Condensed Statement of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Cash flows from operating activities
Net income (loss)	$ 3,606	$ (204)
Adjustments to reconcile net income (loss) to net cash (used in) provided by operating activities:
Depreciation and amortization	462	756
Gain on sale of property and equipment	(167)
Stock-based compensation	2,135	1,447
Non-cash warrant revaluation	(21)	5
Non-cash interest expense	62	168
Changes in operating assets and liabilities:
Accounts receivable	(1,090)	(2,776)
Inventory	20	(850)
Prepaid expenses and other current assets	(38)	49
Other assets	664
Accounts payable	(201)	861
Accrued liabilities	(1,414)	(126)
Deferred revenue	(832)	1,815
Lease liabilities	164	(64)
Net cash (used in) provided by operating activities	3,350	1,081
Cash flows from investing activities
Purchases of property and equipment	(996)	(554)
Proceeds received from sale of property and equipment	202
Net cash used in investing activities	(794)	(554)
Cash flows from financing activities
Payments on long-term debt	(1,200)	(1,200)
Proceeds from exercise of stock options and purchase of shares in employee stock purchase plan	286	293
Net cash used in financing activities	(914)	(907)
Net increase (decrease) in cash and cash equivalents	1,642	(380)
Cash and cash equivalents at beginning of period	21,409	14,599
Cash and cash equivalents at end of period	23,051	14,219
Supplementary cash flow information:
Interest paid	83	128
Operating cash flows paid for operating leases	635	814
Financing cash flows paid for finance leases	5
Non-cash investing and financing activities:
Right-of-use assets obtained in exchange for operating lease liabilities	3,350
Right-of-use assets obtained in exchange for finance lease liabilities	36
Purchases of property and equipment in accounts payable and accrued liabilities	$ 783
Bonus settled in shares of common stock		$ 364