contingencies which would impact the customer’s obligation. In situations where these or other contingencies are included, all related revenue is deferred until the contingency is resolved. In the third quarter of 2012, the Company began shipping systems under a limited commercial evaluation program to allow certain strategic accounts to install and utilize systems for a limited trial period while the purchase opportunity is being evaluated by the hospital. Systems under this program remain the property of the Company and are recorded in inventory and a sale only occurs upon the issuance of a purchase order from the customer.
		•	Collectability. The Company assesses whether collection is probable based on a number of factors, including the customer’s past transaction history and credit worthiness. If collection of the sales price is not deemed probable, the revenue is deferred and recognized at the time collection becomes probable, which is usually upon receipt of cash. The Company’s sales contracts generally do not allow the customer the right of cancellation, refund or return, except as provided under the Company’s standard warranty. If such rights were allowed, all related revenues would be deferred until such rights expired.
	Significant management judgments and estimates are made in connection with the determination of revenue to be recognized and the period in which it is recognized. If different judgments and estimates were utilized, the amount of revenue to be recognized and the period in which it is recognized could differ materially from the amounts reported.
	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, short-term investments and accounts receivable. Cash and cash equivalents are deposited in demand and money market accounts at two financial institutions. At times, such deposits may be in excess of insured limits. The Company has not experienced any losses on its deposits of cash and cash equivalents.
	The Company had three customers who constituted 26%, 22%, and 10%, respectively of the Company’s net accounts receivable at December 31, 2013. The Company had three customers who constituted 22%, 20%, and 16%, respectively of the Company’s net accounts receivable at December 31, 2012. One customer accounted for 10% of revenues in 2013. One customer accounted for 14% of revenues in 2012. One customer accounted for 15% of revenues in 2011. The Company carefully monitors the creditworthiness of potential customers. As of December 31, 2013, the Company has not experienced any significant losses on its accounts receivable.
	Most of the products developed by the Company require clearance from the FDA or corresponding foreign regulatory agencies prior to commercial sales. The Company received CE Mark approval to market its Sensei system in Europe in the fourth quarter of 2006 and received CE Mark approval to market its Artisan Control Catheter in Europe in May 2007. The Company received FDA clearance for the marketing of its Sensei system and Artisan catheters for manipulation, positioning and control of certain mapping catheters during electrophysiology procedures in the United States in May 2007. The Company received CE Mark approval to market its Lynx catheter in Europe in July 2010. The Company received CE Mark approval for its Magellan Robotic System in July 2011 and received CE Mark approval for the Magellan Robotic Catheter and related accessories designed for use with the Magellan Robotic System in October 2011. The Company received FDA clearance for marketing its Magellan Robotic System, including the catheter and accessories in June 2012 and Magellan 6Fr Robotic Catheter in February 2014. However, there can be no assurance that current products or any new products the Company develops in the future will receive the clearances necessary to allow the Company to market those products in certain desirable markets. If the Company is denied clearance or clearance is delayed, it could 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, and have asserted in the past, that its products or the use of the Company’s products are covered by United States or foreign patents held by them. This risk is heightened due to the numerous issued and pending patents relating to the use of catheter-based procedures in the medical technology field.
	Loss Contingencies
	The Company evaluates potential loss contingencies as circumstances dictate. Should a specific loss contingency meet the definition of a liability under authoritative accounting guidance, the Company would record a loss and a liability. As of December 31, 2013, the Company had not recorded any loss contingencies as liabilities. However, if estimates and assumptions change in the future, the Company may record charges to its financial statements. This could materially impact its operating results and financial position.
	Foreign Currency
	The functional currency of the Company’s domestic and foreign operations is the U.S. dollar. Accordingly, the effects of foreign currency transactions, and of remeasuring the financial condition and results of operations from local currencies into the functional currency, are included in other expense, net in the accompanying consolidated statements of operations. Remeasurement and foreign currency transaction losses, net, for fiscal years ended December 31, 2013, 2012 and 2011 were immaterial.
	Fair Value of Financial Instruments
	Carrying amounts of certain of the Company’s financial instruments, including cash and cash equivalents, accounts receivable, prepaid expenses and other current assets, accounts payable and accrued liabilities approximate fair value due to their short maturities.
	Cash and Cash Equivalents, and Restricted Cash
	The Company considers all highly liquid investments with maturities of three months or less at the time of purchase to be cash equivalents. Cash and cash equivalents, and restricted cash include money market funds and various deposit accounts, which are readily convertible to cash and are stated at cost, which approximates market. Pursuant to the Company’s secured term loan agreement executed in 2013, the Company is obligated to maintain $5.0 million of restricted cash subject to lenders’ control.
	Short-Term Investments
	Available-for-sale investments. The Company determines the appropriate classification of investments at the time of purchase and evaluates such classification as of each balance sheet date. The Company classifies all investments with maturities greater than three months at the time of purchase as short-term investments as they are subject to use within one year in current operations. The Company makes investments based upon specific guidelines approved by its board of directors with a view to liquidity and capital preservation and regularly reviews its investments for performance. As of December 31, 2013, all of the Company’s investments have been classified as available-for-sale and are carried on the balance sheet at fair value with the unrealized gains and losses, if any, included in other comprehensive income within stockholders’ equity. Any unrealized losses which are determined to be other than temporary are included in earnings. Realized gains and losses are recognized on the specific identification method.
	Other-than-temporary impairment. The Company periodically evaluates its investments for impairment. In the event that the carrying value of an investment exceeds its fair value and the decline in fair value is determined to be other than temporary, an impairment charge is recorded and a new cost basis for the investment is established. In order to determine whether a decline in value is other than temporary, the Company evaluates many factors, including the following: the duration and extent to which the fair value has been less than the carrying value; the company’s financial condition and business outlook, including key operational and cash flow metrics, current market conditions and future trends in the industry; and the Company’s intent and ability to retain the investment for a period of time sufficient to allow for any anticipated recovery in fair value. In fiscal 2010 and 2011, the Company determined that the impairment of its investment in Luna Innovations, Incorporated (together with its wholly-owned subsidiary, “Luna”) common stock was other than temporary and as such, permanently wrote down the value of that investment and recorded a loss of $1.9 million $0.3 million, respectively in other expense on the consolidated statement of operations. In the first quarter of 2013, the Company recorded an additional write down of the investment and recorded an additional loss of $0.6 million in other expense on the condensed consolidated statement of operations. The carrying value of the Luna investment as of December 31, 2013 was $1.9 million. Significant management judgment is required in determining whether an other-than-temporary decline in the fair value of an investment exists. Changes in the Company’s assessment of the valuation of investments could materially impact future operating results and financial position.
	Allowance for Doubtful Accounts
	The Company establishes allowances for doubtful accounts based on a review of the credit profiles of customers, contractual terms and conditions, current economic trends and historical collection experience. The allowance for doubtful accounts is reassessed each period. If different judgments and estimates were utilized in establishing the allowance, the amount or timing of bad debt expense or revenue recognized could differ materially from the amounts reported. In the Company’s limited historical experience, actual losses and credits related to accounts receivable have been consistent with the recorded provisions. If, however, actual future receipts differ materially from the current assessments due, among other things, to unexpected events or significant changes in trends, additional provisions may be necessary and future cash flows and statements of operations could be materially negatively impacted. Provisions for doubtful accounts as a percentage of revenues have been immaterial for all periods presented.
	Inventories
	Inventory, which includes material, labor and overhead costs, is stated at standard cost, which approximates actual cost, determined on a first-in, first-out basis, not in excess of market value. The Company records reserves, when necessary, to reduce the carrying value of excess or obsolete inventories to their net realizable value. These reserves are based on our best estimates after considering projected future demand. In the event that actual demand for our inventory differs from our best estimates or we fail to receive the necessary regulatory approvals, increases to inventory reserves may become necessary.
	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 two to five 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 balance sheet and the resulting gain or loss is recognized. Maintenance and repairs are charged to operations as incurred. Depreciation expense was $2.9 million, $3.3 million and $3.4 million for the years ended December 31, 2013, 2012 and 2011, respectively.
	Impairment of Long-Lived Assets
	The Company evaluates the recoverability of its long-lived assets in accordance with authoritative accounting guidance. When events or changes in circumstances indicate that the carrying value of long-lived assets may not be recoverable, the Company recognizes such impairment if the net book value of such assets exceeds the future undiscounted cash flows attributable to such assets. 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 discounted estimates of future cash flows attributable to the assets. As of December 31, 2013, the Company had $3.6 million of property and equipment, net. If estimates or the related assumptions change in the future, the Company may record impairment charges to reduce the carrying value of certain groups of these assets. Changes in the valuation of long-lived assets could materially impact the Company’s operating results and financial position.
	Advertising Expense
	The Company expenses advertising costs as incurred. Advertising costs are recorded in general, sales and marketing expenses within the accompanying Consolidated Statements of Operations and were immaterial for fiscal years 2013, 2012 and 2011.
	Stock-Based Compensation
	Under the fair value recognition provisions of authoritative guidance related to stock-based compensation, stock-based payment expense is estimated at the grant date based on the fair value of the award and is recognized as expense ratably over the requisite service period of the award. The recording of compensation expense related to stock-based awards is significant to the Company’s financial statements but does not result in the payment of cash by the Company. Determining the appropriate fair value model used to calculate the fair value of stock-based awards requires significant management judgment. Additionally, the calculation of the fair value of stock-based awards requires the Company to make significant estimates and judgments, including the expected volatility, the expected term of the award, risk-free interest rate and the dividend yield. If the Company had chosen a different fair value model or made different estimates in the calculation of fair value, the amount or timing of stock-based compensation recorded could have differed materially from the amounts reported.
	The Company selected the Black-Scholes option valuation model as the most appropriate method for determining the estimated fair value for stock-based awards. The Black-Scholes model requires the use of highly subjective and complex assumptions in determining the fair value of stock-based awards, including the expected volatility of the underlying stock, the award’s expected term, risk-free interest rate and the dividend yield.
		•	Expected Volatility. The Company’s estimate of volatility is based on the historical volatilities of its stock price.
		•	Expected Term. The Company estimates the expected term based on its historical settlement experience related to vesting and contractual terms while giving consideration to awards that have life cycles less than the contractual terms and vesting schedules in accordance with authoritative guidance.
		•	Risk-Free Interest Rate. The risk-free interest rate that the Company uses in the Black-Scholes option valuation model is the implied yield in effect at the time of option grant based on U.S. Treasury zero-coupon issues with a remaining term equivalent to the expected term of its option grants. For ESPP grants, the Company uses the 6-month Constant Maturity Treasury (“CMT”) rate.
		•	Dividend Yield. The Company has never paid any cash dividends on its common stock and it does not anticipate paying any cash dividends in the foreseeable future. Consequently, the Company uses a dividend yield of zero in the Black-Scholes option valuation model.
	In addition to the Black-Scholes assumptions noted above, the Company also estimates a forfeiture rate for its stock-based awards. The Company estimates its forfeiture rate based on an analysis of its actual forfeitures based on actual forfeiture experience, analysis of employee turnover behavior and other factors. The impact from any forfeiture rate adjustment would be recognized in full in the period of adjustment and if the actual number of future forfeitures differs from its estimates, the Company might be required to record adjustments to its stock-based compensation in future periods.
	To the extent that future evidence regarding these variables is available and provides estimates that the Company determines are more indicative of actual trends, the Company may refine or change its approach to deriving these input estimates. These changes could significantly impact the stock-based compensation expense recorded in the future.
	Research and Development
	Research and development costs are charged to expense as incurred. Research and development costs include, but are not limited to, payroll and other personnel expenses, prototype materials, laboratory supplies, and consulting costs.
	Income Taxes
	The Company accounts for income taxes using the liability method whereby deferred tax asset and liability account balances are determined based on differences between financial reporting and tax bases of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. Valuation allowances are established to reduce deferred tax assets when management estimates, based on available objective evidence, that it is more likely than not that the benefit will not be realized for the deferred tax assets. The Company accounts for uncertainty in income taxes using a two-step approach to recognizing and measuring uncertain tax positions. The first step is to evaluate the tax position for recognition by determining if the weight of available evidence indicates that it is more likely than not that the position will be sustained on audit, including resolution of related appeals or litigation processes, if any. The second step is to measure the tax benefit as the largest amount that is more than 50% likely of being realized upon settlement. The Company recognizes interest and penalties related to unrecognized tax benefits as a component of income tax expense. As of December 31, 2013, the Company has no accrued interest or penalties related to uncertain tax positions. The Company does not anticipate that total unrecognized tax benefits will significantly change due to the settlement of audits and the expiration of statute of limitations periods in 2014.
	Comprehensive Loss
	The Company follows the accounting standards for the reporting and presentation of comprehensive income (loss) and its components. In June 2011, the Financial Accounting Standards Board (“FASB”) issued new accounting guidance that revised the manner in which entities present comprehensive income in their financial statements. The new guidance requires entities to present comprehensive income either in a continuous statement of comprehensive income, which replaces the statement of operations, or in two separate, consecutive statements. The new guidance does not change the items that must be reported in other comprehensive income, nor does it require new disclosures. On January 1, 2012 The Company adopted new accounting guidance and presents comprehensive income (loss) in a separate statement. Comprehensive loss includes all changes in stockholders’ equity during a period from non-owner sources. Comprehensive loss for each of the years ended December 31, 2013, 2012, and 2011 was equal to net loss adjusted for unrealized gains and losses on investments, reclassifications of realized gains and losses on investments to other income (expense) and foreign currency translation adjustments.
	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. Such dilutive potential shares are excluded when the effect would be to reduce a net loss per share. The Company’s dilutive potential shares, which include outstanding common stock options, warrants, estimated shares to be issued under the Company’s employee stock purchase plan and unvested restricted stock, have not been included in the computation of diluted net loss per share for all yearly periods as the result would be anti-dilutive.
	Retirement Plan
	The Company sponsors a 401(k) defined contribution plan covering all employees. There have been no employer contributions to the plan since inception.
	Segment Reporting
	The Company has determined that it operates in one segment.
	Recent Accounting Pronouncements
In February 2013, the FASB issued Accounting Standards Update (“ASU”) 2013-02, Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income. This update requires entities to disclose items reclassified out of accumulated other comprehensive income and into net income in a single location within the financial statements. This new guidance was effective for the Company beginning January 1, 2013, with early adoption permitted. The Company adopted this guidance in the first quarter of 2013. The adoption of ASU 2013-02 did not have a material impact on the Company’s consolidated financial position or results of operations.
In July 2013, the Financial Accounting Standards Board (“FASB”) issued ASU 2013-11, Income Taxes (Topic 740): Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists. The standard will be effective for the Company beginning January 1, 2014. The Company is currently evaluating the effects of adoption, but does not anticipate it will have a significant impact upon the Company’s consolidated financial statements.

