Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating activities:
Net loss	$ (7,002)	$ (3,225)
Adjustments to reconcile net loss to net cash (used in) provided by operating activities:
Depreciation and amortization	1,998	2,497
Non-cash lease expense	338	307
Provision for doubtful accounts and other adjustments to accounts receivable	5	(3)
Provision for excess and obsolete inventory		(97)
Stock based compensation	1,065	1,016
Changes in operating accounts:
Accounts receivable	(1,472)	4,018
Prepaid expenses and other assets	(218)	381
Accounts payable and accrued liabilities	(1,172)	(649)
Deferred revenue	(131)	(545)
Net cash (used in) provided by operating activities	(6,589)	3,700
Investing activities:
Capital expenditures	(63)	(190)
Other investing activities	12	11
Net cash used in investing activities	(51)	(179)
Financing activities:
Proceeds from common stock offering, net of offering expenses		59,898
Proceeds from exercise of common stock warrants		40
Proceeds from financing arrangements	541
Repayments of financing arrangements	(181)
Other financing activities	33	34
Net cash provided by financing activities	393	59,972
Net (decrease) increase in cash and cash equivalents	(6,247)	63,493
Cash and cash equivalents, beginning of period	16,078	25,754
Cash and cash equivalents, end of period	9,831	89,247
Supplemental disclosures of cash flow information:
Cash paid for income taxes	$ 41	$ 23