Statements Of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Statements Of Comprehensive Income [Abstract]
Net Sales	$ 7,840	$ 7,174
Cost of Goods Sold	3,541	3,290
Gross Profit	4,299	3,884
Operating Expenses
Selling and marketing	1,469	1,576
General and administrative	1,608	1,371
Research and development	812	767
Total Operating Expenses	3,889	3,714
Operating Income	410	170
Non-operating Income (Expense)
Interest expense	0	(1)
Interest income	38	20
Other income	10	15
Total Non-operating Income, Net	48	34
Income before Income Taxes	458	204
Income taxes	163	2
Net Income	295	202
Other Comprehensive Income
Change in unrealized value of available-for-sale securities, net of income tax	41	4
Other Comprehensive Income	41	4
Net Comprehensive Income	$ 336	$ 206
Basic
Net income per share	$ 0.09	$ 0.06
Weighted average shares	3,395,521	3,395,521
Diluted
Net income per share	$ 0.09	$ 0.06
Weighted average shares	3,401,017	3,395,945