Condensed Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
CASH FLOWS FROM OPERATING ACTIVITIES
Net loss	$ (5,865)	$ (7,238)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	219	314
Stock-based compensation	453	675
(Gain) loss on sale of equipment	(18)	3
(Increase) decrease in current assets:
Accounts receivable - trade	(4)	(16)
Accounts receivable - other	123
Other assets	2	3
Prepaid expenses	(24)	38
Inventory	78	(24)
Increase (decrease) in current liabilities:
Accounts payable	179	118
Accrued expenses	(639)	46
Deferred rent		(11)
Net cash used in operating activities	(5,496)	(6,092)
CASH FLOWS FROM INVESTING ACTIVITIES
Cash received on sale of property and equipment	44
Purchase of property and equipment	(48)	(64)
Net cash used in investing activities	(4)	(64)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of common stock, net	5,741	3,631
Proceeds from the issuance of notes payable	646
Repayments of notes payable	(44)	(184)
Repayments of finance lease obligations	(62)
Proceeds from the exercise of warrants		1,789
Payment of employee withholding taxes relating to share-based awards		(55)
Net cash provided by financing activities	6,281	5,181
NET CHANGE IN CASH	781	(975)
CASH AT BEGINNING OF PERIOD	1,936	4,920
CASH AT END OF PERIOD	2,717	3,945
SUPPLEMENTAL INFORMATION:
Interest paid	22	34
Income taxes paid
NON-CASH INVESTING AND FINANCING ACTIVITIES:
Forgiveness of accrual in warrant exercise	238
Deemed dividend	414
Common stock issued on accrued bonus		$ 32