Hansen Medical (HNSN) 10-Q 11 May 15 2015 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Mar. 31, 2015	Apr. 30, 2015
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	FALSE
Document Period End Date	31-Mar-15
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1
Trading Symbol	HNSN
Entity Registrant Name	HANSEN MEDICAL INC
Entity Central Index Key	1276591
Current Fiscal Year End Date	-19
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		133,149,092

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$51,400	$24,528
Short-term investments	1,876	1,973
Accounts receivable	3,745	5,121
Inventories	10,192	11,492
Prepaids and other current assets	1,513	1,678
Total current assets	68,726	44,792
Property and equipment, net	2,823	2,328
Restricted cash	5,362	5,376
Other assets	732	1,179
Total assets	77,643	53,675
Current liabilities:
Accounts payable	2,828	2,534
Accrued liabilities	4,508	4,942
Current portion of deferred revenue	3,011	3,422
Warrant liability	16,452
Total current liabilities	26,799	10,898
Deferred rent, net of current portion	354	366
Deferred revenue, net of current portion	89	105
Long-term debt	34,227	34,385
Other long-term liabilities	152	152
Total liabilities	61,621	45,906
Commitments and contingencies (Note 7)
Series A convertible preferred stock, par value $0.0001, authorized 10,000 shares at March 31, 2015 and December 31, 2014, respectively; 54 and zero shares issued and outstanding at March 31, 2015 and December 31, 2014, respectively	19,742
Stockholders' equity (deficit):
Common stock, par value $0.0001: Authorized: 200,000 shares; issued and outstanding: 133,304 and 133,262 shares at March 31, 2015 and December 31, 2014, respectively	13	13
Additional paid-in capital	414,971	414,361
Accumulated other comprehensive income	139	305
Accumulated deficit	-418,843	-406,910
Total stockholders' equity (deficit)	-3,720	7,769
Total liabilities, convertible preferred stock and stockholders' equity (deficit)	$77,643	$53,675

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Mar. 31, 2015	Dec. 31, 2014
Preferred stock, par value	$0.00	$0.00
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	54,000	0
Preferred stock, shares outstanding	54,000	0
Common stock, par value	$0.00	$0.00
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	133,304,000	133,262,000
Common stock, shares outstanding	133,304,000	133,262,000

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Operations (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Revenues:
Product	$4,474	$2,352
Service	1,320	1,347
Total revenues	5,794	3,699
Cost of revenues:
Product	3,896	2,744
Service	742	557
Total cost of revenues	4,638	3,301
Gross profit	1,156	398
Operating expenses:
Research and development	3,435	4,415
Selling, general and administrative	6,702	9,161
Total operating expenses	10,137	13,576
Loss from operations	-8,981	-13,178
Warrant expense	-1,676
Interest and other expense, net	-1,267	-1,249
Loss before income taxes	-11,924	-14,427
Income tax expense	-9	-18
Net loss	($11,933)	($14,445)
Basic and diluted net loss per share	($0.09)	($0.14)
Shares used to compute basic and diluted net loss per share:	133,283	103,334

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Comprehensive Loss (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Net loss	($11,933)	($14,445)
Other comprehensive income (loss), net:
Change in unrealized gains and losses on investments	-102	83
Foreign currency translation adjustment	-64	2
Change in other comprehensive income (loss)	-166	85
Comprehensive loss	($12,099)	($14,360)

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Cash Flows (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Cash flows from operating activities:
Net loss	($11,933)	($14,445)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	244	665
Stock-based compensation	610	757
Payment-in-kind interest on loan	258	257
Amortization of deferred finance costs and discount on debt	97	97
Warrant expense	1,676
Recovery of doubtful accounts		-100
Changes in operating assets and liabilities:
Accounts receivable	1,375	819
Inventories	608	-604
Prepaids and other current assets	161	287
Other assets	-65	1,274
Accounts payable	-81	-164
Accrued liabilities	-464	340
Deferred revenue	-427	65
Other long-term liabilities	17
Net cash used in operating activities	-7,924	-10,752
Cash flows from investing activities:
Purchase of property and equipment	-47	-126
Change in restricted cash	14
Net cash used in investing activities	-33	-126
Cash flows from financing activities:
Proceeds from issuance of Series A convertible preferred stock	35,000
Proceeds from exercise of Series A warrants		14,000
Costs related to issuance of Series A convertible preferred stock	-107
Proceeds from exercise of common stock options		479
Withholding taxes paid on vested restricted stock units		-620
Net cash provided by financing activities	34,893	13,859
Effect of exchange rate changes on cash and cash equivalents	-64
Net increase in cash and cash equivalents	26,872	2,981
Cash and cash equivalents at beginning of period	24,528	27,995
Cash and cash equivalents at end of period	51,400	30,976
Supplemental disclosure of:
Cash paid for interest	945	917
Non-cash financing activity:
Equipment transfer from inventories to property and equipment	692
Convertible preferred stock issuance costs not yet paid	$375

The_Company

The Company	3 Months Ended
	Mar. 31, 2015
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 in September 2002 and is headquartered in Mountain View, California. The Company has wholly-owned subsidiaries located in the United Kingdom and Germany. Both subsidiaries are engaged in marketing the Company’s products in the Europe, Middle East and Africa (“EMEA”) region.
	Need to Raise Additional Capital
	These condensed consolidated financial statements are prepared on a going concern basis that contemplates the realization of assets and discharge of liabilities in the normal course of business. Since inception, the Company has incurred cumulative net losses of approximately $418.8 million. The Company expects such losses to continue through at least the year ending December 31, 2015 as it continues to commercialize its technologies and develop new applications and products.
	The Company continues to face significant uncertainties and challenges. The Company faces uncertainty related to the commercialization of its Magellan™ Robotic System and its projected revenue is heavily dependent on a successful commercialization of this system and the Sensei system. In addition, the Company is also subject to minimum liquidity requirements under its existing borrowing arrangements with White Oak Global Advisors, LLC (“White Oak”) 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 and the remaining $2.0 million in accounts receivable. In addition, $5.0 million investment in Certificate of Deposit along with investments in Luna Innovations, Inc., is required to be restricted subject to lenders’ control.
	On March 11, 2015, the Company raised $35.0 million in gross proceeds from the sale of convertible preferred stock and a related issuance of warrants to purchase common stock (see Note 9). As of March 31, 2015, the Company’s cash, cash equivalents, short-term investments and restricted cash balances were $58.6 million. The Company anticipates that its existing available capital resources as of March 31, 2015 and the estimated amounts received through the sale of its products and services will be sufficient to meet its anticipated cash requirements for the next twelve months. This assumes that the company will continue to at least maintain a level of consistent sales and adhere to cost control efforts implemented in 2014. The Company will need to obtain sufficient additional funding to satisfy its longer term liquidity requirements 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, refinancing or restructuring existing debt arrangements or entering into a credit facility in order to meet its continuing cash needs. The Company cannot guarantee that future equity or debt financing or credit facilities will be available in amounts or on terms acceptable to it, if at all, nor can the Company guarantee that it will be able to license core or non-core intellectual property assets or enter into future research and development funding arrangements. If such financing, licensing, funding or credit arrangements do not meet the Company’s current longer term needs or if future sales do not meet the Company’s current forecast, the Company may be required to extend its existing cash and liquidity by adopting additional cost-cutting measures, including reductions in its work force, reducing the scope of, delaying or eliminating some or all of its planned research, development and commercialization activities and/or reducing marketing, customer support or other resources devoted to the Company’s products. Any of these factors could harm the Company’s financial condition. 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 cost reductions if and as circumstances warrant.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2015
Summary of Significant Accounting Policies	2	Summary of Significant Accounting Policies
	Basis of Presentation
	The accompanying unaudited condensed consolidated financial statements (the “condensed consolidated financial statements”) have been prepared in accordance with generally accepted accounting principles in the United States of America (“GAAP”) for interim financial information and therefore do not contain all of the information and footnotes required by GAAP and the rules and regulations of the Securities and Exchange Commission (the “SEC”) for annual financial statements. The Company’s fiscal year ends on December 31. The condensed consolidated balance sheet as of December 31, 2014 was derived from audited financial statements. In the opinion of the Company’s management, these unaudited statements include all adjustments, which are of a normal recurring nature, necessary for a fair presentation. Interim results are not necessarily indicative of results for a full year or any other interim period. The information included in this Quarterly Report on Form 10-Q should be read in conjunction with the Company’s Annual Report on Form 10-K for the year ended December 31, 2014 as filed with the SEC.
	The accompanying condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation.
	Reclassification of Prior Period Balances
	Certain reclassifications have been made to prior period amounts to conform to the current period presentation.
	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, the valuation of warrants, and deferred tax assets, among others. Actual results may 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, which includes post-contract customer support (“PCS”). The Company sells its products directly to customers as well as through distributors. Under the Company’s revenue recognition policy, revenues are recognized when persuasive evidence of an arrangement exists, title and risk of loss has passed, delivery to the customer has occurred or the services have been fully rendered, the sales price is fixed or determinable and collectability is reasonably assured.
		•		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 or 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 its PCS contracts which includes planned and corrective maintenance services, software updates, bug fixes, and warranty. 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 have standalone value and 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. For multiple-element arrangements revenue is allocated to each element based on their relative selling prices. Relative selling prices are based first on vendor specified objective evidence (“VSOE”), then on third-party evidence of selling price (“TPE”) when VSOE does not exist, and then on management’s best estimate of the selling price (“ESP”) when VSOE and TPE do not exist. Because the Company has neither VSOE nor TPE for its system, the allocation of revenue is based on ESP for the systems sold. The objective of ESP is to determine the price at which the Company would transact a sale, had the product been sold on a stand-alone basis. 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, or extended payment terms or 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 of three to six months 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 reasonably assured 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 reasonably assured, the revenue is deferred and recognized at the time collection becomes reasonably assured, 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 22%, 15% and 13%, respectively, of the Company’s accounts receivable at March 31, 2015. The Company had four customers who constituted 26%, 14%, 12%, and 12%, respectively of the Company’s net accounts receivable at December 31, 2014. As of March 31, 2015, the Company has not experienced any significant losses on its accounts receivable.
	Three customers accounted for 22%, 13% and 10%, respectively of total revenues during the three months ended March 31, 2015. Two customers accounted for 30% and 13%, respectively of total revenues during the three months ended March 31, 2014.
	Most of the products developed by the Company require clearance from the U.S. Food and Drug Administration (“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 Robotic Catheter System (“Sensei system”) and Artisan catheters for manipulation, positioning and control of certain mapping catheters during electrophysiology (“EP”) 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, Magellan 6Fr Robotic Catheter in February 2014, and Magellan 10Fr Robotic Catheter in April 2015. 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.
	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 the Company to develop its 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.
	Recent Accounting Pronouncements
	In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09,Revenue from Contracts with Customers (Topic 606), which supersedes the revenue recognition requirements in ASC 605, Revenue Recognition. ASU 2014-09 is based on the principle that revenue is recognized to depict the transfer of goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. ASU 2014-09 also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments and assets recognized from costs incurred to obtain or fulfill a contract. This new guidance is effective for annual reporting periods beginning after December 15, 2016, including interim periods within those fiscal years. Early adoption is not permitted. In April 2015, the FASB proposed a date deferral of the effective date of the updated standard by one year, but allows entities to adopt one year earlier. The proposed effective date deferral is not currently approved. The Company is currently assessing the impact of the adoption of ASU2014-09 on its consolidated financial statements.
	In April 2015, the FASB issued ASU 2015-03, “Interest—Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Cost”, which changes the presentation of debt issuance costs in financial statements. Under the ASU, an entity presents costs in the balance sheet as a direct deduction from the related debt liability rather than as an asset. Amortization of the costs is reported as interest expense. Under current guidance, an entity reports debt issuance costs in the balance sheet as deferred charges (i.e. as an asset). For public companies, the ASU is effective for fiscal years beginning after December 15, 2015, and interim periods beginning after December 15, 2016, with early adoption permitted. Entities would apply the new guidance retrospectively to all prior periods. The Company will adopt this standard in 2016. The Company is currently assessing the impact of the adoption of ASU2015-03 on its consolidated financial statements.
	In January 2015, the FASB issued ASU 2015-01, “Simplifying Income Statement Presentation by Eliminating the Concept of Extraordinary Items.” This ASU that eliminates from GAAP the concept of extraordinary items, and is effective for annual periods beginning after December 15, 2015, with early adoption permitted. The change primarily involves presentation and disclosure and, therefore, is not expected to have a material impact on the Company’s financial condition, results of operations or its cash flows.
	In August 2014, the FASB issued ASU No. 2014-15, Presentation of Financial Statements—Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern. The ASU provides guidance on determining when and how to disclose going-concern uncertainties in the financial statements. The new standard requires management to perform interim and annual assessments of an entity’s ability to continue as a going concern within one year of the date the financial statements are issued. An entity must provide certain disclosures if “conditions or events raise substantial doubt about the entity’s ability to continue as a going concern.” The ASU applies to all entities and is effective for annual periods ending after December 15, 2016, and interim periods thereafter, with early adoption permitted. The Company has been assessing the going concern issue since 2010 on an interim and annual basis and will continue to assess whether the financial conditions based on this new guidance have an impact on the Company’s consolidated financial statements or footnotes.

