Note 11 - Stock Options (Tables)

6 Months Ended

Jun. 30, 2017

Notes Tables

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

	For the Three Months Ended								For the Six Months Ended
	June 30,								June 30,
	2017				2016				2017				2016
Expected volatility		89%	-	93%		81%	-	84%		89%	-	93%		81%	-	102%
Risk-free interest rate			1.4%				0.9%				1.4%			0.9%	-	1.2%
Forfeiture rate			0%				0%				0%				0%
Dividend yield			0%				0%				0%				0%
Expected term (in years)		3.0	-	3.5		3.1	-	3.5		3.0		3.5		3.1	-	3.5

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

	Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value
Outstanding at December 31 , 2016		4,211,168		$	1.09		2.85	$	46,233
Granted		2,171,600			0.31		4.93		24,000
Exercised		-			-		-		-
Forfeited or Expired		(533,335	)		1.38		1.55
Outstanding at June 30, 2017		5,849,433		$	0.78		2.81		24,000
Vested or Expected to Vest at June 30, 2017		3,732,666		$	0.99		1.82		8,333
Exercisable at June 30, 2017		3,732,666		$	0.99		1.82	$	8,333

Schedule of Nonvested Share Activity [Table Text Block]

	Number of Shares			Weighted-Average Grant- Date Fair Value
Non-vested at December 31, 2016		1,659,834		$	0.58
Granted		2,171,600			0.18
Vested		(1,651,333	)		0.45
Forfeited		(70,001	)		0.35
Non-vested at June 30, 2017		2,110,100		$	0.26