Note 3 - Patents, Net (Tables)

12 Months Ended

Dec. 31, 2019

Notes Tables

Schedule of Finite-Lived Intangible Assets [Table Text Block]

	2019			2018
Patents	$	198,655		$	228,669
Less: accumulated amortization		(52,392	)		(82,213	)
Patents, net	$	146,263		$	146,456

Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]

2019		11,957
2020		10,655
2021		10,251
2022		10,251
2023		10,251
Thereafter		92,898
Total expense	$	146,263