CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2017	Jul. 31, 2016
CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS
Revenues, net	$ 17	$ 19	$ 36	$ 52
Cost of goods sold	9	17	20	37
Gross margin	8	2	16	15
Operating expenses:
Research and development	2,413	2,973	5,354	5,146
Sales and marketing	586	895	1,383	2,002
General and administrative	1,280	1,169	2,583	2,362
Total operating expenses	4,279	5,037	9,320	9,510
Loss from operations	(4,271)	(5,035)	(9,304)	(9,495)
Change in fair value of warrant liability	525		161
Other income	5	1	6	2
Loss before income taxes	(3,741)	(5,034)	(9,137)	(9,493)
Provision for income taxes			1	2
Net loss and comprehensive loss	$ (3,741)	$ (5,034)	$ (9,138)	$ (9,495)
Basic and diluted net loss per share	$ (0.05)	$ (0.18)	$ (0.13)	$ (0.35)
Shares used in computing basic and diluted net loss per share	74,357,000	28,674,000	71,069,000	27,459,000