CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Apr. 30, 2018	Apr. 30, 2017
Cash flows from operating activities:
Net loss	$ (3,685)	$ (3,392)
Adjustments to reconcile net loss to net cash provided by operating activities:
Stock-based compensation expense	2,314	2,971
Depreciation and amortization of property and equipment	504	468
Amortization of acquired intangible assets	145	83
Amortization and accretion of premiums from investments	(57)	75
Changes in operating assets and liabilities:
Accounts receivable, net	(874)	272
Inventories	(311)	(1,154)
Other assets	(564)	343
Accounts payable and other liabilities	2,770	569
Deferred revenue	52	(70)
Net cash provided by operating activities	294	165
Cash flows from investing activities:
Purchases of short-term investments	(5,409)	(5,441)
Proceeds from maturities of short-term investments	8,531	9,860
Proceeds from sales of short-term investments	2,995	450
Purchases of property and equipment	(405)	(579)
Business acquisition, net of cash assumed	(2,402)
Net cash provided by investing activities	3,310	4,290
Cash flows from financing activities:
Taxes paid related to net share settlement of equity awards	(759)	(300)
Proceeds from issuance of common stock	1,166	863
Net cash provided by financing activities	407	563
Net increase in cash and cash equivalents	4,011	5,018
Cash and cash equivalents at beginning of period	4,483	3,990
Cash and cash equivalents at end of period	8,494	9,008
Non-cash investing and financing activities:
Unpaid portion of property and equipment purchases	200	$ 199
Contingent consideration for business acquisition	231
Holdback payable for business acquisition	780
Shares issued for business acquisition	$ 390