Fair_Value_of_Assets_and_Liabi

Fair Value of Assets and Liabilities	12 Months Ended
	Dec. 31, 2013
Fair Value of Assets and Liabilities	'
	3	Fair Value of Assets and Liabilities
	The amortized cost and fair value of assets, along with gross unrealized gains and losses, were as follows (in thousands):
			Amortized			Gross		Gross			Fair		Balance Sheet Classification
			Cost			Unrealized		Unrealized			Value
						Gains		Losses					Cash and		Short-term		Restricted
													cash		Investments		Cash
													Equivalents
	December 31, 2013:
	Cash		$	1,665		$	—	$	—		$	1,665	$	1,665	$	—	$	—
	Money market funds			31,724			—		—			31,724		26,330		—		5,394
	Corporate equity securities			1,572			373		—			1,945		—		1,945		—
			$	34,961		$	373	$	—		$	35,334	$	27,995	$	1,945	$	5,394
	December 31, 2012:
	Cash		$	1,283		$	—	$	—		$	1,283	$	1,283	$	—	$	—
	Money market funds			31,466			—		—			31,466		31,466		—		—
	Corporate debt and commercial paper			6,704			—		—			6,704		—		6,704		—
	Corporate equity securities			2,158			132		(661	)		1,629		—		1,629		—
			$	41,611		$	132	$	(661	)	$	41,082	$	32,749	$	8,333	$	—
	The Company periodically assesses whether significant facts and circumstance have arisen to indicate that an impairment, which is other than temporary, of the fair value of any underlying investment has occurred. In fiscal 2010 and 2011, the Company determined that the impairment of its investment in Luna Innovations’ common stock was other than temporary and as such wrote down the value of that investment and recorded a loss of $1.9 million and $0.3 million, respectively in other expense on the consolidated statement of operations. In the first quarter of 2013, the Company recorded an additional write down of the investment and recorded an additional loss of $0.6 million in other expense on the condensed consolidated statement of operations. No investments have been in an unrealized loss position for longer than twelve months.
	Fair Value Measurements
	GAAP defines fair value as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, authoritative guidance establishes a three-tier value hierarchy, which prioritizes the inputs used in measuring fair value as follows:
	•    Level 1 Inputs		Quoted prices (unadjusted) in active markets for identical assets or liabilities.
	•    Level 2 Inputs		Inputs other than quoted prices in active markets that are observable either directly or indirectly.
	•    Level 3 Inputs		Unobservable inputs in which there is little or no market data, which require us to develop our own assumptions.
	This hierarchy requires the use of observable market data when available and to minimize the use of unobservable inputs when determining fair value. Investment instruments valued using Level 1 inputs include money market securities and certain of the corporate equity securities which were obtained by the Company as part of the Luna litigation settlement for which there is now not a significant non-marketability issue.
	Investment instruments valued using Level 2 inputs include investment-grade corporate debts, such as bonds and commercial paper and U.S. governmental agency securities. The fair value of these investments is determined based on modeling techniques that include inputs such as the credit rating of the company issuing the debt and the observable market value of similarly-termed corporate debts with similar credit ratings.
	The warrants to purchase corporate equity securities obtained as a part of the Luna litigation settlement and certain of the corporate equity securities obtained upon the exercise of certain of those warrants are valued using Level 3 inputs. The warrant to purchase corporate equity securities was valued based on an estimate of the number of shares which will be issued over the initial three-year life of the warrant, which were then valued utilizing the Black-Scholes option pricing model. The corporate equity securities obtained upon the exercise of certain of those warrants are initially unregistered and their valuation consists of the quoted stock price adjusted for the impact of the non-marketability during the period in which they are unregistered. The non-marketability discount was determined based primarily on an analysis utilizing the Black-Scholes model to value a hypothetical put option to approximate the cost of hedging the restricted stock over the expected period of non-marketability, which was then corroborated by reviewing published restricted stock studies. The inputs used to determine the value of these securities are subjective. Changes in these unobservable inputs would have an impact on the reported value of these securities.
	The fair value hierarchy of the Company’s assets is as follows (in thousands):
			Fair Value Measurements Using
			Quoted Prices in			Significant other		Unobservable			Total
			Active Markets for			Observable		Inputs
			Identical Assets			Inputs		(Level 3 Inputs)
			(Level 1 Inputs)			(Level 2 Inputs)
	December 31, 2013:
	Money market funds		$	31,724		$	—	$	—		$	31,724
	Corporate equity securities			1,945			—		—			1,945
			$	33,669		$	—	$	—		$	33,669
	December 31, 2012:
	Money market funds		$	31,466		$	—	$	—		$	31,466
	Corporate debt and commercial paper			—			6,704		—			6,704
	Corporate equity securities			1,629			—		—			1,629
	Warrants to purchase corporate equity securities			—			—		91			91
			$	33,095		$	6,704	$	91		$	39,890
	The following tables present a reconciliation for all assets measured at fair value on a recurring basis using significant unobservable inputs (Level 3) for the years ended December 31, 2012 (in thousands):
			Investments Valued Using Level
			3 Inputs for the Year Ended
			December 31,
			2012
	Balance at beginning of period		$	153
	Total gains and losses:
	Included in other expense, net			(41	)
	Included in accumulated other comprehensive loss			1
	Transfers out			(22	)
	Balance at end of period		$	91
	The fair value of the Company’s long-term debt was estimated to be $33.1 million as of December 31, 2013 based on an internal valuation model that utilized the then-current rates available to the Company for debt of a similar term and remaining maturity, which constitutes Level 2 inputs under the fair value hierarchy. Considerable judgment is required in interpreting market data to develop estimates of fair value. Accordingly, the fair value estimate presented herein is not necessarily indicative of the amount that the Company or holders of the instruments could realize in a current market exchange. The use of different assumptions and/or estimation methodologies may have a material effect on the estimated fair value. See Note 8 for further information regarding the Company’s long-term debt.

Balance_Sheet_Components

Balance Sheet Components	12 Months Ended
	Dec. 31, 2013
Balance Sheet Components	'
	4	Balance Sheet Components
	Inventories (in thousands)
			December 31,
			2013			2012
	Raw materials		$	4,167		$	3,333
	Work in process			5,285			3,644
	Finished goods			2,751			2,157
	Inventories		$	12,203		$	9,134
	Property and equipment, net (in thousands)
			December 31,
			2013			2012
	Furniture and leasehold improvements		$	11,466		$	11,451
	Laboratory equipment			10,209			9,985
	Computer equipment and software			2,850			2,640
				24,525			24,076
	Less: Accumulated depreciation and amortization			(20,884	)		(18,036	)
	Property and equipment, net		$	3,641		$	6,040
	Accrued liabilities (in thousands)
			December 31,
			2013			2012
	Accrued salaries, commission, bonus and benefits		$	1,867		$	1,455
	Accrued royalties			796			481
	Accrued legal and other professional fees			183			144
	Accrued other expenses			1,088			1,242
	Total		$	3,934		$	3,322

Updated_Agreements_with_Intuit

Updated Agreements with Intuitive Surgical	12 Months Ended
	Dec. 31, 2013
Updated Agreements with Intuitive Surgical	'
	5	Updated Agreements with Intuitive Surgical
	In October 2012, the Company signed an updated license agreement with Intuitive Surgical Operations, Inc. and Intuitive Surgical, Inc. (collectively, “Intuitive Surgical”), under which Intuitive Surgical paid the Company a $20 million licensing fee, and a stock purchase agreement to sell 5,291,000 shares of the Company’s common stock to Intuitive Surgical for an aggregate purchase price of $10 million. The amendment of the license agreement is an update to the co-exclusive cross license agreement signed by the companies in 2005. Under the terms of the amended agreement, Intuitive Surgical’s existing co-exclusive rights to the Company’s patent portfolio to certain non-vascular procedures have been extended to include patents filed or conceived by the Company subsequent to the original 2005 agreement up to and including the period three years subsequent to the amendment though the Company has no obligations to conduct any research activities under the amendment. The Company retains the right to use its intellectual property for all clinical applications, both vascular and non-vascular.
	The Company has concluded that the value associated with patents filed or conceived in the three years subsequent to the amendment is de minimis and therefore the $20.0 million upfront payments for the licensing of intellectual property was recognized immediately in the statement of operations. The $10.0 million associated with the stock purchase agreement was recorded to common stock and additional paid-in capital on the balance sheet.

Agreements_with_Philips

Agreements with Philips	12 Months Ended
	Dec. 31, 2013
Agreements with Philips	'
	6	Agreements with Philips
	In February 2011, the Company entered, directly and through a wholly-owned subsidiary, into patent and technology license, sublicense and purchase agreements with Philips to allow them to develop and commercialize the non-robotic applications of the Company’s Fiber Optic Shape Sensing and Localization (“FOSSL”) technology. Under the terms of the agreements, Philips has the exclusive right to develop and commercialize the FOSSL technology in the non-robotic vascular, endoluminal and orthopedic fields. Philips also receives non-exclusive rights in other non-robotic medical device fields, but not to any multi-degree of freedom robotic applications. If Philips does not meet certain specified commercialization obligations, the Company has the rights to re-acquire the licenses granted to Philips for pre-determined payments, which payments in the aggregate would be greater than the upfront payment amounts received by the Company from Philips in connection with the agreements related to the FOSSL technology. The agreement also contains customary representations, warranties and indemnification provisions by each party. Each party may terminate the agreements for material breach by the other party. Philips also has the right to terminate the agreement and its rights under the agreement if the Company is acquired by a competitor of the relevant business unit of Philips.
	Also in February 2011, the Company amended its extended joint development agreement with Philips, increasing the amount of funding provided by Philips for the development of the Vascular System and potentially extending and increasing certain royalty fees to be paid to Philips based on sales of the Vascular System, subject to caps based on the amounts Philips contributes to the development of the system. Under the amendment, the Company will be eligible to receive up to an additional $78.0 million in future payments associated with the successful commercialization by Philips or its collaborators of products containing FOSSL technology. Approximately two-thirds of these potential future payments could arise from Philips’ sublicensing the FOSSL technology and approximately one-third of the potential future payments are based on Philips’ royalty obligations on its sales of products containing the FOSSL technology. The Company would receive less than half of Philips’ proceeds for its sublicensing FOSSL technology, if and following Philips entering into an applicable sublicensing transaction. Philips’ FOSSL-related royalty obligations are calculated on a consistent annual basis between 2014 and 2020 and arise in any year only to the extent that Philips achieves a substantial number of commercial placements of FOSSL-enabled products in the calendar year. The Company received arrangement consideration of $29.0 million and recognized $23.0 million immediately in net loss and $6.0 million as a reduction of research and development costs in 2011.

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2013
Commitments and Contingencies	'
	7	Commitments and Contingencies
	Operating Leases
	The Company rents its office and laboratory facilities in Mountain View, California under an operating lease which has been extended until January 2020, with an option to extend the lease for another five years. We also lease approximately 3,300 square feet of office space in London, England. That lease ends in June 2020, but the Company has an option to exit the lease in 2015. Rent expense on a straight-line basis was as follows (in thousands):
			Years Ended December 31,
			2013			2012			2011
	Rent expense		$	2,310		$	2,280		$	2,231
	At December 31, 2013, future minimum payments under the leases are as follows (in thousands):
	Years ended December 31,		Future Minimum
			Lease Payments
	2014		$	2,149
	2015			1,979
	2016			2,140
	2017			2,205
	Thereafter			4,415
	Total		$	12,888
	Warranties
	The Company generally provides one year of post-contract customer service on the sale of its systems. Post-contract customer service revenue is recognized ratably over the term of the service period and associated expenses are charged to cost of revenues as incurred. The Company provides a limited warranty on the sale of catheters and records a warranty reserve at the time of sale to cover the estimated warranty costs. The Company’s warranty obligation may be impacted by product failure rates, material usage and service costs associated with its warranty obligations. The Company periodically evaluates and adjusts the warranty reserve to the extent actual warranty expense differs from the original estimates. Movement in the warranty liability was as follows (in thousands):
			Years Ended December 31,
			2013			2012
	Balance at beginning of period		$	9		$	12
	Warranties issued during the period			105			112
	Warranty costs incurred during the period			(105	)		(115	)
	Balance at end of period		$	9		$	9
	Other
	The Company has minimum royalty obligations of $100,000 per year under a license agreement with Mitsubishi Electric Research Laboratories, Inc. which reduces to $55,000 per year if the license becomes non-exclusive. The royalty obligation expires in 2018. The Company also has minimum royalty obligations of $200,000 per year under the terms of its cross license agreement with Intuitive Surgical. Additionally, the Company also has royalty obligations under the amended joint development agreement with Philips which provides for the payment of royalties to Philips through October 2017. As of December 31, 2013, the Company had $3.9 million in uncertain tax positions. If it is determined in some future period that these amounts are not allowed to be deducted for tax purposes and if the Company does not have credits or carryforwards to cover these amounts, they could result in payments by the Company to taxing authorities.
	Indemnification
	The Company has agreements with each member of its board of directors, its Interim Chief Executive Officer, its former President and Chief Executive Officer, and its Chief Financial Officer indemnifying them against liabilities arising from actions taken against the Company. To date, the Company has not incurred any material costs as a result of such indemnifications and has not accrued any liabilities related to such obligations in the accompanying financial statements.
	The Company has agreements with certain customers indemnifying them against liabilities arising from legal actions relating to the customer’s use of intellectual property owned by the Company. To date, the Company has not incurred any material costs as a result of such indemnifications and has not accrued any liabilities related to such obligations in the accompanying financial statements.
	Legal Proceedings
	Following the Company’s October 19, 2009 announcement that it would restate certain of its financial statements, a securities class action lawsuit was filed on October 23, 2009 in the United States District Court for the Northern District of California, naming the Company and certain of its now former officers. Curry v. Hansen Medical, Inc. et al., Case No. 09-05094. The complaint asserted claims for violation of Sections 10(b) and 20(a) of the Securities Exchange Act of 1934 on behalf of a putative class of purchasers of Hansen stock between May 1, 2008 and October 18, 2009, inclusive, and alleged, among other things, that defendants made false and/or misleading statements and/or failed to make disclosures regarding the Company’s financial results and compliance with GAAP while improperly recognizing revenue; that these misstatements and/or nondisclosures resulted in overstatement of Company revenue and financial results and/or artificially inflated the Company’s stock price; and that following the Company’s October 19, 2009 announcement, the price of the Company’s stock declined. On November 4, 2009 and November 13, 2009, substantively identical complaints were filed in the Northern District of California by other purported Hansen stockholders asserting the same claims on behalf of the same putative class of Hansen stockholders. Livingstone v. Hansen Medical, Inc. et al., Case No. 09-05212 and Prenter v. Hansen Medical, Inc., et al., Case No. 09-05367. All three complaints sought certification as a class action and unspecified compensatory damages plus interest and attorneys fees. On December 22, 2009, two purported Hansen stockholders, Mina and Nader Farr, filed a joint application for appointment as lead plaintiffs and for consolidation of the three actions. On February 25, 2010, the Court issued an order granting Mina and Nader Farr’s application for appointment as lead plaintiffs and consolidating the three securities class actions. On July 15, 2010, the Court entered an order granting lead plaintiffs’ motion for leave to file a second amended complaint. Lead plaintiffs’ second amended complaint, in addition to alleging that shareholders suffered damages as a result of the decline in the Company’s stock price following the October 19, 2009 announcement, also alleged that shareholders suffered additional damages as the result of share price declines on July 28, 2009, July 31, 2009, January 8, 2009, July 6, 2009, and August 4, 2009, all of which lead plaintiffs alleged were caused by the disclosure of what they claim was previously misrepresented information. The Defendants filed their motion to dismiss the second amended complaint on October 13, 2010. The Court granted Defendants’ motion to dismiss with leave to amend on August 25, 2011. Plaintiffs’ third amended complaint was filed on October 18, 2011. Defendants filed their motions to dismiss on January 9, 2012. On August 10, 2012, the Court denied in part and granted in part Defendants’ motions to dismiss. On January 4, 2013, lead plaintiffs sought leave to amend their complaint to add certain of Hansen’s current and former directors and Hansen’s former auditor. Hansen filed an opposition to lead plaintiffs’ motion on February 11, 2013.
	On May 9, 2013, the parties entered a stipulation of settlement pursuant to which the plaintiffs would receive an aggregate of $8.5 million, $4.0 million of which would be funded in cash by the Company’s insurer and other sources. The Company would fund the remaining portion by issuing $4.25 million worth of the Company’s common stock, the number of shares to be determined based on the average closing price of the common stock for the 10 trading days preceding final Court approval of the settlement of the class action, and paying $250,000 in cash. The Company recorded a loss on litigation settlement of $4.5 million in its first quarter ended March 31, 2013. On December 5, 2013, the U.S. District Court for the Northern District of California granted final approval of a settlement. On December 19, 2013, the Company issued 2,298,539 shares, as determined by the average closing price of the Company’s common stock for the 10 trading days preceding final court approval of the settlement, which average was $1.8490 per share.

