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Document and Entity Information - USD ($)	12 Months Ended
Document and Entity Information - USD ($)	Dec. 31, 2014	Feb. 27, 2015	Jun. 30, 2014
Document Information [Line Items]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2014
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Trading Symbol	ETRM
Entity Registrant Name	EnteroMedics Inc
Entity Central Index Key	0001371217
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		73,789,178
Entity Public Float			$ 84,881,411

Consolidated Balance Sheets - USD ($)	Dec. 31, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 11,619,167	$ 23,297,479
Accounts receivable	2,812	17,742
Inventory	980,519	1,127,941
Prepaid expenses and other current assets	421,673	546,744
Total current assets	13,024,171	24,989,906
Property and equipment, net	481,522	577,095
Other assets	879,905	820,767
Total assets	14,385,598	26,387,768
Current liabilities:
Current portion of notes payable (net of discounts of $23,836 at December 31, 2014)	2,976,164	4,000,000
Accounts payable	399,336	127,329
Accrued expenses	3,830,766	4,186,060
Accrued interest payable	514,937	526,672
Total current liabilities	7,721,203	8,840,061
Notes payable, less current portion (net of discounts of $131,670 at December 31, 2013)		2,868,330
Total liabilities	7,721,203	11,708,391
Commitments and contingencies (Note 15)
Stockholders' equity:
Common stock, $0.01 par value; 200,000,000 and 125,000,000 shares authorized at December 31, 2014 and 2013, respectively; 69,570,444 and 63,551,350 shares issued and outstanding at December 31, 2014 and 2013, respectively	695,704	635,514
Additional paid-in capital	258,050,482	239,996,934
Accumulated deficit	(252,081,791)	(225,953,071)
Total stockholders' equity	6,664,395	14,679,377
Total liabilities and stockholders' equity	$ 14,385,598	$ 26,387,768

Consolidated Balance Sheets (Parenthetical) - USD ($)	Dec. 31, 2014	Dec. 31, 2013
Current portion of notes payable, discounts	$ 23,836
Notes payable, less current portion, discounts		$ 131,670
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	200,000,000	125,000,000
Common stock, shares issued	69,570,444	63,551,350
Common stock, shares outstanding	69,570,444	63,551,350

Consolidated Statements of Operations - USD ($)	12 Months Ended
Consolidated Statements of Operations - USD ($)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Sales			$ 311,493
Cost of goods sold			231,520
Gross profit			79,973
Operating expenses:
Research and development	$ 11,031,619	$ 11,075,493	10,668,044
Selling, general and administrative	14,561,656	13,658,824	11,960,893
Total operating expenses	25,593,275	24,734,317	22,628,937
Operating loss	(25,593,275)	(24,734,317)	(22,548,964)
Other income (expense):
Interest income	3,331	5,717	9,877
Interest expense	(530,222)	(932,364)	(901,835)
Other, net	(8,554)	(119,695)	(19,181)
Net loss	$ (26,128,720)	$ (25,780,659)	$ (23,460,103)
Net loss per share-basic and diluted	$ (0.39)	$ (0.47)	$ (0.59)
Shares used to compute basic and diluted net loss per share	67,866,427	55,009,916	39,536,500

Consolidated Statements of Comprehensive Loss - USD ($)	12 Months Ended
Consolidated Statements of Comprehensive Loss - USD ($)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Net loss	$ (26,128,720)	$ (25,780,659)	$ (23,460,103)
Change in unrealized gain (loss) on available for sale investments			(692)
Comprehensive loss	$ (26,128,720)	$ (25,780,659)	$ (23,460,795)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References + Details

Consolidated Statements of Stockholders' Equity (Deficit) - USD ($)	Total	Common Stock	Common Stock Maximum	Additional Paid-in Capital	Accumulated Other Comprehensive Income	Accumulated Deficit
Beginning Balance at Dec. 31, 2011	$ 20,040,905	$ 367,527		$ 196,384,995	$ 692	$ (176,712,309)
Beginning Balance (in shares) at Dec. 31, 2011		36,752,746
Net loss	(23,460,103)					(23,460,103)
Change in unrealized gain (loss) on available for sale investments	(692)				$ (692)
Employee stock-based compensation expense	4,173,132			4,173,132
Nonemployee stock-based compensation expense	52,190			52,190
Issuance of common stock in registered direct offering	4,682,129	$ 22,717		4,659,412
Issuance of common stock in registered direct offering (in shares)		2,271,705
Warrants issued for the purchase of shares of common stock	237,349			237,349
Exercise of common stock options	$ 12,666	$ 53		12,613
Exercise of common stock options (in shares)	5,219	5,219
Exercise of stock warrants	$ 6,137,095	$ 28,136		6,108,959
Exercise of stock warrants (in shares)	2,813,600	2,813,600
Ending Balance (in shares) at Dec. 31, 2012			41,843,270
Ending Balance at Dec. 31, 2012	$ 11,874,671	$ 418,433		211,628,650		(200,172,412)
Net loss	(25,780,659)					(25,780,659)
Employee stock-based compensation expense	5,788,249			5,788,249
Nonemployee stock-based compensation expense	166,679			166,679
Issuance of common stock in registered public offering	12,015,300	$ 137,700		11,877,600
Issuance of common stock in registered public offering (in shares)		13,770,000
Stock issued	10,587,117	$ 79,178		10,507,939
Stock issued (Shares)		7,917,755
Exercise of stock warrants	$ 28,020	$ 203		27,817
Exercise of stock warrants (in shares)	20,325	20,325
Ending Balance (in shares) at Dec. 31, 2013	63,551,350	63,551,350
Ending Balance at Dec. 31, 2013	$ 14,679,377	$ 635,514		239,996,934		(225,953,071)
Net loss	(26,128,720)					(26,128,720)
Employee stock-based compensation expense	6,138,384			6,138,384
Nonemployee stock-based compensation expense	181,323			181,323
Stock issued	9,551,766	$ 46,908		9,504,858
Stock issued (Shares)		4,690,824
Exercise of stock warrants	$ 2,242,265	$ 13,282		2,228,983
Exercise of stock warrants (in shares)	1,328,270	1,328,270
Ending Balance (in shares) at Dec. 31, 2014	69,570,444
Ending Balance (in shares) at Dec. 31, 2014		69,570,444
Ending Balance at Dec. 31, 2014	$ 6,664,395	$ 695,704		$ 258,050,482		$ (252,081,791)

Consolidated Statements of Stockholders' Equity (Deficit) (Parenthetical) - USD ($)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Stock issued, per share			$ 2.22
Issuance of common stock in registered direct offering for cash per share, financing costs			$ 367,871
Exercise of stock warrants (in shares)	1,328,270	20,325	2,813,600
Warrants issued for the purchase of stock (in shares)			106,746
Warrants issued, per share			$ 2.22
Exercise of common stock options (in shares)			5,219
Issuance of common stock and warrants to purchase number of shares of common stock		5,508,000
Issuance of common stock in public offering for cash per share		$ 0.95
Payments of stock issuance costs public offering		$ 1,066,200
At-The-Market
Payments of stock issuance costs public offering	$ 284,698	$ 381,981
Minimum
Exercise of stock warrants, per share	$ 1.14	$ 1.14	$ 1.9
Exercise of common stock options, per share			1.9
Minimum \| At-The-Market
Stock issued, per share	1.10	1.10
Maximum
Exercise of stock warrants, per share	2.19	1.9	2.19
Exercise of common stock options, per share			$ 2.58
Maximum \| At-The-Market
Stock issued, per share	$ 2.54	$ 2.10

Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
Consolidated Statements of Cash Flows - USD ($)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash flows from operating activities:
Net loss	$ (26,128,720)	$ (25,780,659)	$ (23,460,103)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	188,904	174,629	226,990
Loss on sale of equipment			767
Stock-based compensation	6,319,707	5,954,928	4,225,322
Amortization of commitment fees, debt issuance costs and original issue discount	123,068	199,592	207,310
Amortization of short-term investment premium or discount			4,719
Other, net		8,030
Change in operating assets and liabilities:
Accounts receivable	14,930	26,634	(52,406)
Inventory	147,422	143,266	(202,584)
Prepaid expenses and other current assets	125,071	24,910	233,145
Other assets	(74,372)	246,764	(813,063)
Accounts payable	267,356	60,732	(224,562)
Accrued expenses	(355,294)	512,451	(2,699,761)
Accrued interest payable	(11,735)	2,994	74,857
Net cash used in operating activities	(19,383,663)	(18,425,729)	(22,479,369)
Cash flows from investing activities:
Decrease in restricted cash		200,000
Maturities of short-term investments available for sale			1,000,000
Purchases of property and equipment	(88,680)	(416,010)	(76,394)
Net cash (used in) provided by investing activities	(88,680)	(216,010)	923,606
Cash flows from financing activities:
Proceeds from stock options exercised			12,666
Proceeds from warrants exercised	2,242,265	28,020	6,137,095
Proceeds from sale of common stock and warrants for purchase of common stock	9,836,464	24,050,598	5,050,000
Common stock financing costs	(284,698)	(1,448,181)	(367,871)
Proceeds from notes payable and convertible notes payable			5,347,807
Repayments on notes payable	(4,000,000)	(3,000,000)	(752,841)
Debt issuance costs			(50,000)
Net cash provided by financing activities	7,794,031	19,630,437	15,376,856
Net (decrease) increase in cash and cash equivalents	(11,678,312)	988,698	(6,178,907)
Cash and cash equivalents:
Beginning of period	23,297,479	22,308,781	28,487,688
End of period	11,619,167	23,297,479	22,308,781
Supplemental disclosure:
Interest paid	$ 418,889	$ 729,778	619,668
Noncash investing and financing activities:
Value of warrants issued with debt and for debt commitment			$ 237,349

Formation and Business of the Company

12 Months Ended

Dec. 31, 2014

Formation and Business of the Company

(1)

Formation and Business of the Company

EnteroMedics Inc. (EnteroMedics or the Company) is developing implantable systems to treat obesity, metabolic diseases and other gastrointestinal disorders. The Company was incorporated in the state of Minnesota on December 19, 2002, originally as two separate legal entities, Alpha Medical, Inc. and Beta Medical, Inc., both of which were owned 100% by a common stockholder. Effective October 1, 2003, the two entities were combined and the combined entity changed its name to EnteroMedics Inc. The Company reincorporated in Delaware on July 22, 2004. The Company has devoted substantially all of its resources to recruiting personnel, developing its product technology, obtaining patents to protect its intellectual property and raising capital, and thus far has only derived revenues from its primary business activity in 2012. The Company is headquartered in St. Paul, Minnesota.

EnteroMedics Europe Sárl (EnteroMedics Europe), a wholly owned subsidiary of the Company, was formed in January 2006. EnteroMedics Europe is a Swiss entity established as a means to conduct clinical trials in Switzerland. Upon establishment there were 20 shares of EnteroMedics Europe issued and outstanding with a par value of 1,000 Swiss Francs. EnteroMedics purchased 100% of the shares and then issued one share to a fiduciary agent. The one share is the property of EnteroMedics and is held by the fiduciary in a fiduciary capacity under terms of the Fiduciary Agreement. The functional currency of EnteroMedics Europe has been determined to be the U.S. Dollar.

EnteroMedics has incurred losses through December 31, 2014 and has not generated positive cash flows from operations. The Company expects such losses to continue into the foreseeable future as it continues to develop and commercialize its technologies. The Company may need to obtain additional financing and there can be no assurance that the Company will be successful in obtaining additional financing on favorable terms, or at all. If adequate funds are not available, the Company may have to delay development or commercialization of products or license to third parties the rights to commercialize products or technologies that the Company would otherwise seek to commercialize.

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2014

Summary of Significant Accounting Policies

(2)

Summary of Significant Accounting Policies

Basis of Presentation

The Company has prepared the accompanying consolidated financial statements in conformity with accounting principles generally accepted in the United States of America. The Company’s fiscal year ends on December 31.

Use of Estimates

The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates.

Principles of Consolidation

The consolidated financial statements include the accounts of the Company and its wholly owned subsidiary. All intercompany transactions and accounts have been eliminated in consolidation.

Concentration of Credit Risk and Other Risks and Uncertainties

Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash and cash equivalents. Cash and cash equivalents are primarily deposited in demand and money market accounts. At times, such deposits may be in excess of insured limits. Investments in money market funds are not considered to be bank deposits and are not insured or guaranteed by the federal deposit insurance company or other government agency. These money market funds seek to preserve the value of the investment at $1.00 per share; however, it is possible to lose money investing in these funds. The Company has not experienced any losses on its deposits of cash and cash equivalents.

