UNAUDITED CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 24,835	$ 11,534
Restricted cash	40	1,790
Accounts receivable, net of allowance for doubtful accounts of $684 and $659 at March 31, 2022 and December 31, 2021, respectively	13,239	13,297
Inventories, net	10,143	9,454
Income taxes receivable	32	22
Other current assets	3,372	3,740
Current contract assets	3,533	0
Assets held for sale	2,752	2,762
Total current assets	57,946	42,599
Property and equipment, net	5,079	5,296
Operating lease right-of-use assets	1,827	2,041
Deferred tax assets, net	282	279
Other long-term assets	17	0
Long term contract assets	7,067	29
Total assets	72,218	50,244
Current liabilities:
Accounts payable	8,233	7,616
Accrued liabilities	6,747	8,996
Income taxes payable	4	4
Interest payable	94	82
Current portion of operating lease liabilities	619	602
Current portion of finance lease liabilities	33	41
Current portion of long-term debt	1,553	1,436
Convertible notes payable	17,609	0
Contingent convertible notes payable	14,050	0
Total current liabilities	48,942	18,777
Deferred revenue, long-term	84	91
Long-term operating lease liabilities	6,806	7,779
Long-term finance lease liabilities	47	53
Long-term debt	3,235	3,352
TOTAL LIABILITIES	59,114	30,052
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.0001 par value, 100,000 shares authorized; no shares issued and outstanding	0	0
Common stock, $0.0001 par value, 140,000,000 shares authorized; 82,563,610 shares issued and 76,490,522 shares outstanding at March 31, 2022 ; 79,483,837 shares issued and 73,461,203 shares outstanding at December 31, 2021	8	8
Additional paid-in capital	367,104	363,417
Accumulated other comprehensive income	89	81
Accumulated deficit	(319,938)	(309,214)
Treasury stock, at cost; 6,073,088 and 6,022,634 shares at March 31, 2022 and December 31, 2021 , respectively	(34,159)	(34,100)
Total stockholders’ equity	13,104	20,192
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 72,218	$ 50,244