Note 2 - Summary of Significant Accounting Policies (Tables)

6 Months Ended

Jun. 30, 2021

Notes Tables

Schedule of Property Plant and Equipment Useful Life [Table Text Block]

Operating lease assets – Senhance System leasing (in years)	5
Machinery, manufacturing and demonstration equipment (in years)	3-5
Computer equipment (in years)	3
Furniture (in years)	5
Leasehold improvements	Lesser of lease term or 3 to 10 years

Disaggregation of Revenue [Table Text Block]

	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
	(in thousands)				(in thousands)
U.S.
Systems	$	91	$	45	$	184	$	75
Instruments and accessories		79		7		141		67
Services		104		103		202		171
Total U.S. revenue		274		155		527		313
Outside of U.S. ("OUS")
Systems		258		117		1,430		127
Instruments and accessories		268		146		645		288
Services		302		237		583		527
Total OUS revenue		828		500		2,658		942
Total
Systems		349		162		1,614		202
Instruments and accessories		347		153		786		355
Services		406		340		785		698
Total revenue	$	1,102	$	655	$	3,185	$	1,255