Most of the products developed by the Company require approval from the U.S. Food and Drug Administration (FDA) or corresponding foreign regulatory agencies prior to commercial sales. The Company received FDA approval on January 14, 2015 for VBLOC therapy, delivered via the Maestro Rechargeable System, and has begun a controlled commercial launch at select bariatric centers of excellence in the United States. The Maestro Rechargeable System has also received CE Mark and is listed on the Australian Register of Therapeutic Goods.

The medical device industry is characterized by frequent and extensive litigation and administrative proceedings over patent and other intellectual property rights. Whether a product infringes a patent involves complex legal and factual issues, the determination of which is often difficult to predict, and the outcome may be uncertain until the court has entered final judgment and all appeals are exhausted. The Company’s competitors may assert that its products or the use of the Company’s products are covered by U.S. or foreign patents held by them.

The Company’s activities are subject to significant risk and uncertainties, including the ability to obtain additional financing and there can be no assurance that the Company will be successful in obtaining additional financing on favorable terms, or at all. If adequate funds are not available, the Company may have to delay development or commercialization of products or license to third parties the rights to commercialize products or technologies that the Company would otherwise seek to commercialize.

Fair Value of Financial Instruments

Carrying amounts of certain of the Company’s financial instruments, including cash and cash equivalents, restricted cash, accounts receivable, prepaid expenses and other current assets, accounts payable and accrued liabilities approximate fair value due to their short maturities. The fair values of investments in debt and equity securities, if any, are disclosed in Note 4. The fair value of the Company’s debt is approximately $3.4 million as of December 31, 2014 based on the present value of estimated future cash flows using a discount rate commensurate with borrowing rates available to the Company. If measured at fair value in the consolidated financial statements, long-term debt (including the current portion) would be classified as Level 2 in the fair value hierarchy.

Cash and Cash Equivalents

The Company considers highly liquid investments generally with maturities of 90 days or less when purchased to be cash equivalents. Cash equivalents are stated at cost, which approximates market value. The Company’s cash equivalents are primarily in money market funds and certificates of deposit. The Company deposits its cash and cash equivalents in high-quality credit institutions. Under terms of the Company’s notes payable agreements (see Note 8), in the event of default, the lender has the right to enforce account control agreements and restrict the Company’s access to their cash and investment accounts.

Restricted Cash

The Company had $200,000 in a cash collateral money market account as of December 31, 2012. Pursuant to the Lease Agreement the Company entered into with Roseville Properties Management Company in July 2008, the Company was required to deliver to Roseville Properties an irrevocable, unconditional, standby letter of credit in the amount of $200,000 on the second anniversary of the commencement of lease payments. The irrevocable standby letter of credit was issued by Silicon Valley Bank, who required the Company to set up a restricted cash collateral money market account to fully secure the standby letter of credit. The fully secured standby letter of credit was maintained through October 1, 2013, per the terms of the lease agreement.

Short-Term Investments

The Company considers all investments with maturities greater than three months and less than one year at the time of purchase as short-term investments and classifies them as either available for sale or held to maturity. The Company also considers certain investments with maturities greater than one year but which are also held for liquidity purposes and are available for sale as short-term investments.

Available-for-sale securities are carried at fair value based on quoted market prices, with the unrealized gains and losses included in other comprehensive income within stockholders’ equity (deficit) in the consolidated balance sheets. Realized gains and losses and declines in value judged to be other than temporary on available-for-sale securities are included in interest and other income. Interest and dividends on securities classified as available for sale are included in interest income. The cost of securities sold is based on the specific identification method.

Short-term investments in debt securities which the Company has the positive intent and ability to hold to maturity are reported at cost, adjusted for premiums and discounts that are recognized in interest income, using the interest method, over the period to maturity. Unrealized losses on held-to-maturity securities reflecting a decline in value determined to be other than temporary are charged to income.

Inventory

The Company accounts for inventory at the lower of cost or market and records any long-term inventory as other assets in the consolidated balance sheets.

Property and Equipment, Net

Property and equipment are stated at cost less accumulated depreciation and amortization. Depreciation of property and equipment is computed using the straight-line method over their estimated useful lives of five to seven years for furniture and equipment and three to five years for computer hardware and software. Leasehold improvements are amortized on a straight-line basis over the lesser of their useful life or the term of the lease. Upon retirement or sale, the cost and related accumulated depreciation or amortization are removed from the consolidated balance sheets and the resulting gain or loss is reflected in the consolidated statements of operations. Repairs and maintenance are expensed as incurred.

Impairment of Long-Lived Assets

The Company evaluates its long-lived assets for impairment by comparison of the carrying amounts to future net undiscounted cash flows expected to be generated by such assets when events or changes in circumstances indicate the carrying amount of an asset may not be recoverable. Should an impairment exist, the impairment loss would be measured based on the excess carrying value of the asset over the asset’s fair value or estimates of future discounted cash flows. The Company has not identified any such impairment losses to date.

Income Taxes

Income taxes are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carry-forwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. A valuation allowance for deferred income tax assets is recorded when it is more likely than not that some portion or all of the deferred income tax assets will not be realized. The Company has provided a full valuation allowance against the gross deferred tax assets as of December 31, 2014 and 2013 (see Note 11). The Company’s policy is to classify interest and penalties related to income taxes as income tax expense in the consolidated statements of operations.

Comprehensive Loss

Comprehensive loss is defined as the change in equity of a company during a period from transactions and other events and circumstances excluding transactions resulting from investment owners and distributions to owners. There was no difference from reported net loss for the years ended December 31, 2014 and 2013. The difference from reported net loss for the year ended December 31, 2012 related entirely to changes in unrealized gains (losses) on available-for-sale investments.

Revenue Recognition

Revenue is recognized when persuasive evidence of an arrangement exists, title or risk of loss has passed, the selling price is fixed or determinable and collection is reasonably assured. Products are sold internationally through distributors and revenue is recognized upon sale to the distributor as these sales are considered to be final and no right of return or price protection exists. Terms of sales to international distributors are generally EXW, reflecting that goods are shipped “ex works,” in which risk of loss is assumed by the distributor at the shipping point. We do not provide for rights of return to customers on product sales and therefore do not record a provision for returns.

Research and Development Expenses

Research and development expenses are charged to expense as incurred. Research and development expenses include, but are not limited to, product development, clinical trial expenses, including supplies, devices, explants and revisions, quality assurance, regulatory expenses, payroll and other personnel expenses, materials and consulting costs.

Patent Costs

Costs associated with the submission of a patent application are expensed as incurred given the uncertainty of the patents resulting in probable future economic benefits to the Company. Patent-related legal expenses included in general and administrative costs were $338,055, $296,575 and $278,987 for the years ended December 31, 2014, 2013 and 2012, respectively.

Derivative Instruments

The Company accounts for outstanding warrants that are not indexed to the Company’s stock or warrants issued when the Company has insufficient authorized and unissued stock available to share settle the outstanding warrants as derivative instruments, which require that the warrants be classified as a liability and measured at fair value with changes in fair value recognized currently in earnings and recorded separately in the consolidated statements of operations. The Company did not have any such instruments during the years ended December 31, 2014, 2013 and 2012.

Stock-Based Compensation

The fair value method is applied to all share-based payment awards issued to employees and where appropriate, nonemployees, unless another source of literature applies. When determining the measurement date of a nonemployee’s share-based payment award, the Company measures the stock options at fair value and remeasures such stock options to the current fair value until the performance date has been reached. All option grants are expensed on a straight-line basis over the vesting period.

Net Loss Per Share

Basic net loss per share is computed by dividing net loss by the weighted-average number of common shares outstanding during the period. Diluted net loss per share is based on the weighted-average common shares outstanding during the period plus dilutive potential common shares calculated using the treasury stock method. Such potentially dilutive shares are excluded when the effect would be to reduce a net loss per share. The Company’s potential dilutive shares, which include outstanding common stock options and warrants, have not been included in the computation of diluted net loss per share for all periods as the result would be anti-dilutive.

The following table sets forth the computation of basic and diluted net loss per share for the years ended December 31, 2014, 2013 and 2012:


	Years ended December 31,
	2014			2013			2012
Numerator:
Net loss	$	(26,128,720	)	$	(25,780,659	)	$	(23,460,103	)

Denominator for basic and diluted net loss per share:
Weighted-average common shares outstanding		67,866,427			55,009,916			39,536,500

Net loss per share—basic and diluted	$	(0.39	)	$	(0.47	)	$	(0.59	)

The following table sets forth the potential shares of common stock that are not included in the calculation of diluted net loss per share because to do so would be anti-dilutive as of the end of each period presented:


	December 31,
	2014		2013		2012
Stock options outstanding		12,655,792		11,687,300		7,835,533
Warrants to purchase common stock		24,199,705		25,550,625		21,216,447

Recently Issued Accounting Standards

In June 2014, the Financial Accounting Standards Board (FASB) issued Development Stage Entities, Topic 915 (Accounting Standards Update No. 2014-10 (ASU 2014-10)), which eliminates certain financial reporting requirements, with the objective of improving financial reporting by reducing the cost and complexity associated with the incremental reporting requirements for development stage entities. This guidance is effective for interim and annual reporting periods beginning after December 15, 2014; however, early application is permitted for any annual reporting period or interim period for which an entity’s financial statements have not yet been issued. The Company elected to adopt ASU 2014-10 effective with the quarter ending June 30, 2014. Therefore, the accompanying consolidated financial statements no longer present or disclose any information previously required by Topic 915.

In May 2014, FASB issued Revenue from Contracts with Customers, Topic 606 (Accounting Standards Update No. 2014-09 (ASU 2014-09)), which provides a framework for the recognition of revenue, with the objective that recognized revenues properly reflect amounts an entity is entitled to receive in exchange for goods and services. This guidance will be effective for interim and annual reporting periods beginning after December 15, 2016. The Company is currently evaluating the impact of adopting ASU 2014-09 on its consolidated financial statements.

Various other accounting standards and interpretations have been issued with 2014 effective dates and effective dates subsequent to December 31, 2014. We have evaluated the recently issued accounting pronouncements that are currently effective or will be effective in 2015 and believe that none of them have had or will have a material effect on our financial position, results of operations or cash flows.

Liquidity and Management's Plans

12 Months Ended

Dec. 31, 2014

Liquidity and Management's Plans

(3)

Liquidity and Management’s Plans

The accompanying consolidated financial statements have been prepared assuming the Company will continue as a going concern. The Company has financed its operations to date principally through the sale of equity securities, debt financing and interest earned on investments. As of December 31, 2014, the Company had $11.6 million of cash and cash equivalents to fund its anticipated operations for 2015 and also has an “at-the-market” equity offering program (ATM) under which it can raise additional funds by instructing Cowen and Company, LLC (Cowen), the Company’s sales agent, to sell shares of the Company’s common stock having aggregate gross sales proceeds of up to $25.0 million (the Cowen ATM), of which $17.6 million remains available as of March 13, 2015 (further described in Note 10). These anticipated operations include plans that consider the controlled commercial launch of VBLOC therapy, delivered via the Maestro Rechargeable System, which was approved by the FDA on January 14, 2015. In order to finance these anticipated operations, including the increase in internal expenditures resulting from the controlled commercial launch noted above, the Company has raised $6.4 million in gross proceeds before deducting offering expenses from the Cowen ATM subsequent to December 31, 2014 through March 13, 2015. In addition, the Company believes that it has the ability to raise additional capital through (i) the sale of additional equity securities, including, but not limited to, the use of the Cowen ATM and the exercise of outstanding warrants; (ii) the sale of debt securities; or (iii) establishing a credit facility, and has the flexibility to manage the growth of its expenditures and expand operations.

Short-term Investments and Fair Value Measurements

12 Months Ended

Dec. 31, 2014

Short-term Investments and Fair Value Measurements

(4)

Short-term Investments and Fair Value Measurements

Fair value of financial assets and liabilities is defined as the price that would be received to sell an asset or transfer a liability in an orderly transaction between market participants at the measurement date. A fair value hierarchy has been established that prioritizes the inputs to valuation techniques used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements). The three levels of the fair value hierarchy are described below:

•

Level 1—Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities.

•

Level 2—Quoted prices for similar assets and liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active or model-derived valuations for which all significant inputs are observable, either directly or indirectly.

•

Level 3—Prices or valuation techniques that require inputs that are both significant to the fair value measurement and unobservable.

The Company’s assets that are measured at fair value on a recurring basis are classified within Level 1 or Level 2 of the fair value hierarchy. The Company does not hold any assets that are measured at fair value using Level 3 inputs. The types of instruments the Company invests in that are valued based on quoted market prices in active markets include U.S. treasury securities. Such instruments are classified by the company within Level 1 of the fair value hierarchy. U.S. treasuries are valued using unadjusted quoted prices for identical assets in active markets that the Company can access.

