Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Operating activities:
Net loss	$ (5,541)	$ (6,501)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	651	694
Amortization of debt discounts and financing issuance costs	197	394
Restructuring costs		(146)
Loss on related party debt extinguishment		405
Provision for doubtful accounts and other adjustments to accounts receivable	6	78
Provision for excess and obsolete inventory	(18)
Gain on disposal of fixed assets		(6)
Stock based compensation	674	1,002
Change in fair value of warrant liability	3,126
Change in operating accounts:
Accounts receivable	(1,189)	(325)
Prepaid expenses and other assets	(145)	7
Accounts payable and accrued liabilities	(838)	(1,564)
Deferred revenue	47	269
Net cash used in operating activities	(3,030)	(5,693)
Investing activities:
Capital expenditures	(172)	(68)
Net cash used in investing activities	(172)	(68)
Financing activities:
Proceeds from stock sale for employee stock purchase plan	5	2
Proceeds from common stock offering, net of expenses	10,749	2,056
Proceeds from preferred stock offering, net of expenses		2,413
Proceeds from (payments of) short-term secured promissory notes	(1,000)	3,000
Dividends paid on preferred stock	(370)
Net cash provided by financing activities	9,384	7,471
Net increase in cash and cash equivalents	6,182	1,710
Cash and cash equivalents, beginning of period	2,205	2,229
Cash and cash equivalents, end of period	8,387	3,939
Supplemental disclosures of cash flow information:
Cash paid for income taxes	4	5
Cash paid for interest expense	334	552
Supplemental schedule of non-cash financing activities:
Issuance of common stock warrants in connection with stock offering	$ 6,792	$ 2,292