Note 8 - Stockholders' Equity (Tables)

6 Months Ended

Jun. 30, 2019

Notes Tables

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

	Three Months Ended June 30,				Six Months Ended June 30,
	2019		2018		2019		2018
Cost of revenues	$	1,000	$	4,000	$	1,000	$	7,000
Sales and marketing		44,000		9,000		56,000		17,000
Research and development		22,000		28,000		37,000		55,000
General and administrative		58,000		122,000		112,000		221,000
	$	125,000	$	163,000	$	206,000	$	300,000

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
Forfeited		(16,139	)	$	11.71
Outstanding at June 30, 2019		286,229		$	14.12		9		--
Vested and expected to vest at June 30, 2019		196,219		$	16.92		8.6		--
Exercisable at June 30, 2019		84,804		$	28.17		7.7		--

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		(200,000	)	$	0.10
Outstanding at June 30, 2019		1,951,331		$	22.26
Exercisable at June 30, 2019		1,881,478		$	20.11