The types of instruments the Company invests in that are valued based on quoted prices in less active markets, broker or dealer quotations, or alternative pricing sources with reasonable levels of price transparency include the Company’s U.S. agency securities, commercial paper, U.S. corporate bonds and municipal obligations. Such instruments are classified by the Company within Level 2 of the fair value hierarchy. The Company values these types of assets using consensus pricing or a weighted average price, which is based on multiple pricing sources received from a variety of industry standard data providers (e.g. Bloomberg), security master files from large financial institutions, and other third-party sources. The multiple prices obtained are then used as inputs into a distribution-curve-based algorithm to determine the daily market price.

The Company did not hold any short-term investments classified as available for sale or held to maturity as of December 31, 2014 and 2013.

Inventory

12 Months Ended

Dec. 31, 2014

Inventory

(5)

Inventory

From inception, inventory related purchases had been used for research and development related activities and had accordingly been expensed as incurred. In December 2011, the Company began receiving Australian Register of Therapeutic Goods (ARTG) listings for components of the Maestro Rechargeable System from the Australian Therapeutic Goods Administration (TGA), with the final components being listed on the ARTG in January 2012. As a result, the Company determined certain assets were recoverable as inventory beginning in December 2011. The Company accounts for inventory at the lower of cost or market and records any long-term inventory as other assets in the consolidated balance sheets. There was approximately $825,000 and $794,000 of long-term inventory, primarily consisting of raw materials, as of December 31, 2014 and 2013, respectively.

Current inventory consists of the following as of:


	December 31,
	2014		2013
Raw materials	$	322,157	$	385,565
Work-in-process		632,615		624,530
Finished goods		25,747		117,846

Inventory	$	980,519	$	1,127,941

Property and Equipment

12 Months Ended

Dec. 31, 2014

Property and Equipment

(6)

Property and Equipment

Property and equipment consists of the following as of:


	December 31,
	2014			2013
Furniture and equipment	$	2,295,433		$	2,274,633
Computer hardware and software		556,556			499,922
Leasehold improvements		62,651			46,754

		2,914,640			2,821,309
Less accumulated depreciation and amortization		(2,433,118	)		(2,244,214	)

Property and equipment, net	$	481,522		$	577,095

Accrued Expenses

12 Months Ended

Dec. 31, 2014

Accrued Expenses

(7)

Accrued Expenses

Accrued expenses consists of the following as of:


	December 31,
	2014		2013
Professional service related expenses	$	2,107,712	$	2,650,163
Payroll related expenses		1,267,141		1,043,028
Other expenses		455,913		492,869

Accrued expenses	$	3,830,766	$	4,186,060

Notes Payable

12 Months Ended

Dec. 31, 2014

Notes Payable

(8)

Notes Payable

Notes payable consists of the following as of:


	December 31,
	2014			2013
Growth capital loan dated April 16, 2012 (net of discounts of $23,836 and $131,670 at December 31, 2014 and 2013, respectively)	$	2,976,164		$	6,868,330
Less current portion		(2,976,164	)		(4,000,000	)

Total long-term debt	$	—		$	2,868,330

On April 16, 2012, the Company entered into a Loan and Security Agreement (the Loan Agreement) with Silicon Valley Bank (SVB) pursuant to which SVB agreed to make term loans in an aggregate principal amount of up to $20.0 million ($10.0 million of which is not available as the Company did not meet the predefined primary efficacy measures of the ReCharge trial and did not meet certain financial objectives for 2012), on the terms and conditions set forth in the Loan Agreement.

Pursuant to the Loan Agreement, a term loan was funded in the aggregate principal amount of $10.0 million on April 23, 2012, a portion of which was used to repay in full outstanding debt of approximately $4.7 million. The term loan required interest only payments monthly through March 31, 2013 followed by 30 equal payments of principal in the amount of $333,333 plus accrued interest beginning on April 1, 2013 and ending on September 1, 2015, payable monthly. Amounts borrowed under the Loan Agreement bear interest at a fixed annual rate equal to 8.0%. A 5.0% final payment fee will be due on September 1, 2015. The Company may voluntarily prepay the term loan in full, but not in part, and any voluntary or mandatory prepayment is subject to applicable prepayment premiums and will also include the final payment fee. The Company was required to comply with certain financial covenants that required the Company to generate certain minimum amounts of revenue from the sale of its Maestro Rechargeable System and to implant certain minimum numbers of Maestro Rechargeable Systems during cumulative quarterly measurement periods beginning with the period ended March 31, 2013 and ending with the period ending June 30, 2015. The Company did not meet the financial covenants for the period ended March 31, 2013 and therefore entered into a First Amendment (the First Amendment) to the Loan Agreement on May 9, 2013 pursuant to which the Company and SVB agreed to new financial covenants.

The First Amendment eliminated the financial covenants that required the Company to generate certain minimum amounts of revenue from the sale of its Maestro Rechargeable System and to implant certain minimum numbers of Maestro Rechargeable Systems during cumulative quarterly measurement periods beginning with the period ended March 31, 2013 and ending with the period ending June 30, 2015. It also removed SVB’s ability to require the Company to maintain a restricted cash balance of $7.5 million in an SVB account as a result of the Company not meeting the predefined primary efficacy measures of the ReCharge trial.

The First Amendment added two new financial covenants, one of which required the Company to receive cumulative aggregate net proceeds of at least $5.0 million by November 15, 2013 and $10.0 million by April 15, 2014 from new capital transactions, both of which have been fulfilled through the use of the equity distribution agreement with Canaccord Genuity Inc. (see Note 10). The second financial covenant required the Company to maintain a liquidity ratio (unrestricted cash divided by outstanding debt) of at least 1.25:1.00 until it received FDA approval for the Maestro Rechargeable System on January 14, 2015, at which point it was reduced to 0.75:1.00. The First Amendment did not change the interest rate or the amortization structure. The Company is required to pay SVB a $187,000 success fee as a result of receiving FDA approval for the Maestro Rechargeable System on January 14, 2015.

The Company has granted SVB a security interest in all of the Company’s assets, excluding intellectual property except with respect to all license, royalty fees and other revenues and income arising out of or relating to any of the intellectual property and all proceeds of the intellectual property. The Company also has entered into a negative pledge arrangement with SVB pursuant to which it has agreed not to encumber any of its intellectual property without SVB’s prior written consent.

Pursuant to the Loan Agreement, on April 16, 2012, the Company issued SVB a warrant to purchase 106,746 shares of common stock, exercisable for ten years from the date of grant, at an exercise price of $2.34 per share.

Scheduled debt principal payments are as follows as of December 31, 2014:


Year ending December 31:
2015	$	3,000,000

Less original issue discount		(23,836	)

Notes payable, net	$	2,976,164

Preferred Stock

12 Months Ended

Dec. 31, 2014

Preferred Stock

(9)

Preferred Stock

The Company’s Amended and Restated Certificate of Incorporation currently authorizes 5,000,000 shares of $0.01 par value preferred stock. As of December 31, 2014 and 2013, there were no shares of preferred stock issued or outstanding.

Stock Sales

12 Months Ended

Dec. 31, 2014

Stock Sales

(10)

Stock Sales

Registered Direct Offering—April 2012

On April 16, 2012, the Company entered into a securities purchase agreement with a current investor for the sale of 2,271,705 shares of its common stock in a registered direct offering, at a purchase price of $2.22 per share. On April 20, 2012, the offering closed and the Company received gross proceeds of $5.0 million before deducting offering expenses.

Public Offering—February 2013

On February 27, 2013, the Company closed a public offering, selling 13,770,000 shares of common stock, together with warrants to purchase approximately 5,508,000 shares of common stock at an aggregate price of $0.95 per share and corresponding warrant, for gross proceeds of $13.1 million before deducting offering expenses. Certain directors of the Company participated in the public offering (see Note 14).

The warrants have an exercise price of $1.14 per share of common stock and are exercisable for a period of five years from February 27, 2013. Holders of the warrants are not permitted to exercise those warrants for an amount of common stock that would result in the holder owning more than 19.99% of the Company’s common stock.

Equity Distribution Agreement—July 2013

On July 31, 2013, the Company entered into an equity distribution agreement with Canaccord Genuity Inc. (Canaccord) to sell shares of the Company’s common stock having aggregate gross sales proceeds of up to $20.0 million, from time to time, through an ATM under which Canaccord acted as the Company’s sales agent (the Canaccord ATM). The Company determined, at its sole discretion, the timing and number of shares sold under the Canaccord ATM. The Company paid Canaccord a commission for its services in acting as agent in the sale of common stock equal to 2.0% of the gross sales price per share of all shares sold through it as agent under the equity distribution agreement. During 2013 the Company sold 7,917,755 shares under the Canaccord ATM at a weighted-average selling price of $1.39 per share for gross proceeds of $11.0 million before deducting offering expenses. During 2014 the Company sold an additional 4,006,222 shares under the Canaccord ATM at a weighted-average selling price of $2.22 per share for gross proceeds of $8.9 million before deducting offering expenses. The equity distribution agreement with Canaccord was terminated effective June 10, 2014. As of the termination date, the Company had sold a total of 11,923,977 shares under the Canaccord ATM at a weighted-average selling price of $1.67 per share for gross proceeds of $19.9 million before deducting offering expenses.

Sales Agreement—June 2014

On June 13, 2014, the Company entered into a sales agreement with Cowen and Company, LLC (Cowen) to sell shares of the Company’s common stock having aggregate gross sales proceeds of up to $25.0 million, from time to time, through an ATM under which Cowen will act as the Company’s sales agent (the Cowen ATM). The Company will determine, at its sole discretion, the timing and number of shares to be sold under the Cowen ATM. The Company will pay Cowen a commission for its services in acting as agent in the sale of common stock equal to 3.0% of the gross sales price per share of all shares sold through it as agent under the sales agreement. As of December 31, 2014, the Company had sold 684,602 shares under the Cowen ATM at a weighted-average selling price of $1.35 per share for gross proceeds of $927,000 before deducting offering expenses. Subsequent to December 31, 2014 through March 13, 2015, the Company has sold 4,627,934 shares under the Cowen ATM at a weighted-average selling price of $1.39 per share for gross proceeds of $6.4 million before deducting offering expenses.

Income Taxes

12 Months Ended

Dec. 31, 2014

Income Taxes

(11)

Income Taxes

The Company has incurred net operating losses (NOLs) since inception. The Company has not reflected any benefit of such net operating loss carryforwards in the accompanying consolidated financial statements.

The income tax expense benefit differed from the amount computed by applying the U.S. federal income tax rate of 34% to income before income taxes as a result of the following:


	2014			2013			2012
Computed ‘expected’ tax benefit		34.0	%		34.0	%		34.0	%
Other permanent adjustments		-2.3	%		-2.3	%		-2.2	%
Research and development credit		0.3	%		3.5	%		0.0	%
Federal valuation allowance		-32.0	%		-35.2	%		-31.8	%

		0.0	%		0.0	%		0.0	%

The tax effect of temporary differences that give rise to significant portions of the deferred tax assets as of December 31 is presented below:


	2014			2013
Deferred tax assets (liabilities):
Start-up costs	$	8,739,000		$	8,851,000
Capitalized research and development costs		30,276,000			24,844,000
Reserves and accruals		6,052,000			4,530,000
Property and equipment		94,000			105,000
Research and development credit		1,636,000			1,508,000
Net operating loss carryforwards		16,656,000			12,198,000

Total gross deferred tax assets		63,453,000			52,036,000
Valuation allowance		(63,453,000	)		(52,036,000	)

Net deferred tax assets	$	—		$	—

In assessing the realization of deferred tax assets, management considers whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during periods in which those temporary differences become deductible. In addition, certain limitations imposed under the Internal Revenue Code (IRC) could further limit the Company’s realization of these deferred tax assets in the event of changes in ownership of the Company (as described below).

Based on the level of historical taxable losses and projections of future taxable income (losses) over the periods in which the deferred tax assets can be realized, management currently believes that it is more likely than not that the Company will not realize the benefits of these deductible differences. Accordingly, the Company has provided a valuation allowance against the gross deferred tax assets as of December 31, 2014 and 2013.

As of December 31, 2014, the Company has generated U.S. federal net operating loss carryforwards of approximately $91.9 million. Of this amount, approximately $44.0 million is available after the application of Section 382 limitations described below. Of the total federal net operating loss, $221,000 would result in tax benefits recorded to additional paid-in capital. The federal net operating loss carryforwards expire in the years 2022 through 2034.

