Note 8 - Income Taxes - Reconciliation of Income Tax Benefit (Expense) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Statutory federal income tax benefit	$ 2,118,160	$ 2,633,841
State tax benefit, net of federal taxes	66,117	76,922
Foreign tax benefit	132,931
Foreign operations tax rate differential	(94,373)
State rate adjustment	15,355	(77,556)
R&D tax credit	22,532
Nondeductible/nontaxable items	(118,905)	(757,149)
State NOL adjustment	746,479
OID and derivatives	(159,037)
NQSO adjustment		537,884
New federal rate adjustment		(4,974,121)
Other	47,868	(8,336)
Valuation allowance decrease (increase)	(2,777,127)	2,568,515
Total income tax benefit (expense)