Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Income Statement [Abstract]
Net sales	$ 5,172	$ 6,011	$ 9,831	$ 10,117
Cost of sales	3,876	4,510	7,719	8,055
Gross profit	1,296	1,501	2,112	2,062
Operating expenses:
Product development	673	763	1,302	1,534
Selling, general, and administrative	2,421	2,778	5,068	6,409
Restructuring	3	1,060	(47)	1,734
Total operating expenses	3,097	4,601	6,323	9,677
Loss from operations	(1,801)	(3,100)	(4,211)	(7,615)
Other expenses (income):
Interest expense	1	0	2	0
Other (income) expense	2	14	(19)	21
Loss from operations before income taxes	(1,804)	(3,114)	(4,194)	(7,636)
Provision for income taxes	0	0	0	0
Net loss	$ (1,804)	$ (3,114)	$ (4,194)	$ (7,636)
Net loss per share - basic and diluted (in dollars per share)	$ (0.15)	$ (0.26)	$ (0.35)	$ (0.65)
Weighted average shares used in computing net loss per share:
Weighted Average Number of Shares Outstanding, Basic and Diluted	11,949	11,791	11,925	11,755