The IRC imposes restrictions on the utilization of various carryforward tax attributes in the event of a change in ownership of the Company, as defined by IRC Section 382. In addition, IRC Section 382 may limit the Company’s built-in items of deduction, including capitalized start-up costs and research and development costs. During 2011, the Company completed an IRC Section 382 review and the results of this review indicate ownership changes have occurred which would cause a limitation on the utilization of carryforward attributes. The Company’s gross net operating loss carryforwards, start-up costs and research and development credits are all subject to limitation. Under these tax provisions, the limitation is applied first to any built-in losses, then to any net operating losses and then to any general business credits. The Section 382 limitation and accompanying recognized built-in loss limitation is currently estimated to result in the expiration of $48.1 million of the Company’s gross federal net operating loss carryforward, as well as a write-off of $5.9 million of capitalized start-up costs, $5.5 million of capitalized research and development costs, $1.5 million of property and equipment and $2.4 million of research and development credits. Any ownership changes since we completed the IRC Section 382 review in 2011 could result in further limitations on the utilization of carryforward attributes.

As of December 31, 2014 and 2013, there were no unrecognized tax benefits. Accordingly, a tabular reconciliation from beginning to ending periods is not provided. The Company will classify any future interest and penalties as a component of income tax expense if incurred. To date, there have been no interest or penalties charged or accrued in relation to unrecognized tax benefits.

The Company does not anticipate that the total amount of unrecognized tax benefits will change significantly in the next twelve months.

The Company is subject to U.S. federal examinations for the years 2011 forward. With limited exceptions, the Company is no longer subject to U.S. federal, state or local examinations by tax authorities for years prior to 2011. There are no U.S. federal tax examinations currently in progress.

The Company’s Minnesota Corporation Franchise Tax returns for tax years ending December 31, 2010 through December 31, 2013, are currently under review.

Stock Options

12 Months Ended

Dec. 31, 2014

Stock Options

(12)

Stock Options

The Company has adopted the Amended and Restated 2003 Stock Incentive Plan (the Plan) that includes both incentive stock options and nonqualified stock options to be granted to employees, officers, consultants, independent contractors, directors and affiliates of the Company. At December 31, 2014 and 2013, according to the Plan, 19,800,000 and 12,300,000 shares, respectively have been authorized and reserved. The board of directors establishes the terms and conditions of all stock option grants, subject to the Plan and applicable provisions of the IRC. Incentive stock options must be granted at an exercise price not less than the fair market value of the common stock on the grant date. The options granted to participants owning more than 10% of the Company’s outstanding voting stock must be granted at an exercise price not less than 110% of fair market value of the common stock on the grant date. The options expire on the date determined by the board of directors, but may not extend more than 10 years from the grant date, while incentive stock options granted to participants owning more than 10% of the Company’s outstanding voting stock expire five years from the grant date. The vesting period for employees is generally over four years. The vesting period for nonemployees is determined based on the services being provided.

On May 7, 2014, the annual meeting of stockholders was held and the stockholders approved the Amended and Restated 2003 Stock Incentive Plan which authorized an additional 7,500,000 shares for issuance under the Plan.

Stock option activity is as follows:


	Shares Available For Grant			Outstanding Options					Aggregate Intrinsic Value
	Shares Available For Grant			Number of Shares			Weighted-Average Exercise Price		Aggregate Intrinsic Value
Balance, December 31, 2011		763,829			3,470,908		$	3.17
Shares reserved		8,000,000			—			—
Options granted		(4,462,873	)		4,462,873			3.35
Options exercised		—			(5,219	)		2.43
Options cancelled		93,029			(93,029	)		2.79

Balance, December 31, 2012		4,393,985			7,835,533			3.28
Shares reserved		—			—			—
Options granted		(4,346,000	)		4,346,000			1.32
Options exercised		—			—			—
Options cancelled		494,233			(494,233	)		3.00

Balance, December 31, 2013		542,218			11,687,300			2.56	$	3,284,696

Shares reserved		7,500,000			—			—
Options granted		(1,257,500	)		1,257,500			1.63
Options exercised		—			—			—
Options cancelled		289,008			(289,008	)		2.41

Balance, December 31, 2014		7,073,726			12,655,792		$	2.47	$	519,622

The options outstanding, vested and currently exercisable by exercise price at December 31, 2014:


	Outstanding Options and Expected to Vest						Options Exercisable and Vested
Exercise Price	Number of Shares Outstanding		Weighted-Average Remaining Contractual Life (Years)		Aggregate Intrinsic Value		Number of Options		Weighted-Average Exercise Price		Aggregate Intrinsic Value
$0.01 to $2.00		6,310,699		8.0	$	519,622		2,766,588	$	1.52	$	216,439
$2.01 to $3.00		2,146,297		5.9		—		1,963,787		2.63		—
$3.01 to $5.00		4,085,480		7.4		—		2,529,663		3.41		—
$5.01 to $10.00		4,166		4.1		—		4,166		8.40		—
> $10.00		109,150		3.3		—		109,150		23.54		—

		12,655,792			$	519,622		7,373,354	$	2.79	$	216,439

Stock-Based Compensation for Nonemployees

Stock-based compensation expenses related to stock options granted to nonemployees is recognized as the stock options are earned. The Company believes that the fair value of the stock options is more reliably measurable than the fair value of the services received. The fair value of the stock options granted is calculated at each reporting date, using the Black-Scholes option-pricing model, until the award vests or there is a substantial disincentive for the nonemployee not to perform the required services. The fair value for the years ended December 31, 2014, 2013 and 2012 was calculated using the following assumptions, defined below:


	Years Ended December 31,
	2014	2013	2012
Risk-free interest rates	0.08%–2.63%	0.26%–2.98%	0.24%–2.05%
Expected life	0.50 years–9.51 years	1.50 years–9.76 years	2.00 years–9.25 years
Expected dividends	0%	0%	0%
Expected volatility	56.54%–139.65%	80.00%–143.00%	63.48%–142.25%

Stock-based compensation expense charged to operations on options granted to nonemployees for the years ended December 31, 2014, 2013 and 2012 was $181,323, $166,679 and $52,190, respectively.

Employee Stock-Based Awards

Compensation cost for employee stock-based awards is based on the estimated grant-date fair value and is recognized over the vesting period of the applicable award on a straight-line basis. The weighted average estimated fair value of the employee stock options granted for the years ended December 31, 2014, 2013 and 2012 was $1.42, $1.22 and $3.19 per share, respectively.

The Company uses the Black-Scholes pricing model to determine the fair value of stock options. The determination of the fair value of stock-based payment awards on the date of grant is affected by the Company’s stock price as well as assumptions regarding a number of complex and subjective variables. These variables include the Company’s expected stock price volatility over the term of the awards, actual and projected employee stock option exercise behaviors, risk-free interest rates and expected dividends. The estimated grant-date fair values of the employee stock options were calculated using the Black-Scholes valuation model, based on the following assumptions for the years ended December 31, 2014, 2013 and 2012:


	Years Ended December 31,
	2014	2013	2012
Risk-free interest rates	1.73%–1.96%	0.94%–1.33%	0.90%–1.09%
Expected life	6.00 years–6.25 years	6.00 years–6.25 years	6.00 years–6.25 years
Expected dividends	0%	0%	0%
Expected volatility	118.64%–120.70%	148.00%–149.00%	137.58%–143.98%

Expected Life. The expected life is based on the “simplified” method described in the SEC Staff Accounting Bulletin, Topic 14: Share-Based Payment.

Volatility. Since the Company was a private entity for most of 2007 and a limited amount of historical data regarding the volatility of its common stock was available, the expected volatility used for 2012 was based on both the volatility of similar entities, referred to as “guideline” companies, and the Company’s historical volatility. In evaluating similarity, the Company considered factors such as industry, stage of life cycle and size. Effective with the year ended December 31, 2013, the expected volatility was based solely on the Company’s historical volatility.

Risk-Free Interest Rate. The risk-free rate is based on the daily yield curve rate from the U.S. Treasury with remaining terms similar to the expected term on the options.

Dividend Yield. The Company has never declared or paid any cash dividends and does not plan to pay cash dividends in the foreseeable future, and, therefore, used an expected dividend yield of zero in the valuation model.

Forfeitures. The Company is required to estimate forfeitures at the time of grant, and revise those estimates in subsequent periods if actual forfeitures differ from those estimates. The Company uses historical data to estimate pre-vesting option forfeitures and record stock-based compensation expense only for those awards that are expected to vest. All stock-based payment awards are amortized on a straight-line basis over the requisite service periods of the awards, which are generally the vesting periods. If the Company’s actual forfeiture rate is materially different from its estimate, the stock-based compensation expense could be significantly different from what the Company has recorded in the current period.

As of December 31, 2014 there was approximately $9.2 million of total unrecognized compensation costs, net of estimated forfeitures, related to employee unvested stock option awards, which are expected to be recognized over a weighted-average period of 2.00 years.

There were no stock option exercises for the years ended December 31, 2014 and 2013. The aggregate intrinsic value of stock options (the amount by which the market price of the stock on the date of exercise exceeded the exercise price of the option) exercised during the year ended December 31, 2012, was $3,044.

Warrants

12 Months Ended

Dec. 31, 2014

Warrants

(13)

Warrants

Stock warrant activity is as follows:


	Common Shares			Price(1)
Balance, December 31, 2011		23,923,301		$	2.55
Granted(2)		106,746			2.34
Exercised		(2,813,600	)		2.18
Cancelled		—			—

Balance, December 31, 2012		21,216,447			2.60
Granted(2)		5,508,000			1.14
Exercised		(20,325	)		1.38
Cancelled		(1,153,497	)		9.14

Balance, December 31, 2013		25,550,625			1.99
Granted		—			—
Exercised		(1,328,270	)		1.69
Cancelled		(22,650	)		48.56

Balance, December 31, 2014		24,199,705		$	1.96

(1)	Represents weighted-average exercise price per share.

(2)	See Notes 8 and 10 for discussions relating to the issuance of warrants in 2013 and 2012.

At December 31, 2014 and 2013, the weighted-average remaining contractual life of outstanding warrants was 1.85 and 2.87 years, respectively. All of the warrants outstanding are currently exercisable at the option of the holder into the equivalent number of shares of common stock.

Related Party Transactions

12 Months Ended

Dec. 31, 2014

Related Party Transactions

(14)

Related Party Transactions

Public Offerings

As discussed in Note 10, on February 27, 2013, the Company closed a public offering, selling 13,770,000 shares of common stock, together with warrants to purchase approximately 5,508,000 shares of common stock at an aggregate price of $0.95 per share and corresponding warrant. The following principal stockholder purchased shares of common stock and warrants at a price of $0.95 per share and corresponding warrant. The shares purchased, together with the proceeds, before expenses, to the Company, are shown in the table below:


Beneficial Owner	Shares Purchased		Warrants Purchased		Proceeds, before expenses, to the Company
Anthony Jansz		150,000		60,000	$	142,500

Anthony Jansz is a director of the Company.

Consulting Agreement—Anthony Jansz

Effective June 1, 2011, the Company entered into a four year consulting agreement with Anthony Jansz, who is a member of the board of directors. Pursuant to the agreement, in exchange for consulting services provided, Mr. Jansz was entitled to receive a consulting fee of $96,000 AUD (approximately $79,000 USD as of December 31, 2014) per year and the reimbursement of reasonable expenses. Mr. Jansz also received an option to purchase 50,000 shares of common stock at $2.76 per share that vests in 48 equal monthly installments beginning on July 1, 2011. The full grant date fair value of the option grant was approximately $108,000.

On December 20, 2012, the Company entered into an amendment, effective October 1, 2012, to the consulting agreement with Mr. Jansz. Pursuant to the amendment, during the period from October 1, 2012 until June 30, 2013, Mr. Jansz agreed to commit additional time to performing consulting services for the Company. In exchange for these additional services, Mr. Jansz was entitled to receive a consulting fee of $12,000 AUD (approximately $10,000 USD as of December 31, 2014) per month from October 1, 2012 until June 30, 2013. Mr. Jansz also received an option to purchase 75,000 shares of the Company’s common stock on January 22, 2013 at $2.65 per share, which vests as follows: (A) 16,667 of such 75,000 shares vested on January 22, 2013, the date of grant; (B) 16,667 of such 75,000 shares vested on January 22, 2014; (C) 16,666 of such 75,000 shares vested on January 22, 2015; and (D) the remaining 25,000 of such 75,000 shares would have vested upon the occurrence of both (i) the Company successfully obtaining full Australian reimbursement approval for both surgeon’s fees and hospital fees for VBLOC therapy and the Maestro Rechargeable System from the Australian Medical Services Advisory Committee prior to June 30, 2014 and (ii) the Company successfully obtaining device listing for the Maestro Rechargeable System on the Australian Prostheses List prior to June 30, 2014. The full grant date fair value of the option grant was approximately $153,000. The Company did not successfully obtain full Australian reimbursement approval for both surgeon’s fees and hospital fees for VBLOC therapy and the Maestro Rechargeable System from the Australian Medical Services Advisory Committee prior to June 30, 2014 nor a device listing for the Maestro Rechargeable System on the Australian Prostheses List prior to June 30, 2014 resulting in 25,000 shares not vesting.

