Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Cash flows from operating activities
Net income	$ 6,129	$ 4,343
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	982	1,455
Gain on sale of property and equipment	(167)
Stock-based compensation	4,408	3,227
Non-cash warrant revaluation	(23)	19
Non-cash interest expense	105	319
Changes in operating assets and liabilities:
Accounts receivable	(2,472)	(586)
Inventory	(287)	(675)
Prepaid expenses and other current assets	158	(492)
Other assets	(28)	11
Accounts payable	563	(571)
Accrued liabilities	(46)	1,696
Deferred revenue	(11)	832
Lease liabilities	182	(219)
Net cash provided by operating activities	9,493	9,359
Cash flows from investing activities
Purchases of property and equipment	(2,788)	(1,030)
Proceeds received from sale of property and equipment	202
Net cash used in investing activities	(2,586)	(1,030)
Cash flows from financing activities
Payments on long-term debt	(2,400)	(3,400)
Payments of debt issuance costs	(10)	(11)
Proceeds from exercise of stock options and purchase of shares in employee stock purchase plan	889	1,892
Net cash used in financing activities	(1,521)	(1,519)
Net increase in cash and cash equivalents	5,386	6,810
Cash and cash equivalents at beginning of period	21,409	14,599
Cash and cash equivalents at end of period	26,795	21,409
Supplementary cash flow information:
Interest paid	169	228
Operating cash flows paid for operating leases	1,320	1,603
Financing cash flows paid for finance leases	11
Non-cash investing and financing activities:
Right-of-use assets obtained in exchange for operating lease liabilities	6,837
Right-of-use assets obtained in exchange for finance lease liabilities	36
Purchases of property and equipment in accounts payable and accrued liabilities	$ 807	340
Bonus settled in shares of common stock		$ 364