CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($)	3 Months Ended
	Aug. 31, 2021	Aug. 31, 2020
Cash flows from operating activities:
Net loss	$ (1,542,581)	$ (1,892,394)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	34,722	32,570
Change in allowance on accounts receivable	(94,891)	201,375
Inventory reserve	179,744	5,005
Stock option expense	319,622	246,787
Amortization of right-of-use asset	62,897	57,257
Changes in assets and liabilities:
Accounts receivable	777,752	(18,924)
Inventories	164,732	(1,255,573)
Prepaid expenses and other	55,069	1,038,149
Reduction in lease liability	(55,649)	(49,880)
Other assets	(2,431)	(276,438)
Accounts payable and accrued expenses	58,024	284,202
Accrued compensation	118,826	30,718
Net cash provided by (used in) operating activities	75,836	(1,597,146)
Cash flows from investing activities:
Increase in intangibles	(72,375)	(53,158)
Purchases of property and equipment	(5,141)	(39,588)
Net cash used in investing activities	(77,516)	(92,746)
Cash flows from financing activities:
Proceeds from sale of common stock, net	800,710
Proceeds from exercise of stock options	3,895	14,900
Net cash provided by financing activities	804,605	14,900
Effect of exchange rate changes in cash	(5,613)	(1,721)
Net increase (decrease) in cash and cash equivalents	797,312	(1,676,713)
Cash and cash equivalents at beginning of period	4,199,311	8,641,027
Cash and cash equivalents at end of period	4,996,623	6,964,314
Cash paid during the period for:
Income taxes	$ 9,017	$ 1,125