CONSOLIDATED STATEMENT OF CASH FLOWS - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Cash flows from operating activities:
Net loss	$ (61,618,000)	$ (62,493,000)	$ (77,702,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	3,254,000	3,000,000	2,518,000
Provision for bad debts	301,000	204,000	123,000
Amortization of investment discount	0	98,000	226,000
Equity-based compensation expense	5,387,000	10,625,000	22,047,000
Unrealized (gain) loss on equity investments	(114,000)	211,000	0
Loss (gain) on disposal of property and equipment	150,000	133,000	(75,000)
Gain on fair value adjustment	(12,955,000)	0	0
Paid-in-kind interest	1,718,000	0	0
Inventory write-down	1,184,000	0	4,500,000
(Increase) decrease in assets:
Deferred compensation plan	(39,000)	(298,000)	(484,000)
Accounts receivable	(234,000)	(100,000)	(893,000)
Inventory	446,000	(236,000)	(415,000)
Prepaid expense and other assets	965,000	(62,000)	1,014,000
Increase (decrease) in liabilities:
Accounts payable	295,000	2,920,000	273,000
Accrued liabilities and other	(411,000)	(861,000)	(469,000)
Deferred revenue and income	2,120,000	96,000	75,000
Deferred compensation	290,000	66,000	473,000
Net cash used in operating activities	(40,196,000)	(48,728,000)	(47,323,000)
Cash flows from investing activities:
Purchases of equipment	(1,035,000)	(554,000)	(603,000)
Purchase of marketable securities	0	(27,506,000)	(30,081,000)
Proceeds from sales of marketable securities	0	0	250,000
Maturities of marketable securities	9,695,000	40,477,000	38,738,000
Net cash provided by investing activities	8,660,000	12,417,000	8,304,000
Cash flows from financing activities:
Proceeds from exercise of options	0	7,000	1,620,000
Proceeds from issuance of common stocks under employee purchase plan	0	224,000	326,000
Proceeds from issuance of 5.00% Notes	10,000,000	0	0
Payment of debt	0	(80,000)	(360,000)
Payments on finance leases	(1,250,000)	(1,201,000)	0
Transaction costs related to debt	(3,731,000)	(192,000)	(1,240,000)
Net cash provided by financing activities	9,019,000	31,630,000	43,226,000
Effect of exchange rate on cash	(250,000)	(312,000)	(90,000)
(Decrease) increase in cash and cash equivalents	(22,767,000)	(4,993,000)	4,117,000
Cash and cash equivalents, beginning of period	34,905,000	39,898,000	35,781,000
Cash and cash equivalents, end of period	12,138,000	34,905,000	39,898,000
Non-cash investing activities:
Net transfer of instruments from inventory to property and equipment, net	401,000	168,000	688,000
Non-cash financing activities:
Exchange of 2.50% Notes and accrued interest for 5.00% Notes	56,893,000	0	0
Debt premium on issuance of 5.00% Notes	6,023,000	0	0
Derivative liability associated with the bifurcated conversion option	38,160,000	0	0
Reclassification of bifurcated conversion option to contributed capital	26,908,000	0	0
Extinguishment of derivative liability in connection with extinguishment of 5.00% Notes	380,000	0	0
Issuance of common stock in connection with extinguishment of 5.00% Notes	819,000	0	0
Capital contribution from the exchange of secured note and accrued interest through the issuance of common stock with related party	25,366,000	29,847,000	0
2.50% Notes extinguished in connection with exchange transaction	0	49,624,000	0
Fair value of new note issued in connection with the exchange transaction	0	16,024,000	0
Fair value of common stock warrant issued in connection with the exchange transaction	0	3,753,000	0
Right-of-use assets obtained in exchange for finance lease obligations	200,000	3,096,000	0
Supplemental cash flow information:
Interest paid	122,000	2,214,000	4,288,000
Income taxes paid, net of refunds	363,000	0	0
Convertible Notes
Adjustments to reconcile net loss to net cash used in operating activities:
Amortization of debt discount and issuance costs	3,278,000	474,000	11,542,000
2.50% Convertible Notes due 2023 | Convertible Notes
Adjustments to reconcile net loss to net cash used in operating activities:
Loss (gain) on extinguishment of debt		(3,600,000)	(4,900,000)
Non-cash financing activities:
Extinguishment of 2.50% Notes through issuance of common stock	0	10,180,000	38,902,000
Nonrelated Party
Adjustments to reconcile net loss to net cash used in operating activities:
Amortization of debt discount and issuance costs	3,278,000	474,000	11,542,000
Loss (gain) on extinguishment of debt	6,499,000	(3,565,000)	(9,793,000)
Increase (decrease) in liabilities:
Accrued interest	716,000	(437,000)	(283,000)
Cash flows from financing activities:
Proceeds from issuance of common and preferred stock, net	0	32,872,000	42,880,000
Related Party
Adjustments to reconcile net loss to net cash used in operating activities:
Amortization of debt discount and issuance costs	1,033,000	834,000	0
Loss (gain) on extinguishment of debt	6,755,000	0	0
Increase (decrease) in liabilities:
Accrued interest	784,000	663,000	0
Cash flows from financing activities:
Proceeds from issuance of common stock to related party	$ 4,000,000	$ 0	$ 0