Note 6 - Equity Transactions (Details Textual) - USD ($)		1 Months Ended		3 Months Ended					9 Months Ended			12 Months Ended
	Nov. 19, 2021	Mar. 31, 2021	Jan. 31, 2021	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Mar. 31, 2021	Sep. 30, 2022	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021	Jun. 24, 2021	Dec. 08, 2020
Common Stock, Shares Authorized (in shares)				20,000,000					20,000,000	20,000,000		20,000,000	20,000,000	10,000,000
Shares Issued, Value, Share-Based Payment Arrangement, before Forfeiture					$ 15,750		$ 124,998
Stock Issued During Period, Value, Issued for Services				$ 30,752	$ 41,256
Proceeds from Warrant Exercises									$ 0		$ 7,991,101
November 2021 Public Offering [Member]
Stock Issued During Period, Shares, New Issues (in shares)	1,950,000
Shares Issued, Price Per Share (in dollars per share)	$ 6.00
Proceeds from Issuance or Sale of Equity, Total	$ 11,700,000
Underwriting Discounts and Commissions, Percent	7.00%
Payments of Stock Issuance Costs	$ 927,000
Warrants Issued in Connection with December 2020 Public Offering [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)												1,599,204
Proceeds from Warrant Exercises												$ 7,991,101
Warrants Exercised in Net Share Settlement [Member]
Class of Warrant or Right, Exercised During Period (in shares)		9,436
Stock Issued During Period, Shares, Warrants Exercised (in shares)		2,913
Warrants To Purchase Common Stock [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)				2,045,846					2,045,846	2,045,846
Warrants To Purchase Common Stock [Member] | Minimum [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)				$ 5.00					$ 5.00	$ 5.00
Warrants To Purchase Common Stock [Member] | Maximum [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)				$ 65.00					$ 65.00	$ 65.00
Warrants to Purchase Units Sold in May 2016 Private Placement [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)				4,800					4,800	4,800
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)				$ 25.00					$ 25.00	$ 25.00
Warrants and Rights Outstanding, Term (Year)				7 years					7 years	7 years
Warrants to Purchase Units Sold in February 2017 Private Placement [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)				1,641					1,641	1,641
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)				$ 35.00					$ 35.00	$ 35.00
Warrants to Purchase Units Sold in October 2017 Private Placement [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)				2,400					2,400	2,400
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)				$ 25.00					$ 25.00	$ 25.00
Warrants to Purchase Units Sold in May 2016, February 2017 and October 2017 Private Placement [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)				17,681					17,681	17,681
Warrants and Rights Outstanding				$ 474,852					$ 474,852	$ 474,852
Share-Based Payment Arrangement, Nonemployee [Member]
Stock Issued During Period, Shares, Issued for Services (in shares)								10,000
Stock Issued During Period, Value, Issued for Services						$ 41,004		$ 50,300
Employee [Member]
Shares Issued, Shares, Share-Based Payment Arrangement, before Forfeiture (in shares)			53,938	0					7,500
Shares Issued, Value, Share-Based Payment Arrangement, before Forfeiture			$ 271,308						$ 15,750
Share-Based Payment Arrangement, Expense							$ 0		$ 15,570		$ 125,000
Scientific Advisory Board [Member]
Shares Issued, Shares, Share-Based Payment Arrangement, before Forfeiture (in shares)				0			0		5,000		0
Shares Issued, Value, Share-Based Payment Arrangement, before Forfeiture									$ 10,500
Share-Based Payment Arrangement, Expense									$ 10,500
Board Members [Member]
Shares Issued, Shares, Share-Based Payment Arrangement, before Forfeiture (in shares)				16,017		11,327			39,083
Shares Issued, Value, Share-Based Payment Arrangement, before Forfeiture				$ 30,752		$ 41,004				$ 102,512