CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets
Cash and cash equivalents	$ 10,777	$ 6,120
Restricted cash	5	5
Accounts receivable, net	1,080	1,113
Inventories	814	866
Prepaid expenses and other current assets	391	392
Total current assets	13,067	8,496
Property, plant and equipment, net	338	407
Intangible assets, net	131	195
Right-of-use assets	163	334
Deferred tax assets	8	527
Other assets	72	63
Total assets	13,779	10,022
Current liabilities
Accounts payable	338	235
Accrued liabilities	507	343
Lease liabilities, current	138	219
PPP loan payable		186
Accrued income taxes	54	59
Total current liabilities	1,037	1,042
Long-term liabilities
Lease liabilities, long term	37	140
Total long-term liabilities	37	140
Total liabilities	1,074	1,182
Commitments and contingencies (Note 11)
Stockholders' equity
Preferred stock, $0.01 par value: 1,000 shares authorized, 200 and 0 shares of Series A Convertible Preferred Stock issued and outstanding at December 31, 2021 ($5.0 million liquidation preference) and 2020, respectively	2
Common stock, $0.001 par value: 30,000 shares authorized, 6,602 and 6,601 shares issued and outstanding at December 31, 2021 and 2020, respectively	7	7
Additional paid-in-capital	62,552	57,966
Accumulated other comprehensive income	96	37
Accumulated deficit	(49,952)	(49,170)
Total stockholders' equity	12,705	8,840
Total liabilities and stockholders' equity	$ 13,779	$ 10,022