Note 3 - Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2019

Notes Tables

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

	December 31, 2019					December 31, 2018
	Gross Carrying		Accumulated			Gross Carrying		Accumulated
	Amount		Amortization			Amount		Amortization
Amortized intangible assets:
Patents	$	452,978	$	(181,609	)	$	526,146	$	(149,740	)

	2019		2018
Aggregate amortization expense:
For the years ended December 31	$	31,869	$	24,749

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

2020	$	26,000
2021		25,000
2022		25,000
2023		25,000
2024		24,000