CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2018	Jan. 31, 2017
Cash flows from operating activities:
Net loss	$ (16,640)	$ (18,406)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	1,887	1,491
Expense related to modification of warrants	151
Depreciation expense	52	141
Amortization expense		119
Non-cash interest expense		145
Change in fair value of warrant liability	(364)	(163)
Changes in assets and liabilities:
Accounts receivable	(3)	3
Inventories	28	62
Prepaid expenses and other assets	50	(68)
Accounts payable	(1,175)	774
Accrued expenses and other liabilities	427	156
Net cash used in operating activities	(15,587)	(15,746)
Cash flows from investing activities:
Purchases of property and equipment	(41)	(45)
Net cash used in investing activities	(41)	(45)
Cash flows from financing activities:
Proceeds from the issuance of common stock, preferred stock and warrants, net of issuance costs	16,049	16,712
Proceeds from exercises of common stock warrants	644
Proceeds from exercises of stock options	10	41
Proceeds from issuance of convertible notes		1,500
Net cash provided by financing activities	16,703	18,253
Net decrease in cash and cash equivalents	1,075	2,462
Cash and cash equivalents at beginning of period	6,501	4,039
Cash and cash equivalents at end of period	7,576	6,501
Non-cash investing and financing activities:
Conversion of Series A convertible preferred stock to common stock	1,515
Conversion of convertible notes payable and accrued interest to common stock		1,645
Fair value of beneficial conversion feature issued in connection with convertible notes		88
Deemed dividend on Series A convertible preferred stock		126
Supplemental disclosures:
Income taxes paid	$ 2	$ 2