Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Cash flows from operating activities:
Net loss	$ (4,410,000)	$ (4,086,000)
Reconciliation of net loss to net cash used in operating activities
Depreciation	365,000	454,000
Amortization of intellectual property	45,000	45,000
Fair value of RSUs issued for consulting services	0	34,000
Stock-based compensation	605,000	679,000
Loss on disposal of property and equipment	150,000	0
Forgiveness of PPP Loan	0	(131,000)
Changes in operating assets and liabilities
Accounts receivable	72,000	32,000
Inventory	78,000	0
Prepaid expenses and other current assets	(71,000)	61,000
Accounts payable	87,000	447,000
Accrued expenses	(221,000)	457,000
Other assets and liabilities	(289,000)	(148,000)
Net cash used in operating activities	(3,589,000)	(2,156,000)
Cash flows from investing activities:
Purchases of property and equipment	(258,000)	(469,000)
Proceeds from sale of equipment	1,145,000	0
Equipment deposits and other assets	30,000	(158,000)
Investment in LINICO	(500,000)	(232,000)
Net cash (used in) provided by investing activities	417,000	(859,000)
Cash flows from financing activities:
Lease of building	185,000	0
Stock option exercise	0	724,000
Proceeds from ATM, net	3,890,000	7,485,000
Net cash provided by financing activities	4,075,000	8,209,000
Net increase in cash and cash equivalents	903,000	5,194,000
Cash and cash equivalents at beginning of period	8,137,000	6,533,000
Cash and cash equivalents at end of period	9,040,000	11,727,000
Supplemental disclosure of cash flows information
Cash paid for income taxes	2,000	2,000
Cash paid for interest	3,000	0
Supplemental disclosure of non-cash transactions
Change in property and equipment resulting from change in accounts payable	(253,000)	303,000
Change in investing activity resulting from issuance of equity	$ 0	$ (1,268,000)