Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Current assets
Cash and cash equivalents	$ 23,978	$ 14,437
Accounts receivable	1,177	905
Inventories	2,656	2,957
Other current assets	413	237
Total current assets	28,224	18,536
Property, plant and equipment, net	1,260	1,200
Operating lease right-of-use asset, net	156	255
Other assets	0	21
TOTAL ASSETS	29,640	20,012
Current liabilities
Accounts payable	1,787	1,097
Accrued compensation	1,577	2,192
Current portion of operating lease liability	160	206
Current portion of finance lease liability	25	24
Other current liabilities	54	66
Total current liabilities	3,603	3,585
Operating lease liability	0	55
Finance lease liability	41	54
Total liabilities	3,644	3,694
Commitments and contingencies
Stockholders' equity
Preferred stock	0	0
Common stock as of June 30, 2021 and December 31, 2020, par value $0.0001 per share; authorized 100,000,000 shares, issued and outstanding 6,532,018 and 2,736,060, respectively	0	0
Additional paid-in capital	269,296	249,663
Accumulated other comprehensive loss:
Foreign currency translation adjustment	(10)	(7)
Accumulated deficit	(243,290)	(233,338)
Total stockholders' equity	25,996	16,318
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	29,640	20,012
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