Longterm_Debt

Long-term Debt	12 Months Ended
	Dec. 31, 2013
Long-term Debt	'
	8	Long-term Debt
	Oxford Loan
	In December 2011, the Company entered into a $30.0 million loan and security agreement with Oxford Finance LLC and Silicon Valley Bank (the “Oxford Loan”). Under the agreement, the Company was obligated to pay interest only payments on the Oxford Loan through June 30, 2013, following which time the Oxford Loan required interest and principal payments through January 1, 2016. The Oxford Loan accrued interest at a stated rate of 9.45% and included an additional final interest payment of 3.95% of the original principal amount. The Oxford Loan provided for a prepayment option that allowed the Company to prepay all of the outstanding principal balance, subject to a pre-payment fee.
	In connection with the Oxford Loan, the Company issued warrants to purchase 660,793 shares of common stock. The warrants have an exercise price of $2.27 per share and expire in December 2018. The fair value of the warrants was estimated at $0.9 million using the Black-Scholes valuation model with the following assumptions: expected volatility of 58.0%, risk free interest rate of 1.41%, expected life of 7 years and no dividends. The fair value of the warrants was recorded as a discount to the loan and was amortized to interest expense using the effective interest rate method over the term of the loan. A total of $0.2 million was amortized to interest expense in 2013. A total of $0.3 million was amortized to interest expense in 2012.
	In August 2013, the Oxford Loan was fully repaid and extinguished under the loan agreement’s prepayment option. The Company paid a final interest balloon of $1.2 million plus accrued interest and a prepayment penalty of $0.9 million. The Company recognized a loss on extinguishment of debt of $1.9 million that included a prepayment penalty of $0.9 million, an additional end of term payment of $0.5 million and write-off of the unamortized discount from warrants and capitalized issuance costs of $0.5 million.
	White Oak Loan
	In July 2013, the Company executed a secured term loan agreement with White Oak Global Advisors, LLC (“White Oak”), as a lender and agent for several lenders. On August 23, 2013, the loan agreement was amended and restated and the loan was funded. The amended loan agreement provides for term loan debt financing of $33.0 million with a single principal balloon payment due at maturity on December 30, 2017. Cash interest accrues at an 11.0% per annum rate and is payable quarterly. Additionally, a 3.0% per annum payment-in-kind accrues quarterly and is accretive to the principal amount owed under the agreement. Substantially all of the proceeds from the loan were used to fully repay and extinguish the prior Oxford Loan. In connection with the loan, the Company incurred costs of approximately $1.5 million including payments to the lender agent totaling $0.7 million and the placement agent totaling $0.3 million that in aggregate are accounted for as debt issuance costs and amortized to interest expense over the life of the loan. Under the amended loan agreement, the Company is obligated to pay White Oak certain servicing, administration and monitoring fees of $32,000 annually. The Company may prepay all or a portion of the outstanding principal balance, subject to paying a prepayment fee of 3.5% of the principal amount of the loan prepaid if the prepayment is made on or before the third anniversary of the funding of the loan or 1.0% of the principal amount of the loan prepaid if the prepayment is made after the third anniversary and on or before the fourth anniversary of the funding of the loan. The Company is also required to make mandatory prepayments upon certain events of loss and certain dispositions of the Company’s assets as described in the amended loan agreement. In 2013, the Company recognized expense of $0.1 million for the amortization of debt issuance costs related to the White Oak loan.
	The loan is collateralized by substantially all of the Company’s assets then owned or thereafter acquired, other than its intellectual property, and all proceeds and products thereof. Two of the Company’s wholly-owned subsidiaries, AorTx, Inc. and Hansen Medical International, Inc., have entered into agreements to guarantee the Company’s obligations under the amended loan agreement and have granted first priority security interests in their assets, excluding any of their intellectual property, to secure their guarantee obligations. Under the amended loan agreement, neither the Company nor AorTx, Inc. and Hansen Medical International, Inc. may grant a lien on any intellectual property to third parties. The Company additionally agreed to pledge to lenders shares of each of its direct and indirect subsidiaries as collateral for the loan. Pursuant to the loan agreement, the Company is subject to certain affirmative and negative covenants and also to minimum liquidity requirements which require the Company to maintain $15.0 million in liquidity at all times, consisting of at least $13.0 million in cash, cash equivalents and investments, of which $5.0 million is required to be restricted subject to lenders’ control, and up to $2.0 million in certain accounts receivable. The loan also limits the Company’s ability to (a) undergo certain change of control events; (b) convey, sell, lease, transfer, assign or otherwise dispose of any of its assets; (c) create, incur, assume, or be liable with respect to certain indebtedness, not including, among other items, subordinated debt; (d) grant liens; (e) pay dividends and make certain other restricted payments; (f) make certain investments; (g) make payments on any subordinated debt; or (g) enter into transactions with any of its affiliates outside of the ordinary course of business, or permit its subsidiaries to do the same. In the event the Company were to violate any covenants or if White Oak has reason to believe that the Company has violated any covenants including a significant adverse event clause, and such violations are not cured pursuant to the terms of the loan and security agreement, the Company would be in default under the loan and security agreement, which would entitle lenders to exercise their remedies, including the right to accelerate the debt, upon which the Company may be required to repay all amounts then outstanding under the loan and security agreement. As of December 31, 2013, the Company was in compliance with all financial covenants.
	Future annual payments due on the debt outstanding as of December 31, 2013 are as follows (in thousands):
	2014		$	3,763
	2015			3,879
	2016			4,009
	2017			41,781
	Total remaining payments			53,432
	Less: Amount representing interest			(20,074	)
				33,358
	Less: Current portion of long-term debt			—
	Long-term debt, net of current portion		$	33,358

Stockholders_Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2013
Stockholders' Equity	'
	9	Stockholders’ Equity
	Stock Option and Equity Incentive Plans
	2002 Stock Option Plan
	The Company’s 2002 Stock Option Plan (the “2002 Plan”) was created for the purpose of issuing stock options to employees, directors and consultants of the Company. Options granted under the 2002 Plan were either incentive stock options (“ISO”) or nonqualified stock options (“NSO”). ISOs may be granted only to Company employees (including officers and directors), whereas NSOs may be granted to Company employees and consultants. Options expire on terms as determined by the board of directors but not more than ten years after the date of grant. The Company reserved a total of 4,579,009 shares of its common stock for issuance under its 2002 Plan. Upon effectiveness of the Company’s IPO in November 2006, the Company ceased issuing stock options under the 2002 Plan. At that time, all shares remaining available for grant under the 2002 Plan became available for grant instead under the 2006 Equity Incentive Plan. However, cancelled shares under the 2002 Plan do not become available for grant under the 2006 Equity Incentive Plan. All outstanding options granted under the 2002 Plan continue to be administered under the 2002 Plan.
	Stock options granted under the 2002 Plan provided employee option holders the right to elect to exercise unvested options in exchange for restricted common stock. Unvested shares were subject to a repurchase right held by the Company at the original issuance price in the event the optionees’ employment is terminated either voluntarily or involuntarily. For exercises of employee options, this right usually lapsed 25% on the first anniversary of the vesting start date and in 36 equal monthly amounts thereafter. These repurchase terms were considered to be a forfeiture provision and did not result in variable accounting. As of December 31, 2013, there were no unvested shares outstanding.
	2006 Equity Incentive Plan
	In August 2006, the Company’s board of directors approved the 2006 Equity Incentive Plan (the “2006 Plan”) to be effective on the date of the Company’s IPO. The 2006 Plan provides for the grant of ISOs, nonstatutory stock options, restricted stock awards, restricted stock unit awards, stock appreciation rights, performance-based stock awards, and other forms of equity compensation, or collectively, stock awards, and performance-based cash awards, all of which may be granted to employees, including officers, non-employee directors and consultants. Options expire on terms as determined by the board of directors but not more than ten years after the date of grant.
	The Company initially reserved a total of 2,000,000 shares for issuance under the 2006 Plan in addition to those shares which remained available for grant under the 2002 Plan. In addition, the number of shares of common stock reserved for issuance under the 2006 Plan automatically increases on January 1st each year by the lowest of (a) 4% of the total number of shares of our common stock outstanding on December 31st of the preceding calendar year, (b) 3,500,000 shares, or (c) a number determined by the board of directors that is less than (a) or (b). At December 31, 2013, 2,806,000 shares were available for grant under the 2006 Plan.
	Option activity under both the 2002 Plan and the 2006 Plan for 2013 is as follows:
			Shares			Weighted-		Weighted-		Aggregate
						Average		Average		Intrinsic
						Exercise		Remaining		Value
						Price		Contractual
								Term
			(in thousands)					(in years)		(in thousands)
	Balance at January 1, 2013			7,176		$	3.97		5.12	$	182
	Granted			2,249		$	1.97
	Exercised			(53	)	$	2.13
	Cancelled			(1,593	)	$	6.86
	Balance at December 31, 2013			7,779		$	3.24		4.76	$	169
	Options vested and expected to vest at December 31, 2013			7,620		$	3.2		4.79	$	156
	Options vested at December 31, 2013			4,167		$	4.12		3.89	$	56
	The weighted-average grant-date fair value of options granted in 2013, 2012, 2011 and 2010 was $1.25, $1.31 and $1.32 per share, respectively. The total fair value of options that vested in 2013, 2012 and 2011 was $2.6 million, $1.5 million and $3.0 million, respectively. As of December 31, 2013, total unamortized stock-based compensation related to unvested stock options was $4.4 million, with a weighted-average remaining recognition period of 2.33 years.
	The intrinsic value of exercised stock options is calculated based on the difference between the exercise price and the quoted market price of the Company’s common stock as of the close of the exercise date. The total intrinsic value of stock options exercised in 2013, 2012 and 2011 was $19 thousand, $0.1 million and $0.5 million, respectively.
	The options outstanding, vested and currently exercisable by exercise price under both the 2002 Plan and the 2006 Plan at December 31, 2013 are as follows:
			Options Outstanding					Options Exercisable and Vested
	Exercise Price		Number of			Weighted-		Number of		Weighted-		Weighted-
			Options			Average		Options		Average		Average
						Remaining				Exercise Price		Remaining
						Contractual						Contractual
						Life						Life
						(in years)						(in years)
	$0.40-$4.88			7,259			5.02		3,647	$	2.37		4.29
	$6.65-$12.69			155			2.35		155	$	8.54		2.35
	$15.25-$20.25			340			0.55		340	$	19.31		0.55
	$24.60-$31.20			25			0.76		25	$	27.37		0.76
				7,779			4.76		4,167	$	4.12		3.89
	Restricted stock unit activity under the 2006 Plan is as follows:
			Restricted Stock			Weighted-
			Units			Average Grant-
						Date Fair Value
			(in thousands)
	Balance at January 1, 2013			1,365		$	3.03
	Awarded			1,317		$	2.01
	Vested			(745	)	$	2.61
	Cancelled			(619	)	$	2.42
	Balance at December 31, 2013			1,318		$	1.99
	The fair value of restricted stock units is the quoted market price of the Company’s common stock as of the close of the grant date. The total fair value of shares vested pursuant to restricted stock units in 2013, 2012, 2011 and 2010 was $2.6 million, $2.4 million and $0.9 million, respectively. As of December 31, 2013, total unamortized stock-based compensation related to unvested restricted stock units was $0.5 million, with a weighted-average remaining recognition period of 0.8 years.
	Stock-based Compensation Associated with Awards to Employees
	Stock-based compensation expense charged to operations for options and restricted stock units granted to employees in 2013, 2012 and 2011 was $4.9 million, $2.9 million and $6.7 million, respectively.
	In 2011, the Company modified stock option agreements with an existing employee. The modification consisted of acceleration of vesting. The modifications resulted in the recording of additional employee stock compensation expense of $634,000 in 2011.
	The estimated grant date fair values of the employee stock options were calculated using the following assumptions:
			Years Ended December 31,
			2013		2012	2011
	Expected volatility		77%-89%		61%-90%	60%-61%
	Risk-free interest rate		0.6%-1.5%		0.5%-1.0%	0.9%-2.3%
	Expected term (in years)		4.38-4.57		4.29-4.75	4.50-4.75
	Dividend yield		0%		0%	0%
	Stock-Based Compensation for Non-employees
	Stock-based compensation expense related to stock options granted to non-employees is recognized on an accelerated basis as the stock options are earned. The final measurement occurs at the later of a performance commitment or when performance is complete. 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 valuation model.
	Stock-based compensation expense charged to operations for options granted to non-employees for the years ended December 31, 2013, 2012 and 2011 was immaterial.
	2006 Employee Stock Purchase Plan
	In August 2006, the Company’s board of directors approved the 2006 Employee Stock Purchase Plan (the “Stock Purchase Plan”) which became effective upon the Company’s IPO. Commencing on January 1, 2007, the Stock Purchase Plan allows participating employees to contribute up to 15% of their earnings, up to a maximum of $25,000, to purchase shares of the Company’s stock at a price per share equal to the lower of (a) 85% of the fair market value of a share of our common stock on the first date of the offering period, or (b) 85% of the fair market value of a share of our common stock on the date of purchase. The Company’s board of directors may specify offerings with durations of not more than 27 months, and may specify shorter purchase periods within each offering. Each offering will have one or more purchase dates on which shares of the Company’s common stock will be purchased for employees participating in the offering.
The Company initially reserved a total of 625,000 shares of common stock for issuance under the Stock Purchase Plan. In addition, the plan provides for automatic increases on January 1st, from January 1, 2007 through January 1, 2016, by the lesser of (a) 2% of the total number of shares of common stock outstanding on December 31st of the preceding calendar year, (b) 750,000 shares of common stock or (c) a number determined by the board of directors that is less than (a) and (b).
The estimated fair values of the shares issued under the Stock Purchase Plan were calculated using the following assumptions:
		Years Ended December 31,
		2013		2012	2011
Expected volatility		57%-99%		62%-110%	74%-110%
Risk-free interest rate		0.10%		0.10%	0.1%-0.2%
Expected term (in years)		0.5		0.5	0.5
Dividend yield		0%		0%	0%
Total Stock-based Compensation
Total stock-based compensation expense was allocated to cost of revenues, research and development and selling, general and administrative expense as follows (in thousands):
		Years Ended December 31,
		2013			2012		2011
Cost of revenues		$	402		$	319	$	805
Research and development			1,320			444		1,703
Selling, general and administrative			3,167			2,119		4,168
Total		$	4,889		$	2,882	$	6,676
Total stock-based compensation for the year ended December 31, 2012 includes a $740,000 reduction in expense recorded in the first quarter of 2012 resulting from an out of period adjustment related to compensation recorded in 2011 and prior periods for the Company’s employee stock purchase plan. This out of period correction is not material to the year ended December 31, 2012 or to prior periods.
Equity Transactions
In March 2013, the Company executed an “at the market” agreement pursuant to which the Company may have offered to sell shares of common stock up to an aggregate offering price of up to $25.0 million. In July 2013, the Company exercised its right to terminate the agreement. No shares were offered or sold pursuant to the agreement.
On July 30, 2013, the Company entered into a securities purchase agreement to sell an aggregate of 28,455,284 shares of its common stock at a per share price of $1.23 and warrants to purchase an aggregate of 34,146,339 shares of common stock at a per warrant price of $0.125 in a private placement transaction. The warrants were comprised of the following three series: Series A warrants exercisable for an aggregate 11,382,113 shares of common stock, with an exercise price equal to $1.23; Series B warrants exercisable for an aggregate 11,382,113 shares of common stock, with an exercise price equal to $1.50 per share; and Series C warrants exercisable for an aggregate 11,382,113 shares of common stock, with an exercise price equal to $2.00 per share. Series A warrants were subject to mandatory exercise subsequent to the receipt of regulatory approval for the new 6Fr Magellan catheter in the U.S., which occurred in February 2014. The financing resulted in gross proceeds to the Company of approximately $39.3 million prior to placement fees and offering costs of approximately $2.1 million. At the closing of the private placement financing, the Company entered into an investor rights agreement with the purchasers of the shares and warrants in which the Company agreed to file a registration statement covering resales of the shares and the purchasers agreed not to transact in any shares of the Company’s common stock for a one-year period following the closing, subject to certain exceptions. As of December 31, 2013, all of the warrants were outstanding. As of February 28, 2014, 11.4 million Series A warrants were exercised for total proceeds of $14.0 million, and the Company had remaining outstanding warrants exercisable for up to 22.8 million shares of common stock, which if exercised in full would yield gross proceeds of up to approximately $39.8 million.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2013
Income Taxes	'
	10	Income Taxes
	The Company’s pre-tax loss consists of the following (in thousands):
			Years Ended December 31,
			2013			2012			2011
	Domestic		$	(55,877	)	$	(22,343	)	$	(16,888	)
	Foreign			270			312			176
	Pre-tax loss		$	(55,607	)	$	(22,031	)	$	(16,712	)
	The Company’s tax provision for 2013 of $115,000 consisted of $13,000 in state taxes and $102,000 in foreign taxes. The Company’s effective tax rate differs from the U.S. federal statutory rate as follows:
			Years Ended December 31,
			2013			2012			2011
	Federal tax benefit at statutory rate			(34	)%		(34	)%		(34	)%
	Permanent difference due to non-deductible expenses			1	%		1	%		10	%
	State tax benefit, net of federal impact			—	%		—	%		(5	)%
	Change in deferred tax asset valuation allowance			33	%		32	%		34	%
	General business credits			—	%		—	%		(5	)%
	Effective tax rate			—	%		(1	)%		—	%
	The tax effects of temporary differences and carryforwards that give rise to significant portions of the deferred tax assets are as follows (in thousands):
			December 31,
			2013			2012
	Net operating loss carryforwards		$	93,744		$	75,929
	Research and development credits			9,682			8,366
	Capitalized research and development			19,107			17,151
	Fixed assets			2,222			1,957
	Stock-based compensation			2,478			2,200
	Accruals, reserves and other			2,061			2,158
	Intangibles			1,092			1,273
				130,386			109,034
	Less: Valuation allowance			(130,386	)		(109,034	)
	Net deferred tax asset		$	—		$	—
	At December 31, 2013, the Company has federal and state net operating loss carryforwards of approximately $242.0 million and $205.3 million, respectively, available to offset future taxable income. These net operating loss carryforwards will expire in varying amounts from 2014 through 2033 if not utilized. The net operating loss carryforwards include $1.5 million which relates to stock option deductions that will be recognized through additional paid-in capital when utilized. As such, these deductions are not reflected in our deferred tax assets. The Company also has federal and California research and development tax credit carryforwards of $8.2 million and $7.1 million, respectively, available to offset future taxes payable. The federal credits begin to expire in 2023, while the state credits have no expiration.
	Due to uncertainty surrounding realization of the deferred tax assets in future periods, the Company has placed a 100% valuation allowance against its net deferred tax assets. The valuation allowance increased by $21.4 million, $5.9 million and $5.7 million during the years ended December 31, 2013, 2012 and 2011, respectively. At such time as it is determined that it is more likely than not that the deferred tax assets are realizable, the valuation allowance will be reduced. Sections 382 and 383 of the Internal Revenue Code of 1986, as amended, provide for annual limitations on the utilization of net operating loss and research and experimentation credit carryforwards if the Company were to undergo an ownership change, as defined in Section 382. In general, an ownership change occurs whenever the percentage of the shares of a corporation owned, directly or indirectly, by 5-percent shareholders, as defined in Section 382, increases by more than 50 percentage points over the lowest percentage of the shares of such corporation owned, directly or indirectly, by such 5-percent shareholders at any time over the preceding three years. As the result of the sale of 11,700,000 shares of common stock in April 2009, the sale of 16,100,000 shares of common stock in April 2010, the sale of 4,785,000 shares of common stock in November 2011, the sale of 5,291,000 shares of common stock in October 2012, the sale of 28,455,284 shares of common stock in August 2013, such an ownership change may have occurred. Accordingly, the Company’s utilization of net operating loss and credit carryforwards which existed at that time could be limited. The Company has not completed a study to assess whether an ownership change has occurred or whether there have been multiple ownership changes since the Company became a “loss corporation” under the Code. The Company has and will continue to evaluate alternative analyses permitted under Section 382 and IRS notices to determine whether or not any ownership changes have occurred and may occur (and if so, when they occurred) that would result in limitations on its NOLs or certain other tax attributes.
	The Company has not provided for U.S. federal income and foreign withholding taxes on any undistributed earnings from non-U.S. operations because such earnings are intended to be reinvested indefinitely outside of the United States. If these earnings were distributed, foreign tax credits may become available under current law to reduce or eliminate the resulting U.S. income tax liability. As of December 31, 2013, there is $1.3 million in cumulative foreign earnings upon which U.S. income taxes have not been provided.
	The Company files income tax returns in the United States, various state jurisdictions and in the countries of United Kingdom and Germany. As of December 31, 2013, the Company’s federal tax returns for the years ended December 31, 2010 through the current period and most state returns for the years ended December 31, 2009 through the current period are open to examination. In addition, all of the net operating loss and research and development credit carryforwards that may be used in future years are still subject to adjustment. The Company is also subject to examination in the United Kingdom and Germany for the years ended December 31, 2010 through the current period. There are no tax examinations currently in progress.
	A reconciliation of the beginning and ending balance of unrecognized tax benefits is as follows (in thousands):
			Years Ended December 31,
			2013			2012			2011
	Balance at beginning of period		$	3,358		$	1,697		$	1,498
	Additions based on tax positions related to the current year			301			122			199
	Additions based on tax positions related to prior years			205			1,539			—
	Reduction for tax positions of prior years			—			—			—
	Balance at end of period		$	3,864		$	3,358		$	1,697
	If the Company is able to eventually recognize these uncertain tax positions, a total of $3.3 million of the unrecognized benefit would affect the Company’s effective tax rate. The Company currently has a full valuation allowance against its net deferred tax asset which would impact the timing of the effective tax rate benefit should any of these uncertain tax positions be favorably settled in the future. While it is often difficult to predict the final outcome of any particular uncertain tax position, management does not believe that it is reasonably possible that the estimates of unrecognized tax benefits will change significantly in the next twelve months.
	We recognize interest and penalties related to uncertain tax positions in income tax expense. As of December 31, 2013, we have no accrued interest or penalties related to uncertain tax positions. The Company does not anticipate that total unrecognized tax benefits will significantly change due to the settlement of audits and the expiration of statute of limitations period to December 31, 2014.