Fair_Value_of_Assets_and_Liabi

Fair Value of Assets and Liabilities	3 Months Ended
	Mar. 31, 2015
Fair Value of Assets and Liabilities	3	Fair Value of Assets and Liabilities
	The Company’s financial instruments consist principally of cash and cash equivalents, short-term investments, accounts receivable, accounts payable and short-term and long-term debt. Cash and cash equivalents, short-term investments and accounts receivable, net of allowance, are reported at their respective fair values on the Consolidated Balance Sheets. Short-term and long-term debt are reported at their amortized cost on the Consolidated Balance Sheets. The remaining financial instruments are reported on the Consolidated Balance Sheets at amounts that approximate current fair values.
	The amortized cost and fair value of assets, along with gross unrealized gains and losses, were as follows (in thousands):
	Cash, Cash Equivalents, Short-term Investments and Restricted Cash
			Amortized			Gross		Gross		Fair		Balance Sheet Classification
			Cost			Unrealized		Unrealized		Value
						Gains		Losses				Cash and		Short-term		Restricted
												cash		Investments		Cash
												Equivalents
	March 31, 2015:
	Cash		$	5,458		$	—	$	—	$	5,458	$	5,458	$	—	$	—
	Money market funds			51,304			—		—		51,304		45,942		—		5,362
	Corporate equity securities			1,572			304		—		1,876		—		1,876		—
			$	58,334		$	304	$	—	$	58,638	$	51,400	$	1,876	$	5,362
	December 31, 2014:
	Cash		$	3,586		$	—	$	—	$	3,586	$	3,586	$	—	$	—
	Money market funds			26,318			—		—		26,318		20,942		—		5,376
	Corporate equity securities			1,572			401		—		1,973		—		1,973		—
			$	31,476		$	401	$	—	$	31,877	$	24,528	$	1,973	$	5,376
	Fair Value Measurements
	The fair value hierarchy of the Company’s assets and liabilities that are measured at fair value, by level, 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)
	March 31, 2015:
	Assets:
	Money market funds		$	51,304		$	—	$	—	$	51,304
	Corporate equity securities			1,876			—		—		1,876
			$	53,180		$	—	$	—	$	53,180
	Liabilities:
	Warrant liability							$	16,452	$	16,452
			$	—		$	—	$	16,452	$	16,452
	December 31, 2014:
	Assets:
	Money market funds		$	26,318		$	—	$	—	$	26,318
	Corporate equity securities			1,973			—		—		1,973
			$	28,291		$	—	$	—	$	28,291
	Liabilities:
	Warrant liability			—			—		—		—
			$	—		$	—	$	—	$	—
	Investment instruments valued using Level 1 inputs include the Company’s 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.
	The Company periodically assesses whether significant facts and circumstances have arisen to indicate that an impairment, which is other than temporary, of the fair value of any underlying investment has occurred.
	There were no transfers between Level 1 and Level 2, or into or out of Level 3, during the three months ended March 31, 2015.
	The changes in Level 3 liabilities measured at fair value on a recurring basis was as follow (in thousands):
			Level 3 input for quarter
			ended March 31, 2015
			(In thousands)
	Balance at December 31, 2014		$	—
	Additions at March 11, 2015			(14,776	)
	Total fair value measurement
	Warrant expense			(1,676	)
	Balance at March 31, 2015		$	(16,452	)
	Warrant liability
	In connection with the issuance of convertible Series A preferred stock on March 11, 2015, the Company also issued warrants to the participating investors to purchase an aggregate of 53,846,000 shares of Common Stock with an exercise period of two years from the date of issuance. The exercise price for the warrants will be the lesser of $0.975 per share or a 50% premium on the per share trailing volume weighted average share price of the Common Stock on NASDAQ for the ten trading days ending on dates specified in the form of warrants filed with the SEC. All of the warrants are currently issued and outstanding as of March 31, 2015. However, the exercise of the warrants is predicated on receipt of stockholder approval on May 12, 2015. As a result of this contingency which is deemed outside the Company’s control, such warrants do not meet the criteria for classification as equity under ASC 815. As such, the Company classified the warrants as current liabilities at fair value upon issuance. The warrants are subject to measurement at each balance sheet date, with any change in fair value recognized as warrant expense, a component of other income (expense) reflected within the statement of operations.
	The fair value of the Company’s warrant liability was estimated to be $16.5 million as of March 31, 2015. The Company used a third party valuation that utilized the Monte Carlo simulation model to estimate the fair value of the preferred shares and warrants. The valuation used a simulation of the Company’s periodic stock price expected volatility of the price, adjusted for conversion price, and the remaining contractual term of the warrants to estimate the value of instruments. This is considered a Level 3 input under the fair value hierarchy.
	Long-term Debt
	The fair value of the Company’s long-term debt was estimated to be $34.6 million as of March 31, 2015 and $34.2 million as of December 31, 2014 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	3 Months Ended
	Mar. 31, 2015
Balance Sheet Components	4	Balance Sheet Components
	Inventories (in thousands)
			March 31,			December 31,
			2015			2014
	Raw materials		$	4,266		$	4,996
	Work in process			4,024			4,571
	Finished goods			1,902			1,925
	Total Inventories		$	10,192		$	11,492
	Property and equipment, net (in thousands)
			March 31,			December 31,
			2015			2014
	Furniture and leasehold improvements		$	11,446		$	11,455
	Laboratory equipment			11,987			11,374
	Computer equipment and software			2,971			2,911
				26,404			25,740
	Less: Accumulated depreciation and amortization			(23,581	)		(23,412	)
	Property and equipment, net		$	2,823		$	2,328
	Accrued liabilities (in thousands)
			March 31,			December 31,
			2015			2014
	Accrued salaries, commission, bonus and benefits		$	1,884		$	2,835
	Accrued royalties			925			594
	Accrued legal and other professional fees			459			169
	Clinical related accruals			272			394
	Tax accruals			289			274
	Other accrued expenses			679			676
	Accrued liabilities		$	4,508		$	4,942

