CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Oct. 31, 2019	Oct. 31, 2018
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (3,594)	$ (3,412)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	1,467	1,325
Stock-based compensation	1,254	622
Loss on lease termination	355	0
Loss on disposal of assets	13	0
Gain on sale of research and development assets	0	(1,000)	[1]
Changes in operating assets and liabilities:
Accounts receivable	(48)	(443)
Contract asssets	(1,783)	(2,204)
Inventory	(1,252)	(1,478)
Prepaid expenses and other assets	(217)	(93)
Accounts payable	(86)	880
Accrued payroll and related expenses	(180)	(735)
Contract liabilities	7,548	(2,715)
Other accrued expenses and current liabilities	(61)	(774)
Assets and liabilities of discontinued operations	0	(4,134)
Net cash provided by (used in) operating activities	3,416	(14,161)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of property and equipment	(985)	(446)
Proceeds from sale of research and development assets	0	6,000
Net cash (used in) provided by investing activities	(985)	5,554
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from exercise of stock options	431	1,158
Proceeds from issuance of common stock under employee stock purchase plan	187	114
Dividends paid on preferred stock	(2,162)	(2,162)
Principal payments on finance lease	(78)	(74)
Net cash used in financing activities	(1,622)	(964)
Change in cash, cash equivalents and restricted cash	809	(9,571)
Cash, cash equivalents and restricted cash, beginning of period	33,501	43,415
Cash, cash equivalents and restricted cash, end of period	34,310	33,844
SUPPLEMENTAL DISCLOSURE OF NON-CASH ACTIVITIES:
Unpaid purchases of property and equipment	1,860	434
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.