Condensed Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Cash flows from operating activities:
Net loss	$ (7,537)	$ (8,030)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	114	215
Stock-based compensation expense	711	597
Loss on sale and disposal of property and equipment	2	3
Changes in operating assets and liabilities:
Accounts receivable	105	(14)
Prepaid expenses and other assets	(99)	66
Inventories	(41)	2
Accounts payable, accrued liabilities and other liabilities	(165)	509
Net cash used in operating activities	(6,910)	(6,652)
Cash flows from investing activities:
Purchase of property and equipment	(123)	(82)
Net cash used in investing activities	(123)	(82)
Cash flows from financing activities:
Proceeds from sale of common stock, net of issuance costs		13,630
Principal repayment of DECD loan	(96)	(94)
Proceeds from issuance of common stock from exercise of stock options	296	17
Proceeds from PPP loan	1,006
Proceeds from issuance of warrants	5,059
Net cash provided by financing activities	6,265	13,553
Net decrease in cash and cash equivalents	(768)	6,819
Cash and cash equivalents, beginning of period	11,703	9,360
Cash and cash equivalents, end of period	10,935	16,179
Supplemental disclosure of cash flow information:
Cash paid during the period for interest	18	21
Supplemental disclosure of noncash investing and financing activities:
Net increase in other assets/other liabilities for right of use assets	$ 11	$ 115