Agreements_with_Intuitive_Surg

Agreements with Intuitive Surgical	3 Months Ended
	Mar. 31, 2015
Agreements with Intuitive Surgical	5	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 5,291,005 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. However, 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 in the statement of operations in fiscal year 2012. The $10.0 million associated with the stock purchase agreement was recorded to common stock and additional paid-in capital on the balance sheet in 2012.
	The Company has minimum royalty obligations of $0.2 million per year under the terms of its cross license agreement with Intuitive Surgical. For the three months ended March 31, 2015 and 2014, the Company incurred cost in the amount of $0.1 million and an immaterial amount, respectively, related to the royalty obligations to Intuitive Surgical.

Agreements_with_Philips

Agreements with Philips	3 Months Ended
	Mar. 31, 2015
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 Koninklijke Philips Electronics N.V. (“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 FOSSL 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 FOSSL agreements also contain 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 has royalty obligations under the amended joint development agreement with Philips which provides for the payment of royalties to Philips through October 2017. Under the terms of the agreement, the Company has no minimum obligation with Philips, and the royalty obligation is based on per unit sales of the Magellan systems and vascular catheters. For the three months ended March 31, 2015 and 2014, the Company incurred cost in the amount of $0.6 million and $0.1 million, respectively related to the royalty obligations to Philips.

Commitments_and_Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2015
Commitments and Contingencies	7	Commitments and Contingencies
	Operating Lease Commitments
	The Company leases its office and laboratory facilities in Mountain View, California under an operating lease which expires in January 2020, with an option to extend the lease for another five years. The Company also leases approximately 3,300 square feet of office space in London, England, under an operating lease that ends in June 2015. The Company’s London office is in the process of relocating into a smaller office space, and has entered into a new serviced offices rental agreement that begins in May 2015 and ends in April 2016.
	As of March 31, 2015, future minimum payments under the leases are as follows (in thousands):
	Years ending December 31,		Future Minimum
			Lease Payments
	2015 (remainder of year)		$	1,608
	2016			2,151
	2017			2,216
	2018			2,282
	2019			1,759
	Total		$	10,016
	Rent expense on a straight-line basis was $0.6 million and 0.7 million for the three months ended March 31, 2015 and 2014, respectively.
	Other Royalty Obligations
	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 incurred cost in the amount of $35,000 and $19,000, respectively, related to the royalty obligations to Mitsubishi for the three months ended March 31, 2015 and 2014.
	Indemnification
	The Company has agreements with each member of its Board of Directors, its Chief Executive Officer, its former President and its Interim 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
	From time to time, the Company is involved in litigation that it believes is of the type common to companies engaged in its line of business, including commercial disputes and employment issues. As of the date of this Quarterly Report on Form 10-Q, the Company was not involved in any pending legal proceedings that it believes could have a material adverse effect on its financial condition, results of operations or cash flows. From time to time, the Company may pursue litigation to assert its legal right and such litigation may be costly and divert the efforts and attention of its management and technical personnel which could adversely affect its business.

Longterm_Debt

Long-term Debt	3 Months Ended
	Mar. 31, 2015
Long-term Debt	8	Long-term Debt
	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 and security 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 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 loan and security 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 loan and security agreement. The Company recognized expense of $0.1 million for the amortization of debt issuance costs related to the White Oak loan for each of the three months ended March 31, 2015 and 2014.
	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 loan and security agreement and have granted first priority security interests in their assets, excluding any of their intellectual property, to secure their guarantee obligations. Under the loan and security 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 and security 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 $2.0 million in 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 (h) enter into transactions with any of its affiliates outside of the ordinary course of business, or permit its subsidiaries to do the same. The Company is also required to make mandatory prepayments upon certain events of loss and certain dispositions of its assets described in the loan and security agreement. 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 March 31, 2015, the Company was in compliance with all financial covenants.
	Future annual payments due on the debt (including interest) outstanding as of March 31, 2015 are as follows (in thousands):
	Years ending December 31,
	2015 (remainder of year)		$	2,933
	2016			4,009
	2017			41,782
	Total remaining payments			48,724
	Less: Amount representing interest			(14,497	)
				34,227
	Less: Current portion of long-term debt			—
	Long-term debt, net of current portion		$	34,227

Convertible_Preferred_Stock_Co

Convertible Preferred Stock, Common Stock and Warrants	3 Months Ended
	Mar. 31, 2015
Convertible Preferred Stock, Common Stock and Warrants	9	Convertible Preferred Stock, Common Stock and Warrants
	2015 Private Placement of Redeemable Convertible Preferred Stock and Warrants
	On March 11, 2015, the Company entered into a securities purchase agreement (“Purchase Agreement”) to sell an aggregate of 53,846 shares of convertible Series A preferred stock at a per share price of $650. Each share of preferred stock will be convertible into the number of shares of common stock equal to the number obtained by dividing (i) the sum of $650 and the amount of any accrued but unpaid dividends by (ii) the lesser of $0.65 and the per share trailing volume-weighted average share price of the Company’s common stock on NASDAQ for the ten trading days ending on the day prior to conversion, subject to customary anti-dilution adjustments. The conversion of the preferred stock occurs automatically upon receipt of stockholder approval to, among other things, increase the number of authorized shares of common stock of the Company (the “Requisite Stockholder Approval”), and the proposals relating to such approval will be presented to stockholders for vote at the 2015 Annual Meeting of the Company to be held on May 12, 2015. The Purchase Agreement provides that the holders of the Company’s preferred stock shall be entitled to cumulative quarterly dividends paid in additional shares of preferred stock at an initial quarterly rate of 2% (“regular dividend”). This quarterly dividend rate shall increase by 2% quarterly for as long as the preferred stock is outstanding. Additionally, the preferred stockholders shall also be entitled to dividends payable on outstanding shares of common stock (“participating dividends”), if and when declared by the Board of Directors. At any time on or after the first anniversary of the issuance date, the preferred stockholders may elect to have the Company redeem all or any portion of the preferred stock equal to the stated value of $650 per share plus all accrued and unpaid regular dividends. In addition, the preferred stock is redeemable upon a deemed liquidation event, which includes certain business combinations, the sale of all or substantially all of the Company’s assets or the sale of more than 50% of the Company’s capital stock. The regular dividend will be recorded as in increase to the carrying value of preferred stock when declared because redemption is not probable. However, for loss per share purpose only, undeclared cumulative dividends are reflected as a dividend to preferred stockholders and the loss attributable to common stockholders is increased by the value of the accretion for the period. Since the convertible preferred stock has conditions for redemption that are outside the Company’s control, such preferred stock are presently reported in the mezzanine section of the balance sheet in accordance with accounting guidance (ASR 268) Presentation in Financial Statements of Redeemable Preferred Stocks. The Company also issued warrants to the participating investors to purchase an aggregate of 53,846,000 shares of common stock with an exercise period of two years from the date of issuance. The exercise price for the warrants will be the lesser of $0.975 per share or a 50% premium on the per share trailing volume-weighted average share price of the common stock on NASDAQ for the ten trading days ending on dates specified in the form of warrants filed with the SEC. All of the warrants are currently issued and outstanding as of March 31, 2015. However, certain of the warrants cannot be exercised until the Requisite Stockholder Approval is obtained. As a result of this contingency which is deemed outside the Company’s control, such warrants do not meet the criteria for classification as equity under ASC 815. As such, the Company classified the warrants as current liabilities at fair value upon issuance. The warrants are subject to measurement at each balance sheet date, with any change in fair value recognized as warrant expense, a component of other income (expense) reflected within the statement of operations. The Company used a third party valuation that utilized the Monte Carlo simulation model to estimate the fair value of the preferred shares and warrants. The valuation used a simulation of the Company’s periodic stock price expected volatility of the price, adjusted for conversion price, and the remaining contractual term of the warrants to estimate the value of instruments. The fair value of the warrants was $14.8 million upon issuance and $16.5 million at March 31, 2015, and the change in fair value of $1.7 million was recorded in warrant expense on the condensed consolidated statements of operation for the three months ended March 31, 2015.
	The Company had incurred and capitalized approximately $0.5 million of costs associated with this offering, which were recorded as an offset to convertible preferred stock when the transaction was consummated.
	2014 Warrant Exchange
	On July 30, 2014, the Company entered into a definitive agreement (the “Exchange Agreement”) with certain warrantholders to cancel and exchange (the “Exchange”) an aggregate of 10,221,173 of the Company’s outstanding Series B Warrants and an aggregate of 10,221,173 of the Company’s outstanding Series C Warrants. In exchange, the Company issued warrants (the “Exchange Warrants”) to purchase an aggregate of 26,728,369 shares of common stock. The Exchange was completed in August 2014.
	The Exchange Warrants are comprised of the following two tranches: (a) Series B/C Exchange Warrants (“Series B/C Exchange Warrants”) exercisable for an aggregate of 20,442,346 shares of common stock, with an exercise price equal to $1.13 per share, the NASDAQ consolidated closing bid price for the common stock on July 29, 2014, the last completed trading day before the Exchange Agreement was executed (the “Closing Bid Price”); and (b) Series D Warrants (“Series D Warrants”) exercisable for an aggregate of 6,286,023 shares of common stock, with an exercise price equal to the Closing Bid Price. The Series B/C Exchange Warrants were subject to mandatory exercise within 14 days of issuance and were exercised in August 2014, resulting in gross proceeds to the Company of approximately $23.1 million. The Series D Warrants have an exercise period of five years, and if fully exercised, would result in additional gross proceeds to the Company of approximately $7.1 million. The Series B Warrants and Series C Warrants previously carried an expiration date of August 2015. The remaining Series B Warrants and Series C Warrants not included in the Exchange will remain outstanding until their exercise or expiration.
	As a result of a change in the terms and conditions of the Series B and C Warrants, the transaction was treated as a modification of the original award using the accounting guidance in ASC 718-20-35-3, this guidance implies that the entity repurchases the original instrument by issuing a new instrument of equal or greater value, incurring additional incremental value. Incremental cost shall be measured as the excess, if any, of the fair value of the modified award over the fair value of the original award immediately before its terms are modified, measured based on the share price, Black-Scholes options pricing model and other pertinent factors at that date. These variables include the Company’s expected stock price volatility over the term of the award, expected term, risk-free interest rate and expected dividend rate. The Company recorded $2.9 million warrant exchange charge in 2014 based upon the difference between the fair value of the Series B and C Warrants immediately prior to the exchange and the fair value of the newly issued Series B/C Exchange and Series D Warrants.
	2013 Private Placement Transaction
	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 (the “Series A Warrants”); Series B warrants exercisable for an aggregate 11,382,113 shares of common stock, with an exercise price equal to $1.50 per share (the “Series B Warrants”); 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 (the “Series C Warrants”). The 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 resale of the shares (which occurred in November 2013) 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. In the first quarter of 2014, subsequent to the receipt of regulatory approval for the new Magellan 6Fr Robotic Catheter in the U.S., Series A Warrants for 11.4 million shares of the Company’s common stock were exercised for total proceeds of $14.0 million in accordance with the terms and conditions of a securities purchase agreement dated July 30, 2013. All of the Series A Warrants were mandatorily exercised in the first quarter of 2014 pursuant to the Company’s achievement of a regulatory milestone as set forth in the Series A Warrants.

