CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2018	Jan. 31, 2017
CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS
Revenues, net	$ 73	$ 100
Cost of goods sold	250	516
Gross margin	(177)	(416)
Operating expenses:
Research and development	9,140	10,158
Sales and marketing	2,415	3,198
General and administrative	5,144	4,654
Total operating expenses	16,699	18,010
Loss from operations	(16,876)	(18,426)
Change in fair value of warrant liability	364	163
Other expense, net	(126)	(141)
Loss before provision for income taxes	(16,638)	(18,404)
Provision for income taxes	2	2
Net loss and comprehensive loss	(16,640)	(18,406)
Deemed dividend on Series A convertible preferred stock		(126)
Net loss available to common stockholders	$ (16,640)	$ (18,532)
Basic and diluted net loss per share	$ (0.19)	$ (0.52)
Shares used in computing basic and diluted net loss per share	85,900,000	35,806,000