CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS Unaudited - USD ($) shares in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Income Statement [Abstract]
Net sales	$ 2,958,000	$ 2,518,000
Cost of sales	2,156,000	1,621,000
Gross profit	802,000	897,000
Costs and expenses:
Research and development	6,024,000	6,895,000
Sales, general and administrative	10,673,000	14,029,000
Total costs and expenses	16,697,000	20,924,000
Loss from operations	(15,895,000)	(20,027,000)
Other income (expense):
Interest expense	(917,000)	(4,090,000)
Gain on extinguishment of debt	3,366,000	0
Foreign currency exchange loss	9,000	(159,000)
Interest income	22,000	43,000
Other expense, net	(50,000)	(6,000)
Total other income (expense), net	2,430,000	(4,212,000)
Net loss before income taxes	(13,465,000)	(24,239,000)
Provision for income taxes	0	0
Net loss	$ (13,465,000)	$ (24,239,000)
Basic net loss per share (in usd per share)	$ (0.20)	$ (0.41)
Diluted net loss per share (in usd per share)	$ (0.20)	$ (0.41)
Weighted average shares outstanding, basic (in shares)	67,755	58,520
Weighted average shares outstanding, diluted (in shares)	67,755	58,520
Other comprehensive loss:
Net loss	$ (13,465,000)	$ (24,239,000)
Net unrealized loss on debt securities available-for-sale	(93,000)	(19,000)
Foreign currency translation adjustment	(79,000)	(81,000)
Comprehensive loss	$ (13,637,000)	$ (24,339,000)