STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (DEFICIT) (USD $) In Thousands, except Share data	3 Months Ended	6 Months Ended	10 Months Ended	12 Months Ended											150 Months Ended
	Jun. 30, 2011	Jun. 30, 2011	Dec. 31, 1999	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008	Dec. 31, 2007	Dec. 31, 2006	Dec. 31, 2005	Dec. 31, 2004	Dec. 31, 2003	Dec. 31, 2002	Dec. 31, 2001	Dec. 31, 2000	Jun. 30, 2011
Sale of Common Stock			$ 4						$ 3,066		$ 1
Sale of Series D Preferred Stock through private placement at an average price of $35.00 per share						4,932	14,770	11,612
Conversion of note payable to Common Stock at $2.17 per share										2,372
Fair value of beneficial conversion rights issued in connection with the issuance of Series D and Seried C Preferred Stock						562	2,130	2,621
Conversion of mandatory redeemable preferred stock to Common Stock										500
Accretion of fair value of beneficial conversion charge						(562)
Sale of Common Stock at an average price of $1.752 per share and warrants to Medtronic									2,795
Preferred Dividend and accretion of fair value of beneficial conversion charge							(2,130)	(2,621)
Employee share-based compensation expense		371		501	448	489	702	1,193
Amortization of unearned compensation									825	202	164	24
Effects of reverse acquisition										5,900
Non-employee share-based compensation		158		126	185	3	72	83					9
Private placement of Series B convertible preferred stock												2,613
Common stock issued for intangible assets													24
Reclassification of prior year non-employee compensation to prepaid expenses								487
Exercise of stock options							591		127	15
Cumulative Effects of adoption of Accounting Principle					(1,069)
Net loss	(2,951)	(5,033)	(328)	(10,163)	(13,461)	(6,320)	(6,817)	(7,046)	(5,345)	(2,937)	(2,274)	(1,310)	(870)	(1,055)	(62,959)
Ending Balance	(8,664)	(8,664)	(324)	(4,160)	5,376	19,273	20,169	10,851	4,522	3,054	(2,998)	(889)	(2,216)	(1,379)	(8,664)
Series D Preferred Stock
Sale of Series D Preferred Stock through private placement at an average price of $35.00 per share (in shares)						142,857	428,571
Sale of Common Stock			0
Sale of Series D Preferred Stock through private placement at an average price of $35.00 per share						14	43
Preferred Dividend and accretion of fair value of beneficial conversion charge (in shares)							5,108
Preferred Dividend and accretion of fair value of beneficial conversion charge							1
Induced conversion of preferred stock in connection with the issuance of Series D Preferred Stock							16
Adjustment to preferred dividends accrued, shares						(5,108)
Adjustment to preferred dividends accrued						(1)
Ending Balance (in shares)	734,898	734,898		734,898	734,898	734,898	597,149								734,898
Ending Balance	73	73	0	73	73	73	60	0	0	0	0	0	0	0	73
Series C Preferred Stock
Sale of Series D Preferred Stock through private placement at an average price of $35.00 per share (in shares)								342,857
Sale of Common Stock			0
Sale of Series D Preferred Stock through private placement at an average price of $35.00 per share								34
Preferred Dividend and accretion of fair value of beneficial conversion charge (in shares)							68,801	25,298
Preferred Dividend and accretion of fair value of beneficial conversion charge							7	3
Induced conversion of preferred stock in connection with the issuance of Series D Preferred Stock							(23)
Issuance of Series C Preferred Stock in connection with induced conversion of preferred stock (in shares)							93,940
Adjustment to preferred dividends accrued, shares						(3,237)
Adjustment to preferred dividends accrued						(1)
Issuance of Series C Preferred Stock in connection with induced conversion of preferred stock							9
Conversion of Series Preferred Stock to Common Stock (in Shares)		(3,614)		(2,414)	(4,615)	(6,000)	(5,597)
Conversion of Series Preferred Stock to Common Stock					(1)
Ending Balance (in shares)	275,235	275,235		278,849	281,263	285,878	295,115	368,155							275,235
Ending Balance	28	28	0	28	28	29	30	37	0	0	0	0	0	0	28
Common Stock
Conversion of note payable to Common Stock at $2.17 per share (in shares)										1,091,321
Sale of Common Stock (in shares)			6,004,146						2,473,914		276,054
Sale of Common Stock			0						4
Retirement of founder shares												(33,126)
Conversion of note payable to Common Stock at $2.17 per share										1
