Note 8 - Summary of Stock Options (Tables)

3 Months Ended

12 Months Ended

Mar. 31, 2015

Dec. 31, 2014

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

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

	Three Months Ended March 31, 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		635,000		$	0.47
Options exercised		-		$	-
Options canceled		(21,000	)	$	1.00
Options outstanding, end of period		2,905,783		$	0.90		9.20	$	-
Vested and exercisable and expected to vest, end of period		2,664,185		$	0.93		9.16	$	-
Vested and exercisable, end of period		608,492		$	2.16		7.69	$	-

	Year Ended December 31,
	2014									2013
	Number of Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (years)		Aggregate Intrinsic Value (in thousands)		Number of Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (years)		Aggregate Intrinsic Value (in thousands)
Options outstanding, beginning of year		363,413		$	1.24		8.80				360,531		$	1.24		9.74
Options granted		1,901,476		$	0.60						95,581		$	1.24
Options assumed from PLC		68,238		$	10.24						-		$	-
Options exercised		(160	)	$	0.12						-		$	-
Options canceled		(41,184	)	$	1.83						(92,699	)	$	1.24
Options outstanding, end of year		2,291,783		$	1.02		9.32	$	-		363,413		$	1.24		8.80	$	-
Vested and exercisable and expected to vest, end of year		2,099,687		$	1.06		9.29	$	-		348,865		$	1.24		8.80	$	-
Vested and exercisable, end of year		519,901		$	2.45		7.89	$	-		120,955		$	2.48		8.60	$	-

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				March 31, 2015		Price		Term (Years)		March 31, 2015		Price
$	0.46	-	$0.47		635,000	$	0.47		9.86		-	$	-
$			0.60		1,881,476	$	0.60		9.50		219,185	$	0.60
$			1.24		312,373	$	1.24		7.65		312,373	$	1.24
$	7.00	-	$9.00		57,603	$	8.64		2.58		57,603	$	8.64
$	12.00	-	$18.63		19,081	$	15.29		3.07		19,081	$	15.29
$			37.00		250	$	37.00		2.48		250	$	37.00
					2,905,783	$	0.90		9.20		608,492	$	2.16

			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			December 31, 2014		Price		Term (Years)		December 31, 2014		Price
$0.60				1,901,476	$	0.60		9.64		129,594	$	0.60
$1.24				312,373	$	1.24		7.90		312,373	$	1.24
$7.00	-	$9.00		58,603	$	8.64		7.46		58,603	$	8.64
$12.00	-	$18.63		19,081	$	15.29		6.54		19,081	$	15.29
$37.00				250	$	37.00		3.47		250	$	37.00
				2,291,783	$	1.02		9.32		519,901	$	2.45

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

	Three Months Ended
	March 31,
	2015			2014
Expected term (in years)		5			5
Average volatility		62%			67%
Risk-free interest rate	1.29%	-	1.49%	0.80%	-	0.88%
Dividend yield		0%			0%

	Year Ended
	Decenber 31,
	2014			2013
Expected term (in years)		5			5
Average volatility		61	%		68	%
Risk-free interest rate		1.80	%		0.84	%
Dividend yield		0	%		0	%

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

	Three Months Ended
	March 31,
	2015		2014
Research and development	$	4	$	-
Selling, general and administrative		38		13
Total	$	42	$	13

	Year Ended
	Year Ended December 31,
	2014		2013
Research and development	$	5	$	-
Selling, general and administrative		179		87
Total	$	184	$	87