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	$ (4,200)	$ (3,777)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	963	988
Change in fair value of common stock warrant liability	1,501	(1,330)
Stock-based compensation	87	290
Amortization of operating lease right-of-use assets	371	314
Changes in operating assets and liabilities:
Accounts receivable	144	453
Unbilled accounts receivable	139	203
Inventories	362	214
Prepaid expenses and other current assets	(259)	(72)
Deferred revenues	12	96
Operating lease liabilities	(387)	(291)
Accounts payable, accrued expenses, and other current liabilities	1,032	(242)
Net cash used in operating activities	(235)	(3,154)
Cash flows from investing activities:
Purchase of equipment	(676)	(833)
Net cash used in investing activities	(676)	(833)
Cash flows from financing activities:
(Repayments) borrowings under revolving line of credit, net	(2,471)	1,022
Proceeds from public offering, net	3,311	3,303
Proceeds from Paycheck Protection Program loan	1,963
Proceeds from warrant exercise, net	40
Proceeds from exercise of stock options		8
Net cash provided by financing activities	2,843	4,333
Net increase in cash and cash equivalents	1,932	346
Cash and cash equivalents, beginning of period	3,515	3,359
Cash and cash equivalents, end of period	5,447	3,705
Cash paid for interest	40	32
Cash paid for income taxes