CONDENSED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Cash flows from operating activities
Net loss	$ (17,424)	$ (15,699)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	1,681	1,063
Amortization of intangible assets	872	931
Non-cash operating lease cost	391	388
Provision for expected credit losses	0	3
Write-down of inventory	173	307
Loss on disposal of property and equipment	11	133
Stock-based compensation expense	4,916	5,323
Changes in operating assets and liabilities:
Accounts receivable	1,065	(794)
Prepaid and other current assets	398	856
Inventories	(3,105)	(271)
Accounts payable	783	(103)
Accrued liabilities	362	(324)
Other	(221)	(43)
Net cash used in operating activities	(10,098)	(8,230)
Cash flows from investing activities
Purchase of property and equipment	(58)	(198)
Net cash used in investing activities	(58)	(198)
Cash flows from financing activities
Payment of contingent consideration	(2,400)
Proceeds from issuance of common stock under employee stock purchase plan	212	170
Net cash (used in) provided by financing activities	(2,188)	170
Net decrease in cash and cash equivalents	(12,344)	(8,258)
Cash and cash equivalents at beginning of the period	31,637	40,599
Cash and cash equivalents at end of the period	19,293	32,341
Supplemental cash flow information
Cash paid for taxes	10	19
Supplemental schedule of non-cash investing and financing activities
Transfer from Inventories to Equipment under lease, net	1,496	$ 3,285
Transfer from Inventories to Property and equipment, net	34
Accounts payable for purchases of Property and equipment	$ (31)