Note 1 - Summary of Significant Accounting Policies (Details Textual) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended		27 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022		May 31, 2022	Jan. 01, 2023	Dec. 31, 2021	May 31, 2017
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross		3,000	54,000	90,000
Weighted Average Number of Shares Outstanding, Diluted, Adjustment	150,783	212,643	171,723	202,479
Letters of Credit Outstanding, Amount	$ 300		$ 300
Restricted Cash and Cash Equivalents, Current	$ 422	$ 792	$ 422	$ 792	$ 1,454	[1]
Finite-Lived Intangible Assets, Remaining Amortization Period	1 year 1 month 6 days		1 year 1 month 6 days
Finite-Lived Intangible Assets, Net	$ 303		$ 303		422	[1]			$ 501
Amortization of Intangible Assets	39	$ 40	119	$ 111	150
Accounts Receivable, Allowance for Credit Loss, Current	316		316		334
Retained Earnings (Accumulated Deficit)	(14,318)		(14,318)		$ (11,826)	[1]
Accounting Standards Update 2016-13 [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Accounts Receivable, Allowance for Credit Loss, Current								$ 30
Retained Earnings (Accumulated Deficit)								$ 30
Patents Received [Member]
Finite-Lived Intangible Assets, Net	85		85
Patents In Process [Member]
Finite-Lived Intangible Assets, Net	$ 110		$ 110
Service-based Options [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross	25,000	3,000	54,000	69,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 6.13
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value			$ 5.88
Market Condition Options [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross	0	0	0	21,000
Share-Based Payment Arrangement, Option [Member]
Share-Based Payment Arrangement, Expense	$ 42	$ 62	$ 184	$ 168
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount	$ 724		$ 724
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition			3 years 9 months 18 days
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	47,538	34,211	37,869	44,070
Restricted Stock Units (RSUs) [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value			$ 9.37
Share-Based Payment Arrangement, Expense	$ 38	$ 31	$ 115	$ 66
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount	$ 154		$ 154
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition			1 year 2 months 12 days
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period			18,000
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	16,784		15,027
Stock Incentive Plan 2017 [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized										350,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Additional Shares Authorized							325,000
Stock Incentive Plan 2017 [Member] | Restricted Stock Units (RSUs) [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value			$ 9.37
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period	0
Stock Incentive Plan 2017 [Member] | Restricted Stock Units (RSUs) [Member] | Non-employee Directors [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period		0	18,000	21,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period			2 years	2 years

[1] The balance sheet at December 31, 2022 has been derived from the audited financial statements at that date