Note 6 - Accrued Expenses and Other Current Liabilities - Summary of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Accrued expenses	$ 116	$ 75
Accrued salaries and employee benefits	837	661
Accrued clinical trial costs	1,140	1,017
Grant liability	471	471
Customer deposits	90	90
Total	2,696	2,385
Related Party [Member]
Payable to related party	$ 42	$ 71