Quarterly report pursuant to Section 13 or 15(d)

Note 7 - Patents (Details Textual)

v3.21.2
Note 7 - Patents (Details Textual) - USD ($)
3 Months Ended 6 Months Ended
Jun. 30, 2021
Jun. 30, 2020
Jun. 30, 2021
Jun. 30, 2020
Amortization of Intangible Assets, Total     $ 22,705 $ 26,506
Patents [Member]        
Amortization of Intangible Assets, Total $ 11,000 $ 22,000 $ 11,000 $ 22,000
Patents [Member] | Minimum [Member]        
Finite-Lived Intangible Asset, Useful Life (Year)     3 years  
Patents [Member] | Maximum [Member]        
Finite-Lived Intangible Asset, Useful Life (Year)     20 years