Stockbased_Compensation

Stock-based Compensation	3 Months Ended
	Mar. 31, 2015
Stock-based Compensation	10	Stock-based Compensation
	Total stock-based compensation expense consisted of the following (in thousands):
			Three months ended
			March 31,
			2015			2014
	Cost of goods sold		$	47		$	44
	Research and development			147			180
	Selling, general and administrative			416			533
	Total		$	610		$	757
	The Company uses the Black-Scholes option pricing model to determine the fair value of stock options. The determination of the fair value of stock options on the date of grant is affected by the Company’s stock price as well as assumptions regarding a number of complex and subjective variables. These variables include the Company’s expected stock price volatility over the term of the award, expected term, risk-free interest rate and expected dividend rate. The Company estimates the expected term based on its historical experience of grants, exercise pattern and post-vesting cancellations. The Company considered its historical volatility over the expected term and implied volatility of traded stock options in developing its estimate of volatility. There were no option grants for the three months ended March 31, 2015. The estimated grant date fair values of the employee stock options under the 2006 Equity Incentive Plan for the three months ended March 31, 2014 was calculated using the following assumptions:
	Employee Stock Options:		Three months ended
			March 31,
			2015			2014
	Expected volatility			—		72%-74%
	Risk-free interest rate			—		1.2%-1.5%
	Expected term (in years)			—		4.34
	Expected dividend rate			—		0%
	The estimated fair values of the shares issued under the Company’s Employee Stock Purchase Plan were calculated using the following assumptions:
	Employee Stock Purchase Plan:		Three months ended
			March 31,
			2015			2014
	Expected volatility			75	%		99	%
	Risk-free interest rate			0.08	%		0.1	%
	Expected term (in years)			0.5			0.5
	Expected dividend rate			0	%		0	%
	Stock Option and Equity Incentive Plans
	The following table summarizes the option activity for the period ended March 31, 2015:
			Options			Weighted-			Weighted-		Aggregate
			Outstanding			Average			Average		Intrinsic Value
						Exercise Price			Remaining
									Contractual
									Term
			(In thousands)						(In years)		(In thousands)
	Balance at December 31, 2014			9,191		$	1.69			7.8	$	—
	Options granted			—		$	—
	Options exercised			(1	)	$	0.4				$	1
	Options cancelled			(709	)	$	3.47				$	23
	Balance at March 31, 2015			8,481		$	1.55			7.77	$	804
	Options vested at March 31, 2015			2,601		$	2.67			5.05	$	1
	Options vested and expected to vest at March 31, 2015			8,305		$	1.51			7.8	$	784
	The total fair value of options that vested in the three months ended March 31, 2015 and 2014 was $0.4 million and $0.6 million, respectively.
	As of March 31, 2015, total unamortized stock-based compensation related to unvested stock options was $3.2 million, with a weighted-average remaining recognition period of 2.77 years.
	The intrinsic value of exercised stock options is calculated based on the difference between the exercise price and the quoted closing market price of the Company’s common stock on the exercise date. The total intrinsic value of stock options exercised in the three months ended March 31, 2015 and 2014 was $1,000 and $0.2 million, respectively.
	Restricted stock unit activity is as follows:
			Restricted Stock			Weighted-
			Units			Average Fair
			Outstanding			Value When
						Awarded
			(In thousands)
	Balance at December 31, 2014			841		$	1.8
	Awarded			2,119		$	0.88
	Vested			(41	)	$	2.51
	Cancelled			(84	)	$	2.42
	Balance at March 31, 2015			2,835		$	1.09
	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 the three months ended March 31, 2015 and 2014 was $0.1 million and $2.0 million, respectively. As of March 31, 2015, total unamortized stock-based compensation related to unvested restricted stock units was $2.4 million, with a weighted-average remaining recognition period of 3.55 years.
	As of March 31, 2015, 5,601,204 shares of common stock were available for grant under the 2006 Equity Incentive Plan.

Income_Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2015
Income Taxes	11	Income Taxes
	The Company’s tax provision for the three months ended March 31, 2015 and 2014 was $9,000 and $18,000, respectively, which primarily consist of foreign taxes. The Company currently has uncertain tax positions in the amount of $4.3 million, none of which would affect the effective tax rate upon realization. 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.

Net_Loss_Per_Share

Net Loss Per Share	3 Months Ended
	Mar. 31, 2015
Net Loss Per Share	12	Net Loss Per Share
	The Company computes basic net loss per share by dividing net loss available to common stockholders by the weighted average number of common shares outstanding during the period. To determine diluted shares, the Company applies the treasury stock method to determine the dilutive effect of outstanding stock option shares, restricted stock units (“RSU”), Employee Stock Purchase Plan (“ESPP”) shares and warrants.
	The following table sets forth the computation of basic and diluted net loss per share (in thousands, except per share data):
			Three months ended
			March 31,
			2015			2014
	Net loss		$	(11,933	)	$	(14,445	)
	Adjust: Dividend for Series A convertible preferred stock			(156	)		—
	Net loss attributable to common stockholders		$	(12,089	)	$	(14,445	)
	Shares used to compute basic and diluted net loss per share			133,283			103,334
	Basic and diluted net loss per share		$	(0.09	)	$	(0.14	)
	The following table sets forth potential shares of common stock equivalents that are not included in the calculation of diluted net loss per common share due to the anti-dilutive affect they would have for each period presented (in thousands):
			March 31,
			2015			2014
	Stock options outstanding			8,481			7,268
	Unvested restricted stock units			2,835			531
	Estimated shares issuable under the employee stock purchase plan			415			157
	Warrants			63,115			23,425

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Income (Loss)	3 Months Ended
	Mar. 31, 2015
Accumulated Other Comprehensive Income (Loss)	13	Accumulated Other Comprehensive Income (Loss)
	The component of accumulated other comprehensive income (loss), net of tax for the three months ended March 31, 2015 and 2014 are as follows (in thousands):
			Unrealized			Foreign			Total
			Gains			Currency
			(Losses)			Translation
			on			Gains
			Securities			(Losses)
	Three Months Ended March 31, 2015:
	Beginning balance		$	392		$	(87	)	$	305
	Net current-period other comprehensive loss			(102	)		(64	)		(166	)
	Ending Balance		$	290		$	(151	)	$	139
	Three Months Ended March 31, 2014:
	Beginning balance		$	373		$	(13	)	$	360
	Net current-period other comprehensive gain			83			2			85
	Ending Balance		$	456		$	(11	)	$	445