The Company continued to pay Mr. Jansz a consulting fee of $12,000 AUD per month subsequent to June 30, 2013 as a result of the additional time he continued to spend providing consulting services to the Company. Mr. Jansz also received an additional option to purchase 100,000 shares of the Company’s common stock on May 31, 2013 at $1.31 per share, which vests as follows: (A) 16,667 of such 100,000 shares vested on May 31, 2013, the date of the grant; (B) 16,667 of such 100,000 shares vested on May 31, 2014; (C) 16,666 of such 100,000 shares will vest on May 31, 2015; (D) 25,000 of such 100,000 shares would have vested upon the implementation of the Australian Specialty Clinic Commercial Validation Project as evidenced by the implantation of 10 or more Maestro Rechargeable Systems in an Australian Clinic prior to December 31, 2013; and (E) the remaining 25,000 of such 100,000 shares would have vested upon the Company successfully obtaining an Item Listing for Maestro Rechargeable System implantation by December 31, 2014. The Australian Specialty Clinic Commercial Validation Project was not implemented prior to December 31, 2013 resulting in 25,000 shares not vesting and the Company did not obtain an Item Listing for Maestro Rechargeable System implantation by December 31, 2014 resulting in an additional 25,000 shares not vesting. The full grant date fair value of the option grant was approximately $103,000.

On September 25, 2014, the Company entered into Amendment No. 2, effective September 1, 2014, to the consulting agreement with Mr. Jansz. Pursuant to the amendment, during the period from October 1, 2012 until April 30, 2015, Mr. Jansz agreed to commit additional time to performing consulting services for the Company. In exchange for these additional services, Mr. Jansz is entitled to receive a consulting fee of $12,000 AUD (approximately $10,000 USD as of December 31, 2014) a month for consulting services during the period beginning on October 1, 2012 and ending on April 30, 2015. Mr. Jansz also received an additional option to purchase 25,000 shares of the Company’s common stock on October 6, 2014 at $1.14 per share, which vested upon the occurrence of both the development of a reimbursement-focused clinical trial protocol in Australia and a recommendation to the Company’s management regarding Australian commercialization. The full grant date fair value of the option grant was approximately $16,000.

Total stock-based compensation expense recorded was approximately $40,000, $126,000 and $23,000 for the years ended December 31, 2014, 2013 and 2012, respectively. In addition to the option grant, the Company paid Mr. Jansz approximately $196,000, $154,000 and $195,000 in fees and expenses for consulting services provided during the years ended December 31, 2014, 2013 and 2012, respectively.

Other

The Company entered into an agreement with an advisory firm to provide various consulting services. The advisory firm is partially owned by a company with whom a member of our board of directors is a partner. The Company recognized $253,000 and $146,000 in selling, general and administrative expense for the year ended December 31, 2014 and 2013, respectively, for consulting services provided by the advisory firm.

- Definition

The entire disclosure for related party transactions. Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates.

+ References + Details

Commitments and Contingencies

12 Months Ended

Dec. 31, 2014

Commitments and Contingencies

(15)

Commitments and Contingencies

Effective October 1, 2008 the Company entered into a seven-year non-cancelable operating lease agreement for office/warehouse space. The lease expires on September 30, 2015 with monthly base rent ranging from $19,570 to $24,643. Total rent expense recognized for each of the years ended December 31, 2014, 2013 and 2012 was $270,872. Facility related expenses are included as general and administrative costs on the consolidated statements of operations.

The following is a schedule of total future minimum lease payments due as of December 31, 2014:


Year ending December 31:
2015	$	221,789

The Company is exposed to product liability claims that are inherent in the testing, production, marketing and sale of medical devices. Management believes any losses that may occur from these matters are adequately covered by insurance, and the ultimate outcome of these matters will not have a material effect on the Company’s financial position or results of operations. The Company is not currently a party to any litigation and is not aware of any pending or threatened litigation that could have a material adverse effect on the Company’s business, operating results or financial condition.

The Company is evaluating the Maestro System in human clinical trials, including the EMPOWER trial and ReCharge trial. Both of these clinical trials require patients to be followed out to 60 months. The Company is required to pay for patient follow up visits only to the extent they occur. In the event a patient does not attend a follow up visit, the Company has no financial obligation. The Company is also required to pay for explants or revisions, including potential conversions of ReCharge control devices to active devices, should a patient request or be required to have one during the course of the clinical trials. The Company has no financial obligation unless an explant, revision or conversion is requested or required. Clinical trial costs are expensed as incurred.

In 2005, EnteroMedics entered into an exclusive collaborative obesity device research and development agreement with the Mayo Foundation for Medical Education and Research (Mayo Foundation), Rochester, Minnesota. Through this agreement, EnteroMedics collaborated with a group of physicians and researchers at Mayo Clinic in the field of obesity. Under the terms of this five-year agreement, EnteroMedics and this group of Mayo specialists collectively worked toward the development of new and innovative medical devices for the treatment of obesity. The agreement also includes a similar collaboration for the development of products to address a wide variety of disorders susceptible to treatment by electrically blocking neural impulses on the vagus nerve.

The Mayo Foundation received an annual $250,000 retainer fee which commenced in 2005 and continued through January 2009.

On March 11, 2010, the Company entered into Amendment No. 1 to the agreement with the Mayo Foundation extending the Company’s collaboration with the Mayo Foundation for a period of two years. Pursuant to the amendment, the Mayo Foundation granted the Company certain royalty-bearing, worldwide exclusive and non-exclusive licenses and committed to the joint collaboration between the Company and a designated group of physicians and researchers at the Mayo Clinic for the development and testing of products for the treatment of obesity, including devices that use electrical signaling to block the vagal nerve, and for the treatment of other gastrointestinal diseases, solely using devices that use electrical signaling to block the vagal nerve. The Mayo Foundation received an annual retainer of $100,000 in 2010 and 2011. The agreement was further amended on January 15, 2011 with Amendment No. 2. Under the terms of Amendment No. 2, the annual retainer the Mayo Foundation received for 2011 was reduced to $75,000. The agreement was further amended on February 3, 2012 with Amendment No. 3. Under the terms of Amendment No. 3, beginning in 2012 the Mayo Foundation will be reimbursed for services provided at an hourly rate only. Amendment No. 3 does not provide for additional annual retainer payments. No other terms were changed by Amendment Nos. 2 or 3. The agreement was further amended on February 3, 2013 and on February 3, 2014 with Amendment Nos. 4 and 5, respectively, extending the joint collaboration between the company and a designated group of physicians and researchers at the Mayo Clinic. No other terms were changed by Amendment Nos. 4 or 5.

The Company may also be obligated to pay the Mayo Foundation, contingent upon the occurrence of certain future events, earned royalty payments, including a minimum annual royalty as defined by the agreement, as amended, for the commercial sale of products developed and patented by the Mayo Foundation, jointly patented by the Company and the Mayo Foundation, or a product where the Mayo Foundation provided know-how as defined by the agreement, as amended. If no products are patented, the minimum royalty is not due.

Retirement Plan

12 Months Ended

Dec. 31, 2014

Retirement Plan

(16)

Retirement Plan

The Company has a 401(k) profit-sharing plan that provides retirement benefits to employees. Eligible employees may contribute a percentage of their annual compensation, subject to Internal Revenue Service limitations. The Company’s matching is at the discretion of the Company’s board of directors. For the years ended December 31, 2014, 2013 and 2012, the Company did not provide any matching of employees’ contributions.

Quarterly Data

12 Months Ended

Dec. 31, 2014

Quarterly Data

(17)

Quarterly Data (unaudited)

The following table represents certain unaudited quarterly information for each of the eight quarters in the period ended December 31, 2014. In management’s opinion, this information has been prepared on the same basis as the audited consolidated financial statements and includes all the adjustments necessary to fairly state the unaudited quarterly results of operations (in thousands, except per share data).


	First Quarter			Second Quarter			Third Quarter			Fourth Quarter
2014:
Net loss	$	(6,732	)	$	(7,501	)	$	(5,714	)	$	(6,181	)
Basic and diluted net loss per share	$	(0.10	)	$	(0.11	)	$	(0.08	)	$	(0.09	)
2013:
Net loss	$	(6,581	)	$	(6,323	)	$	(6,303	)	$	(6,573	)
Basic and diluted net loss per share	$	(0.14	)	$	(0.11	)	$	(0.11	)	$	(0.11	)

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2014

Basis of Presentation

Basis of Presentation

Use of Estimates

Use of Estimates

Principles of Consolidation

Principles of Consolidation

The consolidated financial statements include the accounts of the Company and its wholly owned subsidiary. All intercompany transactions and accounts have been eliminated in consolidation.

Concentration of Credit Risk and Other Risks and Uncertainties

Concentration of Credit Risk and Other Risks and Uncertainties

Fair Value of Financial Instruments

Fair Value of Financial Instruments

Cash and Cash Equivalents

Cash and Cash Equivalents

Restricted Cash

Restricted Cash

Short-Term Investments

Short-Term Investments

Inventory

Inventory

The Company accounts for inventory at the lower of cost or market and records any long-term inventory as other assets in the consolidated balance sheets.

Property and Equipment, Net

Property and Equipment, Net

Impairment of Long-Lived Assets

Impairment of Long-Lived Assets

Income Taxes

Income Taxes

Comprehensive Loss

Comprehensive Loss

Revenue Recognition

Revenue Recognition

Research and Development Expenses

Research and Development Expenses

Patent Costs

Patent Costs

Derivative Instruments

Derivative Instruments

Stock-Based Compensation

Stock-Based Compensation

Net Loss Per Share

Net Loss Per Share

The following table sets forth the computation of basic and diluted net loss per share for the years ended December 31, 2014, 2013 and 2012:


	Years ended December 31,
	2014			2013			2012
Numerator:
Net loss	$	(26,128,720	)	$	(25,780,659	)	$	(23,460,103	)

Denominator for basic and diluted net loss per share:
Weighted-average common shares outstanding		67,866,427			55,009,916			39,536,500

Net loss per share—basic and diluted	$	(0.39	)	$	(0.47	)	$	(0.59	)

Recently Issued Accounting Standards

Recently Issued Accounting Standards

Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2014

Computation of Basic and Diluted Net Loss per Share

The following table sets forth the computation of basic and diluted net loss per share for the years ended December 31, 2014, 2013 and 2012:


	Years ended December 31,
	2014			2013			2012
Numerator:
Net loss	$	(26,128,720	)	$	(25,780,659	)	$	(23,460,103	)

Denominator for basic and diluted net loss per share:
Weighted-average common shares outstanding		67,866,427			55,009,916			39,536,500

Net loss per share—basic and diluted	$	(0.39	)	$	(0.47	)	$	(0.59	)

Antidilutive Securities


	December 31,
	2014		2013		2012
Stock options outstanding		12,655,792		11,687,300		7,835,533
Warrants to purchase common stock		24,199,705		25,550,625		21,216,447

Inventory (Tables)

12 Months Ended

Dec. 31, 2014

Current Inventory

Current inventory consists of the following as of:


	December 31,
	2014		2013
Raw materials	$	322,157	$	385,565
Work-in-process		632,615		624,530
Finished goods		25,747		117,846

Inventory	$	980,519	$	1,127,941

Property and Equipment (Tables)

12 Months Ended

Dec. 31, 2014

Property and Equipment

Property and equipment consists of the following as of:


	December 31,
	2014			2013
Furniture and equipment	$	2,295,433		$	2,274,633
Computer hardware and software		556,556			499,922
Leasehold improvements		62,651			46,754

		2,914,640			2,821,309
Less accumulated depreciation and amortization		(2,433,118	)		(2,244,214	)

Property and equipment, net	$	481,522		$	577,095

Accrued Expenses (Tables)

12 Months Ended

Dec. 31, 2014

Accrued Expenses

Accrued expenses consists of the following as of:


	December 31,
	2014		2013
Professional service related expenses	$	2,107,712	$	2,650,163
Payroll related expenses		1,267,141		1,043,028
Other expenses		455,913		492,869

