CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Jul. 31, 2019	Jul. 31, 2018
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (3,164)	$ (1,961)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	726	642
Stock-based compensation	603	297
Changes in operating assets and liabilities:
Accounts receivable	(849)	803
Contract asssets	(1,262)	(1,887)
Inventory	(1,474)	(910)
Prepaid expenses and other current assets	(68)	153
Accounts payable	(410)	1,151
Accrued payroll and related costs	(310)	(534)
Contract liabilities	3,453	(2,028)
Other liabilities	287	(579)
Assets and liabilities of discontinued operations	0	(2,595)
Net cash used in operating activities	(2,468)	(7,448)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of property and equipment	(38)	(192)
Proceeds from sale of research and development assets	0	3,000
Net cash (used in) provided by investing activities	(38)	2,808
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from exercise of stock options	258	1,014
Dividends paid on preferred stock	(1,081)	(1,081)
Principal payments on finance lease	(78)	(74)
Net cash used in financing activities	(901)	(141)
Change in cash, cash equivalents and restricted cash	(3,407)	(4,781)
Cash, cash equivalents and restricted cash, beginning of period	33,501	43,415
Cash, cash equivalents and restricted cash, end of period	30,094	38,634
SCHEDULE OF NON-CASH INVESTING AND FINANCING ACTIVITIES:
Unpaid purchases of property and equipment	1,516	62
Property and equipment acquired under finance lease	$ 0	$ 245