Net_Loss_per_Share

Net Loss per Share	12 Months Ended
	Dec. 31, 2013
Net Loss per Share	'
	11	Net Loss per Share
	The following table sets forth the computation of basic and diluted net loss per share (in thousands, except per share data):
			Years Ended December 31,
			2013			2012			2011
	Net loss		$	(55,722	)	$	(22,145	)	$	(16,712	)
	Shares used to calculated basic and diluted net loss per share			79,052			62,472			55,362
	Basic and diluted net loss per share		$	(0.70	)	$	(0.35	)	$	(0.30	)
	The following securities that could potentially dilute basic net loss per share 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 (in thousands):
			December 31,
			2013			2012			2011
	Stock options outstanding			7,779			7,176			6,827
	Unvested restricted stock units			1,318			1,365			1,631
	Estimated shares to be issued under the employee stock purchase plan			41			31			35
	Warrants			34,807			661			661

Segment_Information

Segment Information	12 Months Ended
	Dec. 31, 2013
Segment Information	'
	12	Segment Information
	The Company operates its business in one operating segment: the development and marketing of medical devices. The Company’s chief operating decision maker is its Chief Executive Officer who reviews the financial information presented on a consolidated basis for the purpose of making operating decisions and assessing financial performance.
	The Company attributes revenues to different geographic areas on the basis of the location of the customer and attributes long-lived assets to different geographic areas based on the location of those assets. Information regarding geographic areas is as follows (in thousands):
			United		Belgium		Saudi		Other (1)		Total
			States				Arabia
	2013:00:00
	Revenues		$	8,580	$	1,656	$	1,965	$	4,781	$	16,982
	Long-lived assets			3,569		—		—		72		3,641
	2012:00:00
	Revenues		$	8,197	$	1,687	$	119	$	7,633	$	17,636
	Long-lived assets			6,351		—		—		267		6,618
	2011:00:00
	Revenues		$	10,477	$	2,089	$	1,816	$	7,747	$	22,129
	Long-lived assets			8,775		—		—		262		9,037
	-1	No single location within other accounts for greater than 10% of revenues.

Quarterly_Data_unaudited

Quarterly Data (unaudited)	12 Months Ended
	Dec. 31, 2013
Quarterly Data (unaudited)	'
	13	Quarterly Data (unaudited)
	The following table represents certain unaudited quarterly information for the eight quarters ended December 31, 2013. This data has been derived from unaudited consolidated financial statements that, in the opinion of the Company’s management, include all adjustments, consisting only of normal recurring adjustments, necessary for a fair presentation of such information when read in conjunction with the Company’s annual audited consolidated financial statements and notes thereto appearing elsewhere in this report. These operating results are not necessarily indicative of results for any future period (in thousands, except per share data):
			First			Second			Third			Fourth
			Quarter			Quarter			Quarter			Quarter
			-1									-2
	2013:00:00
	Revenues		$	2,951		$	3,343		$	5,068		$	5,620
	Gross profit			469			576			1,340			1,116
	Net loss			(17,187	)		(13,446	)		(13,201	)		(11,888	)
	Basic net loss per share			(0.26	)		(0.20	)		(0.16	)		(0.12	)
	Diluted net loss per share			(0.26	)		(0.20	)		(0.16	)		(0.12	)
	2012:00:00
	Revenues		$	4,654		$	3,535		$	5,103		$	4,344
	Gross profit			732			753			1,257			868
	Net income (loss)			(11,811	)		(11,476	)		(8,431	)		9,537
	Basic net income (loss) per share			(0.20	)		(0.19	)		(0.14	)		0.15
	Diluted net income (loss) per share			(0.20	)		(0.19	)		(0.14	)		0.15
	-1	Net income and basic and diluted net income per share for the first quarter of 2013 include the impact of the loss on settlement of litigation of $4.5 million.
	-2	Net income and basic and diluted net income per share for the fourth quarter of 2012 include the impact of the gain on licensing of intellectual property of $20.0 million.