Accrued expenses	$	3,830,766	$	4,186,060

Notes Payable (Tables)

12 Months Ended

Dec. 31, 2014

Notes Payable

Notes payable consists of the following as of:


	December 31,
	2014			2013
Growth capital loan dated April 16, 2012 (net of discounts of $23,836 and $131,670 at December 31, 2014 and 2013, respectively)	$	2,976,164		$	6,868,330
Less current portion		(2,976,164	)		(4,000,000	)

Total long-term debt	$	—		$	2,868,330

Scheduled of Debt Principal Payments

Scheduled debt principal payments are as follows as of December 31, 2014:


Year ending December 31:
2015	$	3,000,000

Less original issue discount		(23,836	)

Notes payable, net	$	2,976,164

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2014

Tax Rate Reconciliation

The income tax expense benefit differed from the amount computed by applying the U.S. federal income tax rate of 34% to income before income taxes as a result of the following:


	2014			2013			2012
Computed ‘expected’ tax benefit		34.0	%		34.0	%		34.0	%
Other permanent adjustments		-2.3	%		-2.3	%		-2.2	%
Research and development credit		0.3	%		3.5	%		0.0	%
Federal valuation allowance		-32.0	%		-35.2	%		-31.8	%

		0.0	%		0.0	%		0.0	%

Deferred Tax Assets

The tax effect of temporary differences that give rise to significant portions of the deferred tax assets as of December 31 is presented below:


	2014			2013
Deferred tax assets (liabilities):
Start-up costs	$	8,739,000		$	8,851,000
Capitalized research and development costs		30,276,000			24,844,000
Reserves and accruals		6,052,000			4,530,000
Property and equipment		94,000			105,000
Research and development credit		1,636,000			1,508,000
Net operating loss carryforwards		16,656,000			12,198,000

Total gross deferred tax assets		63,453,000			52,036,000
Valuation allowance		(63,453,000	)		(52,036,000	)

Net deferred tax assets	$	—		$	—

Stock Options (Tables)

12 Months Ended

Dec. 31, 2014

Summary of Stock Option Activity

Stock option activity is as follows:


	Shares Available For Grant			Outstanding Options					Aggregate Intrinsic Value
	Shares Available For Grant			Number of Shares			Weighted-Average Exercise Price		Aggregate Intrinsic Value
Balance, December 31, 2011		763,829			3,470,908		$	3.17
Shares reserved		8,000,000			—			—
Options granted		(4,462,873	)		4,462,873			3.35
Options exercised		—			(5,219	)		2.43
Options cancelled		93,029			(93,029	)		2.79

Balance, December 31, 2012		4,393,985			7,835,533			3.28
Shares reserved		—			—			—
Options granted		(4,346,000	)		4,346,000			1.32
Options exercised		—			—			—
Options cancelled		494,233			(494,233	)		3.00

Balance, December 31, 2013		542,218			11,687,300			2.56	$	3,284,696

Shares reserved		7,500,000			—			—
Options granted		(1,257,500	)		1,257,500			1.63
Options exercised		—			—			—
Options cancelled		289,008			(289,008	)		2.41

Balance, December 31, 2014		7,073,726			12,655,792		$	2.47	$	519,622

Options Outstanding Vested and Currently Exercisable by Exercise Price

The options outstanding, vested and currently exercisable by exercise price at December 31, 2014:


	Outstanding Options and Expected to Vest						Options Exercisable and Vested
Exercise Price	Number of Shares Outstanding		Weighted-Average Remaining Contractual Life (Years)		Aggregate Intrinsic Value		Number of Options		Weighted-Average Exercise Price		Aggregate Intrinsic Value
$0.01 to $2.00		6,310,699		8.0	$	519,622		2,766,588	$	1.52	$	216,439
$2.01 to $3.00		2,146,297		5.9		—		1,963,787		2.63		—
$3.01 to $5.00		4,085,480		7.4		—		2,529,663		3.41		—
$5.01 to $10.00		4,166		4.1		—		4,166		8.40		—
> $10.00		109,150		3.3		—		109,150		23.54		—

		12,655,792			$	519,622		7,373,354	$	2.79	$	216,439

Nonemployees

Stock Option Valuation Assumptions

The fair value for the years ended December 31, 2014, 2013 and 2012 was calculated using the following assumptions, defined below:


	Years Ended December 31,
	2014	2013	2012
Risk-free interest rates	0.08%–2.63%	0.26%–2.98%	0.24%–2.05%
Expected life	0.50 years–9.51 years	1.50 years–9.76 years	2.00 years–9.25 years
Expected dividends	0%	0%	0%
Expected volatility	56.54%–139.65%	80.00%–143.00%	63.48%–142.25%

Employees Stock Option Plan

Stock Option Valuation Assumptions

The estimated grant-date fair values of the employee stock options were calculated using the Black-Scholes valuation model, based on the following assumptions for the years ended December 31, 2014, 2013 and 2012:


	Years Ended December 31,
	2014	2013	2012
Risk-free interest rates	1.73%–1.96%	0.94%–1.33%	0.90%–1.09%
Expected life	6.00 years–6.25 years	6.00 years–6.25 years	6.00 years–6.25 years
Expected dividends	0%	0%	0%
Expected volatility	118.64%–120.70%	148.00%–149.00%	137.58%–143.98%

Warrants (Tables)

12 Months Ended

Dec. 31, 2014

Stock Warrants Activity

Stock warrant activity is as follows:


	Common Shares			Price(1)
Balance, December 31, 2011		23,923,301		$	2.55
Granted(2)		106,746			2.34
Exercised		(2,813,600	)		2.18
Cancelled		—			—

Balance, December 31, 2012		21,216,447			2.60
Granted(2)		5,508,000			1.14
Exercised		(20,325	)		1.38
Cancelled		(1,153,497	)		9.14

Balance, December 31, 2013		25,550,625			1.99
Granted		—			—
Exercised		(1,328,270	)		1.69
Cancelled		(22,650	)		48.56

Balance, December 31, 2014		24,199,705		$	1.96

(1)	Represents weighted-average exercise price per share.

(2)	See Notes 8 and 10 for discussions relating to the issuance of warrants in 2013 and 2012.

- Definition

Tabular disclosure of warrants or rights issued. Warrants and rights outstanding are derivative securities that give the holder the right to purchase securities (usually equity) from the issuer at a specific price within a certain time frame. Warrants are often included in a new debt issue to entice investors by a higher return potential. The main difference between warrants and call options is that warrants are issued and guaranteed by the company, whereas options are exchange instruments and are not issued by the company. Also, the lifetime of a warrant is often measured in years, while the lifetime of a typical option is measured in months. Disclose the title of issue of securities called for by warrants and rights outstanding, the aggregate amount of securities called for by warrants and rights outstanding, the date from which the warrants or rights are exercisable, and the price at which the warrant or right is exercisable.

+ References + Details

Related Party Transactions (Tables)

12 Months Ended

Dec. 31, 2014

Anthony Jansz

Shares Purchased by Related Parties

corresponding warrant. The shares purchased, together with the proceeds, before expenses, to the Company, are shown in the table below:


Beneficial Owner	Shares Purchased		Warrants Purchased		Proceeds, before expenses, to the Company
Anthony Jansz		150,000		60,000	$	142,500

Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2014

Future Minimum Lease Payment

The following is a schedule of total future minimum lease payments due as of December 31, 2014:


Year ending December 31:
2015	$	221,789

Quarterly Data (Tables)

12 Months Ended

Dec. 31, 2014

Quarterly Information


	First Quarter			Second Quarter			Third Quarter			Fourth Quarter
2014:
Net loss	$	(6,732	)	$	(7,501	)	$	(5,714	)	$	(6,181	)
Basic and diluted net loss per share	$	(0.10	)	$	(0.11	)	$	(0.08	)	$	(0.09	)
2013:
Net loss	$	(6,581	)	$	(6,323	)	$	(6,303	)	$	(6,573	)
Basic and diluted net loss per share	$	(0.14	)	$	(0.11	)	$	(0.11	)	$	(0.11	)

Formation and Business of the Company - Additional Information (Detail)		1 Months Ended
	Apr. 16, 2012 shares	Jan. 31, 2006 SFr / shares shares	Dec. 31, 2014 $ / shares shares	Dec. 31, 2013 $ / shares shares
Organization And Description Of Business [Line Items]
Common stock, shares outstanding			69,570,444	63,551,350
Common stock, par value \| $ / shares			$ 0.01	$ 0.01
Stock Issued (in shares)	2,271,705
Alpha Medical, Inc.
Organization And Description Of Business [Line Items]
Ownership percentage of an entity combined to form the Company			100.00%
Beta Medical, Inc.
Organization And Description Of Business [Line Items]
Ownership percentage of an entity combined to form the Company			100.00%
EnteroMedics Europe
Organization And Description Of Business [Line Items]
Common stock, shares outstanding		20
Common stock, par value \| SFr / shares		SFr 1,000
Repurchased shares percentage		100.00%
Stock Issued (in shares)		1

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Schedule Of Significant Accounting Policies [Line Items]
Long-term debt	$ 3,400,000
Cash equivalents maturity period	90 days
Cash collateral money market	$ 200,000
Standby letter of credit amount	200,000
Patent related legal expenses	338,055	$ 296,575	$ 278,987
Derivative instruments outstanding	$ 0	$ 0	$ 0
Minimum
Schedule Of Significant Accounting Policies [Line Items]
Short term investment maturity period	3 months
Maximum
Schedule Of Significant Accounting Policies [Line Items]
Short term investment maturity period	1 year
Furniture and Fixtures \| Minimum
Schedule Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful lives	5 years
Furniture and Fixtures \| Maximum
Schedule Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful lives	7 years
Computer hardware and software \| Minimum
Schedule Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful lives	3 years
Computer hardware and software \| Maximum
Schedule Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful lives	5 years
Standby letters of credit
Schedule Of Significant Accounting Policies [Line Items]
Stand by letter of credit expiration date	Oct. 01, 2013
Money Market Funds
Schedule Of Significant Accounting Policies [Line Items]
Money market funds preserve the value of investment per share	$ 1.00

Computation of Basic and Diluted Net Loss Per Share (Detail) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Numerator:
Net loss	$ (6,181,000)	$ (5,714,000)	$ (7,501,000)	$ (6,732,000)	$ (6,573,000)	$ (6,303,000)	$ (6,323,000)	$ (6,581,000)	$ (26,128,720)	$ (25,780,659)	$ (23,460,103)
Denominator for basic and diluted net loss per share:
Weighted-average common shares outstanding									67,866,427	55,009,916	39,536,500
Net loss per share-basic and diluted	$ (0.09)	$ (0.08)	$ (0.11)	$ (0.10)	$ (0.11)	$ (0.11)	$ (0.11)	$ (0.14)	$ (0.39)	$ (0.47)	$ (0.59)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References + Details

Potential Shares of Common Stock Not Included in Calculation of Diluted Net Loss per Share (Detail) - shares	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Stock Option Outstanding
Anti-dilutive Securities
Anti-dilutive as of end of each period	12,655,792	11,687,300	7,835,533
Warrants to purchase common stock
Anti-dilutive Securities
Anti-dilutive as of end of each period	24,199,705	25,550,625	21,216,447

Liquidity and Management's Plans - Additional Information (Detail) - USD ($)						2 Months Ended	12 Months Ended
	Mar. 13, 2015	Jun. 13, 2014	Jul. 31, 2013	Feb. 27, 2013	Apr. 20, 2012	Mar. 13, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Liquidity and Managements Plans [Line Items]
Cash and cash equivalents							$ 11,619,167	$ 23,297,479	$ 22,308,781	$ 28,487,688
Gross proceeds before deducting estimate offering expenses				$ 13,100,000	$ 5,000,000			$ 11,000,000
Maximum
Liquidity and Managements Plans [Line Items]
Gross proceeds before deducting estimate offering expenses			$ 20,000,000
Cowen and Company Llc
Liquidity and Managements Plans [Line Items]
Cash and cash equivalents							11,600,000
Gross proceeds before deducting estimate offering expenses							$ 927,000
Cowen and Company Llc \| Subsequent Event
Liquidity and Managements Plans [Line Items]
Gross proceeds before deducting estimate offering expenses	$ 17,600,000					$ 6,400,000
Cowen and Company Llc \| Maximum
Liquidity and Managements Plans [Line Items]
Gross proceeds before deducting estimate offering expenses		$ 25,000,000

Inventory - Additional Information (Detail) - USD ($)	Dec. 31, 2014	Dec. 31, 2013
Inventory [Line Items]
Long-term inventory	$ 825,000	$ 794,000

