Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Statement [Abstract]
Net sales	$ 5,158	$ 5,002	$ 14,989	$ 15,119
Cost of sales	3,877	3,865	11,596	11,920
Gross profit	1,281	1,137	3,393	3,199
Operating expenses:
Product development	638	732	1,940	2,266
Selling, general, and administrative	2,543	2,393	7,611	8,802
Restructuring	1	(200)	(46)	1,534
Total operating expenses	3,182	2,925	9,505	12,602
Loss from operations	(1,901)	(1,788)	(6,112)	(9,403)
Other expenses (income):
Interest expense	2	1	4	1
Other expenses (income)	17	(16)	(2)	5
Loss from operations before income taxes	(1,920)	(1,773)	(6,114)	(9,409)
Provision for income taxes	0	0	0	0
Net loss	$ (1,920)	$ (1,773)	$ (6,114)	$ (9,409)
Net loss per share - basic and diluted (in dollars per share)	$ (0.16)	$ (0.15)	$ (0.51)	$ (0.80)
Weighted average shares used in computing net loss per share:
Weighted Average Number of Shares Outstanding, Basic and Diluted	12,059	11,856	11,970	11,789