Note 2 - Summary of Significant Accounting Policies (Tables)

3 Months Ended

Mar. 31, 2022

Notes Tables

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

	Three Months Ended
	March 31,
	2022		2021
Asia Pacific	$	868	$	519
North America		770		925
Europe and Middle East		3		6
Total	$	1,641	$	1,450

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

		Three Months Ended
		March 31,
		2022		2021
Convertible preferred stock:
Series B convertible preferred stock	(a)		2,729,869		2,414,183
Series C convertible preferred stock	(b)				-
Warrants to purchase common stock			9,793,599		9,793,605
Stock options to purchase common stock			4,110,009		981,551
Deferred restricted common stock units			674,000		687,000
Deferred restricted common stock awards			228		232