Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Current assets
Cash and cash equivalents	$ 15,345	$ 24,205
Accounts receivable	1,313	750
Inventories	3,010	2,843
Other current assets	252	328
Total current assets	19,920	28,126
Property, plant and equipment, net	1,063	1,188
Operating lease right-of-use asset	994	1,082
Other assets	21	21
TOTAL ASSETS	21,998	30,417
Current liabilities
Accounts payable	1,550	1,414
Accrued compensation	1,633	1,664
Current portion of operating lease liability	186	167
Current portion of finance lease liability	27	26
Other current liabilities	63	36
Total current liabilities	3,459	3,307
Operating lease liability	860	956
Finance lease liability	15	28
Other long-term liability	0	179
Total liabilities	4,334	4,470
Commitments and contingencies
Stockholders' equity
Preferred stock	0	0
Common stock as of June 30, 2022 and December 31, 2021, par value $0.0001 per share; authorized 100,000,000 shares, issued and outstanding 10,537,606 shares	1	1
Additional paid-in capital	279,350	278,873
Accumulated other comprehensive income:
Foreign currency translation adjustment	(12)	(11)
Accumulated deficit	(261,675)	(252,916)
Total stockholders' equity	17,664	25,947
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	21,998	30,417
Series A Junior Participating Preferred Stock [Member]
Stockholders' equity
Preferred stock	0	0
Series F Convertible Preferred Stock [Member]
Stockholders' equity
Preferred stock	$ 0	$ 0