Note 6 - Equity Transactions (Details Textual) - USD ($)				3 Months Ended
	Feb. 27, 2023	Jan. 25, 2023	Jan. 03, 2023	Mar. 31, 2023	Mar. 03, 2023	Dec. 31, 2022	Jun. 24, 2021
Common Stock, Shares Authorized (in shares)				50,000,000	50,000,000	20,000,000	20,000,000
Pre-funded Warrants [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)			1,678,696
Class of Warrant or Right, Purchase Price of Warrants or Rights (in dollars per share)			$ 1.61
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)			$ 0.0001
Class of Warrant or Right, Maximum Beneficial Ownership Percent.			9.99%
Stock Issued During Period, Shares, Warrants Exercised (in shares)	741,000	400,696
Stock Issued During Period, Value, Warrants Exercised	$ 74	$ 40
Series A-1 Warrants [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)			2,608,696
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)			$ 1.36
Warrants and Rights Outstanding, Term (Year)			5 years
Class of Warrant or Right, Maximum Beneficial Ownership Percent.			4.99%
Series A-2 Warrants [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)			2,608,696
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)			$ 1.36
Warrants and Rights Outstanding, Term (Year)			3 years
Class of Warrant or Right, Maximum Beneficial Ownership Percent.			4.99%
Warrants Issued to Placement Agent [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)			156,522
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)			$ 2.0125
Warrants and Rights Outstanding, Term (Year)			5 years
Warrants To Purchase Common Stock [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)				7,419,760
Warrants To Purchase Common Stock [Member] | Minimum [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)				$ 1.36
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
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
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)				$ 25.00
Warrants and Rights Outstanding, Term (Year)				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
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)				$ 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
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)				$ 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
Warrants and Rights Outstanding				$ 474,852
Registered Direct Offering [Member]
Stock Issued During Period, Shares, New Issues (in shares)			930,000
Shares Issued, Price Per Share (in dollars per share)			$ 1.61
Proceeds from Issuance or Sale of Equity, Net of Issuance Costs			$ 3,700,000
Stock Issued, Offering Fee, Percentage of Proceeds			7.50%
Stock Issued, Management Fee, Percentage of Proceeds			1.00%
Non-accountable Expense			$ 35,000
Legal Counsel Expense and Other Out-of-pocket Expense			50,000
Clearing Expense			$ 15,950
Board Members [Member]
Share-Based Payment Arrangement, Expense				30,750
Deferred Compensation Liability, Current and Noncurrent				$ 61,500
Shares Issued, Shares, Share-Based Payment Arrangement, before Forfeiture (in shares)				11,327
Shares Issued, Value, Share-Based Payment Arrangement, before Forfeiture				$ 41,004
Employees [Member]
Shares Issued, Shares, Share-Based Payment Arrangement, before Forfeiture (in shares)				0