Statements of Cash Flows - USD ($)	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Cash flows from operating activities
Net loss	$ (7,910,000)	$ (5,391,000)
Adjustments to reconcile net loss to net cash used in operating activities
Stock-based compensation, net of forfeitures	277,000	101,000
Depreciation and amortization	591,000	736,000
Paycheck Protection Program forgiveness	(544,000)	0
Issuance of common stock for services	80,000	60,000
Derivative gain	(156,000)	(822,000)
Changes in operating assets and liabilities
Increase in prepaid expenses and other	(229,000)	(1,216,000)
(Decrease) increase in accounts payable and accrued expenses	(1,758,000)	752,000
Decrease in lease liability	(38,000)	(114,000)
Proceeds received under the Paycheck Protection Program	544,000	0
Net cash used in operating activities	(9,143,000)	(5,894,000)
Cash flows used in investing activities
Purchase of fixed assets	0	(14,000)
Net cash used in investing activities	0	(14,000)
Cash flows from financing activities
Proceeds from sale of common stock in connection with the Sales Agreement	7,913,000	142,000
Costs related to sale of common stock in connection with the Sales Agreement	(560,000)	(144,000)
Proceeds from sale of common stock in connection with the public offering	0	12,000,000
Costs related to sale of common stock in connection with the public offering	0	(1,243,000)
Proceeds from warrant exercises	100,000	350,000
Net cash provided by financing activities	7,453,000	11,105,000
Net change in cash and cash equivalents	(1,690,000)	5,197,000
Cash and cash equivalents at beginning of period	6,532,000	7,585,000
Cash and cash equivalents at end of period	4,842,000	12,782,000
Non-cash transactions:
Commercial insurance premium financing agreement	1,347,000	0
Initial lease liability arising from the adoption of ASU 842	0	1,704,000
Initial recognition of right-of-use asset arising from the adoption of ASU 842	$ 0	$ 1,168,000