Segment_Information

Segment Information	3 Months Ended
	Mar. 31, 2015
Segment Information	14	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’s medical robotics systems are developed and marketed to a broad base of hospitals and distributors in the United States and internationally. The Company considers all such sales to be part of a single operating segment. Information regarding total revenue is as follows (in thousands):
			Three months ended
			March 31,
			2015		2014
	Revenues:
	United States		$	1,962	$	2,490
	International			3,832		1,209
	Total		$	5,794	$	3,699
	Revenues are attributed to countries based on the location of the customer. Revenues in the United States, China, Saudi Arabia and Italy each accounted for 10% or more of total revenues for the three months ended March 31, 2015 at 34%, 22%, 14% and 10%, respectively. Revenues in the United States and Belgium each accounted for 10% or more of total revenues for the three months ended March 31, 2014 at 67% and 10%, respectively.
	The majority of the Company’s long-lived assets are located in the United States.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2015
Basis of Presentation	Basis of Presentation
	The accompanying unaudited condensed consolidated financial statements (the “condensed consolidated financial statements”) have been prepared in accordance with generally accepted accounting principles in the United States of America (“GAAP”) for interim financial information and therefore do not contain all of the information and footnotes required by GAAP and the rules and regulations of the Securities and Exchange Commission (the “SEC”) for annual financial statements. The Company’s fiscal year ends on December 31. The condensed consolidated balance sheet as of December 31, 2014 was derived from audited financial statements. In the opinion of the Company’s management, these unaudited statements include all adjustments, which are of a normal recurring nature, necessary for a fair presentation. Interim results are not necessarily indicative of results for a full year or any other interim period. The information included in this Quarterly Report on Form 10-Q should be read in conjunction with the Company’s Annual Report on Form 10-K for the year ended December 31, 2014 as filed with the SEC.
	The accompanying condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation.
Reclassification of Prior Period Balances	Reclassification of Prior Period Balances
	Certain reclassifications have been made to prior period amounts to conform to the current period presentation.
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, the valuation of warrants, and deferred tax assets, among others. Actual results may 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, which includes post-contract customer support (“PCS”). The Company sells its products directly to customers as well as through distributors. Under the Company’s revenue recognition policy, revenues are recognized when persuasive evidence of an arrangement exists, title and risk of loss has passed, delivery to the customer has occurred or the services have been fully rendered, the sales price is fixed or determinable and collectability is reasonably assured.
		•		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 or 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 its PCS contracts which includes planned and corrective maintenance services, software updates, bug fixes, and warranty. 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 have standalone value and 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. For multiple-element arrangements revenue is allocated to each element based on their relative selling prices. Relative selling prices are based first on vendor specified objective evidence (“VSOE”), then on third-party evidence of selling price (“TPE”) when VSOE does not exist, and then on management’s best estimate of the selling price (“ESP”) when VSOE and TPE do not exist. Because the Company has neither VSOE nor TPE for its system, the allocation of revenue is based on ESP for the systems sold. The objective of ESP is to determine the price at which the Company would transact a sale, had the product been sold on a stand-alone basis. 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, or extended payment terms or 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 of three to six months 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 reasonably assured 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 reasonably assured, the revenue is deferred and recognized at the time collection becomes reasonably assured, 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 22%, 15% and 13%, respectively, of the Company’s accounts receivable at March 31, 2015. The Company had four customers who constituted 26%, 14%, 12%, and 12%, respectively of the Company’s net accounts receivable at December 31, 2014. As of March 31, 2015, the Company has not experienced any significant losses on its accounts receivable.
	Three customers accounted for 22%, 13% and 10%, respectively of total revenues during the three months ended March 31, 2015. Two customers accounted for 30% and 13%, respectively of total revenues during the three months ended March 31, 2014.
	Most of the products developed by the Company require clearance from the U.S. Food and Drug Administration (“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 Robotic Catheter System (“Sensei system”) and Artisan catheters for manipulation, positioning and control of certain mapping catheters during electrophysiology (“EP”) 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, Magellan 6Fr Robotic Catheter in February 2014, and Magellan 10Fr Robotic Catheter in April 2015. 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.
Fair Value Measurements	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 the Company to develop its 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.
Recent Accounting Pronouncements	Recent Accounting Pronouncements
	In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09,Revenue from Contracts with Customers (Topic 606), which supersedes the revenue recognition requirements in ASC 605, Revenue Recognition. ASU 2014-09 is based on the principle that revenue is recognized to depict the transfer of goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. ASU 2014-09 also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments and assets recognized from costs incurred to obtain or fulfill a contract. This new guidance is effective for annual reporting periods beginning after December 15, 2016, including interim periods within those fiscal years. Early adoption is not permitted. In April 2015, the FASB proposed a date deferral of the effective date of the updated standard by one year, but allows entities to adopt one year earlier. The proposed effective date deferral is not currently approved. The Company is currently assessing the impact of the adoption of ASU2014-09 on its consolidated financial statements.
	In April 2015, the FASB issued ASU 2015-03, “Interest—Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Cost”, which changes the presentation of debt issuance costs in financial statements. Under the ASU, an entity presents costs in the balance sheet as a direct deduction from the related debt liability rather than as an asset. Amortization of the costs is reported as interest expense. Under current guidance, an entity reports debt issuance costs in the balance sheet as deferred charges (i.e. as an asset). For public companies, the ASU is effective for fiscal years beginning after December 15, 2015, and interim periods beginning after December 15, 2016, with early adoption permitted. Entities would apply the new guidance retrospectively to all prior periods. The Company will adopt this standard in 2016. The Company is currently assessing the impact of the adoption of ASU2015-03 on its consolidated financial statements.
	In January 2015, the FASB issued ASU 2015-01, “Simplifying Income Statement Presentation by Eliminating the Concept of Extraordinary Items.” This ASU that eliminates from GAAP the concept of extraordinary items, and is effective for annual periods beginning after December 15, 2015, with early adoption permitted. The change primarily involves presentation and disclosure and, therefore, is not expected to have a material impact on the Company’s financial condition, results of operations or its cash flows.
	In August 2014, the FASB issued ASU No. 2014-15, Presentation of Financial Statements—Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern. The ASU provides guidance on determining when and how to disclose going-concern uncertainties in the financial statements. The new standard requires management to perform interim and annual assessments of an entity’s ability to continue as a going concern within one year of the date the financial statements are issued. An entity must provide certain disclosures if “conditions or events raise substantial doubt about the entity’s ability to continue as a going concern.” The ASU applies to all entities and is effective for annual periods ending after December 15, 2016, and interim periods thereafter, with early adoption permitted. The Company has been assessing the going concern issue since 2010 on an interim and annual basis and will continue to assess whether the financial conditions based on this new guidance have an impact on the Company’s consolidated financial statements or footnotes.

Fair_Value_of_Assets_and_Liabi1

Fair Value of Assets and Liabilities (Tables)	3 Months Ended
	Mar. 31, 2015
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):
	Cash, Cash Equivalents, Short-term Investments and Restricted Cash
		Amortized			Gross		Gross		Fair		Balance Sheet Classification
		Cost			Unrealized		Unrealized		Value
					Gains		Losses				Cash and		Short-term		Restricted
											cash		Investments		Cash
											Equivalents
	March 31, 2015:
	Cash	$	5,458		$	—	$	—	$	5,458	$	5,458	$	—	$	—
	Money market funds		51,304			—		—		51,304		45,942		—		5,362
	Corporate equity securities		1,572			304		—		1,876		—		1,876		—
		$	58,334		$	304	$	—	$	58,638	$	51,400	$	1,876	$	5,362
	December 31, 2014:
	Cash	$	3,586		$	—	$	—	$	3,586	$	3,586	$	—	$	—
	Money market funds		26,318			—		—		26,318		20,942		—		5,376
	Corporate equity securities		1,572			401		—		1,973		—		1,973		—
		$	31,476		$	401	$	—	$	31,877	$	24,528	$	1,973	$	5,376
Fair Value Hierarchy of Company's Assets and Liabilities	The fair value hierarchy of the Company’s assets and liabilities that are measured at fair value, by level, 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)
	March 31, 2015:
	Assets:
	Money market funds	$	51,304		$	—	$	—	$	51,304
	Corporate equity securities		1,876			—		—		1,876
		$	53,180		$	—	$	—	$	53,180
	Liabilities:
	Warrant liability						$	16,452	$	16,452
		$	—		$	—	$	16,452	$	16,452
	December 31, 2014:
	Assets:
	Money market funds	$	26,318		$	—	$	—	$	26,318
	Corporate equity securities		1,973			—		—		1,973
		$	28,291		$	—	$	—	$	28,291
	Liabilities:
	Warrant liability		—			—		—		—
		$	—		$	—	$	—	$	—
Changes in Level 3 Liabilities Measured at Fair value on a Recurring Basis	The changes in Level 3 liabilities measured at fair value on a recurring basis was as follow (in thousands):
		Level 3 input for quarter
		ended March 31, 2015
		(In thousands)
	Balance at December 31, 2014	$	—
	Additions at March 11, 2015		(14,776	)
	Total fair value measurement
	Warrant expense		(1,676	)
	Balance at March 31, 2015	$	(16,452	)

