CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jul. 31, 2018	Jul. 31, 2017
Cash flows from operating activities:
Net loss	$ (8,812)	$ (9,138)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	1,039	951
Depreciation expense	33	24
Change in fair value of warrant liability	43	(161)
Changes in assets and liabilities:
Accounts receivable	(9)	2
Inventories	(3)	18
Prepaid expenses and other assets	(292)	(185)
Accounts payable	150	(181)
Accrued expenses and other liabilities	(93)	297
Net cash used in operating activities	(7,944)	(8,373)
Cash flows from investing activities:
Purchases of property and equipment	(4)	(28)
Net cash used in investing activities	(4)	(28)
Cash flows from financing activities:
Proceeds from the issuance of common stock, preferred stock and warrants, net of issuance costs		6,355
Proceeds from exercises of common stock warrants	6,961
Proceeds from exercises of stock options	1	10
Payments on capital lease obligation	(9)
Net cash provided by financing activities	6,953	6,365
Net decrease in cash and cash equivalents	(995)	(2,036)
Cash and cash equivalents as of beginning of period	7,576	6,501
Cash and cash equivalents as of end of period	$ 6,581	$ 4,465