The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

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The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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The risk-free interest rate assumption that is used in valuing an option on its own shares.

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Number of shares authorized for issuance under share-based payment arrangement.

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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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

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The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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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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Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The weighted average price as of the balance sheet date at which grantees could acquire the underlying shares with respect to all outstanding stock options which are in the customized range of exercise prices.

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Note 9 - Equity Incentive Plan (Details Textual) - $ / shares			3 Months Ended	9 Months Ended
	Mar. 07, 2023	Jun. 24, 2021	Sep. 30, 2023	Sep. 30, 2023	Aug. 29, 2019
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross			6,700	321,631
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Dividend Rate				0.00%
Minimum [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Term				5 years
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Risk Free Interest Rate				3.90%
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate				101.24%
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value				$ 0.97
Maximum [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Term				6 years 3 months
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Risk Free Interest Rate				4.20%
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate				103.11%
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value				$ 0.92
Officers and Employees [Member]
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share)	$ 1.28
Three Employees [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross				2,500
Share-Based Payment Arrangement, Option, Exercise Price Range, Outstanding, Weighted Average Exercise Price (in dollars per share)			$ 1.28	$ 1.28
Each of Five Non-employee Directors [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross				3,350
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share)				$ 1.28
Share-Based Payment Arrangement, Option [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Expiration Period				10 years
Share-Based Payment Arrangement, Option [Member] \| Nonemployees [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross				113,400
Share-Based Payment Arrangement, Option [Member] \| Nonemployees [Member] \| Minimum [Member]
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share)				$ 1.17
Share-Based Payment Arrangement, Option [Member] \| Nonemployees [Member] \| Maximum [Member]
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share)				$ 1.37
The 2019 Omnibus Incentive Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized					68,437
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross				68,437
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares)			0	0
The 2019 Omnibus Incentive Plan [Member] \| Share-Based Payment Arrangement, Option [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Expiration Period				10 years
The 2021 Equity Incentive Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized		3,000,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross				792,100
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares)			1,917,331	1,917,331
The 2021 Equity Incentive Plan [Member] \| Share-Based Payment Arrangement, Option [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Expiration Period		10 years
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross				290,569