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 accordance with generally accepted accounting principles in the United States of America (“GAAP”). The Company’s fiscal year ends on December 31. The consolidated financial statements include the accounts of the Company and its subsidiaries. All significant intercompany accounts and transactions have been eliminated.
Use of Estimates	'
	Use of Estimates
	The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Significant estimates relate to the recognition of revenue, the evaluation of customer credit risk, the valuation of investments, inventory valuations, the determination of impairment of assets, stock-based compensation, loss contingencies and the valuation of our deferred tax assets, among others. Actual results could differ from those estimates.
Revenue Recognition	'
	Revenue Recognition
	The Company’s revenues are primarily derived from the sale of the Sensei system and the Magellan Robotic System and the associated catheters as well as the sale of customer service contracts. Under the Company’s revenue recognition policy, revenues are recognized when persuasive evidence of an arrangement exists, delivery to the customer has occurred or the services have been fully rendered, the sales price is fixed or determinable and collectability is probable.
		•	Persuasive Evidence of an Arrangement. Persuasive evidence of an arrangement for sales of systems is generally determined by a sales contract signed and dated by both the customer and the Company, including approved terms and conditions and the receipt of an approved purchase order. Evidence of an arrangement for the sale of disposable products is determined through an approved purchase order from the customer. Evidence of an arrangement for the sale of customer service is determined through either a signed sales contract or an approved purchase order from the customer. Sales to customers are generally not subject to any performance, cancellation, termination or return rights.
		•	Delivery.
		•	Systems and Disposable Products. Typically, ownership of systems, catheters and other disposable products passes to customers upon shipment, at which time delivery is deemed to be complete.
		•	Customer Service Revenue. The Company recognizes customer service revenue from the sale of product maintenance plans. Revenue from customer services, whether sold individually or as a separate unit of accounting in a multi-element arrangement, is deferred and amortized over the service period, which is typically one year.
		•	Multiple-element Arrangements. It is common for the sale of Sensei and Magellan systems to include multiple elements which qualify as separate units of accounting. These elements commonly include the sale of the system and a product maintenance plan, in addition to installation of the system and initial training. Less commonly, these elements may include the sale of certain disposable products or other elements. Generally, under multiple-element arrangements, the systems are delivered at the beginning of the arrangement and the related revenue is recognized at that time. Installation and training is generally completed within 90 days at which time the revenue is recognized. Customer service revenue associated with the product maintenance plan is recognized ratably over the service period, which is typically one year. Other elements are recognized once delivered in accordance with contract terms. In arrangements that include multiple elements, the Company allocates revenue to the various elements based on vendor-specific objective evidence of fair value (“VSOE”) of the elements if VSOE exists. VSOE for each element is based on the price for which the item is sold separately, determined based on historical evidence of stand-alone sales of these elements or stated renewal rates for the element. If VSOE does not exist for an element, the Company allocates revenue based on third-party evidence (“TPE”) of selling price for the elements if TPE exists. TPE is the price of the Company’s or any competitor’s largely interchangeable products or services in standalone sales to similarly-situated customers. If neither VSOE nor TPE exist for a specific element, the Company allocates revenue to the various elements based on its best estimate of the selling price for that element or estimated selling price (“ESP”) using a top-down approach, which takes into account the Company’s target prices and overall pricing objectives. In situations where the Company has delivered certain elements but not delivered other elements, the Company, after it has allocated revenue to the various elements under the relative selling price method based on VSOE, TPE or ESP, defers revenue for the undelivered elements. Because the Company has neither VSOE nor TPE for its systems, the allocation of revenue is based on ESP for the systems sold. The Company determines ESP for its systems by considering multiple factors, including, but not limited to, features and functionality of the system, geographies, type of customer, and market conditions. The Company regularly reviews ESP and maintains internal controls over the establishment and updates of these estimates.
		•	Sales Price Fixed or Determinable. The Company assesses whether the sales price is fixed or determinable at the time of the transaction. Sales prices are documented in the executed sales contract or purchase order received prior to shipment The Company’s standard terms do not allow for contingencies, such as trial or evaluation periods, refundable orders, payments contingent upon the customer obtaining financing or other contingencies which would impact the customer’s obligation. In situations where these or other contingencies are included, all related revenue is deferred until the contingency is resolved. In the third quarter of 2012, the Company began shipping systems under a limited commercial evaluation program to allow certain strategic accounts to install and utilize systems for a limited trial period while the purchase opportunity is being evaluated by the hospital. Systems under this program remain the property of the Company and are recorded in inventory and a sale only occurs upon the issuance of a purchase order from the customer.
		•	Collectability. The Company assesses whether collection is probable based on a number of factors, including the customer’s past transaction history and credit worthiness. If collection of the sales price is not deemed probable, the revenue is deferred and recognized at the time collection becomes probable, which is usually upon receipt of cash. The Company’s sales contracts generally do not allow the customer the right of cancellation, refund or return, except as provided under the Company’s standard warranty. If such rights were allowed, all related revenues would be deferred until such rights expired.
	Significant management judgments and estimates are made in connection with the determination of revenue to be recognized and the period in which it is recognized. If different judgments and estimates were utilized, the amount of revenue to be recognized and the period in which it is recognized could differ materially from the amounts reported.
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, short-term investments and accounts receivable. Cash and cash equivalents are deposited in demand and money market accounts at two financial institutions. At times, such deposits may be in excess of insured limits. The Company has not experienced any losses on its deposits of cash and cash equivalents.
	The Company had three customers who constituted 26%, 22%, and 10%, respectively of the Company’s net accounts receivable at December 31, 2013. The Company had three customers who constituted 22%, 20%, and 16%, respectively of the Company’s net accounts receivable at December 31, 2012. One customer accounted for 10% of revenues in 2013. One customer accounted for 14% of revenues in 2012. One customer accounted for 15% of revenues in 2011. The Company carefully monitors the creditworthiness of potential customers. As of December 31, 2013, the Company has not experienced any significant losses on its accounts receivable.
	Most of the products developed by the Company require clearance from the FDA or corresponding foreign regulatory agencies prior to commercial sales. The Company received CE Mark approval to market its Sensei system in Europe in the fourth quarter of 2006 and received CE Mark approval to market its Artisan Control Catheter in Europe in May 2007. The Company received FDA clearance for the marketing of its Sensei system and Artisan catheters for manipulation, positioning and control of certain mapping catheters during electrophysiology procedures in the United States in May 2007. The Company received CE Mark approval to market its Lynx catheter in Europe in July 2010. The Company received CE Mark approval for its Magellan Robotic System in July 2011 and received CE Mark approval for the Magellan Robotic Catheter and related accessories designed for use with the Magellan Robotic System in October 2011. The Company received FDA clearance for marketing its Magellan Robotic System, including the catheter and accessories in June 2012 and Magellan 6Fr Robotic Catheter in February 2014. However, there can be no assurance that current products or any new products the Company develops in the future will receive the clearances necessary to allow the Company to market those products in certain desirable markets. If the Company is denied clearance or clearance is delayed, it could 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, and have asserted in the past, that its products or the use of the Company’s products are covered by United States or foreign patents held by them. This risk is heightened due to the numerous issued and pending patents relating to the use of catheter-based procedures in the medical technology field.
Loss Contingencies	'
	Loss Contingencies
	The Company evaluates potential loss contingencies as circumstances dictate. Should a specific loss contingency meet the definition of a liability under authoritative accounting guidance, the Company would record a loss and a liability. As of December 31, 2013, the Company had not recorded any loss contingencies as liabilities. However, if estimates and assumptions change in the future, the Company may record charges to its financial statements. This could materially impact its operating results and financial position.
Foreign Currency	'
	Foreign Currency
	The functional currency of the Company’s domestic and foreign operations is the U.S. dollar. Accordingly, the effects of foreign currency transactions, and of remeasuring the financial condition and results of operations from local currencies into the functional currency, are included in other expense, net in the accompanying consolidated statements of operations. Remeasurement and foreign currency transaction losses, net, for fiscal years ended December 31, 2013, 2012 and 2011 were immaterial.
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, accounts receivable, prepaid expenses and other current assets, accounts payable and accrued liabilities approximate fair value due to their short maturities.
Cash and Cash Equivalents, and Restricted Cash	'
	Cash and Cash Equivalents, and Restricted Cash
	The Company considers all highly liquid investments with maturities of three months or less at the time of purchase to be cash equivalents. Cash and cash equivalents, and restricted cash include money market funds and various deposit accounts, which are readily convertible to cash and are stated at cost, which approximates market. Pursuant to the Company’s secured term loan agreement executed in 2013, the Company is obligated to maintain $5.0 million of restricted cash subject to lenders’ control.
Short-Term Investments	'
	Short-Term Investments
	Available-for-sale investments. The Company determines the appropriate classification of investments at the time of purchase and evaluates such classification as of each balance sheet date. The Company classifies all investments with maturities greater than three months at the time of purchase as short-term investments as they are subject to use within one year in current operations. The Company makes investments based upon specific guidelines approved by its board of directors with a view to liquidity and capital preservation and regularly reviews its investments for performance. As of December 31, 2013, all of the Company’s investments have been classified as available-for-sale and are carried on the balance sheet at fair value with the unrealized gains and losses, if any, included in other comprehensive income within stockholders’ equity. Any unrealized losses which are determined to be other than temporary are included in earnings. Realized gains and losses are recognized on the specific identification method.
	Other-than-temporary impairment. The Company periodically evaluates its investments for impairment. In the event that the carrying value of an investment exceeds its fair value and the decline in fair value is determined to be other than temporary, an impairment charge is recorded and a new cost basis for the investment is established. In order to determine whether a decline in value is other than temporary, the Company evaluates many factors, including the following: the duration and extent to which the fair value has been less than the carrying value; the company’s financial condition and business outlook, including key operational and cash flow metrics, current market conditions and future trends in the industry; and the Company’s intent and ability to retain the investment for a period of time sufficient to allow for any anticipated recovery in fair value. In fiscal 2010 and 2011, the Company determined that the impairment of its investment in Luna Innovations, Incorporated (together with its wholly-owned subsidiary, “Luna”) common stock was other than temporary and as such, permanently wrote down the value of that investment and recorded a loss of $1.9 million $0.3 million, respectively in other expense on the consolidated statement of operations. In the first quarter of 2013, the Company recorded an additional write down of the investment and recorded an additional loss of $0.6 million in other expense on the condensed consolidated statement of operations. The carrying value of the Luna investment as of December 31, 2013 was $1.9 million. Significant management judgment is required in determining whether an other-than-temporary decline in the fair value of an investment exists. Changes in the Company’s assessment of the valuation of investments could materially impact future operating results and financial position.
Allowance for Doubtful Accounts	'
	Allowance for Doubtful Accounts
	The Company establishes allowances for doubtful accounts based on a review of the credit profiles of customers, contractual terms and conditions, current economic trends and historical collection experience. The allowance for doubtful accounts is reassessed each period. If different judgments and estimates were utilized in establishing the allowance, the amount or timing of bad debt expense or revenue recognized could differ materially from the amounts reported. In the Company’s limited historical experience, actual losses and credits related to accounts receivable have been consistent with the recorded provisions. If, however, actual future receipts differ materially from the current assessments due, among other things, to unexpected events or significant changes in trends, additional provisions may be necessary and future cash flows and statements of operations could be materially negatively impacted. Provisions for doubtful accounts as a percentage of revenues have been immaterial for all periods presented.
Inventories	'
	Inventories
	Inventory, which includes material, labor and overhead costs, is stated at standard cost, which approximates actual cost, determined on a first-in, first-out basis, not in excess of market value. The Company records reserves, when necessary, to reduce the carrying value of excess or obsolete inventories to their net realizable value. These reserves are based on our best estimates after considering projected future demand. In the event that actual demand for our inventory differs from our best estimates or we fail to receive the necessary regulatory approvals, increases to inventory reserves may become necessary.
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 two to five 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 balance sheet and the resulting gain or loss is recognized. Maintenance and repairs are charged to operations as incurred. Depreciation expense was $2.9 million, $3.3 million and $3.4 million for the years ended December 31, 2013, 2012 and 2011, respectively.
Impairment of Long-Lived Assets	'
	Impairment of Long-Lived Assets
	The Company evaluates the recoverability of its long-lived assets in accordance with authoritative accounting guidance. When events or changes in circumstances indicate that the carrying value of long-lived assets may not be recoverable, the Company recognizes such impairment if the net book value of such assets exceeds the future undiscounted cash flows attributable to such assets. 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 discounted estimates of future cash flows attributable to the assets. As of December 31, 2013, the Company had $3.6 million of property and equipment, net. If estimates or the related assumptions change in the future, the Company may record impairment charges to reduce the carrying value of certain groups of these assets. Changes in the valuation of long-lived assets could materially impact the Company’s operating results and financial position.
Advertising Expense	'
	Advertising Expense
	The Company expenses advertising costs as incurred. Advertising costs are recorded in general, sales and marketing expenses within the accompanying Consolidated Statements of Operations and were immaterial for fiscal years 2013, 2012 and 2011.
Stock-Based Compensation	'
	Stock-Based Compensation
	Under the fair value recognition provisions of authoritative guidance related to stock-based compensation, stock-based payment expense is estimated at the grant date based on the fair value of the award and is recognized as expense ratably over the requisite service period of the award. The recording of compensation expense related to stock-based awards is significant to the Company’s financial statements but does not result in the payment of cash by the Company. Determining the appropriate fair value model used to calculate the fair value of stock-based awards requires significant management judgment. Additionally, the calculation of the fair value of stock-based awards requires the Company to make significant estimates and judgments, including the expected volatility, the expected term of the award, risk-free interest rate and the dividend yield. If the Company had chosen a different fair value model or made different estimates in the calculation of fair value, the amount or timing of stock-based compensation recorded could have differed materially from the amounts reported.
	The Company selected the Black-Scholes option valuation model as the most appropriate method for determining the estimated fair value for stock-based awards. The Black-Scholes model requires the use of highly subjective and complex assumptions in determining the fair value of stock-based awards, including the expected volatility of the underlying stock, the award’s expected term, risk-free interest rate and the dividend yield.
		•	Expected Volatility. The Company’s estimate of volatility is based on the historical volatilities of its stock price.
		•	Expected Term. The Company estimates the expected term based on its historical settlement experience related to vesting and contractual terms while giving consideration to awards that have life cycles less than the contractual terms and vesting schedules in accordance with authoritative guidance.
		•	Risk-Free Interest Rate. The risk-free interest rate that the Company uses in the Black-Scholes option valuation model is the implied yield in effect at the time of option grant based on U.S. Treasury zero-coupon issues with a remaining term equivalent to the expected term of its option grants. For ESPP grants, the Company uses the 6-month Constant Maturity Treasury (“CMT”) rate.
		•	Dividend Yield. The Company has never paid any cash dividends on its common stock and it does not anticipate paying any cash dividends in the foreseeable future. Consequently, the Company uses a dividend yield of zero in the Black-Scholes option valuation model.
	In addition to the Black-Scholes assumptions noted above, the Company also estimates a forfeiture rate for its stock-based awards. The Company estimates its forfeiture rate based on an analysis of its actual forfeitures based on actual forfeiture experience, analysis of employee turnover behavior and other factors. The impact from any forfeiture rate adjustment would be recognized in full in the period of adjustment and if the actual number of future forfeitures differs from its estimates, the Company might be required to record adjustments to its stock-based compensation in future periods.
	To the extent that future evidence regarding these variables is available and provides estimates that the Company determines are more indicative of actual trends, the Company may refine or change its approach to deriving these input estimates. These changes could significantly impact the stock-based compensation expense recorded in the future.
Research and Development	'
	Research and Development
	Research and development costs are charged to expense as incurred. Research and development costs include, but are not limited to, payroll and other personnel expenses, prototype materials, laboratory supplies, and consulting costs.
Income Taxes	'
	Income Taxes
	The Company accounts for income taxes using the liability method whereby deferred tax asset and liability account balances are determined based on differences between financial reporting and tax bases of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. Valuation allowances are established to reduce deferred tax assets when management estimates, based on available objective evidence, that it is more likely than not that the benefit will not be realized for the deferred tax assets. The Company accounts for uncertainty in income taxes using a two-step approach to recognizing and measuring uncertain tax positions. The first step is to evaluate the tax position for recognition by determining if the weight of available evidence indicates that it is more likely than not that the position will be sustained on audit, including resolution of related appeals or litigation processes, if any. The second step is to measure the tax benefit as the largest amount that is more than 50% likely of being realized upon settlement. The Company recognizes interest and penalties related to unrecognized tax benefits as a component of income tax expense. As of December 31, 2013, the Company has no accrued interest or penalties related to uncertain tax positions. The Company does not anticipate that total unrecognized tax benefits will significantly change due to the settlement of audits and the expiration of statute of limitations periods in 2014.
Comprehensive Loss	'
	Comprehensive Loss
	The Company follows the accounting standards for the reporting and presentation of comprehensive income (loss) and its components. In June 2011, the Financial Accounting Standards Board (“FASB”) issued new accounting guidance that revised the manner in which entities present comprehensive income in their financial statements. The new guidance requires entities to present comprehensive income either in a continuous statement of comprehensive income, which replaces the statement of operations, or in two separate, consecutive statements. The new guidance does not change the items that must be reported in other comprehensive income, nor does it require new disclosures. On January 1, 2012 The Company adopted new accounting guidance and presents comprehensive income (loss) in a separate statement. Comprehensive loss includes all changes in stockholders’ equity during a period from non-owner sources. Comprehensive loss for each of the years ended December 31, 2013, 2012, and 2011 was equal to net loss adjusted for unrealized gains and losses on investments, reclassifications of realized gains and losses on investments to other income (expense) and foreign currency translation adjustments.
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. Such dilutive potential shares are excluded when the effect would be to reduce a net loss per share. The Company’s dilutive potential shares, which include outstanding common stock options, warrants, estimated shares to be issued under the Company’s employee stock purchase plan and unvested restricted stock, have not been included in the computation of diluted net loss per share for all yearly periods as the result would be anti-dilutive.
Retirement Plan	'
	Retirement Plan
	The Company sponsors a 401(k) defined contribution plan covering all employees. There have been no employer contributions to the plan since inception.
Segment Reporting	'
	Segment Reporting
	The Company has determined that it operates in one segment.
Recent Accounting Pronouncements	'
	Recent Accounting Pronouncements
	In February 2013, the FASB issued Accounting Standards Update (“ASU”) 2013-02, Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income. This update requires entities to disclose items reclassified out of accumulated other comprehensive income and into net income in a single location within the financial statements. This new guidance was effective for the Company beginning January 1, 2013, with early adoption permitted. The Company adopted this guidance in the first quarter of 2013. The adoption of ASU 2013-02 did not have a material impact on the Company’s consolidated financial position or results of operations.
	In July 2013, the Financial Accounting Standards Board (“FASB”) issued ASU 2013-11, Income Taxes (Topic 740): Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists. The standard will be effective for the Company beginning January 1, 2014. The Company is currently evaluating the effects of adoption, but does not anticipate it will have a significant impact upon the Company’s consolidated financial statements.

Fair_Value_of_Assets_and_Liabi1

Fair Value of Assets and Liabilities (Tables)	12 Months Ended
	Dec. 31, 2013
Amortized Cost and Fair Value of Assets, with Gross Unrealized Gains and Losses	'
	The amortized cost and fair value of assets, along with gross unrealized gains and losses, were as follows (in thousands):
		Amortized			Gross		Gross			Fair		Balance Sheet Classification
		Cost			Unrealized		Unrealized			Value
					Gains		Losses					Cash and		Short-term		Restricted
												cash		Investments		Cash
												Equivalents
	December 31, 2013:
	Cash	$	1,665		$	—	$	—		$	1,665	$	1,665	$	—	$	—
	Money market funds		31,724			—		—			31,724		26,330		—		5,394
	Corporate equity securities		1,572			373		—			1,945		—		1,945		—
		$	34,961		$	373	$	—		$	35,334	$	27,995	$	1,945	$	5,394
	December 31, 2012:
	Cash	$	1,283		$	—	$	—		$	1,283	$	1,283	$	—	$	—
	Money market funds		31,466			—		—			31,466		31,466		—		—
	Corporate debt and commercial paper		6,704			—		—			6,704		—		6,704		—
	Corporate equity securities		2,158			132		(661	)		1,629		—		1,629		—
		$	41,611		$	132	$	(661	)	$	41,082	$	32,749	$	8,333	$	—
Fair Value Hierarchy of Company's Assets	'
	The fair value hierarchy of the Company’s assets is as follows (in thousands):
		Fair Value Measurements Using
		Quoted Prices in			Significant other		Unobservable			Total
		Active Markets for			Observable		Inputs
		Identical Assets			Inputs		(Level 3 Inputs)
		(Level 1 Inputs)			(Level 2 Inputs)
	December 31, 2013:
	Money market funds	$	31,724		$	—	$	—		$	31,724
	Corporate equity securities		1,945			—		—			1,945
		$	33,669		$	—	$	—		$	33,669
	December 31, 2012:
	Money market funds	$	31,466		$	—	$	—		$	31,466
	Corporate debt and commercial paper		—			6,704		—			6,704
	Corporate equity securities		1,629			—		—			1,629
	Warrants to purchase corporate equity securities		—			—		91			91
		$	33,095		$	6,704	$	91		$	39,890
Fair value on a recurring basis using significant unobservable inputs (Level 3)	'
	The following tables present a reconciliation for all assets measured at fair value on a recurring basis using significant unobservable inputs (Level 3) for the years ended December 31, 2012 (in thousands):
		Investments Valued Using Level
		3 Inputs for the Year Ended
		December 31,
		2012
	Balance at beginning of period	$	153
	Total gains and losses:
	Included in other expense, net		(41	)
	Included in accumulated other comprehensive loss		1
	Transfers out		(22	)
	Balance at end of period	$	91

Balance_Sheet_Components_Table

Balance Sheet Components (Tables)	12 Months Ended
	Dec. 31, 2013
Components of inventories	'
	Inventories (in thousands)
		December 31,
		2013			2012
	Raw materials	$	4,167		$	3,333
	Work in process		5,285			3,644
	Finished goods		2,751			2,157
	Inventories	$	12,203		$	9,134
Property and equipment, net	'
	Property and equipment, net (in thousands)
		December 31,
		2013			2012
	Furniture and leasehold improvements	$	11,466		$	11,451
	Laboratory equipment		10,209			9,985
	Computer equipment and software		2,850			2,640
			24,525			24,076
	Less: Accumulated depreciation and amortization		(20,884	)		(18,036	)
	Property and equipment, net	$	3,641		$	6,040
Accrued liabilities	'
	Accrued liabilities (in thousands)
		December 31,
		2013			2012
	Accrued salaries, commission, bonus and benefits	$	1,867		$	1,455
	Accrued royalties		796			481
	Accrued legal and other professional fees		183			144
	Accrued other expenses		1,088			1,242
	Total	$	3,934		$	3,322

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2013
Rent expense on a straight-line basis	'
	Rent expense on a straight-line basis was as follows (in thousands):
		Years Ended December 31,
		2013			2012			2011
	Rent expense	$	2,310		$	2,280		$	2,231
Future Minimum Payments under Operating Leases	'
	At December 31, 2013, future minimum payments under the leases are as follows (in thousands):
	Years ended December 31,	Future Minimum
		Lease Payments
	2014	$	2,149
	2015		1,979
	2016		2,140
	2017		2,205
	Thereafter		4,415
	Total	$	12,888
Movement in Warranty Liability during Period	'
	Movement in the warranty liability was as follows (in thousands):
		Years Ended December 31,
		2013			2012
	Balance at beginning of period	$	9		$	12
	Warranties issued during the period		105			112
	Warranty costs incurred during the period		(105	)		(115	)
	Balance at end of period	$	9		$	9

