Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash flows from operating activities:
Net loss	$ (7,129)	$ (4,364)
Adjustments to reconcile net loss to net cash used in operations:
Depreciation and amortization	2,009	2,262
Stock-based compensation expense	1,758	646
Provision for excess and obsolete inventory	1,250	196
Change in fair value of warrants		(4,092)
Non-cash interest income		(112)
Other non-cash items	233	(888)
Unrealized foreign exchange loss on cash and cash equivalents	272
Changes in operating asset and liability accounts:
Accounts receivable	157	(2,244)
Inventory	3,591	(3,589)
Prepaid expenses and other assets	(866)	(1,810)
Accounts payable and accrued expenses	(3,192)	2,799
Deferred revenue	(4,636)	711
Net cash used in operating activities	(6,553)	(10,485)
Cash flows from investing activities:
Purchase of property, plant and equipment	(1,326)	(1,736)
Proceeds from the sale of property, plant and equipment		3,001
Purchase of marketable securities		(10,000)
Sale of marketable securities	25,006
Change in other assets	63	66
Net cash (used in)/provided by investing activities	23,743	(8,669)
Cash flows from financing activities:
Repurchase of treasury stock	(670)	(505)
Proceeds from exercise of employee stock options and ESPP	99	100
Net cash used in financing activities	(571)	(405)
Effect of exchange rate changes on cash	53	(74)
Net increase/(decrease) in cash, cash equivalents and restricted cash	16,672	(19,633)
Cash, cash equivalents and restricted cash at beginning of period	30,864	78,198
Cash, cash equivalents and restricted cash at end of period	47,536	58,565
Supplemental schedule of cash flow information:
Cash paid for income taxes, net of refunds	275	130
Issuance of common stock to settle liabilities	189	173
Hercules [Member]
Supplemental schedule of cash flow information:
Issuance of common stock to Hercules to settle warrant liability		$ 294