Balance_Sheet_Components_Table

Balance Sheet Components (Tables)	3 Months Ended
	Mar. 31, 2015
Components of inventories, Net	Inventories (in thousands)
		March 31,			December 31,
		2015			2014
	Raw materials	$	4,266		$	4,996
	Work in process		4,024			4,571
	Finished goods		1,902			1,925
	Total Inventories	$	10,192		$	11,492
Property and equipment, net	Property and equipment, net (in thousands)
		March 31,			December 31,
		2015			2014
	Furniture and leasehold improvements	$	11,446		$	11,455
	Laboratory equipment		11,987			11,374
	Computer equipment and software		2,971			2,911
			26,404			25,740
	Less: Accumulated depreciation and amortization		(23,581	)		(23,412	)
	Property and equipment, net	$	2,823		$	2,328
Accrued liabilities	Accrued liabilities (in thousands)
		March 31,			December 31,
		2015			2014
	Accrued salaries, commission, bonus and benefits	$	1,884		$	2,835
	Accrued royalties		925			594
	Accrued legal and other professional fees		459			169
	Clinical related accruals		272			394
	Tax accruals		289			274
	Other accrued expenses		679			676
	Accrued liabilities	$	4,508		$	4,942

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2015
Future Minimum Payments under Operating Leases	As of March 31, 2015, future minimum payments under the leases are as follows (in thousands):
	Years ending December 31,	Future Minimum
		Lease Payments
	2015 (remainder of year)	$	1,608
	2016		2,151
	2017		2,216
	2018		2,282
	2019		1,759
	Total	$	10,016

Longterm_Debt_Tables

Long-term Debt (Tables)	3 Months Ended
	Mar. 31, 2015
Future Annual Payments Due on Amounts Outstanding	Future annual payments due on the debt (including interest) outstanding as of March 31, 2015 are as follows (in thousands):
	Years ending December 31,
	2015 (remainder of year)	$	2,933
	2016		4,009
	2017		41,782
	Total remaining payments		48,724
	Less: Amount representing interest		(14,497	)
			34,227
	Less: Current portion of long-term debt		—
	Long-term debt, net of current portion	$	34,227

Stockbased_Compensation_Tables

Stock-based Compensation (Tables)	3 Months Ended
	Mar. 31, 2015
Total Stock-based Compensation	Total stock-based compensation expense consisted of the following (in thousands):
		Three months ended
		March 31,
		2015			2014
	Cost of goods sold	$	47		$	44
	Research and development		147			180
	Selling, general and administrative		416			533
	Total	$	610		$	757
Assumptions Used to Estimate Grant Date Fair Values of Stock Options	The estimated grant date fair values of the employee stock options under the 2006 Equity Incentive Plan for the three months ended March 31, 2014 was calculated using the following assumptions:
	Employee Stock Options:	Three months ended
		March 31,
		2015			2014
	Expected volatility		—		72%-74%
	Risk-free interest rate		—		1.2%-1.5%
	Expected term (in years)		—		4.34
	Expected dividend rate		—		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 Company’s Employee Stock Purchase Plan were calculated using the following assumptions:
	Employee Stock Purchase Plan:	Three months ended
		March 31,
		2015			2014
	Expected volatility		75	%		99	%
	Risk-free interest rate		0.08	%		0.1	%
	Expected term (in years)		0.5			0.5
	Expected dividend rate		0	%		0	%
Summary of Option Activity	The following table summarizes the option activity for the period ended March 31, 2015:
		Options			Weighted-			Weighted-		Aggregate
		Outstanding			Average			Average		Intrinsic Value
					Exercise Price			Remaining
								Contractual
								Term
		(In thousands)						(In years)		(In thousands)
	Balance at December 31, 2014		9,191		$	1.69			7.8	$	—
	Options granted		—		$	—
	Options exercised		(1	)	$	0.4				$	1
	Options cancelled		(709	)	$	3.47				$	23
	Balance at March 31, 2015		8,481		$	1.55			7.77	$	804
	Options vested at March 31, 2015		2,601		$	2.67			5.05	$	1
	Options vested and expected to vest at March 31, 2015		8,305		$	1.51			7.8	$	784
Summary of Restricted Stock Unit Activity	Restricted stock unit activity is as follows:
		Restricted Stock			Weighted-
		Units			Average Fair
		Outstanding			Value When
					Awarded
		(In thousands)
	Balance at December 31, 2014		841		$	1.8
	Awarded		2,119		$	0.88
	Vested		(41	)	$	2.51
	Cancelled		(84	)	$	2.42
	Balance at March 31, 2015		2,835		$	1.09

Net_Loss_Per_Share_Tables

Net Loss Per Share (Tables)	3 Months Ended
	Mar. 31, 2015
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):
		Three months ended
		March 31,
		2015			2014
	Net loss	$	(11,933	)	$	(14,445	)
	Adjust: Dividend for Series A convertible preferred stock		(156	)		—
	Net loss attributable to common stockholders	$	(12,089	)	$	(14,445	)
	Shares used to compute basic and diluted net loss per share		133,283			103,334
	Basic and diluted net loss per share	$	(0.09	)	$	(0.14	)
Common Stock Equivalents that are Not Included In the Calculation of Diluted Net Loss Per Common Share	The following table sets forth potential shares of common stock equivalents that are not included in the calculation of diluted net loss per common share due to the anti-dilutive affect they would have for each period presented (in thousands):
		March 31,
		2015			2014
	Stock options outstanding		8,481			7,268
	Unvested restricted stock units		2,835			531
	Estimated shares issuable under the employee stock purchase plan		415			157
	Warrants		63,115			23,425

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Income (Loss) (Tables)	3 Months Ended
	Mar. 31, 2015
Component of Accumulated Other Comprehensive Income (Loss), Net of Tax	The component of accumulated other comprehensive income (loss), net of tax for the three months ended March 31, 2015 and 2014 are as follows (in thousands):
		Unrealized			Foreign			Total
		Gains			Currency
		(Losses)			Translation
		on			Gains
		Securities			(Losses)
	Three Months Ended March 31, 2015:
	Beginning balance	$	392		$	(87	)	$	305
	Net current-period other comprehensive loss		(102	)		(64	)		(166	)
	Ending Balance	$	290		$	(151	)	$	139
	Three Months Ended March 31, 2014:
	Beginning balance	$	373		$	(13	)	$	360
	Net current-period other comprehensive gain		83			2			85
	Ending Balance	$	456		$	(11	)	$	445

Segment_Information_Tables

Segment Information (Tables)	3 Months Ended
	Mar. 31, 2015
Information Regarding Total Revenue	Information regarding total revenue is as follows (in thousands):
		Three months ended
		March 31,
		2015		2014
	Revenues:
	United States	$	1,962	$	2,490
	International		3,832		1,209
	Total	$	5,794	$	3,699

The_Company_Additional_Informa

The Company - Additional Information (Detail) (USD $)	0 Months Ended
	Mar. 11, 2015	Mar. 31, 2015	Dec. 31, 2014	Aug. 23, 2013
Description of Business [Line Items]
Accumulated net profit or loss from inception		($418,843,000)	($406,910,000)
Gross proceed from sale of convertible preferred stock and related issuance of warrants	35,000,000
Cash, cash equivalents, short-term investments and restricted cash		58,600,000
White Oak Loan Agreement
Description of Business [Line Items]
Minimum liquidity requirement amount		15,000,000		15,000,000
White Oak Loan Agreement | Cash, Cash Equivalents and Investments
Description of Business [Line Items]
Minimum liquidity requirement amount		13,000,000		13,000,000
White Oak Loan Agreement | Accounts Receivable
Description of Business [Line Items]
Minimum liquidity requirement amount		2,000,000		2,000,000
Luna Innovations Incorporated | Restricted Cash and Cash Equivalents
Description of Business [Line Items]
Minimum liquidity requirement amount		$5,000,000		$5,000,000

Summary_of_Significant_Account2

Summary of Significant Accounting Policies - Additional Information (Detail)	3 Months Ended	12 Months Ended	3 Months Ended
	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
	Entity	Customer	Customer
Summary Of Significant Accounting Policies [Line Items]
Deferred and amortized service period	1 year
Number of financial institutions in which cash deposited	2
Customer concentration risk | Accounts Receivable
Summary Of Significant Accounting Policies [Line Items]
Number of major customers	3	4
Customer concentration risk | Accounts Receivable | Customer 1
Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage	22.00%	26.00%
Customer concentration risk | Accounts Receivable | Customer 2
Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage	15.00%	14.00%
Customer concentration risk | Accounts Receivable | Customer 3
Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage	13.00%	12.00%
Customer concentration risk | Accounts Receivable | Customer 4
Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage		12.00%
Customer concentration risk | Sales
Summary Of Significant Accounting Policies [Line Items]
Number of major customers	3		2
Customer concentration risk | Sales | Customer 1 | Minimum
Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage	22.00%		30.00%
Customer concentration risk | Sales | Customer 2 | Minimum
Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage	13.00%		13.00%
Customer concentration risk | Sales | Customer 3 | Minimum
Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage	10.00%