Longterm_Debt_Tables

Long-term Debt (Tables)	12 Months Ended
	Dec. 31, 2013
Future Annual Payments Due on Amounts Outstanding	'
	Future annual payments due on the debt outstanding as of December 31, 2013 are as follows (in thousands):
	2014	$	3,763
	2015		3,879
	2016		4,009
	2017		41,781
	Total remaining payments		53,432
	Less: Amount representing interest		(20,074	)
			33,358
	Less: Current portion of long-term debt		—
	Long-term debt, net of current portion	$	33,358

Stockholders_Equity_Tables

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2013
Summary of Option Activity Under Company's 2002 Stock Option Plan and 2006 Plan for 2013	'
	Option activity under both the 2002 Plan and the 2006 Plan for 2013 is as follows:
		Shares			Weighted-		Weighted-		Aggregate
					Average		Average		Intrinsic
					Exercise		Remaining		Value
					Price		Contractual
							Term
		(in thousands)					(in years)		(in thousands)
	Balance at January 1, 2013		7,176		$	3.97		5.12	$	182
	Granted		2,249		$	1.97
	Exercised		(53	)	$	2.13
	Cancelled		(1,593	)	$	6.86
	Balance at December 31, 2013		7,779		$	3.24		4.76	$	169
	Options vested and expected to vest at December 31, 2013		7,620		$	3.2		4.79	$	156
	Options vested at December 31, 2013		4,167		$	4.12		3.89	$	56
Options Outstanding, Vested and Currently Exercisable By Exercise Price under Both 2002 Plan And 2006 Plan	'
	The options outstanding, vested and currently exercisable by exercise price under both the 2002 Plan and the 2006 Plan at December 31, 2013 are as follows:
		Options Outstanding					Options Exercisable and Vested
	Exercise Price	Number of			Weighted-		Number of		Weighted-		Weighted-
		Options			Average		Options		Average		Average
					Remaining				Exercise Price		Remaining
					Contractual						Contractual
					Life						Life
					(in years)						(in years)
	$0.40-$4.88		7,259			5.02		3,647	$	2.37		4.29
	$6.65-$12.69		155			2.35		155	$	8.54		2.35
	$15.25-$20.25		340			0.55		340	$	19.31		0.55
	$24.60-$31.20		25			0.76		25	$	27.37		0.76
			7,779			4.76		4,167	$	4.12		3.89
Summary of Restricted Stock Unit Activity	'
	Restricted stock unit activity under the 2006 Plan is as follows:
		Restricted Stock			Weighted-
		Units			Average Grant-
					Date Fair Value
		(in thousands)
	Balance at January 1, 2013		1,365		$	3.03
	Awarded		1,317		$	2.01
	Vested		(745	)	$	2.61
	Cancelled		(619	)	$	2.42
	Balance at December 31, 2013		1,318		$	1.99
Assumptions Used to Estimate Grant Date Fair Values of Stock Options	'
	The estimated grant date fair values of the employee stock options were calculated using the following assumptions:
		Years Ended December 31,
		2013		2012	2011
	Expected volatility	77%-89%		61%-90%	60%-61%
	Risk-free interest rate	0.6%-1.5%		0.5%-1.0%	0.9%-2.3%
	Expected term (in years)	4.38-4.57		4.29-4.75	4.50-4.75
	Dividend yield	0%		0%	0%
Assumptions Used to Estimate Grant Date Fair Values of Shares Issued Under the ESPP	'
	The estimated fair values of the shares issued under the Stock Purchase Plan were calculated using the following assumptions:
		Years Ended December 31,
		2013		2012	2011
	Expected volatility	57%-99%		62%-110%	74%-110%
	Risk-free interest rate	0.10%		0.10%	0.1%-0.2%
	Expected term (in years)	0.5		0.5	0.5
	Dividend yield	0%		0%	0%
Total Stock-based Compensation	'
	Total stock-based compensation expense was allocated to cost of revenues, research and development and selling, general and administrative expense as follows (in thousands):
		Years Ended December 31,
		2013			2012		2011
	Cost of revenues	$	402		$	319	$	805
	Research and development		1,320			444		1,703
	Selling, general and administrative		3,167			2,119		4,168
	Total	$	4,889		$	2,882	$	6,676

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2013
Summary of Company's Pre-tax Loss	'
	The Company’s pre-tax loss consists of the following (in thousands):
		Years Ended December 31,
		2013			2012			2011
	Domestic	$	(55,877	)	$	(22,343	)	$	(16,888	)
	Foreign		270			312			176
	Pre-tax loss	$	(55,607	)	$	(22,031	)	$	(16,712	)
Summary of Company's Effective Tax Rate Differs from U.S. Federal Statutory Rate	'
	The Company’s effective tax rate differs from the U.S. federal statutory rate as follows:
		Years Ended December 31,
		2013			2012			2011
	Federal tax benefit at statutory rate		(34	)%		(34	)%		(34	)%
	Permanent difference due to non-deductible expenses		1	%		1	%		10	%
	State tax benefit, net of federal impact		—	%		—	%		(5	)%
	Change in deferred tax asset valuation allowance		33	%		32	%		34	%
	General business credits		—	%		—	%		(5	)%
	Effective tax rate		—	%		(1	)%		—	%
Summary of Tax Effects of Temporary Differences and Carryforwards That Give Rise to Significant Portions of Deferred Tax Assets	'
	The tax effects of temporary differences and carryforwards that give rise to significant portions of the deferred tax assets are as follows (in thousands):
		December 31,
		2013			2012
	Net operating loss carryforwards	$	93,744		$	75,929
	Research and development credits		9,682			8,366
	Capitalized research and development		19,107			17,151
	Fixed assets		2,222			1,957
	Stock-based compensation		2,478			2,200
	Accruals, reserves and other		2,061			2,158
	Intangibles		1,092			1,273
			130,386			109,034
	Less: Valuation allowance		(130,386	)		(109,034	)
	Net deferred tax asset	$	—		$	—
Reconciliation of Beginning and Ending Balance of Unrecognized Tax Benefits	'
	A reconciliation of the beginning and ending balance of unrecognized tax benefits is as follows (in thousands):
		Years Ended December 31,
		2013			2012			2011
	Balance at beginning of period	$	3,358		$	1,697		$	1,498
	Additions based on tax positions related to the current year		301			122			199
	Additions based on tax positions related to prior years		205			1,539			—
	Reduction for tax positions of prior years		—			—			—
	Balance at end of period	$	3,864		$	3,358		$	1,697

Net_Loss_per_Share_Tables

Net Loss per Share (Tables)	12 Months Ended
	Dec. 31, 2013
Computation of Basic and Diluted Net Income (Loss) Per Share	'
	The following table sets forth the computation of basic and diluted net loss per share (in thousands, except per share data):
		Years Ended December 31,
		2013			2012			2011
	Net loss	$	(55,722	)	$	(22,145	)	$	(16,712	)
	Shares used to calculated basic and diluted net loss per share		79,052			62,472			55,362
	Basic and diluted net loss per share	$	(0.70	)	$	(0.35	)	$	(0.30	)
Common Stock Equivalents that are Not Included In the Calculation of Diluted Net Loss Per Share	'
	The following securities that could potentially dilute basic net loss per share 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 (in thousands):
		December 31,
		2013			2012			2011
	Stock options outstanding		7,779			7,176			6,827
	Unvested restricted stock units		1,318			1,365			1,631
	Estimated shares to be issued under the employee stock purchase plan		41			31			35
	Warrants		34,807			661			661

Segment_Information_Tables

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2013
Summary of revenue and long-lived assets regarding geographic areas	'
	Information regarding geographic areas is as follows (in thousands):
			United		Belgium		Saudi		Other (1)		Total
			States				Arabia
	2013:00:00
	Revenues		$	8,580	$	1,656	$	1,965	$	4,781	$	16,982
	Long-lived assets			3,569		—		—		72		3,641
	2012:00:00
	Revenues		$	8,197	$	1,687	$	119	$	7,633	$	17,636
	Long-lived assets			6,351		—		—		267		6,618
	2011:00:00
	Revenues		$	10,477	$	2,089	$	1,816	$	7,747	$	22,129
	Long-lived assets			8,775		—		—		262		9,037
	-1	No single location within other accounts for greater than 10% of revenues.

Quarterly_Data_unaudited_Table

Quarterly Data (unaudited) (Tables)	12 Months Ended
	Dec. 31, 2013
Summary of certain unaudited quarterly information for the eight quarters	'
	The following table represents certain unaudited quarterly information for the eight quarters ended December 31, 2013. This data has been derived from unaudited consolidated financial statements that, in the opinion of the Company’s management, include all adjustments, consisting only of normal recurring adjustments, necessary for a fair presentation of such information when read in conjunction with the Company’s annual audited consolidated financial statements and notes thereto appearing elsewhere in this report. These operating results are not necessarily indicative of results for any future period (in thousands, except per share data):
			First			Second			Third			Fourth
			Quarter			Quarter			Quarter			Quarter
			-1									-2
	2013:00:00
	Revenues		$	2,951		$	3,343		$	5,068		$	5,620
	Gross profit			469			576			1,340			1,116
	Net loss			(17,187	)		(13,446	)		(13,201	)		(11,888	)
	Basic net loss per share			(0.26	)		(0.20	)		(0.16	)		(0.12	)
	Diluted net loss per share			(0.26	)		(0.20	)		(0.16	)		(0.12	)
	2012:00:00
	Revenues		$	4,654		$	3,535		$	5,103		$	4,344
	Gross profit			732			753			1,257			868
	Net income (loss)			(11,811	)		(11,476	)		(8,431	)		9,537
	Basic net income (loss) per share			(0.20	)		(0.19	)		(0.14	)		0.15
	Diluted net income (loss) per share			(0.20	)		(0.19	)		(0.14	)		0.15
	-1	Net income and basic and diluted net income per share for the first quarter of 2013 include the impact of the loss on settlement of litigation of $4.5 million.
	-2	Net income and basic and diluted net income per share for the fourth quarter of 2012 include the impact of the gain on licensing of intellectual property of $20.0 million.

The_Company_Additional_Informa

The Company - Additional Information (Detail) (USD $)	0 Months Ended			0 Months Ended	1 Months Ended
	Jul. 30, 2013	Dec. 31, 2013	Dec. 31, 2012	Jul. 30, 2013	Feb. 28, 2014
				Series A Warrants	Subsequent Event
					Series A Warrants
Description of Business [Line Items]	'	'	'	'	'
Accumulated net profit or loss from inception	'	($352,664,000)	($296,942,000)	'	'
Cash, cash equivalents, short-term investments and restricted cash	'	35,300,000	'	'	'
Proceeds from warrant exercises if exercised in full	'	'	'	'	14,000,000
Number of warrants exercised	'	'	'	'	11,400,000
Common Stock issuable upon exercise of warrants	34,146,339	'	'	11,382,113	22,800,000
Value of warrants outstanding	'	'	'	'	$39,800,000

Summary_of_Significant_Account2

Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)

12 Months Ended

3 Months Ended

12 Months Ended

12 Months Ended

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Mar. 31, 2013

Dec. 31, 2011

Dec. 31, 2010

Dec. 31, 2013

Aug. 23, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Entity

Luna Innovations Incorporated

Luna Innovations Incorporated

Luna Innovations Incorporated

Luna Innovations Incorporated

Restricted Cash and Cash Equivalents

Sales

Sales

Sales

Accounts Receivable

Accounts Receivable

Customer 1

Customer 1

Customer 2

Customer 2

Customer 3

Customer 3

Minimum

Maximum

Segment

Customer

Customer

Customer

Customer

Customer

Accounts Receivable

Accounts Receivable

Accounts Receivable

Accounts Receivable

Accounts Receivable

Accounts Receivable

Summary Of Significant Accounting Policies [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Deferred and amortized service period

'1 year

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Period for customer service revenue recognition

'1 year

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Revenue recognition, period

'90 days

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of financial institutions in which cash deposited

2

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of major customers

'

'

'

'

'

'

'

'

1

1

1

'

'

'

'

'

'

'

'

'

'

Accounts receivable from number of customers

'

'

'

'

'

'

'

'

'

'

'

3

3

'

'

'

'

'

'

'

'

Concentration risk, percentage

'

'

'

'

'

'

'

'

10.00%

14.00%

15.00%

'

'

26.00%

22.00%

22.00%

20.00%

10.00%

16.00%

'

'

Minimum liquidity requirement amount

'

'

'

'

'

'

'

$5,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Available-for-sale securities, other than temporary impairment recorded loss in other expense

'

'

'

600,000

300,000

1,900,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Available-for-sale securities, carrying value

'

'

'

'

'

'

1,900,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Estimated useful lives

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'2 years

'5 years

Depreciation expense

2,900,000

3,300,000

3,400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Property and equipment, net

3,641,000

6,040,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Accrued interest or penalties

$0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of operating segments

1

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amortized_Cost_and_Fair_Value_

Amortized Cost and Fair Value of Assets, with Gross Unrealized Gains and Losses (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Cash Cash Equivalents And Short Term Investments [Line Items]	'	'
Amortized Cost	$34,961	$41,611
Gross Unrealized Gains	373	132
Gross Unrealized Losses	'	-661
Fair Value	35,334	41,082
Cash	'	'
Cash Cash Equivalents And Short Term Investments [Line Items]	'	'
Amortized Cost	1,665	1,283
Fair Value	1,665	1,283
Money Market Funds	'	'
Cash Cash Equivalents And Short Term Investments [Line Items]	'	'
Amortized Cost	31,724	31,466
Fair Value	31,724	31,466
Corporate Equity Securities	'	'
Cash Cash Equivalents And Short Term Investments [Line Items]	'	'
Amortized Cost	1,572	2,158
Gross Unrealized Gains	373	132
Gross Unrealized Losses	'	-661
Fair Value	1,945	1,629
Corporate Debt and Commercial Paper	'	'
Cash Cash Equivalents And Short Term Investments [Line Items]	'	'
Amortized Cost	'	6,704
Fair Value	'	6,704
Cash and Cash Equivalents	'	'
Cash Cash Equivalents And Short Term Investments [Line Items]	'	'
Fair Value	27,995	32,749
Cash and Cash Equivalents | Cash	'	'
Cash Cash Equivalents And Short Term Investments [Line Items]	'	'
Fair Value	1,665	1,283
Cash and Cash Equivalents | Money Market Funds	'	'
Cash Cash Equivalents And Short Term Investments [Line Items]	'	'
Fair Value	26,330	31,466
Short-term Investments	'	'
Cash Cash Equivalents And Short Term Investments [Line Items]	'	'
Fair Value	1,945	8,333
Short-term Investments | Corporate Equity Securities	'	'
Cash Cash Equivalents And Short Term Investments [Line Items]	'	'
Fair Value	1,945	1,629
Short-term Investments | Corporate Debt and Commercial Paper	'	'
Cash Cash Equivalents And Short Term Investments [Line Items]	'	'
Fair Value	'	6,704
Restricted Cash	'	'
Cash Cash Equivalents And Short Term Investments [Line Items]	'	'
Fair Value	5,394	'
Restricted Cash | Money Market Funds	'	'
Cash Cash Equivalents And Short Term Investments [Line Items]	'	'
Fair Value	$5,394	'

Fair_Value_of_Assets_and_Liabi2

Fair Value of Assets and Liabilities - Additional Information (Detail) (USD $)	12 Months Ended	3 Months Ended	12 Months Ended
	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2011	Dec. 31, 2010
		Luna Innovations Incorporated	Luna Innovations Incorporated	Luna Innovations Incorporated
Fair Value, Measurement Inputs, Disclosure [Line Items]	'	'	'	'
Available-for-sale securities, other than temporary impairment recorded loss in other expense	'	$600,000	$300,000	$1,900,000
Securities in loss position for less than 12 months	0	'	'	'
Life of warrant issued	'3 years	'	'	'
Long term debt, fair value	$33,100,000	'	'	'

