CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2019	Jul. 31, 2018
CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS
Revenues, net		$ 24		$ 42
Cost of goods sold		13		20
Gross margin		11		22
Operating expenses:
Research and development	$ 1,375	2,730	$ 3,574	5,057
Sales and marketing	169	566	433	1,167
General and administrative	1,116	1,182	2,293	2,628
Total operating expenses	2,660	4,478	6,300	8,852
Loss from operations	(2,660)	(4,467)	(6,300)	(8,830)
Change in fair value of warrant liability	2	23	11	(43)
Other income, net	12	34	22	63
Loss before provision for income taxes	(2,646)	(4,410)	(6,267)	(8,810)
Provision for income taxes			2	2
Net loss and comprehensive loss	$ (2,646)	$ (4,410)	$ (6,269)	$ (8,812)
Basic and diluted net loss per share	$ (0.22)	$ (0.58)	$ (0.58)	$ (1.19)
Shares used in computing basic and diluted net loss per share	12,245,000	7,653,000	10,862,000	7,425,000