Note 1 - Organization and Summary of Significant Accounting Policies (Details Textual) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Jun. 30, 2021 USD ($)	Dec. 31, 2021 USD ($) $ / shares shares	Dec. 31, 2020 USD ($) $ / shares shares
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares		$ 0.0001	$ 0.0001
Number of Wholly-owned Subsidiaries		1
Short-term Investment, Allowance for Credit Loss		$ 0	$ 0
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in shares) | shares		5,596,853	7,566,502
Accounts Receivable, Allowance for Credit Loss, Ending Balance		$ 134	$ 10
Inventory Valuation Reserves, Ending Balance		$ 0
Property, Plant and Equipment, Useful Life (Year)		3 years
Impairment, Long-Lived Asset, Held-for-Use, Total		$ 0	0
Advertising Expense		145	287
Marketing Expense		924	747
Cost of Revenue, Total		5,734	2,601
Revenue from Contract with Customer, Including Assessed Tax		7,381	3,868
Product Line Exit Expense		747	0
Write-off, Inventory Cost		641
Retiring Cost		106
Standard Product Warranty Accrual, Ending Balance		96	48
Shipping and Handling [Member]
Cost of Revenue, Total		167	75
Revenue from Contract with Customer, Including Assessed Tax		88	$ 63
Computer Software, Intangible Asset [Member]
Impairment, Long-Lived Asset, Held-for-Use, Total	$ 170	$ 170
Minimum [Member]
Finite-Lived Intangible Asset, Useful Life (Year)		1 year
Maximum [Member]
Finite-Lived Intangible Asset, Useful Life (Year)		20 years