Note 3 - Revenue Recognition - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Revenue	$ 1,123	$ 976
UNITED STATES
Revenue	206	206
Non-US [Member]
Revenue	917	770
Instruments and Accessories [Member]
Revenue	313	293
Instruments and Accessories [Member] | UNITED STATES
Revenue	51	60
Instruments and Accessories [Member] | Non-US [Member]
Revenue	262	233
Service [Member]
Revenue	285	195
Service [Member] | UNITED STATES
Revenue	87	75
Service [Member] | Non-US [Member]
Revenue	198	120
Lease [Member]
Revenue	525	488
Lease [Member] | UNITED STATES
Revenue	68	71
Lease [Member] | Non-US [Member]
Revenue	$ 457	$ 417