Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenues
Total revenues	$ 2,096	$ 3,195	$ 6,635	$ 8,866
Type of Revenue [Extensible List]	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
Expenses
Cost of sales	$ 799	$ 1,315	$ 2,497	$ 3,235
Research and development	79	616	1,001	1,879
Selling and marketing	626	608	2,057	1,940
General and administrative	1,405	1,319	4,324	4,026
Total expenses	2,909	3,858	9,879	11,080
Loss from operations	(813)	(663)	(3,244)	(2,214)
Other income (expense)
Change in fair value of warrant liability	837	758	1,745	1,092
Interest expense	(21)	(17)	(55)	(26)
Miscellaneous income		43	2	45
Total other income (expense), net	816	784	1,692	1,111
Net income (loss)	3	121	(1,552)	(1,103)
Net income (loss) applicable to common stockholders	$ 3	$ 121	$ (1,552)	$ (1,103)
Net income (loss) per common share-basic	$ 0.00	$ 0.02	$ (0.21)	$ (0.18)
Net income (loss) per common share-diluted	$ 0.00	$ 0.02	$ (0.21)	$ (0.18)
Weighted average shares-basic	7,546	6,337	7,502	6,233
Weighted average shares-diluted	7,546	6,404	7,502	6,233