Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash flows from operating activities:
Net loss	$ (541)	$ (2,865)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation	46	105
Stock-based compensation	20	543
Change in fair value of warrant liabilities	(873)	0
Provision for doubtful accounts receivable	(12)	26
Provision for slow-moving and obsolete inventories	(34)	(836)
Provision for warranties	0	101
Amortization of loan discounts and origination fees	38	20
Gain on dispositions of property and equipment	0	(1)
Changes in operating assets and liabilities:
Accounts receivable	445	(210)
Inventories	1,546	643
Prepaid and other assets	(187)	459
Accounts payable	(152)	(1,329)
Accrued and other liabilities	222	(195)
Deferred revenue	(14)	(17)
Total adjustments	1,045	(691)
Net cash provided by (used in) operating activities	504	(3,556)
Cash flows from investing activities:
Acquisitions of property and equipment	(47)	(5)
Proceeds from the sale of property and equipment	0	1
Net cash used in investing activities	(47)	(4)
Cash flows from financing activities:
Proceeds from the issuance of common stock and warrants	2,750
Offering costs paid on the issuance of common stock and warrants	(474)
Principal payments under finance lease obligations	(1)	(1)
Common stock withheld in lieu of income tax withholding on vesting of restricted stock units	0	(111)
Payments on the Iliad Note	(226)	0
Net proceeds from (payment on) credit line borrowings	55	(462)
Proceeds from convertible notes	0	1,660
Net cash provided by financing activities	2,104	1,086
Net increase (decrease) in cash and restricted cash	2,561	(2,474)
Cash and restricted cash, beginning of period	692	6,335
Cash and restricted cash, end of period	3,253	3,861
Classification of cash and restricted cash:
Cash and restricted cash	$ 3,253	$ 3,861