CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Cash flows from operating activities:
Net loss	$ (1,646)	$ (1,512)
Adjustments to reconcile net loss to net cash used in operating activities:
Allowance for sales returns, doubtful accounts and other	28	(1)
Provision for excess and obsolete inventories	678	448
Depreciation and amortization	329	306
Stock-based compensation	542	478
Amortization of premium on investments	(2)	23
Changes in assets and liabilities:
Accounts receivable	(1,596)	188
Inventory	(272)	12
Prepaid expenses and other assets	(28)	(394)
Accounts payable	202	350
Accrued expenses and other liabilities	(266)	(1,221)
Net cash used in operating activities	(2,031)	(1,323)
Cash flows from investing activities:
Purchase of investments	(8,848)	(3,498)
Maturities of short-term investments	6,800	1,250
Decrease in MikaMonu escrow deposit		479
Purchases of property and equipment	(1,239)	(105)
Net cash used in investing activities	(3,287)	(1,874)
Cash flows from financing activities:
Payment of MikaMonu escrow deposit		(479)
Proceeds from issuance of common stock under employee stock plans	1,503	1,811
Net cash provided by financing activities	1,503	1,332
Net decrease in cash and cash equivalents	(3,815)	(1,865)
Cash and cash equivalents at beginning of the period	40,241	33,736
Cash and cash equivalents at end of the period	36,426	31,871
Non-cash financing activities:
Purchases of property and equipment through accounts payable and accruals	277	$ 49
Supplemental cash flow information:
Net cash received from refunds of income taxes	$ 41