Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Operating activities:
Net loss	$ (22,181,000)	$ (19,479,000)
Adjustments required to reconcile net loss to net cash used in operating activities:
Depreciation	1,114,000	1,351,000
Stock-based compensation	3,475,000	4,271,000
Non-cash interest expense	628,000	918,000
Payment of accreted interest for deferred consideration for asset acquisition	(432,000)
Change in fair value of derivative liability		(1,117,000)
Loss on sale of assets (Note 6)		663,000
Changes in operating assets and liabilities:
Accounts receivable	(467,000)
Accounts payable and accrued liabilities	544,000	(1,374,000)
Accrued compensation	(760,000)	(853,000)
Operating lease right-of-use asset and liability, net	(803,000)	310,000
Prepaid expenses and other current assets	(994,000)	348,000
Net cash used in operating activities	(18,270,000)	(15,582,000)
Investing activities:
Purchases of property and equipment	(824,000)	(224,000)
Proceeds from sale of property and equipment		93,000
Cash acquired in reverse merger transaction		3,008,000
Net cash (used in) provided by investing activities	(824,000)	2,877,000
Financing activities:
Principal payment of deferred consideration for asset acquisition	(568,000)	(1,000,000)
Proceeds from Paycheck Protection Program Loan	717,000
Proceeds from sale of common stock, net of offering costs	22,893,000	9,975,000
Proceeds from exercise of employee stock options	87,000
Proceeds from exercise of warrants	81,000
Net cash provided by financing activities	23,210,000	8,975,000
Net increase (decrease) in cash, cash equivalents and restricted cash	4,116,000	(3,730,000)
Cash, cash equivalents and restricted cash, beginning of period	6,733,000	10,463,000
Cash, cash equivalents and restricted cash, end of period	10,849,000	6,733,000
Supplemental schedule of non-cash investing and financing activities:
Unpaid offering costs	65,000	116,000
Property and equipment included in accounts payable	$ 150,000	36,000
Issuance of common stock in reverse merger transaction		10,709,000
Conversion of deferred asset acquisition consideration upon reverse merger		$ 1,463,000