Statements Of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Statements Of Comprehensive Income (Loss) [Abstract]
Net sales	$ 8,607	$ 7,621
Cost of goods sold	3,930	3,691
Gross profit	4,677	3,930
Operating expenses
Selling and marketing	1,373	1,612
General and administrative	1,987	1,686
Research and development	876	836
Total operating expenses	4,236	4,134
Operating income (loss)	441	(204)
Non-operating income (expense)
Interest expense	(1)	(3)
Interest income	5	36
Other income (expense)	14	(1)
Total non-operating income, net	18	32
Income (loss) before income taxes	459	(172)
Income tax expense (benefit)	49	(48)
Net income (loss)	410	(124)
Other comprehensive income (loss)
Change in unrealized value of available-for-sale securities, net of income tax	(1)	1
Other comprehensive income (loss)	(1)	1
Net comprehensive income (loss)	$ 409	$ (123)
Basic
Net income (loss) per share	$ 0.12	$ (0.04)
Weighted average shares	3,395,521	3,395,521
Diluted
Net income (loss) per share	$ 0.12	$ (0.04)
Weighted average shares	3,444,939	3,395,521