Note 10 - Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2013

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of Share-based Compensation, Activity [Table Text Block]

	Number of Shares			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (yrs)		Aggregate Intrinsic Value
Outstanding at December 31, 2012		1,069,141		$	4.50
Granted		210,000			0.52
Exercised		-			-
Forfeited or expired		(82,097	)		4.68
Outstanding at December 31, 2013		1,197,044		$	3.79		6.0	$	7,700
Exercisable at December 31, 2013		812,037		$	5.29		4.3	$	0

Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block]

	2013		2012		2011
Weighted average fair value of options granted during the period	$	0.43	$	0.59	$	0.79
Intrinsic value of options exercised during the period		-		-		-
Total fair value of options vested during the period		165,490		319,920		540,339

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

	2013			2012			2011
Weighted average risk-free interest rates		2.3	%		1.1	%		1.4	%
Expected dividend yield		0.0	%		0.0	%		0.0	%
Expected life of option (years)	7.0			6.7			7.0
Expected volatility		96.60	%		105.2	%		111.2	%

Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block]

	2013		2012		2011
General and administrative expense	$	101,896	$	231,936	$	284,352
Research and development expense		41,539		78,140		179,400
Total stock option expense	$	143,435	$	310,076	$	463,752