Fair_Value_Hierarchy_of_Compan

Fair Value Hierarchy of Company's Assets (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets	$33,669	$39,890
Money Market Funds	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets	31,724	31,466
Corporate Equity Securities	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets	1,945	1,629
Corporate debt and commercial paper	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets	'	6,704
Warrants to purchase corporate equity securities	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets	'	91
Level 1 Inputs	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets	33,669	33,095
Level 1 Inputs | Money Market Funds	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets	31,724	31,466
Level 1 Inputs | Corporate Equity Securities	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets	1,945	1,629
Level 2 Inputs	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets	'	6,704
Level 2 Inputs | Corporate debt and commercial paper	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets	'	6,704
Level 3 Inputs	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets	'	91
Level 3 Inputs | Warrants to purchase corporate equity securities	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets	'	$91

Reconciliation_of_Assets_Measu

Reconciliation of Assets Measured at Fair Value on a Recurring Basis Using Unobservable Inputs (Level 3) (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2012
Schedule of Available-for-sale Securities [Line Items]	'
Balance at beginning of period	$153
Total gains and losses:	'
Included in other expense, net	-41
Included in accumulated other comprehensive loss	1
Transfers out	-22
Balance at end of period	$91

Components_of_Inventories_Deta

Components of Inventories (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Inventory [Line Items]	'	'
Raw materials	$4,167	$3,333
Work in process	5,285	3,644
Finished goods	2,751	2,157
Inventories	$12,203	$9,134

Property_and_Equipment_Net_Det

Property and Equipment, Net (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Property, Plant and Equipment [Line Items]	'	'
Property and equipment, gross	$24,525	$24,076
Less: Accumulated depreciation and amortization	-20,884	-18,036
Property and equipment, net	3,641	6,040
Furniture and leasehold improvements	'	'
Property, Plant and Equipment [Line Items]	'	'
Property and equipment, gross	11,466	11,451
Laboratory equipment	'	'
Property, Plant and Equipment [Line Items]	'	'
Property and equipment, gross	10,209	9,985
Computer equipment and software	'	'
Property, Plant and Equipment [Line Items]	'	'
Property and equipment, gross	$2,850	$2,640

Components_of_Accrued_Liabilit

Components of Accrued Liabilities (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Schedule of Accrued Liabilities [Line Items]	'	'
Accrued salaries, commission, bonus and benefits	$1,867	$1,455
Accrued royalties	796	481
Accrued legal and other professional fees	183	144
Accrued other expenses	1,088	1,242
Total	$3,934	$3,322

Updated_Agreements_with_Intuit1

Updated Agreements with Intuitive Surgical - Additional Information (Detail) (USD $)	0 Months Ended	1 Months Ended	3 Months Ended	12 Months Ended
	Jul. 30, 2013	Oct. 31, 2012	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012
Licenses Agreements [Line Items]	'	'	'	'	'
Proceeds from licensing fees	'	$20,000,000	'	'	$20,000,000
Stock purchase agreement to sell shares	28,455,284	5,291,000	'	'	'
Common stock agreement purchase price	'	10,000,000	'	'	'
Agreement amendment period	'	'	'	'3 years	'
Payment for licensing of intellectual property	'	20,000,000	20,000,000	'	20,000,000
Stock purchase agreement recorded in common stock and additional paid-in capital	'	$10,000,000	'	'	'

Agreements_with_Philips_Additi

Agreements with Philips - Additional Information (Detail) (USD $)

1 Months Ended

3 Months Ended

12 Months Ended

Feb. 28, 2011

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

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

Technology commercialization cash payments to be received in future

$78,000,000

'

'

'

'

'

'

'

'

'

'

'

Potential future payment from sublicensing technology under agreement

'Two-thirds

'

'

'

'

'

'

'

'

'

'

'

Potential future payment based on royalty obligation under agreement

'One-third

'

'

'

'

'

'

'

'

'

'

'

FOSSL-related royalty obligations

'

'

'

'

'

'

'

'

'

'Between 2014 and 2020

'

'

Net loss

'

-11,888,000

-13,201,000

-13,446,000

-17,187,000

[1]

9,537,000

[2]

-8,431,000

-11,476,000

-11,811,000

-55,722,000

-22,145,000

-16,712,000

Collaborative Arrangement, Co-promotion

'

'

'

'

'

'

'

'

'

'

'

'

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

Arrangement consideration received

29,000,000

'

'

'

'

'

'

'

'

'

'

'

Net loss

23,000,000

'

'

'

'

'

'

'

'

'

'

'

Reduction of research and development costs

'

'

'

'

'

'

'

'

'

'

'

($6,000,000)

[1]

Net income and basic and diluted net income per share for the first quarter of 2013 include the impact of the loss on settlement of litigation of $4.5 million.

[2]

Net income and basic and diluted net income per share for the fourth quarter of 2012 include the impact of the gain on licensing of intellectual property of $20.0 million.

Commitments_and_Contingencies_1

Commitments and Contingencies - Additional Information (Detail) (USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2013	Dec. 22, 2009
		sqft	Plaintiff
Other Commitments [Line Items]	'	'	'
Operating lease extended period	'	'5 years	'
Operating lease area leased for office space	'	3,300	'
Operating lease expiration year	'	'2020-06	'
Operating lease expiration year	'	'2015	'
Warranties, Description	'	'The Company generally provides one year of post-contract customer service on the sale of its systems. Post-contract customer service revenue is recognized ratably over the term of the service period and associated expenses are charged to cost of revenues as incurred. The Company provides a limited warranty on the sale of catheters and records a warranty reserve at the time of sale to cover the estimated warranty costs	'
Post-contract customer service period	'	'1 year	'
Number of plaintiffs	'	'	3
Loss contingency settlement value funded by insurer and other sources	'	$4,000,000	'
Settlement paid in cash	'	250,000	'
Loss contingency settlement agreement consideration	'	8,500,000	'
Paid in common stock for settlement	'	'The Company would fund the remaining portion by issuing $4.25 million worth of the Company's common stock, the number of shares to be determined based on the average closing price of the common stock for the 10 trading days preceding final Court approval of the settlement of the class action, and paying $250,000 in cash.	'
Loss on settlement of litigation	-4,500,000	-4,500,000	'
Issuance of common shares in connection with the litigation settlement	'	2,298,539	'
Number of trading days	'	'10 days	'
Common stock issued related to legal settlement per share	'	$1.85	'
Mitsubishi	'	'	'
Other Commitments [Line Items]	'	'	'
Reduction royalty obligation	'	55,000	'
Royalty obligation expiration Year	'	'2018	'
Mitsubishi | Minimum	'	'	'
Other Commitments [Line Items]	'	'	'
Royalty obligations per year	'	100,000	'
Intuitive Surgical Inc	'	'	'
Other Commitments [Line Items]	'	'	'
Uncertain tax positions	'	3,900,000	'
Intuitive Surgical Inc | Minimum	'	'	'
Other Commitments [Line Items]	'	'	'
Royalty obligations per year	'	$200,000	'
Intuitive Surgical Inc | Maximum	'	'	'
Other Commitments [Line Items]	'	'	'
Royalty Payment Obligation	'	'2017-10	'

Rent_Expense_Detail

Rent Expense (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Leases [Line Items]	'	'	'
Rent expense	$2,310	$2,280	$2,231

Future_Minimum_Payments_under_

Future Minimum Payments under Operating Leases (Detail) (USD $)	Dec. 31, 2013
In Thousands, unless otherwise specified
Operating Leased Assets [Line Items]	'
2014	$2,149
2015	1,979
2016	2,140
2017	2,205
Thereafter	4,415
Total	$12,888

Changes_in_Warranty_Liability_

Changes in Warranty Liability during Period (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Movement in Standard and Extended Product Warranty, Increase (Decrease) [Roll Forward]	'	'
Balance at beginning of period	$9	$12
Warranties issued during the period	105	112
Warranty costs incurred during the period	-105	-115
Balance at end of period	$9	$9

Long_Term_Debt_Additional_Info

Long - Term Debt - Additional Information (Detail) (USD $)

12 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

Dec. 31, 2013

Jul. 30, 2013

Aug. 23, 2013

Aug. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Aug. 31, 2013

Aug. 31, 2013

Aug. 23, 2013

Dec. 31, 2013

Aug. 23, 2013

Aug. 23, 2013

Aug. 23, 2013

Aug. 23, 2013

Aug. 23, 2013

Aug. 23, 2013

Aug. 23, 2013

Aug. 23, 2013

Aug. 23, 2013

Restricted Cash and Cash Equivalents

Oxford

Oxford

Oxford

Oxford

Oxford

Oxford

White Oak Loan Agreement

White Oak Loan Agreement

White Oak Loan Agreement

White Oak Loan Agreement

White Oak Loan Agreement

White Oak Loan Agreement

White Oak Loan Agreement

White Oak Loan Agreement

White Oak Loan Agreement

White Oak Loan Agreement

White Oak Loan Agreement

Prepayment Penalty

Accrued Balloon Payment

Interest Payment in Cash

Payment in Kind (PIK)

Payment to Lender Agent

Payment to Placement Agent

Principal Prepaid Before Third Anniversary

Principal Prepaid After Third Anniversary

Cash, Cash Equivalents and Investments

Restricted Cash and Cash Equivalents

Accounts Receivable

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest rate on pay off obligation

'

'

'

'

'

'

9.45%

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest payment on the original principal

'

'

'

'

'

'

3.95%

'

'

'

'

'

'

'

'

'

'

'

'

'

Loan and security agreement

'

'

'

'

'

'

$30,000,000

'

'

$33,000,000

'

'

'

'

'

'

'

'

'

'

Common stock warrants issued

'

'

'

'

'

'

660,793

'

'

'

'

'

'

'

'

'

'

'

'

'

Exercise price of common stock warrants

'

0.125

'

'

'

'

2.27

'

'

'

'

'

'

'

'

'

'

'

'

'

Expiration date of warrants

'

'

'

'

'

'

'December 2018

'

'

'

'

'

'

'

'

'

'

'

'

'

Fair Value of Warrants

'

'

'

'

'

'

900,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Expected Volatility

'

'

'

'

'

'

58.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

Risk Free Interest rate

'

'

'

'

'

'

1.41%

'

'

'

'

'

'

'

'

'

'

'

'

'

Expected life

'

'

'

'

'

'

'7 years

'

'

'

'

'

'

'

'

'

'

'

'

'

Amortized interest expense

'

'

'

'

200,000

300,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Payment of final interest balloon

'

'

'

1,200,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Loss on extinguishment of debt

-1,935,000

'

'

-1,900,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Loss on extinguishment of debt before write-off of unamortized costs

'

'

'

'

'

'

'

-900,000

-500,000

'

'

'

'

'

'

'

'

'

'

'

Write-off of unamortized costs

'

'

'

500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Loan and security agreement, due date

'

'

'

'

'

'

'

'

'

30-Dec-17

'

'

'

'

'

'

'

'

'

'

Loan and security agreement, interest rate

'

'

'

'

'

'

'

'

'

'

'

11.00%

3.00%

'

'

'

'

'

'

'

Capitalized debt issue costs

'

'

'

'

'

'

'

'

'

1,500,000

'

'

'

700,000

300,000

'

'

'

'

'

Administration and monitoring fee

'

'

'

'

'

'

'

'

'

32,000

'

'

'

'

'

'

'

'

'

'

Prepayment fee of the principal

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3.50%

1.00%

'

'

'

Amortization of debt issuance costs

'

'

'

'

'

'

'

'

'

'

100,000

'

'

'

'

'

'

'

'

'

Minimum liquidity requirement amount

'

'

$5,000,000

'

'

'

'

'

'

$15,000,000

'

'

'

'

'

'

'

$13,000,000

$5,000,000

$2,000,000

Future_Annual_Payments_Due_on_

Future Annual Payments Due on Amounts Outstanding (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Debt Instrument [Line Items]	'	'
2014	$3,763	'
2015	3,879	'
2016	4,009	'
2017	41,781	'
Total remaining payments	53,432	'
Less: Amount representing interest	-20,074	'
Long-term debt, Net Total	33,358	'
Less: Current portion of long-term debt	'	-5,156
Long-term debt, net of current portion	$33,358	$24,261

Stockholders_Equity_Additional

Stockholders' Equity - Additional Information (Detail) (USD $)

0 Months Ended

1 Months Ended

12 Months Ended

0 Months Ended

1 Months Ended

12 Months Ended

Jul. 30, 2013

Mar. 31, 2013

Oct. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Jul. 30, 2013

Jul. 30, 2013

Jul. 30, 2013

Feb. 28, 2014

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Series A Warrants

Series B Warrant

Series C Warrant

Subsequent Event

2006 Employee Stock Purchase Plan

Restricted Stock Units (RSUs)

2002 Stock Option Plan

2006 Equity Incentive Plan

Series A Warrants

Share Based Compensation [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common stock for issuance under its stock option plan

'

'

'

'

'

'

'

'

'

'

'

'

4,579,009

2,000,000

Share-based compensation arrangement by share-based payment award expiration period

'

'

'

'10 years

'

'

'

'

'

'

'

'

'10 years

'

Exercises of employee options on the first anniversary

'

'

'

'

'

'

'

'

'

'

'

'

25.00%

'

Percentage of common shares outstanding

'

'

'

4.00%

'

'

'

'

'

'

'

'

'

'

Equity Incentive Plan automatically increases by total number of share outstanding

'

'

'

3,500,000

'

'

'

'

'

'

'

'

'

'

Shares of common stock were available for grant under 2006 Equity Incentive Plan

'

'

'

2,806,000

'

'

'

'

'

'

'

'

'

'

Weighted-average grant-date fair value of options granted

'

'

'

$1.25

$1.31

$1.32

'

'

'

'

'

'

'

'

Total fair value of options vested

'

'

'

$2,600,000

$1,500,000

$3,000,000

'

'

'

'

'

'

'

'

Total unamortized stock-based compensation related to unvested stock options

'

'

'

4,400,000

'

'

'

'

'

'

'

'

'

'

Weighted-average recognition period, unvested stock options

'

'

'

'2 years 3 months 29 days

'

'

'

'

'

'

'

'9 months 18 days

'

'

Total intrinsic value of stock options exercised

'

'

'

19,000

100,000

500,000

'

'

'

'

'

'

'

'

Total fair value of shares vested pursuant to restricted stock units

'

'

'

2,600,000

2,400,000

900,000

'

'

'

'

'

'

'

'

Total unamortized stock-based compensation related to unvested restricted stock units

'

'

'

'

'

'

'

'

'

'

'

500,000

'

'

Stock-based compensation expense charged to operations for options and restricted stock units granted to employees

'

'

'

4,889,000

2,882,000

6,676,000

'

'

'

'

'

'

'

'

Additional stock based compensation expenses

'

'

'

'

'

634,000

'

'

'

'

'

'

'

'

Employees to contribute, Percent

'

'

'

'

'

'

'

'

'

'

15.00%

'

'

'

Employees to contribute, Amount

'

'

'

'

'

'

'

'

'

'

25,000

'

'

'

Maximum range of company's board of directors offerings

'

'

'

'27 months

'

'

'

'

'

'

'

'

'

'

Percentage of fair market value of share for participated by employee

'

'

'

85.00%

'

'

'

'

'

'

'

'

'

'

Company initially reserved

'

'

'

625,000

'

'

'

'

'

'

'

'

'

'

Percentage of share outstanding for automotive increase in share reserve for issuance

'

'

'

2.00%

'

'

'

'

'

'

'

'

'

'

Number of share increase in share reserve for issuance

'

'

'

750,000

'

'

'

'

'

'

'

'

'

'

Reduction in Stock based compensation expense

'

'

'

'

740,000

'

'

'

'

'

'

'

'

'

Maximum common stock offering amount under equity sale agreement

'

25,000,000

'

'

'

'

'

'

'

'

'

'

'

'

Securities purchase agreement to sell shares

28,455,284

'

5,291,000

'

'

'

'

'

'

'

'

'

'

'

Common stock per warrant price

$1.23

'

'

'

'

'

'

'

'

'

'

'

'

'

Common Stock issuable upon exercise of warrants

34,146,339

'

'

'

'

'

11,382,113

11,382,113

11,382,113

22,800,000

'

'

'

'

Common stock per warrant price

0.125

'

'

'

'

'

1.23

1.5

2

'

'

'

'

'

Proceeds from issuance of common stock and warrants

39,300,000

'

'

39,268,000

10,000,000

10,000,000

'

'

'

'

'

'

'

'

Placement fees and offering costs related to issuance of common stock and warrants

2,100,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Restricted period for resales of common stock

