Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Operating Activities:
Net loss	$ (19,578,000)	$ (15,836,000)
Adjustments to reconcile net loss to cash flows used in operating activities:
Depreciation and amortization	488,000	376,000
Stock-based compensation expense, net	1,314,000	1,349,000
Loss on disposal of property and equipment	0	40,000
Realized foreign currency translation gain from dissolution of subsidiary	0	(1,202,000)
Changes in operating assets and liabilities:
Accounts receivable	155,000	(106,000)
Inventory	(143,000)	(1,420,000)
Other current assets	(91,000)	(76,000)
Other assets and liabilities	186,000	112,000
Accounts payable and accrued expenses	(211,000)	191,000
Net cash used in operating activities	(17,880,000)	(16,572,000)
Investing Activities:
Purchases of property and equipment	(219,000)	(298,000)
Proceeds from sale of property and equipment	0	31,000
Net cash used in investing activities	(219,000)	(267,000)
Financing Activities:
Proceeds from public stock offerings, net	27,896,000	25,921,000
Proceeds from warrant exercises	1,300	4,115,000
Payments on finance lease liability	(26,000)	(20,000)
Net cash provided by financing activities	27,871,000	30,016,000
Effect of exchange rate changes on cash	(4,000)	(19,000)
Net increase in cash and cash equivalents	9,768,000	13,158,000
Cash and cash equivalents - beginning of year	14,437,000	1,279,000
Cash and cash equivalents - end of year	24,205,000	14,437,000
Supplemental schedule of non-cash activities
Inventory transferred to property, plant and equipment	257,000	260,000
Equipment acquired through finance lease liability	0	98,000
Operating right-of-use asset recorded as an operating lease liability	901,000	0
Supplemental cash flow information
Cash paid for income taxes	$ 11,000	$ 10,000