Note 11 - Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2020

Notes Tables

Schedule of Stockholders' Equity Note, Warrants or Rights [Table Text Block]

	Number of Shares			Weighted- Average Exercise Price Per Share		Weighted- Average Remaining Contract Term
Balance at January 1, 2019		1,726,522		$	29.88		2.20
Warrants granted		444,445		$	0.10
Warrants exercised		(435,264	)	$	0.35
Warrants expired/canceled		(19,637	)
Outstanding at December 31, 2019		1,716,066		$	25.23		1.57
Exercisable at December 31, 2019		1,646,214		$	22.91		1.63
Balance at January 1, 2020		1,716,066		$	25.23		1.57
Warrants granted		--		$	--
Warrants exercised		(599,582	)	$	2.81
Warrants expired/canceled		--
Outstanding at December 31, 2020		1,116,484		$	37.27		0.49
Exercisable at December 31, 2020		1,046,631		$	34.42		0.54

Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]

	Year Ended December 31,
	2020		2019
Cost of revenues	$	9,000	$	3,000
Sales and marketing		176,000		185,000
Research and development		114,000		98,000
General and administrative		581,000		328,000
	$	880,000	$	614,000

Share-based Payment Arrangement, Option, Activity [Table Text Block]

	Number of Shares			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Life		Aggregate Intrinsic Value
Outstanding at January 1, 2020		291,807		$	13.96		8.3	$	280,000
Granted		615,500		$	5.92
Forfeited/cancelled		(17,671	)	$	5.63			$	1,840
Outstanding at December 31, 2020		889,636		$	8.57		8.7	$	--
Vested and Expected to Vest at December 31, 2020		598,092		$	9.72		8.5	$	--
Exercisable at December 31, 2020		230,836		$	15.21		7.5	$	--

Non Vested Stock Options Activity [Table Text Block]

	Non-vested Stock Options			Weighted-Average Grant Date Fair Value
Outstanding at January 1, 2020		144,683		$	6.38
Granted		615,500		$	5.05
Vested		(88,683	)	$	5.72
Cancelled/forfeited		(12,700	)	$	4.82
Outstanding at December 31, 2020		658,800		$	5.25

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

	Year Ended December 31,
	2020	2019
Expected life (years)	6	5
Expected volatility	116%	103%
Risk-free interest rate	0.54%	1.68%
Dividend yield	0%	0%