Note 6 - Stock Options and Restricted Shares - Stock Options Outstanding (Details) - $ / shares	9 Months Ended	12 Months Ended
Sep. 30, 2023	Dec. 31, 2022
Outstanding (in shares)	1,207,888	608,266
Outstanding Options, weighted average exercise price (in dollars per share)	$ 3.71	$ 5.3
Outstanding, weighted average remaining contractual term (Year)	9 years 2 months 26 days	8 years 9 months 7 days
Option at $2.65 [Member]
Options Granted (in shares)	15,000
Options Granted, Exercise Price (in dollars per share)	$ 2.65
Option at $2.10 [Member]
Outstanding (in shares)	588,495
Outstanding Options, weighted average exercise price (in dollars per share)	$ 2.1
Outstanding, weighted average remaining contractual term (Year)	9 years 11 months 12 days
Options Granted (in shares)	588,495
Options Granted, Exercise Price (in dollars per share)	$ 2.1
Option at $9.00 [Member]
Options expired (in shares)	(1,111)
Options expired, Exercise Price (in dollars per share)	$ 9
Option at $3.62 [Member]
Options expired (in shares)	(2,762)
Options expired, Exercise Price (in dollars per share)	$ 3.62
Subtotal as Follows [Member]
Outstanding (in shares)	1,207,888
Option at 2.00 [Member]
Outstanding (in shares)	250,000
Outstanding Options, weighted average exercise price (in dollars per share)	$ 2
Outstanding, weighted average remaining contractual term (Year)	9 years 18 days
Options at $2.40 [Member]
Outstanding (in shares)	90,893
Outstanding Options, weighted average exercise price (in dollars per share)	$ 2.4
Outstanding, weighted average remaining contractual term (Year)	9 years 18 days
Options at 3.62 [Member]
Outstanding (in shares)	256,750
Outstanding Options, weighted average exercise price (in dollars per share)	$ 9
Outstanding, weighted average remaining contractual term (Year)	7 years 11 months 15 days
Options at 9.00 [Member]
Outstanding (in shares)	6,750
Outstanding Options, weighted average exercise price (in dollars per share)	$ 26.2
Outstanding, weighted average remaining contractual term (Year)	5 years 3 months 18 days
Options at 26.20 [Member]
Outstanding (in shares)	15,000
Outstanding Options, weighted average exercise price (in dollars per share)	$ 2.65
Outstanding, weighted average remaining contractual term (Year)	9 years 6 months 14 days

Number of options or other stock instruments for which the right to exercise has lapsed under the terms of the plan agreements.

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Gross number of share options (or share units) granted during the period.

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Number of options outstanding, including both vested and non-vested options.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

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-Topic 718
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-Section 50
-Paragraph 2
-Subparagraph (c)(1)(ii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options of the plan that expired.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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