Note 5 - Accrued Liabilities - Accrued Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Accrued interest	$ 1,229	$ 0
Accrued bonuses	906	1,209
Accrued payroll and other related expenses	557	495
Deferred revenue - subscription rental program	412	448
Accrued professional fees	332	120
Accrued clinical trial costs	248	337
Other accruals	164	219
Total accrued liabilities	4,101	3,053
Accrued Liabilities [Member]
Current operating lease liabilities	$ 253	$ 225