Amortized_Cost_and_Fair_Value_

Amortized Cost and Fair Value of Assets, with Gross Unrealized Gains and Losses (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Cash Cash Equivalents And Short Term Investments [Line Items]
Amortized Cost	$58,334	$31,476
Gross Unrealized Gains	304	401
Gross Unrealized Losses	0	0
Fair Value	58,638	31,877
Cash and cash equivalents	51,400	24,528	30,976	27,995
Short-term investments	1,876	1,973
Restricted cash	5,362	5,376
Cash
Cash Cash Equivalents And Short Term Investments [Line Items]
Amortized Cost	5,458	3,586
Gross Unrealized Losses	0	0
Fair Value	5,458	3,586
Cash and cash equivalents	5,458	3,586
Money Market Funds
Cash Cash Equivalents And Short Term Investments [Line Items]
Amortized Cost	51,304	26,318
Gross Unrealized Losses	0	0
Fair Value	51,304	26,318
Cash and cash equivalents	45,942	20,942
Restricted cash	5,362	5,376
Corporate Equity Securities
Cash Cash Equivalents And Short Term Investments [Line Items]
Amortized Cost	1,572	1,572
Gross Unrealized Gains	304	401
Gross Unrealized Losses	0	0
Fair Value	1,876	1,973
Short-term investments	$1,876	$1,973

Fair_Value_Hierarchy_of_Compan

Fair Value Hierarchy of Company's Assets (Detail) (USD $)	Mar. 31, 2015	Mar. 11, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	$53,180		$28,291
Warrant liability	16,452	14,800
Liabilities	16,452
Money Market Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	51,304		26,318
Corporate Equity Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	1,876		1,973
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	53,180		28,291
Level 1 | Money Market Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	51,304		26,318
Level 1 | Corporate Equity Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	1,876		1,973
Level 3 Inputs
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrant liability	16,452
Liabilities	$16,452

Changes_in_Level_3_Liabilities

Changes in Level 3 Liabilities Measured at Fair value on a Recurring Basis (Detail) (Level 3 Inputs, USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015
Level 3 Inputs
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Additions at March 11, 2015	($14,776)
Total fair value measurement	0
Warrant expense	-1,676
Balance at March 31, 2015	($16,452)

Fair_Value_of_Assets_and_Liabi2

Fair Value of Assets and Liabilities - Additional Information (Detail) (USD $)	0 Months Ended
	Mar. 11, 2015	Mar. 31, 2015	Mar. 11, 2015	Dec. 31, 2014	Jul. 30, 2013
Fair Value, Measurement Inputs, Disclosure [Line Items]
Common Stock issuable upon exercise of warrants			53,846,000		34,146,339
Warrants exercise period	2 years
Warrants exercise price	$0.98
Premium on per share trailing weighted average share price	50.00%
Warrant liability		$16,452,000
Long term debt, fair value		$34,600,000		$34,200,000

Components_of_Inventories_Net_

Components of Inventories, Net (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Inventory [Line Items]
Raw materials	$4,266	$4,996
Work in process	4,024	4,571
Finished goods	1,902	1,925
Total Inventories	$10,192	$11,492

Property_and_Equipment_Net_Det

Property and Equipment, Net (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$26,404	$25,740
Less: Accumulated depreciation and amortization	-23,581	-23,412
Property and equipment, net	2,823	2,328
Furniture and leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	11,446	11,455
Laboratory equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	11,987	11,374
Computer equipment and software
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$2,971	$2,911

Components_of_Accrued_Liabilit

Components of Accrued Liabilities (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Schedule of Accrued Liabilities [Line Items]
Accrued salaries, commission, bonus and benefits	$1,884	$2,835
Accrued royalties	925	594
Accrued legal and other professional fees	459	169
Clinical related accruals	272	394
Tax accruals	289	274
Other accrued expenses	679	676
Total	$4,508	$4,942

Agreements_with_Intuitive_Surg1

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	Mar. 31, 2015	Dec. 31, 2012
Licenses Agreements [Line Items]
Proceeds from licensing fees		$20,000,000
Stock purchase agreement to sell shares	28,455,284	5,291,005
Common stock agreement purchase price		10,000,000
Agreement amendment period			3 years
Payment for licensing of intellectual property				20,000,000
Stock purchase agreement recorded in common stock and additional paid-in capital				10,000,000
Intuitive Surgical Inc
Licenses Agreements [Line Items]
Cost related to royalty obligations			100,000
Intuitive Surgical Inc | Minimum
Licenses Agreements [Line Items]
Royalty obligations per year			200,000

Agreements_with_Philips_Additi

Agreements with Philips - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Feb. 28, 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
Koninklijke Philips Electronics Nv
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Royalty payment obligation	2017-10
Cost related to royalty obligations	600,000	100,000
Koninklijke Philips Electronics Nv | Minimum
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Royalty obligations	0

Commitments_and_Contingencies_1

Commitments and Contingencies - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Other Commitments [Line Items]
Rent expense	$600,000	$700,000
Mitsubishi
Other Commitments [Line Items]
Reduction royalty obligation	55,000
Royalty obligation expiration Year	2018
Cost related to royalty obligations	35,000	19,000
Mitsubishi | Minimum
Other Commitments [Line Items]
Royalty obligations per year	$100,000
California
Other Commitments [Line Items]
Operating lease expiration year	31-Jan-20
Operating lease extended period	5 years
London, England
Other Commitments [Line Items]
Operating lease expiration year	30-Jun-15
Operating lease area leased for office space	3,300
London, England | New Lease Arrangement
Other Commitments [Line Items]
Operating lease expiration year	30-Apr-16
Operating lease beginning date	1-May-15

Future_Minimum_Payments_under_

Future Minimum Payments under Operating Leases (Detail) (USD $)	Mar. 31, 2015
In Thousands, unless otherwise specified
Operating Leased Assets [Line Items]
2015 (remainder of year)	$1,608
2016	2,151
2017	2,216
2018	2,282
2019	1,759
Total	$10,016

Long_Term_Debt_Additional_Info

Long - Term Debt - Additional Information (Detail) (USD $)	0 Months Ended	3 Months Ended
	Aug. 23, 2013	Mar. 31, 2015	Mar. 31, 2014	Aug. 23, 2013
White Oak Loan Agreement
Debt Instrument [Line Items]
Loan and security agreement	$33,000,000			$33,000,000
Loan and security agreement, due date	30-Dec-17
Capitalized debt issue costs	1,500,000
Administration and monitoring fee	32,000			32,000
Amortization of debt issuance costs		100,000	100,000
Minimum liquidity requirement amount	15,000,000	15,000,000		15,000,000
White Oak Loan Agreement | Cash, Cash Equivalents and Investments
Debt Instrument [Line Items]
Minimum liquidity requirement amount	13,000,000	13,000,000		13,000,000
White Oak Loan Agreement | Accounts Receivable
Debt Instrument [Line Items]
Minimum liquidity requirement amount	2,000,000	2,000,000		2,000,000
White Oak Loan Agreement | Interest Payment in Cash
Debt Instrument [Line Items]
Loan and security agreement, interest rate	11.00%			11.00%
White Oak Loan Agreement | Payment in Kind (PIK)
Debt Instrument [Line Items]
Loan and security agreement, interest rate	3.00%			3.00%
White Oak Loan Agreement | Payment to Lender Agent
Debt Instrument [Line Items]
Capitalized debt issue costs	700,000
White Oak Loan Agreement | Payment to Placement Agent
Debt Instrument [Line Items]
Capitalized debt issue costs	300,000
White Oak Loan Agreement | Principal Prepaid Before Third Anniversary
Debt Instrument [Line Items]
Prepayment fee of the principal	3.50%			3.50%
White Oak Loan Agreement | Principal Prepaid After Third Anniversary
Debt Instrument [Line Items]
Prepayment fee of the principal	1.00%			1.00%
Luna Innovations Incorporated | Restricted Cash and Cash Equivalents
Debt Instrument [Line Items]
Minimum liquidity requirement amount	$5,000,000	$5,000,000		$5,000,000

Future_Annual_Payments_Due_on_

Future Annual Payments Due on Amounts Outstanding (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Debt Instrument [Line Items]
2015 (remainder of year)	$2,933
2016	4,009
2017	41,782
Total remaining payments	48,724
Less: Amount representing interest	-14,497
Long-term debt, Net Total	34,227
Total remaining payments	48,724
Less: Current portion of long-term debt	0
Long-term debt, net of current portion	$34,227	$34,385

