Note 4 - Accrued Expenses and Other Current Liabilities - Summary of Accrued Expenses (Details) - USD ($)	Sep. 30, 2019	Dec. 31, 2018
Accrued payroll and payroll related expenses	$ 392,907	$ 409,889
Accrued professional fees	47,857	69,231
Accrued clinical studies expenses	85,962	34,000
Other accrued expenses	78,311	92,106
Total	$ 605,037	$ 605,226