Note 8 - Stockholders' Equity (Tables)

9 Months Ended

Sep. 30, 2019

Notes Tables

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

	Three Months Ended September 30,				Nine Months Ended September 30,
	2019		2018		2019		2018
Cost of revenues	$	1,000	$	3,000	$	2,000	$	9,000
Sales and marketing		110,000		11,000		166,000		29,000
Research and development		38,000		30,000		75,000		86,000
General and administrative		104,000		131,000		216,000		351,000
	$	253,000	$	175,000	$	459,000	$	475,000

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 December 31, 2018		302,368		$	13.99
Granted		10,200		$	4.38
Forfeited		(16,539	)	$	11.50
Outstanding at September 30, 2019		296,029		$	13.80		8.6	$	763,499
Vested and expected to vest at September 30, 2019		215,932		$	15.95		8.4	$	525,700
Exercisable at September 30, 2019		94,978		$	25.70		7.6	$	171,726

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

	Number of Shares			Weighted-Average Exercise Price Per Share
Balance at December 31, 2018		1,726,523		$	29.88
Warrants granted (1)		444,445		$	0.10
Warrants expired		(19,637	)	$	417.00
Warrants exercised		(416,500	)	$	0.10
Outstanding at September 30, 2019		1,734,831		$	25.02
Exercisable at September 30, 2019		1,664,978		$	22.72