Convertible_Preferred_Stock_Co1

Convertible Preferred Stock, Common Stock and Warrants - Additional Information (Detail) (USD $)	0 Months Ended		1 Months Ended	3 Months Ended		12 Months Ended	0 Months Ended	1 Months Ended
	Mar. 11, 2015	Jul. 30, 2013	Oct. 31, 2012	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014	Jul. 30, 2014	Aug. 31, 2014
	D
Stockholders Equity Note [Line Items]
Convertible preferred stock sold	53,846			54,000		0
Convertible preferred stock Price	$650			$0.00		$0.00
Common stock at conversion price	$0.65
Number of trading days	10
Preferred stock quarterly dividend	2.00%
Preferred stock increase in quarterly dividend	2.00%
Common Stock issuable upon exercise of warrants	53,846,000	34,146,339
Warrants exercise period	2 years
Warrants exercise price	$0.98
Premium on per share trailing weighted average share price	50.00%
Warrant liability	$14,800,000			$16,452,000
Warrant exchange				1,676,000		2,900,000
Capitalized offering cost				500,000
Common stock per warrant price		$0.13
Gross proceed from exercise of warrants					14,000,000
Securities purchase agreement to sell shares		28,455,284	5,291,005
Common stock per warrant price		$1.23
Proceeds from issuance of common stock and warrants		39,300,000
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
Minimum
Stockholders Equity Note [Line Items]
Percentage of capital stock sold at a liquidation event	50.00%
Exchange Agreement
Stockholders Equity Note [Line Items]
Common Stock issuable upon exercise of warrants							26,728,369
Series B Warrant
Stockholders Equity Note [Line Items]
Common Stock issuable upon exercise of warrants		11,382,113
Common stock per warrant price		$1.50
Expiration date of warrants							Aug-15
Series B Warrant | Exchange Agreement
Stockholders Equity Note [Line Items]
Common Stock issuable upon exercise of warrants							10,221,173
Series C Warrant
Stockholders Equity Note [Line Items]
Common Stock issuable upon exercise of warrants		11,382,113
Common stock per warrant price		$2
Expiration date of warrants							Aug-15
Series C Warrant | Exchange Agreement
Stockholders Equity Note [Line Items]
Common Stock issuable upon exercise of warrants							10,221,173
Series B/C Exchange Warrants | Exchange Agreement
Stockholders Equity Note [Line Items]
Common Stock issuable upon exercise of warrants							20,442,346
Common stock per warrant price							1.13
Gross proceed from exercise of warrants								23,100,000
Period at which warrants subject to mandatory exercise after issuance							14 days
Series D Warrants | Exchange Agreement
Stockholders Equity Note [Line Items]
Common Stock issuable upon exercise of warrants							6,286,023
Warrants exercise period							5 years
Gross proceed from exercise of warrants							7,100,000
Series A Warrants
Stockholders Equity Note [Line Items]
Common Stock issuable upon exercise of warrants		11,382,113
Common stock per warrant price		$1.23
Gross proceed from exercise of warrants					$14,000,000
Number of warrants exercised					11,400,000

Total_StockBased_Compensation_

Total Stock-Based Compensation (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation	$610	$757
Cost of goods sold
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation	47	44
Research and development
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation	147	180
Selling, general and administrative
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation	$416	$533

Assumptions_Used_to_Estimate_G

Assumptions Used to Estimate Grant Date Fair Values of Stock Options (Detail)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Stock Options
Estimated grant date fair values
Expected volatility, minimum		72.00%
Expected volatility, maximum		74.00%
Risk-free interest rate, minimum		1.20%
Risk-free interest rate, maximum		1.50%
Expected term (in years)	0 years	4 years 4 months 2 days
Expected dividend rate		0.00%
Employee Stock Purchase Plan
Estimated grant date fair values
Expected volatility	75.00%	99.00%
Risk-free interest rate	0.08%	0.10%
Expected term (in years)	6 months	6 months
Expected dividend rate	0.00%	0.00%

Summary_of_Option_Activity_Det

Summary of Option Activity (Detail) (USD $)	3 Months Ended		12 Months Ended
Share data in Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Balance at December 31, 2014	9,191
Options Outstanding, Options granted	0
Options Outstanding, Options exercised	-1
Options Outstanding, Options cancelled	-709
Options Outstanding, Balance at March 31, 2015	8,481		9,191
Options Outstanding, Options vested at March 31, 2015	2,601
Options Outstanding, Options vested and expected to vest at March 31, 2015	8,305
Weighted- Average Exercise Price, Balance at December 31, 2014	$1.69
Weighted- Average Exercise Price, Options granted	$0
Weighted- Average Exercise Price, Options exercised	$0.40
Weighted- Average Exercise Price, Options cancelled	$3.47
Weighted- Average Exercise Price, Balance at March 31, 2015	$1.55		$1.69
Weighted- Average Exercise Price, Options vested at March 31, 2015	$2.67
Weighted- Average Exercise Price, Options vested and expected to vest at March 31, 2015	$1.51
Weighted- Average Remaining Contractual Term, Balance	7 years 9 months 7 days		7 years 9 months 18 days
Weighted- Average Remaining Contractual Term, Options vested at March 31, 2015	5 years 18 days
Weighted- Average Remaining Contractual Term, Options vested and expected to vest at March 31, 2015	7 years 9 months 18 days
Aggregate Intrinsic Value, Options exercised	$1,000	$200,000
Aggregate Intrinsic Value, Options cancelled	23,000
Aggregate Intrinsic Value, March 31, 2015	804,000
Aggregate Intrinsic Value, Options vested at March 31, 2015	1,000
Aggregate Intrinsic Value, Options vested and expected to vest at March 31, 2015	$784,000

StockBased_Compensation_Additi

Stock-Based Compensation - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total fair value of options vested	$400,000	$600,000
Total unamortized stock-based compensation related to unvested stock options	3,200,000
Weighted-average recognition period, unvested stock options	2 years 9 months 7 days
Total intrinsic value of stock options exercised	1,000	200,000
Shares of common stock were available for grant under 2006 Equity Incentive Plan	5,601,204
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average recognition period, unvested stock options	3 years 6 months 18 days
Total fair value of shares vested pursuant to restricted stock units	100,000	2,000,000
Unamortized stock-based compensation related to unvested restricted stock units	$2,400,000

Summary_of_Restricted_Stock_Un

Summary of Restricted Stock Unit Activity (Detail) (Restricted Stock Units (RSUs), USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted Stock Units Outstanding, Balance at December 31, 2014	841
Restricted Stock Units Outstanding, Awarded	2,119
Restricted Stock Units Outstanding, Vested	-41
Restricted Stock Units Outstanding, Cancelled	-84
Restricted Stock Units Outstanding, Balance at March 31, 2015	2,835
Weighted-Average Fair Value When Awarded, Balance at December 31, 2014	$1.80
Weighted-Average Fair Value When Awarded, Awarded	$0.88
Weighted-Average Fair Value When Awarded, Vested	$2.51
Weighted-Average Fair Value When Awarded, Cancelled	$2.42
Weighted-Average Fair Value When Awarded, Balance at March 31, 2015	$1.09

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Income Tax Disclosure [Line Items]
Income tax provision	$9,000	$18,000
Uncertain benefit that none would affect effective tax rate	$4,300,000

Computation_of_Basic_and_Dilut

Computation of Basic and Diluted Net Income (Loss) per Share (Detail) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Schedule Of Computation Of Basic And Diluted Earnings Per Common Share [Line Items]
Net loss	($11,933)	($14,445)
Adjust: Dividend for Series A convertible preferred stock	-156
Net loss attributable to common stockholders	($12,089)	($14,445)
Shares used to compute basic and diluted net loss per share	133,283	103,334
Basic and diluted net loss per share	($0.09)	($0.14)

Securities_That_could_Potentia

Securities That could Potentially Dilute Basic Net Loss Per Share Not Included In Calculation of Diluted Net Loss per Common Share (Detail)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	8,481	7,268
Unvested restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	2,835	531
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	415	157
Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	63,115	23,425

Component_of_Accumulated_Other

Component of Accumulated Other Comprehensive Income (Loss), Net of Tax (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance	$305	$360
Net current-period other comprehensive gain (loss)	-166	85
Accumulated other comprehensive income (loss), ending balance	139	445
Unrealized Gains (Losses) on Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance	392	373
Net current-period other comprehensive gain (loss)	-102	83
Accumulated other comprehensive income (loss), ending balance	290	456
Foreign Currency Translation Gains (Losses)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance	-87	-13
Net current-period other comprehensive gain (loss)	-64	2
Accumulated other comprehensive income (loss), ending balance	($151)	($11)

Segment_Information_Additional

Segment Information - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Segment Reporting Information [Line Items]
Number of operating segments	1
Sales | Geographic Concentration Risk | United States
Segment Reporting Information [Line Items]
Concentration risk, percentage	34.00%	67.00%
Sales | Geographic Concentration Risk | China
Segment Reporting Information [Line Items]
Concentration risk, percentage	22.00%
Sales | Geographic Concentration Risk | Saudi Arabia
Segment Reporting Information [Line Items]
Concentration risk, percentage	14.00%
Sales | Geographic Concentration Risk | ITALY
Segment Reporting Information [Line Items]
Concentration risk, percentage	10.00%
Sales | Geographic Concentration Risk | Belgium
Segment Reporting Information [Line Items]
Concentration risk, percentage		10.00%

Information_Regarding_Total_Re

Information Regarding Total Revenue (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Revenue, Major Customer [Line Items]
Revenues	$5,794	$3,699
United States
Revenue, Major Customer [Line Items]
Revenues	1,962	2,490
International
Revenue, Major Customer [Line Items]
Revenues	$3,832	$1,209