Condensed Consolidated Statements of Cash Flows - USD ($)	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Operating Activities:
Net loss	$ (12,629,000)	$ (15,224,000)
Adjustments to reconcile net loss to cash flows used in operating activities:
Depreciation and amortization	301,000	383,000
Stock-based compensation expense, net	697,000	993,000
Changes in operating assets and liabilities:
Accounts receivable	(350,000)	(164,000)
Inventory	(113,000)	(105,000)
Other current assets	(40,000)	(183,000)
Other assets and liabilities	(142,000)	279,000
Accounts payable and accrued expenses	254,000	333,000
Net cash used in operating activities	(12,022,000)	(13,688,000)
Investing Activities:
Purchases of property and equipment	(103,000)	(191,000)
Net cash used in investing activities	(103,000)	(191,000)
Financing Activities:
Proceeds from public stock offerings, net	0	27,896,000
Proceeds from warrant exercises	0	1,300
Payments on finance lease liability	(28,000)	(21,000)
Net cash (used in) provided by financing activities	(28,000)	27,876,000
Effect of exchange rate changes on cash	1,000	(3,000)
Net increase (decrease) in cash and cash equivalents	(12,152,000)	13,994,000
Cash and cash equivalents - beginning of period	24,205,000	14,437,000
Cash and cash equivalents - end of period	12,053,000	28,431,000
Supplemental cash flow information
Inventory transferred to property, plant and equipment	$ 37,000	$ 257,000