Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($)	3 Months Ended
	Oct. 31, 2021	Oct. 31, 2020
Operating activities
Net loss	$ (796,000)	$ (180,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Share-based compensation	190,000	229,000
Depreciation and amortization	58,000	45,000
Changes in operating assets and liabilities:
Accounts receivable	130,000	529,000
Inventories	20,000	(186,000)
Prepaid expenses	(36,000)	(30,000)
Accounts payable and accrued liabilities	(142,000)	(606,000)
Net cash used in operating activities	(576,000)	(199,000)
Investing activities
Purchases of property, plant and equipment	(54,000)	(174,000)
Net cash used in investing activities	(54,000)	(174,000)
Net decrease in cash and cash equivalents, and restricted cash	(630,000)	(373,000)
Cash and cash equivalents, and restricted cash at beginning of period	2,465,000	3,914,000
Cash and cash equivalents, and restricted cash at end of period	1,835,000	3,541,000
Reconciliation of cash and cash equivalents, and restricted cash to the condensed consolidated balance sheets
Cash and cash equivalents	1,760,000	3,466,000
Restricted cash	75,000	75,000
Total cash and cash equivalents and restricted cash	$ 1,835,000	$ 3,541,000