CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Current assets
Cash and cash equivalents	$ 4,402	$ 10,777
Restricted cash	5	5
Marketable securities	6,408	0
Accounts receivable, net	719	1,080
Inventories	1,008	814
Prepaid expenses and other current assets	475	391
Total current assets	13,017	13,067
Property, plant and equipment, net	245	338
Intangible assets, net	102	131
Right-of-use assets	252	163
Deferred tax assets	8	8
Other assets	41	72
Total assets	13,665	13,779
Current liabilities
Accounts payable	371	338
Accrued liabilities	289	507
Lease liabilities, current	172	138
Accrued income taxes	136	54
Total current liabilities	968	1,037
Long-term liabilities
Lease liabilities, long-term	87	37
Total long-term liabilities	87	37
Total liabilities	1,055	1,074
Commitments and contingencies (Note 8)
Stockholders' equity
Preferred stock, $0.01 par value: 1,000 shares authorized, 200 shares of Series A Convertible Preferred Stock issued and outstanding at both June 30, 2022 and December 31, 2021 ($5.0 million liquidation preference)	2	2
Common stock, $0.001 par value: 30,000 shares authorized, 6,602 shares issued and outstanding at both June 30, 2022 and December 31, 2021	7	7
Additional paid-in-capital	62,552	62,552
Accumulated other comprehensive income (loss)	(53)	96
Accumulated deficit	(49,898)	(49,952)
Total stockholders' equity	12,610	12,705
Total liabilities and stockholders' equity	$ 13,665	$ 13,779