CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Jan. 31, 2020	Jan. 31, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (5,698)	$ (4,551)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	2,276	2,006
Stock-based compensation	1,849	1,080
Loss on lease termination	355	0
Loss on disposal of assets	13	104
Gain on sale of research and development assets	0	(1,000)	[1]
Changes in operating assets and liabilities:
Accounts receivable	(2,777)	(4,131)
Contract assets	(1,784)	(1,024)
Inventory	(3,008)	(402)
Prepaid expenses and other assets	(54)	114
Accounts payable	491	993
Accrued payroll and related expenses	(555)	(15)
Contract liabilities	11,704	(5,402)
Other accrued expenses and current liabilities	(32)	(590)
Assets and liabilities of discontinued operations	0	(4,425)
Net cash provided by (used in) operating activities	2,780	(17,243)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of property and equipment	(3,025)	(1,248)
Proceeds from sale of research and development assets	0	6,000
Net cash (used in) provided by investing activities	(3,025)	4,752
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from exercise of stock options	916	1,188
Proceeds from issuance of common stock under employee stock purchase plan	187	114
Dividends paid on preferred stock	(3,244)	(3,244)
Principal payments on finance lease	(78)	(74)
Net cash used in financing activities	(2,219)	(2,016)
Net decrease in cash, cash equivalents and restricted cash	(2,464)	(14,507)
Cash, cash equivalents and restricted cash, beginning of period	33,501	43,415
Cash, cash equivalents and restricted cash, end of period	31,037	28,908
SUPPLEMENTAL DISCLOSURES OF NON-CASH ACTIVITIES:
Decapitalization of right of use assets upon lease termination and/or modification	1,469	0
Unpaid purchases of property and equipment	489	14
Property and equipment acquired under finance lease	$ 0	$ 245

[1] The gain on sale of research and development assets before income taxes was recorded in connection with the $1.0 million we received from Oncologie, Inc. ("Oncologie") under the September 2018 Asset Assignment and Purchase Agreement pursuant to which we sold to Oncologie our r84 technology, which included the assignment of certain licenses, patents and other assets useful and/or necessary for the potential commercialization of the r84 technology.