Note 8 - Summary of Stock Options (Tables)

6 Months Ended

Jun. 30, 2015

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

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

	Six Months Ended June 30, 2015
						Weighted
				Weighted		Average		Aggregate
	Number			Average		Remaining		Intrinsic
	of			Exercise		Contractual		Value
	Shares			Price		Term (years)		(in thousands)
Options outstanding, beginning of period		2,291,783		$	1.02		9.32	$	-
Options granted		735,000		$	0.45
Options exercised		-		$	-
Options canceled		(21,000	)	$	1.00
Options outstanding, end of period		3,005,783		$	0.88		8.98	$	764,669
Vested and exercisable and expected to vest, end of period		2,784,084		$	0.91		8.95	$	82,195
Vested and exercisable, end of period		718,086		$	1.93		7.72	$	697,679

Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table Text Block]

		Options Outstanding						Options Exercisable
						Weighted
		Number		Weighted		Average		Number		Weighted
		Outstanding		Average		Remaining		Exercisable		Average
Range of		as of		Exercise		Contractual		as of		Exercise
Exercise Prices		June 30, 2015		Price		Term (Years)		June 30, 2015		Price
	$0.33		100,000	$	0.33		9.87		-	$	-
	$0.46 - $0.47		635,000	$	0.47		9.61		-	$	-
	$0.60		1,881,476	$	0.60		9.25		328,779	$	0.60
	$1.24		312,373	$	1.24		7.40		312,373	$	1.24
	$7.00 - $9.00		57,603	$	8.64		2.33		57,603	$	8.64
	$12.00 - $18.63		19,081	$	15.29		2.82		19,081	$	15.29
	$37.00		250	$	37.00		2.24		250	$	37.00
			3,005,783	$	0.88		8.98		718,086	$	1.93

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

	Three Months Ended		Six Months Ended
	June 30, 2015		June 30, 2015
Expected term (in years)		5		5
Average volatility		64%		62% - 64%
Risk-free interest rate		1.58%		1.29% - 1.58%
Dividend yield		0%		0%

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

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2015		2014		2015		2014
Research and development	$	4	$	-	$	8	$	-
Selling, general and administrative		44		17		82		30
Total	$	48	$	17	$	90	$	30