'1 year

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of warrants exercised

'

'

'

'

'

'

'

'

'

11,400,000

'

'

'

'

Proceed from exercise of warrant

'

'

'

'

'

'

'

'

'

14,000,000

'

'

'

'

Value of warrants outstanding

'

'

'

'

'

'

'

'

'

$39,800,000

'

'

'

'

Summary_of_Option_Activity_Und

Summary of Option Activity Under Company's 2002 Stock Option Plan and 2006 Plan (Detail) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Options Outstanding, Balance, January 1, 2013	7,176	'
Options Outstanding, Granted	2,249	'
Options Outstanding, Exercised	-53	'
Options Outstanding, Cancelled	-1,593	'
Options Outstanding, Balance, December 31, 2013	7,779	7,176
Options Outstanding, Options vested and expected to vest at December 31, 2013	7,620	'
Options Outstanding, Options vested at December 31, 2013	4,167	'
Weighted- Average Exercise Price, Balance, at January 1, 2013	$3.97	'
Weighted- Average Exercise Price, Granted	$1.97	'
Weighted- Average Exercise Price, Exercised	$2.13	'
Weighted- Average Exercise Price, Cancelled	$6.86	'
Weighted- Average Exercise Price, Balance, December 31, 2013	$3.24	$3.97
Weighted- Average Exercise Price, Options vested and expected to vest at December 31, 2013	$3.20	'
Weighted- Average Exercise Price, Options vested at December 31, 2013	$4.12	'
Weighted- Average Remaining Contractual Term, Balance, at January 1, 2013	'4 years 9 months 4 days	'5 years 1 month 13 days
Weighted- Average Remaining Contractual Term, Options vested and expected to vest at December 31, 2013	'4 years 9 months 15 days	'
Weighted- Average Remaining Contractual Term, Options vested at December 31, 2013	'3 years 10 months 21 days	'
Aggregate Intrinsic Value, Balance at December 31, 2013	$169	$182
Aggregate Intrinsic Value, Options vested and expected to vest at December 31, 2013	156	'
Aggregate Intrinsic Value, Options vested at December 31, 2013	$56	'

Options_outstanding_vested_and

Options outstanding, vested and currently exercisable by exercise price under both the 2002 Plan and the 2006 Plan (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Options Outstanding, Number of Options	7,779
Options Outstanding, Weighted-Average Remaining Contractual Life	'4 years 9 months 4 days
Options Exercisable and Vested, Number of Options	4,167
Options Exercisable and Vested, Weighted-Average Exercise Price	$4.12
Options Exercisable and Vested, Weighted- Average Remaining Contractual Life	'3 years 10 months 21 days
Range One	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Options Outstanding, Exercise Price, Lower Limit	$0.40
Options Outstanding, Exercise Price, Upper Limit	$4.88
Options Outstanding, Number of Options	7,259
Options Outstanding, Weighted-Average Remaining Contractual Life	'5 years 7 days
Options Exercisable and Vested, Number of Options	3,647
Options Exercisable and Vested, Weighted-Average Exercise Price	$2.37
Options Exercisable and Vested, Weighted- Average Remaining Contractual Life	'4 years 3 months 15 days
Range Two	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Options Outstanding, Exercise Price, Lower Limit	$6.65
Options Outstanding, Exercise Price, Upper Limit	$12.69
Options Outstanding, Number of Options	155
Options Outstanding, Weighted-Average Remaining Contractual Life	'2 years 4 months 6 days
Options Exercisable and Vested, Number of Options	155
Options Exercisable and Vested, Weighted-Average Exercise Price	$8.54
Options Exercisable and Vested, Weighted- Average Remaining Contractual Life	'2 years 4 months 6 days
Range Three	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Options Outstanding, Exercise Price, Lower Limit	$15.25
Options Outstanding, Exercise Price, Upper Limit	$20.25
Options Outstanding, Number of Options	340
Options Outstanding, Weighted-Average Remaining Contractual Life	'6 months 18 days
Options Exercisable and Vested, Number of Options	340
Options Exercisable and Vested, Weighted-Average Exercise Price	$19.31
Options Exercisable and Vested, Weighted- Average Remaining Contractual Life	'6 months 18 days
Range Four	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Options Outstanding, Exercise Price, Lower Limit	$24.60
Options Outstanding, Exercise Price, Upper Limit	$31.20
Options Outstanding, Number of Options	25
Options Outstanding, Weighted-Average Remaining Contractual Life	'9 months 4 days
Options Exercisable and Vested, Number of Options	25
Options Exercisable and Vested, Weighted-Average Exercise Price	$27.37
Options Exercisable and Vested, Weighted- Average Remaining Contractual Life	'9 months 4 days

Summary_of_Restricted_Stock_Un

Summary of Restricted Stock Unit Activity (Detail) (Restricted Stock Units (RSUs), USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013
Restricted Stock Units (RSUs)	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Restricted Stock Units, Balance, January 1, 2013	1,365
Restricted Stock Units, Awarded	1,317
Restricted Stock Units, Vested	-745
Restricted Stock Units, Cancelled	-619
Restricted Stock Units, Balance, December 31, 2013	1,318
Weighted-Average Grant-Date Fair Value, Balance, January 1, 2013	$3.03
Weighted-Average Grant-Date Fair Value, Awarded	$2.01
Weighted-Average Grant-Date Fair Value, Vested	$2.61
Weighted-Average Grant-Date Fair Value, Cancelled	$2.42
Weighted-Average Grant-Date Fair Value, Balance, December 31, 2013	$1.99

Assumptions_Used_to_Estimate_G

Assumptions Used to Estimate Grant Date Fair Values of Stock Options (Detail)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Stock Options	'	'	'
Estimated grant date fair values	'	'	'
Expected volatility, minimum	77.00%	61.00%	60.00%
Expected volatility, maximum	89.00%	90.00%	61.00%
Risk-free interest rate, minimum	0.60%	0.50%	0.90%
Risk-free interest rate, maximum	1.50%	1.00%	2.30%
Dividend yield	0.00%	0.00%	0.00%
Stock Options | Minimum	'	'	'
Estimated grant date fair values	'	'	'
Expected term (in years)	'4 years 4 months 17 days	'4 years 3 months 15 days	'4 years 6 months
Stock Options | Maximum	'	'	'
Estimated grant date fair values	'	'	'
Expected term (in years)	'4 years 6 months 26 days	'4 years 9 months	'4 years 9 months
Non-Employee Stock Options	'	'	'
Estimated grant date fair values	'	'	'
Expected volatility, minimum	57.00%	62.00%	74.00%
Expected volatility, maximum	99.00%	110.00%	110.00%
Risk-free interest rate, minimum	'	'	0.10%
Risk-free interest rate, maximum	0.10%	0.10%	0.20%
Expected term (in years)	'6 months	'6 months	'6 months
Dividend yield	0.00%	0.00%	0.00%

Total_Stock_Based_Compensation

Total Stock- Based Compensation (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Total Stock-based Compensation	'	'	'
Stock-based compensation	$4,889	$2,882	$6,676
Cost of revenues	'	'	'
Total Stock-based Compensation	'	'	'
Stock-based compensation	402	319	805
Research and development	'	'	'
Total Stock-based Compensation	'	'	'
Stock-based compensation	1,320	444	1,703
Selling, general and administrative	'	'	'
Total Stock-based Compensation	'	'	'
Stock-based compensation	$3,167	$2,119	$4,168

Summary_of_Companys_Pre_Tax_Lo

Summary of Company's Pre Tax Loss (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Summary of Company's Pre Tax Loss	'	'	'
Domestic	($55,877)	($22,343)	($16,888)
Foreign	270	312	176
Pre-tax loss	($55,607)	($22,031)	($16,712)

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	1 Months Ended					12 Months Ended
	Aug. 31, 2013	Oct. 31, 2012	Nov. 30, 2011	Apr. 30, 2010	Apr. 30, 2009	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Line Items]	'	'	'	'	'	'	'	'
Income Tax provision	'	'	'	'	'	$115,000	$114,000	'
State Taxes	'	'	'	'	'	13,000	'	'
Foreign Taxes	'	'	'	'	'	102,000	'	'
Net operating loss carryforwards expiry	'	'	'	'	'	'From 2014 through 2033	'	'
Percentage of valuation allowance against net deferred tax assets	'	'	'	'	'	100.00%	'	'
Increase in valuation allowance	'	'	'	'	'	21,400,000	5,900,000	5,700,000
Ownership change occurrence from percentage of corporation owned increases by specified percentage	'	'	'	'	'	5.00%	'	'
Percentage increase over minimum percentage of corporation owned shares	'	'	'	'	'	50.00%	'	'
Number of years considered in ownership change occurrence	'	'	'	'	'	'3 years	'	'
Sale of common stock shares	28,455,284	5,291,000	4,785,000	16,100,000	11,700,000	'	'	'
Cumulative foreign earnings upon which U.S. income taxes have not been provided	'	'	'	'	'	1,300,000	'	'
Unrecognized benefit that affect Company's effective tax rate	'	'	'	'	'	3,300,000	'	'
Accrued interest or penalties related to uncertain tax positions	'	'	'	'	'	0	'	'
Stock Option	'	'	'	'	'	'	'	'
Income Tax Disclosure [Line Items]	'	'	'	'	'	'	'	'
Net operating loss carryforwards	'	'	'	'	'	1,500,000	'	'
Federal	'	'	'	'	'	'	'	'
Income Tax Disclosure [Line Items]	'	'	'	'	'	'	'	'
Tax credit carryforwards expiration year	'	'	'	'	'	'2023	'	'
Net operating loss carryforwards	'	'	'	'	'	242,000,000	'	'
Tax credit carryforwards	'	'	'	'	'	8,200,000	'	'
State	'	'	'	'	'	'	'	'
Income Tax Disclosure [Line Items]	'	'	'	'	'	'	'	'
Net operating loss carryforwards	'	'	'	'	'	205,300,000	'	'
State | California	'	'	'	'	'	'	'	'
Income Tax Disclosure [Line Items]	'	'	'	'	'	'	'	'
Tax credit carryforwards	'	'	'	'	'	$7,100,000	'	'

Companies_Effective_Tax_Rate_D

Companies Effective Tax Rate Differs From Federal Statutory Rate (Detail)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Summary of company's effective tax rate differs from the U.S. federal statutory rate	'	'	'
Federal tax benefit at statutory rate	-34.00%	-34.00%	-34.00%
Permanent difference due to non-deductible expenses	1.00%	1.00%	10.00%
State tax benefit, net of federal impact	'	'	-5.00%
Change in deferred tax asset valuation allowance	33.00%	32.00%	34.00%
General business credits	'	'	-5.00%
Effective tax rate	'	-1.00%	'

Significant_Portions_of_the_De

Significant Portions of the Deferred Tax Assets (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Deferred Tax Assets [Line Items]	'	'
Net operating loss carryforwards	$93,744	$75,929
Research and development credits	9,682	8,366
Capitalized research and development	19,107	17,151
Fixed assets	2,222	1,957
Stock-based compensation	2,478	2,200
Accruals, reserves and other	2,061	2,158
Intangibles	1,092	1,273
Gross deferred tax asset	130,386	109,034
Less: Valuation allowance	-130,386	-109,034
Net deferred tax asset	'	'

Reconciliation_of_the_Beginnin

Reconciliation of the Beginning and Ending Balance of Unrecognized Tax Benefits (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Reconciliation of Unrecognized Tax Benefits [Line Items]	'	'	'
Balance at beginning of period	$3,358	$1,697	$1,498
Additions based on tax positions related to the current year	301	122	199
Additions based on tax positions related to prior years	205	1,539	'
Reduction for tax positions of prior years	'	'	'
Balance at end of period	$3,864	$3,358	$1,697

Computation_of_Basic_and_Dilut

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

3 Months Ended

12 Months Ended

In Thousands, except Per Share data, unless otherwise specified

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

Computation of basic and diluted net income (loss) per share

'

'

'

'

'

'

'

'

'

'

'

Net loss

($11,888)

($13,201)

($13,446)

($17,187)

[1]

$9,537

[2]

($8,431)

($11,476)

($11,811)

($55,722)

($22,145)

($16,712)

Shares used to calculated basic and diluted net loss per share

'

'

'

'

'

'

'

'

79,052

62,472

55,362

Basic and diluted net loss per share

'

'

'

'

'

'

'

'

($0.70)

($0.35)

($0.30)

[1]

Net income and basic and diluted net income per share for the first quarter of 2013 include the impact of the loss on settlement of litigation of $4.5 million.

[2]

Net income and basic and diluted net income per share for the fourth quarter of 2012 include the impact of the gain on licensing of intellectual property of $20.0 million.

Potential_Shares_of_Common_Sto

Potential Shares of Common Stock Not Included In Calculation of Diluted Net Loss per Share (Detail)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Stock Options	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'
Antidilutive securities excluded from computation of earnings per share	7,779	7,176	6,827
Unvested restricted stock units	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'
Antidilutive securities excluded from computation of earnings per share	1,318	1,365	1,631
Estimated shares issuable under the employee stock purchase plan	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'
Antidilutive securities excluded from computation of earnings per share	41	31	35
Warrants	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'
Antidilutive securities excluded from computation of earnings per share	34,807	661	661

Segment_Information_Additional

Segment Information - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2013
	Segment
Segment Reporting Information [Line Items]	'
Number of operating segments	1
Development and Marketing of Medical Devices	'
Segment Reporting Information [Line Items]	'
Number of operating segments	1

Segment_Information_Detail

Segment Information (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Revenues from External Customers and Long-Lived Assets [Line Items]	'		'		'
Revenues	$16,982		$17,636		$22,129
Long-lived assets	3,641		6,618		9,037
Development and Marketing of Medical Devices | United States	'		'		'
Revenues from External Customers and Long-Lived Assets [Line Items]	'		'		'
Revenues	8,580		8,197		10,477
Long-lived assets	3,569		6,351		8,775
Development and Marketing of Medical Devices | Belgium	'		'		'
Revenues from External Customers and Long-Lived Assets [Line Items]	'		'		'
Revenues	1,656		1,687		2,089
Development and Marketing of Medical Devices | Saudi Arabia	'		'		'
Revenues from External Customers and Long-Lived Assets [Line Items]	'		'		'
Revenues	1,965		119		1,816
Development and Marketing of Medical Devices | Other Countries	'		'		'
Revenues from External Customers and Long-Lived Assets [Line Items]	'		'		'
Revenues	4,781	[1]	7,633	[1]	7,747	[1]
Long-lived assets	$72	[1]	$267	[1]	$262	[1]
[1]	No single location within other accounts for greater than 10% of revenues.

Quarterly_Data_unaudited_Detai

Quarterly Data (unaudited) (Detail) (USD $)	3 Months Ended										12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	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
Summary of certain unaudited quarterly information for the eight quarters	'	'	'	'		'		'	'	'	'	'	'
Revenues	$5,620	$5,068	$3,343	$2,951	[1]	$4,344	[2]	$5,103	$3,535	$4,654	$16,982	$17,636	$22,129
Gross profit	1,116	1,340	576	469	[1]	868	[2]	1,257	753	732	3,501	3,610	4,918
Net income (loss)	($11,888)	($13,201)	($13,446)	($17,187)	[1]	$9,537	[2]	($8,431)	($11,476)	($11,811)	($55,722)	($22,145)	($16,712)
Basic net income (loss) per share	($0.12)	($0.16)	($0.20)	($0.26)	[1]	$0.15	[2]	($0.14)	($0.19)	($0.20)	'	'	'
Diluted net income (loss) per share	($0.12)	($0.16)	($0.20)	($0.26)	[1]	$0.15	[2]	($0.14)	($0.19)	($0.20)	'	'	'
[1]	Net income and basic and diluted net income per share for the first quarter of 2013 include the impact of the loss on settlement of litigation of $4.5 million.
[2]	Net income and basic and diluted net income per share for the fourth quarter of 2012 include the impact of the gain on licensing of intellectual property of $20.0 million.

Quarterly_Data_unaudited_Paren

Quarterly Data (unaudited) (Parenthetical) (Detail) (USD $)	1 Months Ended	3 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Oct. 31, 2012	Mar. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Information [Line Items]	'	'	'	'	'
Loss on settlement of litigation	'	($4,500)	'	($4,500)	'
Gain on licensing of intellectual property	$20,000	'	$20,000	'	$20,000