Current Inventory (Detail) - USD ($)	Dec. 31, 2014	Dec. 31, 2013
Inventory [Line Items]
Raw materials	$ 322,157	$ 385,565
Work-in-process	632,615	624,530
Finished goods	25,747	117,846
Inventory	$ 980,519	$ 1,127,941

Property and Equipment (Detail) - USD ($)	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Furniture and equipment	$ 2,295,433	$ 2,274,633
Computer hardware and software	556,556	499,922
Leasehold improvements	62,651	46,754
Property and Equipment, Gross	2,914,640	2,821,309
Less accumulated depreciation and amortization	(2,433,118)	(2,244,214)
Property and equipment, net	$ 481,522	$ 577,095

Accrued Expenses (Detail) - USD ($)	Dec. 31, 2014	Dec. 31, 2013
Accrued Expenses [Line Items]
Professional service related expenses	$ 2,107,712	$ 2,650,163
Payroll related expenses	1,267,141	1,043,028
Other expenses	455,913	492,869
Accrued expenses	$ 3,830,766	$ 4,186,060

Notes Payable (Detail) - USD ($)	Dec. 31, 2014	Dec. 31, 2013
Accounts Payable [Line Items]
Growth capital loan dated April 16, 2012 (net of discounts of $23,836 and $131,670 at December 31, 2014 and 2013, respectively)	$ 2,976,164	$ 6,868,330
Less current portion	$ (2,976,164)	(4,000,000)
Total long-term debt		$ 2,868,330

Notes Payable (Parenthetical) (Detail) - USD ($)	Dec. 31, 2014	Dec. 31, 2013
Accounts Payable [Line Items]
Notes payable, discounts	$ 23,836	$ 131,670

Notes Payable - Additional Information (Detail)			12 Months Ended
Notes Payable - Additional Information (Detail)	May 09, 2013 USD ($)	Apr. 16, 2012 USD ($) $ / shares shares	Dec. 31, 2014 USD ($)	Feb. 28, 2013 $ / shares	Apr. 23, 2012 USD ($) Installment
Debt Instrument [Line Items]
Principal amount of loan		$ 10,000,000			$ 10,000,000
Amount used to repay outstanding debt					$ 4,700,000
Repayment of principal amount			$ 333,333
Loan agreement with fixed annual rate					8.00%
Final payment fee percentage			5.00%
Conditional amount to be placed in restricted account at SVB			$ 7,500,000
Warrants exercise price \| $ / shares				$ 1.14
Silicon Valley Bank
Debt Instrument [Line Items]
Term loans, agreed sum		$ 20,000,000
Number of installments of repayment of debt \| Installment					30
Issued warrant \| shares		106,746
Time for exercising warrant		10 years
Warrants exercise price \| $ / shares		$ 2.34
Silicon Valley Bank \| First Amendment
Debt Instrument [Line Items]
Success fee percentage in the event the Company receives FDA approval for the Maestro Rechargeable System	$ 187,000
Silicon Valley Bank \| First Amendment \| November 15, 2013
Debt Instrument [Line Items]
Cumulative aggregate proceeds from new capital transactions	5,000,000
Silicon Valley Bank \| First Amendment \| April 15, 2014
Debt Instrument [Line Items]
Cumulative aggregate proceeds from new capital transactions	$ 10,000,000
Silicon Valley Bank \| First Amendment \| Until it receives FDA approval for the Maestro Rechargeable System
Debt Instrument [Line Items]
Liquidity ratio (unrestricted cash divided by outstanding debt)	1.25
Silicon Valley Bank \| First Amendment \| After FDA approval for the Maestro Rechargeable System
Debt Instrument [Line Items]
Liquidity ratio (unrestricted cash divided by outstanding debt)	0.75

Schedule of Debt Principal Payments (Detail) - USD ($)	Dec. 31, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
2015	$ 3,000,000
Less original issue discount	(23,836)	$ (131,670)
Notes payable, net	$ 2,976,164	$ 6,868,330

Preferred Stock - Additional Information (Detail) - $ / shares	Dec. 31, 2014	Dec. 31, 2013
Preferred Stock [Line Items]
Preferred stock, authorized	5,000,000
Preferred stock, par value	$ 0.01
Preferred stock, issued	0	0
Preferred stock, outstanding	0	0

Stock Sales - Additional Information (Detail) - USD ($)								1 Months Ended	2 Months Ended	12 Months Ended
Stock Sales - Additional Information (Detail) - USD ($)	Mar. 13, 2015	Jun. 13, 2014	Jun. 10, 2014	Jul. 31, 2013	Feb. 27, 2013	Apr. 20, 2012	Apr. 16, 2012	Feb. 28, 2013	Mar. 13, 2015	Dec. 31, 2014	Dec. 31, 2013
Class of Stock [Line Items]
Stock Issued (in shares)							2,271,705
Purchase price per share							$ 2.22				$ 1.39
Gross proceeds before deducting estimate offering expenses					$ 13,100,000	$ 5,000,000					$ 11,000,000
Purchase price per share					$ 0.95
Warrants exercise price								$ 1.14
Warrant, exercise period								5 years
Maximum percentage of ownership restriction on warrant exercises								19.99%
Commission or discount percentage on issue of shares				2.00%
Number of shares sold											7,917,755
Warrants to purchase common stock
Class of Stock [Line Items]
Warrant issued					5,508,000
Canaccord Genuity Inc
Class of Stock [Line Items]
Purchase price per share			$ 1.67							$ 2.22
Gross proceeds before deducting estimate offering expenses			$ 19,900,000							$ 8,900,000
Number of shares sold			11,923,977							4,006,222
Agreement termination effective date			Jun. 10, 2014							Jun. 10, 2014
Cowen and Company Llc
Class of Stock [Line Items]
Purchase price per share										$ 1.35
Gross proceeds before deducting estimate offering expenses										$ 927,000
Commission or discount percentage on issue of shares		3.00%
Number of shares sold										684,602
Cowen and Company Llc \| Subsequent Event
Class of Stock [Line Items]
Purchase price per share	$ 1.39								$ 1.39
Gross proceeds before deducting estimate offering expenses	$ 17,600,000								$ 6,400,000
Number of shares sold									4,627,934
Maximum
Class of Stock [Line Items]
Gross proceeds before deducting estimate offering expenses				$ 20,000,000
Maximum \| Cowen and Company Llc
Class of Stock [Line Items]
Gross proceeds before deducting estimate offering expenses		$ 25,000,000
Common Stock
Class of Stock [Line Items]
Stock Issued (in shares)					13,770,000

Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Taxes [Line Items]
U.S. federal income tax rate	34.00%	34.00%	34.00%
U.S. federal net operating loss carryforwards amount	$ 91,900,000
Net operating loss carryforwards amount available for utilization	44,000,000
Tax benefit recorded to additional paid-in capital	221,000
Gross federal net operating loss carryforward expired amount	48,100,000
Deferred tax asset, write-off of capitalized start-up costs	5,900,000
Deferred tax asset, write-off of capitalized research and development costs	5,500,000
Deferred tax asset, write-off of property and equipment	1,500,000
Deferred tax asset, write-off of research and development credits	2,400,000
Unrecognized tax	0	$ 0
Interest or penalties charged or accrued related to unrecognized tax benefits	0
Tax examinations	$ 0
Federal examinations for the years	2011
Minimum
Income Taxes [Line Items]
Federal net operating loss carryforwards expiration date	2022
Maximum
Income Taxes [Line Items]
Federal net operating loss carryforwards expiration date	2034

Tax Rate Reconciliation (Detail)	12 Months Ended
Tax Rate Reconciliation (Detail)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reconciliation of Effective Income Tax Rate [Line Items]
Computed 'expected' tax benefit	34.00%	34.00%	34.00%
Other permanent adjustments	(2.30%)	(2.30%)	(2.20%)
Research and development credit	0.30%	3.50%	0.00%
Federal valuation allowance	(32.00%)	(35.20%)	(31.80%)
Effective Income Tax Rate Reconciliation, Percent, Total	0.00%	0.00%	0.00%

Deferred Tax Assets (Detail) - USD ($)	Dec. 31, 2014	Dec. 31, 2013
Deferred tax assets (liabilities):
Start-up costs	$ 8,739,000	$ 8,851,000
Capitalized research and development costs	30,276,000	24,844,000
Reserves and accruals	6,052,000	4,530,000
Property and equipment	94,000	105,000
Research and development credit	1,636,000	1,508,000
Net operating loss carryforwards	16,656,000	12,198,000
Total gross deferred tax assets	63,453,000	52,036,000
Valuation allowance	(63,453,000)	(52,036,000)
Net deferred tax assets	$ 0	$ 0

Stock Options - Additional Information (Detail) - USD ($)		12 Months Ended
	May 07, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Schedule Of Stock Options [Line Items]
Stock incentive plan, shares authorized		19,800,000	12,300,000
Options granted to participants		10.00%
Stock incentive plan, additional shares authorized	7,500,000
Stock-based compensation		$ 6,319,707	$ 5,954,928	$ 4,225,322
Weighted average estimated fair value of stock options granted		$ 1.42	$ 1.22	$ 3.19
Total unrecognized compensation costs related to non-vested stock options		$ 9,200,000
Total unrecognized compensation costs related to non-vested stock options, weighted-average period of recognition		2 years
Aggregate intrinsic value of stock options		$ 0	$ 0	$ 3,044
Incentive Stock Options
Schedule Of Stock Options [Line Items]
Options granted to participants		10.00%
Employees \| Employee Awards
Schedule Of Stock Options [Line Items]
Award vesting period		4 years
Nonemployees
Schedule Of Stock Options [Line Items]
Stock-based compensation		$ 181,323	$ 166,679	$ 52,190
Minimum
Schedule Of Stock Options [Line Items]
Options granted to participants owning more than 10% of outstanding voting stock, exercise price percentage		110.00%
Minimum \| Incentive Stock Options
Schedule Of Stock Options [Line Items]
Option expiration period		5 years
Maximum
Schedule Of Stock Options [Line Items]
Option expiration period		10 years

Summary of Stock Option Activity (Detail) - USD ($)	12 Months Ended
Summary of Stock Option Activity (Detail) - USD ($)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding Options, Number of Shares, Options exercised			(5,219)
Aggregate Intrinsic Value	$ 519,622
Stock Incentive Plan 2003
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Available For Grant, Beginning Balance	542,218	4,393,985	763,829
Shares Available For Grant, Shares reserved	7,500,000		8,000,000
Shares Available For Grant, Options granted	(1,257,500)	(4,346,000)	(4,462,873)
Shares Available For Grant, Options exercised	0	0	0
Shares Available For Grant, Options cancelled	289,008	494,233	93,029
Shares Available For Grant, Ending Balance	7,073,726	542,218	4,393,985
Outstanding Options, Number of Shares, Beginning Balance	11,687,300	7,835,533	3,470,908
Outstanding Options, Number of Shares, Shares reserved	0	0	0
Outstanding Options, Number of Shares, Options granted	1,257,500	4,346,000	4,462,873
Outstanding Options, Number of Shares, Options exercised			(5,219)
Outstanding Options, Number of Shares, Options cancelled	(289,008)	(494,233)	(93,029)
Outstanding Options, Number of Shares, Ending Balance	12,655,792	11,687,300	7,835,533
Outstanding Options, Weighted-Average Exercise Price, Beginning Balance	$ 2.56	$ 3.28	$ 3.17
Outstanding Options, Weighted-Average Exercise Price, Shares reserved	0	0	0
Outstanding Options, Weighted-Average Exercise Price, Options granted	1.63	1.32	3.35
Outstanding Options, Weighted-Average Exercise Price, Options exercised			2.43
Outstanding Options, Weighted-Average Exercise Price, Options cancelled	2.41	3.00	2.79
Outstanding Options, Weighted-Average Exercise Price, Ending Balance	$ 2.47	$ 2.56	$ 3.28
Aggregate Intrinsic Value	$ 519,622	$ 3,284,696

