Note 2 - Summary of Significant Accounting Policies (Tables)

6 Months Ended

Jun. 30, 2022

Notes Tables

Revenue from External Customers by Geographic Areas [Table Text Block]

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2022		2021		2022		2021
North America	$	1,101	$	994	$	1,871	$	1,919
Asia Pacific		694		658		1,562		1,177
Europe and Middle East		-		2		3		8
Total	$	1,795	$	1,654	$	3,436	$	3,104

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]

	Six Months Ended
	June 30,
	2022		2021
Convertible preferred stock:
Series B convertible preferred stock	(a)	2,814,967		2,489,542
Series C convertible preferred stock	(b)	-		-
Warrants to purchase common stock		9,793,599		9,793,599
Stock options to purchase common stock		4,124,009		3,188,628
Deferred restricted common stock units		674,000		684,000
Deferred restricted common stock awards		228		232