Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 11,494	$ 22,765
Restricted cash	50	50
Accounts and other receivables (net of allowance for doubtful accounts of $934 and $1,172 respectively)	2,448	2,815
Inventory	4,226	3,003
Prepaid expenses and other current assets	1,269	1,622
Total current assets	19,487	30,255
Property and equipment, net	887	1,454
Operating lease right-of-use assets	338	266
Other intangible assets, net	19,915	20,827
Other assets	1,298	1,456
Total assets	41,925	54,258
Current liabilities:
Accounts payable	2,513	3,468
Accrued and other liabilities	5,814	3,169
Warranty liability, current	525	415
Operating lease liabilities, current	338	279
Total current liabilities	9,190	7,331
Warranty liability, noncurrent	5	300
Deferred income taxes, net	367	555
Total liabilities	9,562	8,186
Commitments and contingencies (Note 13)
Stockholders' equity:
Common stock, $0.001 par value; 100,000,000 shares authorized at both June 30, 2022 and December 31, 2021; 19,629,708 and 17,831,875 shares issued and outstanding at June 30, 2022 and December 31, 2021, respectively	20	18
Additional paid-in capital	626,966	622,906
Accumulated deficit	(594,551)	(576,760)
Accumulated other comprehensive loss	(72)	(92)
Total stockholders' equity	32,363	46,072
Total liabilities and stockholders' equity	41,925	54,258
Series C convertible preferred stock
Stockholders' equity:
Preferred stock, Value