Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2013

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Summary of assumptions used to value stock options granted to employees and directors

For the Nine
	Months Ended September 30, 2013
Annual dividend yield	--
Expected life (years)	4.3
Risk-free interest rate	0.65% - 1.33%
Expected volatility	135% - 1.54%

	For the Nine
	Months Ended September 30, 2012
Annual dividend yield	--
Expected life (years)	3.85
Risk-free interest rate	0.43% - 0.58%
Expected volatility	177% - 186%

Summary of stock-based compensation expense

	Three months ended September 30,					Nine months ended September 30,
		2013		2012			2013		2012
Product research and development		$	69	$	73		$	187	$	260
Sales and marketing		$	364		250			749		1,200
General and administrative		$	329		284			1,165		1,497
Stock compensation expense		$	762	$	607		$	2,101	$	2,957

	Remaining unamortized expense at September 30, 2013
Stock-based compensation	$	2,242

Summary of all warrant activity

September 30, 2013
Outstanding and exercisable	Warrants			Weighted  Average  Exercise Price		Weighted  Average  Remaining  Contractual  Life
January 1, 2013		4,704,636		$	1.61		1.41
Issued		--			--		--
Expired/forfeited		--			--		--
Exercised		(3,871,063	)		1.45		--
Outstanding and exercisable, September 30, 2013		833,573		$	2.40		2.31

Summary of outstanding warrants to purchase common stock

Description	Issue   Date	Exercise  Price		Shares	Expiration  Date
August 2009 Employee Warrants	8/25/2009	$	0.50	80,000	8/25/2016
2007 Debt Extension Warrants	9/22/2010	$	1.00	16,000	9/22/2015
December 2010 Employee Warrants	12/3/2010	$	1.63	200,000	12/3/2015
January 2011 Employee Warrant	1/21/2011	$	2.00	7,000	1/21/2014
February 2011 Legal Advisor Warrant	2/22/2011	$	2.50	80,000	2/22/2016
March  2011 Investor Warrants	3/9/2011	$	3.13	376,473	3/9/2016
March  2011 Investor Warrants	4/7/2011	$	3.13	34,100	4/7/2016
May 2011 Consultant Warrant	5/17/2011	$	4.05	20,000	5/17/2014
September 2011 Employee Warrant	9/12/2011	$	3.90	20,000	9/12/2014
Total Warrants Outstanding				833,573

Stock Options [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Summary of all stock option plans / warrant activity

	Number of  Options  Outstanding	Weighted  Average  Exercise  Price
Outstanding at January 1, 2013	1,715,200		$	5.04
Granted	130,000			6.12
Cancelled or expired	(18,256	)		5.57
Exercised	(182,361	)		4.44
Outstanding at September 30, 2013	1,644,583		$	5.18