Note 11 - Income Taxes - Reconciliation of Income Tax Benefit (Details) - USD ($)	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
U.S. federal statutory rate applied to pretax loss	$ (537,620)	$ (737,855)	$ (1,112,378)
Permanent differences	549	436	2,012
Research and development credits	(53,884)	(57,109)	(59,087)
Impact of Tax Act		10,086,795
Change in valuation allowance	590,955	(9,292,267)	1,169,453
Reported income tax expense	$ 0	$ 0	$ 0

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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