CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Cash flows from operating activities:
Net loss	$ (16,795)	$ (13,465)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	802	616
Amortization of investment discount	0	54
Equity-based compensation	555	2,979
Amortization of debt discount and issuance costs	182	162
Amortization of debt discount related-party	572	0
Loss (gain) on disposal of property and equipment	11	152
Unrealized (gain) on equity investments	(50)	0
Gain on extinguishment of debt	0	(3,366)
(Increase) decrease in assets:
Contributions to deferred compensation plan	0	(5)
Accounts receivable	(11)	206
Inventory	(140)	(653)
Prepaid expense and other	(239)	(714)
Increase (decrease) in liabilities:
Accounts payable	(977)	1,154
Accrued liabilities and other	1,945	1,081
Accrued interest	235	(751)
Accrued interest from related-party	441	0
Deferred revenue and income	(79)	(53)
Deferred compensation	181	(3)
Net cash used in operating activities	(13,367)	(12,606)
Cash flows from investing activities:
Purchases of equipment	(12)	(447)
Purchase of marketable securities	0	(24,144)
Maturities of marketable securities	8,221	10,950
Net cash provided (used) by investing activities	8,209	(13,641)
Cash flows from financing activities:
Payments on finance leases	(77)	0
Proceeds from issuance of common stocks under employee purchase plan	0	77
Net cash (used) provided by financing activities	(77)	77
Effect of exchange rate on cash	(262)	(74)
Decrease in cash and cash equivalents	(5,497)	(26,244)
Cash and cash equivalents, beginning of period	34,905	39,898
Cash and cash equivalents, end of period	29,408	13,654
Non-cash investing activities:
Net transfer of instruments from inventory to property and equipment	71	220
Non-cash financing activities:
Extinguishment of convertible senior notes through issuance of common stock	0	1,258
Supplemental cash flow information:
Interest paid	$ 0	$ 1,506