Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 3,643	$ 4,937
Short-term investments	24,862	29,983
Accounts receivable and contract assets	1,405	3,859
Inventories, net	2,033	1,566
Prepaid expenses and other current assets	700	868
Total current assets	32,643	41,213
Property and equipment, net	907	976
Operating lease right-of-use asset, net	337	51
Intangible assets, net	1,941	1,982
Other assets	11	9
Total assets	35,839	44,231
Current liabilities:
Accounts payable	1,362	1,779
Accrued liabilities	912	824
Customer deposits	4	43
Deferred revenue- short term	178	155
Operating lease liability- short term	102	56
Total current liabilities	2,558	2,857
Long-term liabilities:
Deferred revenue- long term	166	110
Operating lease liability - long term	248	0
Total long-term liabilities	414	110
Total liabilities	2,972	2,967
Commitments and contingencies (Note 11)
Stockholders' equity:
Preferred stock - 5,000,000 authorized; par value $0.0001 per share; none issued and outstanding	0	0
Common stock - 150,000,000 authorized; par value $0.0001 per share; 40,992,161 and 40,851,945 shares issued and outstanding each period, respectively	4	4
Additional paid-in capital	92,856	91,025
Accumulated deficit	(59,976)	(49,759)
Accumulated other comprehensive loss	(17)	(6)
Total stockholders' equity	32,867	41,264
Total liabilities and stockholders' equity	$ 35,839	$ 44,231