Note 2 - Summary of Significant Accounting Policies (Details Textual)		12 Months Ended
	Dec. 01, 2020 USD ($) shares	Dec. 31, 2021 USD ($) $ / shares shares	Dec. 31, 2020 USD ($) shares	Mar. 31, 2021 shares	Jan. 31, 2021 shares	Dec. 16, 2020 shares
Common Stock, Shares Authorized (in shares) | shares	75,000,000	75,000,000	75,000,000
Payments for Fractional Shares of Reverse Stock Split	$ 0
Reverse Stock Split, Rounding Adjustment (in shares) | shares	5,931
Number of Financial Institutions		1
Accounts Receivable, Allowance for Credit Loss, Ending Balance		$ 66,000	$ 124,000
Accounts Receivable, Allowance for Credit Loss, Writeoff		183,000	736,000
Inventory, Finished Goods, Net of Reserves		979,000	2,818,000
Inventory, Raw Materials, Net of Reserves		493,000	436,000
Impairment, Long-Lived Asset, Held-for-Use, Total		0
Revenue from Contract with Customer, Excluding Assessed Tax, Total		6,426,000	5,479,000
Contract with Customer, Asset, after Allowance for Credit Loss, Total		0	0
Contract with Customer, Liability, Total		7,000	17,000
Capitalized Contract Cost, Net, Total		84,000	132,000
Capitalized Contract Cost, Amortization		66,000	417,000
Capitalized Contract Cost, Impairment Loss		0
Equity Method Investment, Other than Temporary Impairment		$ 0	$ 0
Series A Preferred Stock [Member]
Convertible Preferred Stock, Shares Issued upon Conversion (in shares) | shares		1
Preferred Stock, Shares Outstanding, Ending Balance (in shares) | shares		0				0
Series B Preferred Stock [Member]
Convertible Preferred Stock, Shares Issued upon Conversion (in shares) | shares		2,647,320	2,341,111
Preferred Stock, Shares Outstanding, Ending Balance (in shares) | shares		40,504	35,819
Conversion of Stock Exchange Ratio		65.36
Preferred Stock, Liquidation Preference Per Share (in dollars per share) | $ / shares		$ 1,000
Conversion of Stock, Conversion Rate (in dollars per share) | $ / shares		$ 15.30
Series C Preferred Stock [Member]
Convertible Preferred Stock, Shares Issued upon Conversion (in shares) | shares		1
Preferred Stock, Shares Outstanding, Ending Balance (in shares) | shares		0	0	0	0
Conversion of Stock Exchange Ratio		1
Rental [Member]
Revenue from Contract with Customer, Excluding Assessed Tax, Total		$ 1,214,000	$ 1,337,000
Contract with Customer, Liability, Current		452,000	345,000
Contract with Customer, Liability, Revenue Recognized		318,000	594,000
Marketing Programs [Member]
Contract with Customer, Liability, Total		$ 7,000	$ 17,000
Minimum [Member]
Property, Plant and Equipment, Useful Life (Year)		3 years
Warranty Period (Year)		1 year
Minimum [Member] | Viveve Systems [Member]
Lessor, Operating Lease, Term of Contract (Month)		6 months
Maximum [Member]
Property, Plant and Equipment, Useful Life (Year)		7 years
Warranty Period (Year)		3 years
Maximum [Member] | Viveve Systems [Member]
Lessor, Operating Lease, Term of Contract (Month)		12 months
Viveve Systems [Member]
Property, Plant and Equipment, Useful Life (Year)		5 years
Customer Concentration Risk [Member] | Revenue Benchmark [Member]
Concentration Risk, Number of Customers		1	1
Customer Concentration Risk [Member] | Revenue Benchmark [Member] | One Customer [Member]
Concentration Risk, Percentage		30.00%	36.00%
Customer Concentration Risk [Member] | Accounts Receivable [Member]
Concentration Risk, Number of Customers		1	1
Customer Concentration Risk [Member] | Accounts Receivable [Member] | One Customer [Member]
Concentration Risk, Number of Customers		10
Concentration Risk, Percentage			37.00%
Reverse Stock Split [Member]
Stockholders' Equity Note, Stock Split, Conversion Ratio	10