CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Cash flows from operating activities
Net loss	$ (61,256)	$ (56,572)
Adjustments to reconcile net loss to net cash used in operating activities
Stock-based compensation	23,061	16,866
Depreciation and amortization	3,452	2,086
Accounts receivable credit losses	150	14
Accretion of discount on marketable securities	229	1,294
Amortization of debt issuance costs	198	288
Loss on extinguishment of debt	0	1,848
Loss on sale and disposal of property and equipment	153	399
Changes in operating assets and liabilities
Accounts receivable	(6,479)	(569)
Inventory	(5,709)	(5,784)
Prepaid expenses and other assets	810	(594)
Accounts payable	2,529	(532)
Accrued liabilities and other	1,207	1,723
Net cash used in operating activities	(41,655)	(39,533)
Cash flows from investing activities
Maturities of marketable securities	126,200	159,990
Purchases of marketable securities	(119,508)	(102,021)
Purchases of property and equipment	(9,507)	(6,389)
Net cash (used in) provided by investing activities	(2,815)	51,580
Cash flows from financing activities
Proceeds from debt financing	0	35,000
Repayments of debt financing	0	(41,000)
Payments of debt issuance costs	0	(111)
Payments of prepayment penalty and lender fees	0	(508)
Proceeds from the exercise of common stock options	379	2,565
Proceeds from issuance of common stock under employee stock purchase plan	1,818	2,343
Net cash provided by (used in) financing activities	2,197	(1,711)
Effect of exchange rate changes on cash and cash equivalents	(429)	(498)
Net (decrease) increase in cash and cash equivalents	(42,702)	9,838
Cash and cash equivalents at
Beginning of year	63,419	53,581
End of year	20,717	63,419
Supplemental disclosure of cash flow information
Cash paid for interest	2,621	3,230
Supplemental disclosure of non-cash information
Vesting of early exercised stock options	0	27
Unpaid purchases of property and equipment	$ 1,115	$ 509