CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS Unaudited - USD ($) shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Income Statement [Abstract]
Net sales	$ 3,861,000	$ 2,798,000	$ 6,820,000	$ 5,316,000
Cost of sales	2,781,000	1,745,000	4,937,000	3,365,000
Gross profit	1,080,000	1,053,000	1,883,000	1,951,000
Costs and expenses:
Research and development	7,576,000	5,733,000	13,600,000	12,629,000
Sales, general and administrative	11,493,000	12,910,000	22,167,000	26,938,000
Total costs and expenses	19,069,000	18,643,000	35,767,000	39,567,000
Loss from operations	(17,989,000)	(17,590,000)	(33,884,000)	(37,616,000)
Other income (expense):
Interest expense	(713,000)	(4,177,000)	(1,630,000)	(8,267,000)
Gain on extinguishment of debt	199,000	0	3,565,000	0
Foreign currency exchange gain (loss)	31,000	0	40,000	(159,000)
Interest income	56,000	12,000	78,000	55,000
Other (expense) income, net	(107,000)	81,000	(157,000)	74,000
Total other income (expense), net	(534,000)	(4,084,000)	1,896,000	(8,297,000)
Net loss before income taxes	(18,523,000)	(21,674,000)	(31,988,000)	(45,913,000)
Provision for income taxes	0	0	0	0
Net loss	$ (18,523,000)	$ (21,674,000)	$ (31,988,000)	$ (45,913,000)
Basic net loss per share (in usd per share)	$ (0.24)	$ (0.36)	$ (0.44)	$ (0.77)
Diluted net loss per share (in usd per share)	$ (0.24)	$ (0.36)	$ (0.44)	$ (0.77)
Weighted average shares outstanding, basic (in shares)	76,231	61,049	71,998	59,790
Weighted average shares outstanding, diluted (in shares)	76,231	61,049	71,998	59,790
Other comprehensive loss:
Net loss	$ (18,523,000)	$ (21,674,000)	$ (31,988,000)	$ (45,913,000)
Net unrealized (loss) gain on debt securities available-for-sale	(39,000)	1,000	(132,000)	(18,000)
Foreign currency translation adjustment	(161,000)	21,000	(240,000)	(60,000)
Comprehensive loss	$ (18,723,000)	$ (21,652,000)	$ (32,360,000)	$ (45,991,000)