Note 7 - Accrued Expenses and Other Current Liabilities - Summary of Accrued Expenses (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Accrued interest payable	$ 37,415	$ 29,359
Accrued Series A dividends	1,062,314
Accrued payroll and payroll related expenses	312,221	399,740
Accrued professional fees	122,711	72,855
Accrued clinical studies expenses	63,350	220,978
Other	30,840	151,332
Total	$ 1,628,851	$ 874,264