Note 2 - Summary of Significant Accounting Policies (Details Textual)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Number of Wholly Owned Subsidiaries		5
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		35.00%
Asset Impairment Charges		$ 0	$ 0
Capitalized Computer Software, Net		427,000	2,000
Capitalized Computer Software, Amortization		36,000	18,000
Amortization of Intangible Assets		46,000	31,000
Research and Development Expense		437,157	433,844
Allowance for Doubtful Accounts Receivable, Current		4,000	2,000
Cash and Cash Equivalents, at Carrying Value		14,210,909	21,677,186	$ 13,073,331
Shipping, Handling and Transportation Costs		42,000	28,000
Including External Customer Orders [Member]
Research and Development Expense		$ 2,220,000	$ 2,448,000
Minimum [Member]
Finite-Lived Intangible Asset, Useful Life		5 years
Maximum [Member]
Finite-Lived Intangible Asset, Useful Life		20 years
Computer Software, Intangible Asset [Member] | Minimum [Member]
Finite-Lived Intangible Asset, Useful Life		3 years
Computer Software, Intangible Asset [Member] | Maximum [Member]
Finite-Lived Intangible Asset, Useful Life		5 years
Scenario, Forecast [Member]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%