Conversion of mandatory redeemable preferred stock to Common Stock (in shares)										6,086,991
Conversion of mandatory redeemable preferred stock to Common Stock										6
Sale of Common Stock at an average price of $1.752 per share and warrants to Medtronic (in shares)									1,141,552
Sale of Common Stock at an average price of $1.752 per share and warrants to Medtronic									1
Issuance of Common Stock in connection with issuance of Series D Preferred Stock (in shares)							192,017
Conversion of Series Preferred Stock to Common Stock (in Shares)		79,553		53,138	100,952	131,250	110,052			1,354,746
Conversion of Series Preferred Stock to Common Stock										1
Effects of reverse acquisition (in shares)										7,103,020
Effects of reverse acquisition										14
Common stock issued for intangible assets, shares												368,761	259,491
Exercise of stock options (in shares)							787,815		406,054	10,000
Exercise of stock options							1
Ending Balance (in shares)	27,997,701	27,997,701	6,004,146	27,918,148	27,865,010	27,764,058	27,632,808	26,542,924	26,542,924	22,521,404	6,875,326	6,599,272	6,263,637	6,004,146	27,997,701
Ending Balance	28	28	0	28	28	28	28	27	27	22	0	0	0	0	28
Additional Paid-in Capital
Sale of Common Stock			4						3,062		90
Sale of Series D Preferred Stock through private placement at an average price of $35.00 per share						4,918	14,727	11,578
Conversion of note payable to Common Stock at $2.17 per share										2,371
Fair value of beneficial conversion rights issued in connection with the issuance of Series D and Seried C Preferred Stock						562	2,130	2,621
Conversion of mandatory redeemable preferred stock to Common Stock										494
Sale of Common Stock at an average price of $1.752 per share and warrants to Medtronic									2,794
Preferred Dividend and accretion of fair value of beneficial conversion charge							(8)	(3)
Contingent beneficial conversion feature related to Series C Preferred Stock				72		212	627
Induced conversion of preferred stock in connection with the issuance of Series D Preferred Stock							(347)
Adjustment to preferred dividends accrued						2
Issuance of Series C Preferred Stock in connection with induced conversion of preferred stock							2,949
Issuance of Common Stock in connection with issuance of Series D Preferred Stock							192
Employee share-based compensation expense		371		501	448	489	702	1,193
Conversion of Series Preferred Stock to Common Stock					1					(1)
Effects of reverse acquisition										5,886
Non-employee share-based compensation		158		126	185	3	72	83	1,305	42			9
Private placement of Series B convertible preferred stock												2,613
Common stock issued for intangible assets												577	24
Exercise of stock options							590		127	15
Cumulative Effects of adoption of Accounting Principle					(6,252)			(311)
Ending Balance	58,003	58,003	4	57,474	56,775	62,393	56,207	34,573	19,412	12,124	3,317	3,227	37	4	58,003
Unearned Compensation
Sale of Common Stock			0								(89)
Amortization of unearned compensation									825	202	164	24
Non-employee share-based compensation									(1,305)	(42)
Common stock issued for intangible assets												(577)
Reclassification of prior year non-employee compensation to prepaid expenses								487
Cumulative Effects of adoption of Accounting Principle								311
Ending Balance	0	0	0	0	0	0	0	0	(798)	(318)	(478)	(553)	0	0	0
Deficit Accumulated During the Development Stage
Sale of Common Stock			0
Accretion of fair value of beneficial conversion charge						(562)
Preferred Dividend and accretion of fair value of beneficial conversion charge							(2,130)	(2,621)
Contingent beneficial conversion feature related to Series C Preferred Stock				(72)		(212)	(627)
Induced conversion of preferred stock in connection with the issuance of Series D Preferred Stock							354
Issuance of Series C Preferred Stock in connection with induced conversion of preferred stock							(2,958)
Issuance of Common Stock in connection with issuance of Series D Preferred Stock							(192)
Cumulative Effects of adoption of Accounting Principle					5,183
Net loss		(5,033)	(328)	(10,163)	(13,461)	(6,320)	(6,817)	(7,046)	(5,345)	(2,937)	(2,274)	(1,310)	(870)	(1,055)
Ending Balance	$ (66,796)	$ (66,796)	$ (328)	$ (61,763)	$ (51,528)	$ (43,250)	$ (36,156)	$ (23,786)	$ (14,119)	$ (8,774)	$ (5,837)	$ (3,563)	$ (2,253)	$ (1,383)	$ (66,796)