Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Cash flows from operating activities:
Net loss	$ (15,223)	$ (13,857)
Adjustments to reconcile net loss to net cash used in operating activities:
Share-based compensation expense	2,740	1,781
Discount amortization on short-term investments	(1,200)	0
Non-cash interest expense	58	58
Non-cash lease expense	116	66
Depreciation and amortization expense	38	74
Changes in operating assets and liabilities:
Accounts receivable	(3,703)	(2,708)
Inventory	(1,942)	(202)
Prepaid expenses and other current assets	(642)	(579)
Other non-current assets	116	125
Operating lease liabilities	(124)	(44)
Accounts payable and accrued liabilities	(1,544)	(4,129)
Net cash used in operating activities	(21,310)	(19,415)
Cash flows from investing activities:
Purchases of property and equipment	(1,369)	(23)
Purchase of short-term investments	(23,052)	0
Maturity of short-term investments	40,750	0
Net cash provided by (used in) investing activities	16,329	(23)
Cash flows from financing activities:
Issuance of common stock upon exercise of stock options	8	244
Issuance of common stock upon exercise of warrants	0	54
Net cash provided by financing activities	8	298
Net decrease in cash, cash equivalents and restricted cash	(4,973)	(19,140)
Cash, cash equivalents and restricted cash at beginning of year	39,083	148,989
Cash, cash equivalents and restricted cash, end of period	34,110	129,849
Supplemental disclosure of cash flow information:
Interest paid during the period	58	58
Supplemental disclosure of non-cash activities:
Deferred transaction costs included in accounts payable and accrued liabilities	0	249
Accrued property and equipment	$ 387	$ 27