Options Outstanding Vested and Currently Exercisable by Exercise Price (Detail)	12 Months Ended
	Dec. 31, 2014 USD ($) $ / shares shares
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of shares outstanding \| shares	12,655,792
Aggregate Intrinsic Value \| $	$ 519,622
Number of Options \| shares	7,373,354
Weighted-Average Exercise Price	$ 2.79
Aggregate Intrinsic Value \| $	$ 216,439
$0.01 to $2.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price, lower limit	$ 0.01
Exercise price, upper limit	$ 2.00
Number of shares outstanding \| shares	6,310,699
Weighted-Average remaining contractual life (Years)	8 years
Aggregate Intrinsic Value \| $	$ 519,622
Number of Options \| shares	2,766,588
Weighted-Average Exercise Price	$ 1.52
Aggregate Intrinsic Value \| $	$ 216,439
$2.01 to $3.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price, lower limit	$ 2.01
Exercise price, upper limit	$ 3.00
Number of shares outstanding \| shares	2,146,297
Weighted-Average remaining contractual life (Years)	5 years 10 months 24 days
Number of Options \| shares	1,963,787
Weighted-Average Exercise Price	$ 2.63
$3.01 to $5.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price, lower limit	3.01
Exercise price, upper limit	$ 5.00
Number of shares outstanding \| shares	4,085,480
Weighted-Average remaining contractual life (Years)	7 years 4 months 24 days
Number of Options \| shares	2,529,663
Weighted-Average Exercise Price	$ 3.41
$5.01 to $10.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price, lower limit	5.01
Exercise price, upper limit	$ 10.00
Number of shares outstanding \| shares	4,166
Weighted-Average remaining contractual life (Years)	4 years 1 month 6 days
Number of Options \| shares	4,166
Weighted-Average Exercise Price	$ 8.40
> $10.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price, lower limit	$ 10
Exercise price, upper limit	>10
Number of shares outstanding \| shares	109,150
Weighted-Average remaining contractual life (Years)	3 years 3 months 18 days
Number of Options \| shares	109,150
Weighted-Average Exercise Price	$ 23.54

Stock-Based Compensation for Non Employees (Detail) - Nonemployees	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rates, minimum	0.08%	0.26%	0.24%
Risk-free interest rates, maximum	2.63%	2.98%	2.05%
Expected dividends	0.00%	0.00%	0.00%
Expected Volatility, minimum	56.54%	80.00%	63.48%
Expected Volatility, maximum	139.65%	143.00%	142.25%
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life	6 months	1 year 6 months	2 years
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life	9 years 6 months 4 days	9 years 9 months 4 days	9 years 3 months

Estimated Grant-Date Fair Values of Employee Stock Options (Detail) - Employees	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate, minimum	1.73%	0.94%	0.90%
Risk-free interest rate, maximum	1.96%	1.33%	1.09%
Expected dividends	0.00%	0.00%	0.00%
Expected volatility factor, minimum	118.64%	148.00%	137.58%
Expected volatility factor, maximum	120.70%	149.00%	143.98%
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life	6 years	6 years	6 years
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life	6 years 3 months	6 years 3 months	6 years 3 months

Stock Warrant Activity (Detail) - Common Stock

12 Months Ended

Dec. 31, 2014

$ / Warrants

Dec. 31, 2013

$ / Warrants

Dec. 31, 2012

$ / Warrants

Class of Warrant or Right [Line Items]

Beginning Balance | shares

25,550,625

21,216,447

23,923,301

Granted | shares

^[1]

5,508,000

106,746

Exercised | shares

(1,328,270)

(20,325)

(2,813,600)

Cancelled | shares

(22,650)

(1,153,497)

Ending Balance | shares

24,199,705

25,550,625

21,216,447

Beginning Balance | $ / Warrants

^[2]

1.99

2.60

2.55

Granted | $ / Warrants

^[1],[2]

1.14

2.34

Exercised | $ / Warrants

^[2]

1.69

1.38

2.18

Cancelled | $ / Warrants

^[2]

48.56

9.14

Ending Balance | $ / Warrants

^[2]

1.96

1.99

2.60

[1]	See Notes 8 and 10 for discussions relating to the issuance of warrants in 2013 and 2012.
[2]	Represents weighted-average exercise price per share.

Warrants - Additional Information (Detail)	12 Months Ended
Warrants - Additional Information (Detail)	Dec. 31, 2014	Dec. 31, 2013
Warrants to purchase common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrant outstanding, weighted-average remaining contractual life	1 year 10 months 6 days	2 years 10 months 13 days

Related Party Transactions - Additional Information (Detail)															12 Months Ended
	Dec. 31, 2014 USD ($) shares	Oct. 06, 2014 USD ($) $ / shares shares	Sep. 25, 2014 USD ($)	Sep. 25, 2014 AUD ($)	Jun. 30, 2014 shares	Jan. 22, 2014 shares	Dec. 31, 2013 shares	May 31, 2013 USD ($) $ / shares shares	Feb. 27, 2013 $ / shares shares	Jan. 22, 2013 $ / shares shares	Dec. 20, 2012 AUD ($)	Apr. 16, 2012 shares	Jun. 01, 2011 USD ($) $ / shares shares	Jun. 01, 2011 AUD ($) shares	Dec. 31, 2014 USD ($) shares	Dec. 31, 2014 AUD ($) shares	Dec. 31, 2013 USD ($) shares	Dec. 31, 2012 USD ($)	May 31, 2015 shares	Jan. 22, 2015 shares	May 31, 2014 shares
Transactions with Third Party [Line Items]
Stock Issued (in shares)												2,271,705
Purchase price per share \| $ / shares									$ 0.95
Selling,general and administrative expenses \| $															$ 14,561,656		$ 13,658,824	$ 11,960,893
Warrants to purchase common stock
Transactions with Third Party [Line Items]
Warrant issued									5,508,000
Consulting Agreement - Anthony Jansz
Transactions with Third Party [Line Items]
Consulting agreement term													4 years	4 years
Consulting fee	$ 10,000										$ 12,000			$ 96,000	79,000	$ 12,000
Stock-based compensation \| $															40,000		126,000	23,000
Payment for consulting services \| $															$ 196,000		$ 154,000	$ 195,000
Consulting Agreement - Anthony Jansz \| Amendment No. 2
Transactions with Third Party [Line Items]
Consulting fee			$ 10,000	$ 12,000
Consulting Agreement - Anthony Jansz \| Stock Option Outstanding
Transactions with Third Party [Line Items]
Award granted, shares								100,000		75,000			50,000	50,000
Award granted, price per share \| $ / shares								$ 1.31		$ 2.65			$ 2.76
Award vesting period													48 months	48 months
Grant date fair value of award grant \| $	$ 153,000							$ 103,000					$ 108,000
Award vested, shares								16,667		16,667
Consulting Agreement - Anthony Jansz \| Stock Option Outstanding \| Amendment No. 2
Transactions with Third Party [Line Items]
Award granted, shares		25,000
Award granted, price per share \| $ / shares		$ 1.14
Grant date fair value of award grant \| $		$ 16,000
Consulting Agreement - Anthony Jansz \| Stock Option Outstanding \| Vest on January 22, 2014
Transactions with Third Party [Line Items]
Award vested, shares						16,667
Award vesting date															Jan. 22, 2014	Jan. 22, 2014
Consulting Agreement - Anthony Jansz \| Stock Option Outstanding \| Vest on January 22, 2015
Transactions with Third Party [Line Items]
Award vesting date															Jan. 22, 2015	Jan. 22, 2015
Consulting Agreement - Anthony Jansz \| Stock Option Outstanding \| Prior to June 30, 2014
Transactions with Third Party [Line Items]
Award expected to vest, shares	25,000														25,000	25,000
Latest date for approval of Australian reimbursement for the remaining options to vest															Jun. 30, 2014	Jun. 30, 2014
Number of shares not vested					25,000
Consulting Agreement - Anthony Jansz \| Stock Option Outstanding \| Vest on May 31, 2014
Transactions with Third Party [Line Items]
Award expected to vest, shares																					16,667
Award vesting date															May 31, 2014	May 31, 2014
Consulting Agreement - Anthony Jansz \| Stock Option Outstanding \| Vest on May 31, 2015
Transactions with Third Party [Line Items]
Award vesting date															May 31, 2015	May 31, 2015
Consulting Agreement - Anthony Jansz \| Stock Option Outstanding \| Vest on May 31, 2015 \| Scenario, Forecast
Transactions with Third Party [Line Items]
Award expected to vest, shares																			16,666
Consulting Agreement - Anthony Jansz \| Stock Option Outstanding \| Vest upon implementation of Australian Specialty Clinic Commercial Validation Project prior to December 31, 2013
Transactions with Third Party [Line Items]
Award expected to vest, shares							25,000										25,000
Consulting Agreement - Anthony Jansz \| Stock Option Outstanding \| Vest upon Company successfully obtaining an Item Listing for Maestro Rechargeable System implantation by December 31, 2014
Transactions with Third Party [Line Items]
Award expected to vest, shares	25,000														25,000	25,000
Consulting Agreement - Anthony Jansz \| Stock Option Outstanding \| Prior to December 31, 2014
Transactions with Third Party [Line Items]
Latest date for approval of Australian reimbursement for the remaining options to vest															Dec. 31, 2014	Dec. 31, 2014
Number of shares not vested	25,000
Consulting Agreement - Anthony Jansz \| Stock Option Outstanding \| Prior to December 31, 2013
Transactions with Third Party [Line Items]
Latest date for approval of Australian reimbursement for the remaining options to vest															Dec. 31, 2013	Dec. 31, 2013
Number of shares not vested							25,000
Consulting Agreement - Anthony Jansz \| Subsequent Event \| Stock Option Outstanding \| Vest on January 22, 2015
Transactions with Third Party [Line Items]
Award expected to vest, shares																				16,666
Consulting Services
Transactions with Third Party [Line Items]
Selling,general and administrative expenses \| $															$ 253,000		$ 146,000
Common Stock
Transactions with Third Party [Line Items]
Stock Issued (in shares)									13,770,000						4,690,824	4,690,824	7,917,755

Shares Purchased by Related Parties (Detail) - USD ($)				12 Months Ended
Shares Purchased by Related Parties (Detail) - USD ($)	Feb. 27, 2013	Apr. 20, 2012	Apr. 16, 2012	Dec. 31, 2014	Dec. 31, 2013
Transactions with Third Party [Line Items]
Stock Issued (in shares)			2,271,705
Proceeds, before expenses, to the Company	$ 13,100,000	$ 5,000,000			$ 11,000,000
Common Stock
Transactions with Third Party [Line Items]
Stock Issued (in shares)	13,770,000			4,690,824	7,917,755
Anthony Jansz
Transactions with Third Party [Line Items]
Proceeds, before expenses, to the Company	$ 142,500
Anthony Jansz \| Common Stock
Transactions with Third Party [Line Items]
Stock Issued (in shares)	150,000
Warrants to purchase common stock
Transactions with Third Party [Line Items]
Warrants Purchased	5,508,000
Warrants to purchase common stock \| Anthony Jansz
Transactions with Third Party [Line Items]
Warrants Purchased	60,000

Commitments and Contingencies - Additional Information (Detail) - USD ($)			12 Months Ended
	Mar. 31, 2010	Oct. 01, 2008	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008	Dec. 31, 2007	Dec. 31, 2006	Dec. 31, 2005
Loss Contingencies [Line Items]
Operating lease agreement term		7 years
Operating lease agreement expiration date		Sep. 30, 2015
Total rent expense			$ 270,872	$ 270,872	$ 270,872
Number of months that require patients to be followed out in clinical trials			60 months
Collaborative obesity device research and development agreement, term												5 years
Research and development expense			$ 11,031,619	$ 11,075,493	$ 10,668,044
Amendment One
Loss Contingencies [Line Items]
Collaborative obesity device research and development agreement, extension period	2 years
Retainer Fees
Loss Contingencies [Line Items]
Research and development expense								$ 250,000	$ 250,000	$ 250,000	$ 250,000	$ 250,000
Retainer Fees \| Amendment One
Loss Contingencies [Line Items]
Research and development expense						$ 100,000	$ 100,000
Retainer Fees \| Amendment No. 2
Loss Contingencies [Line Items]
Research and development expense						$ 75,000
Minimum
Loss Contingencies [Line Items]
Operating lease, monthly base rent		$ 19,570
Maximum
Loss Contingencies [Line Items]
Operating lease, monthly base rent		$ 24,643

Future Minimum Lease Payment (Detail)	Dec. 31, 2014 USD ($)
Leases Future Minimum Payments [Line Items]
2015	$ 221,789

Quarterly Information (Detail) - USD ($)	3 Months Ended								12 Months Ended
Quarterly Information (Detail) - USD ($)	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Data [Line Items]
Net loss	$ (6,181,000)	$ (5,714,000)	$ (7,501,000)	$ (6,732,000)	$ (6,573,000)	$ (6,303,000)	$ (6,323,000)	$ (6,581,000)	$ (26,128,720)	$ (25,780,659)	$ (23,460,103)
Basic and diluted net loss per share	$ (0.09)	$ (0.08)	$ (0.11)	$ (0.10)	$ (0.11)	$ (0.11)	$ (0.11)	$ (0.14)	$ (0.39)	$ (0.47)	$ (0.59)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References + Details