Note 4 - Accrued Expenses and Other Current Liabilities - Summary of Accrued Expenses (Details) - USD ($)	Sep. 30, 2021	Dec. 31, 2020
Accrued payroll and payroll related expenses	$ 773,917	$ 653,899
Accrued professional fees	59,126	31,809
Accrued clinical studies expenses	1,081,453	1,055,398
Other accrued expenses	88,485	35,364
Total	$ 2,002,981	$ 1,776,470