Consolidated Statements of Cash Flows - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	Jan. 31, 2017	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Operating activities:
Net loss				$ (5,624)	$ (8,258)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization				11	46
Loss on disposal of leasehold improvements				2
Amortization of debt issuance costs non-cash interest expense				141	25
Non-cash interest expense				249	73
Accretion of debt discount				96
Stock-based compensation expense				86	162
Re-measurement of warrant liability		$ (10)	$ (7)	(13)	33
Change in inventory reserve					(76)
Changes in operating assets and liabilities:
Accounts receivable				40	(11)
Prepaid expenses and other current assets				6	53
Inventory					289
Accounts payable				(442)	122
Accrued expenses				246	(105)
Net cash used in operating activities				(5,202)	(7,647)
Investing activities
Purchases of property and equipment					(5)
Net cash used in investing activities					(5)
Financing activities
Proceeds from issuance of common stock, net of issuance costs	$ 200			3,607	198
Debt issuance costs				(85)	(115)
Proceeds from long term debt, related party				1,750	5,000
Payments on short term note payable					(214)
Net cash provided by financing activities				5,272	4,869
Net increase (decrease) in cash and cash equivalents				70	(2,783)
Cash, cash equivalents and restricted cash at beginning of period	$ 8,323			3,064	8,323	$ 8,323
Cash, cash equivalents and restricted cash at end of period		$ 3,134	$ 5,540	3,134	5,540	$ 3,064
Supplemental cash flow disclosures
Income taxes paid				25	31
Effect on retained earnings of adopting ASU No. 2016-09 in 2017					$ 28
Beneficial conversion feature discount associated with 2018 Note				1,007
Relative fair value of warrant issued with 2018 Note				$ 743