Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash flows from operating activities:
Net loss	$ (6,046)	$ (6,065)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	140	277
Stock-based compensation	96	557
Change in fair value of warrant liabilities	2,274	0
Provision for doubtful accounts receivable	(21)	20
Provision for slow-moving and obsolete inventories	(229)	(643)
Provision for warranties	34	107
Amortization of loan discounts and origination fees	221	72
Loss on dispositions of property and equipment	0	15
Changes in operating assets and liabilities:
Accounts receivable	(1,070)	400
Inventories	1,138	1,301
Prepaid and other assets	(471)	368
Accounts payable	1,811	(2,311)
Accrued and other liabilities	453	(421)
Deferred revenue	87	(6)
Total adjustments	4,463	(264)
Net cash used in operating activities	(1,583)	(6,329)
Cash flows from investing activities:
Acquisitions of property and equipment	(171)	(57)
Net cash used in investing activities	(171)	(57)
Cash flows from financing activities:
Proceeds from the issuance of common stock and warrants	2,749	0
Proceeds from the exercise of warrants	676	0
Offering costs paid on the issuance of common stock and warrants	(474)	0
Proceeds from PPP loan	795	0
Principal payments under finance lease obligations	(3)	(2)
Proceeds from exercise of stock options and employee stock purchase plan purchases	30	0
Common stock withheld in lieu of income tax withholding on vesting of restricted stock units	(3)	(116)
Payments on the Iliad Note	(976)	0
Payments for Deferred Financing & Termination Fees	(320)	0
Proceeds from convertible notes	0	1,700
Net cash provided by financing activities	3,978	686
Effect of exchange rate changes on cash	0	(1)
Net increase (decrease) in cash and restricted cash	2,224	(5,701)
Cash and restricted cash, beginning of period	692	6,335
Cash and restricted cash, end of period	2,916	634
Classification of cash and restricted cash:
Cash and restricted cash	2,916	634
Austin Credit Facility
Cash flows from financing activities:
Net proceeds from (payment on) credit line borrowings	(719)	(896)
New Credit Facilities
Cash flows from financing activities:
Net proceeds from (payment on) credit line borrowings	$ 2,223	$ 0