Unaudited Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenue	$ 6,420	$ 6,971	$ 12,725	$ 14,260
Cost of goods sold	3,481	3,721	7,082	6,911
Gross profit	2,939	3,250	5,643	7,349
Operating expenses:
Sales and marketing	2,261	2,760	4,214	5,628
Research and product development	1,307	1,920	2,894	3,976
General and administrative	1,475	1,542	3,030	3,159
Total operating expenses	5,043	6,222	10,138	12,763
Operating loss	(2,104)	(2,972)	(4,495)	(5,414)
Other income, net	51	49	93	73
Loss before income taxes	(2,053)	(2,923)	(4,402)	(5,341)
Provision for (benefit from) income taxes	45	(760)	45	(1,332)
Net loss	$ (2,098)	$ (2,163)	$ (4,447)	$ (4,009)
Basic weighted average shares outstanding (in shares)	16,630,770	8,301,094	16,630,684	8,304,093
Diluted weighted average shares outstanding (in shares)	16,630,770	8,301,094	16,630,684	8,304,093
Basic loss per share (in dollars per share)	$ (0.13)	$ (0.26)	$ (0.27)	$ (0.48)
Diluted loss per share (in dollars per share)	$ (0.13)	$ (0.26)	$ (0.27)	$ (0.48)
Comprehensive income:
Net loss	$ (2,098)	$ (2,163)	$ (4,447)	$ (4,009)
Unrealized gain (loss) on available-for-sale securities, net of tax	84	(1)	154	(71)
Change in foreign currency translation adjustment	9	(60)	(17)	(38)
Comprehensive loss	$ (2,005)	$ (2,224)	$ (4,310)	$ (4,118)