CONSOLIDATED STATEMENTS OF SHAREHOLDERS` EQUITY - USD ($)	Series A Preferred Stock [Member] 5% Convertible Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	AOCI Attributable to Parent [Member]	Retained Earnings [Member]	Total
Balances at May. 31, 2019		$ 774,173	$ 22,830,006	$ (36,531)	$ (19,586,678)	$ 3,980,970
Balances (in Shares) at May. 31, 2019		9,677,188
Exercise of stock options		$ 11,037	212,497			223,534
Exercise of stock options (in Shares)		137,958
Net proceeds from ATM		$ 133,995	10,098,862			10,232,857
Net proceeds from ATM (in Shares)		1,674,943
Issuance of preferred stock	$ 45,714		1,871,872			1,917,586
Issuance of preferred stock (in Shares)	571,429
Foreign currency translation				(3,310)		(3,310)
Conversion of preferred to common stock	$ (20,000)	$ 20,000
Conversion of preferred to common stock (in Shares)	(250,000)	250,000
Compensation expense in connection with options granted			200,470			200,470
Net loss					(2,339,054)	(2,339,054)
Balances at May. 31, 2020	$ 25,714	$ 939,205	35,213,707	(39,841)	(21,925,732)	14,213,053
Balances (in Shares) at May. 31, 2020	321,429	11,740,089
Exercise of stock options		$ 6,940	95,315			102,255
Exercise of stock options (in Shares)		86,750
Net proceeds from ATM		$ 12,712	998,763			$ 1,011,475
Net proceeds from ATM (in Shares)		158,889				158,889
Foreign currency translation				(8,115)		$ (8,115)
Conversion of preferred to common stock	$ (25,714)	$ 25,714
Conversion of preferred to common stock (in Shares)	(321,429)	321,429
Compensation expense in connection with options granted			377,391			377,391
Net loss					(6,469,036)	(6,469,036)
Balances at May. 31, 2021		$ 984,571	$ 36,685,176	$ (47,956)	$ (28,394,768)	$ 9,227,023
Balances (in Shares) at May. 31, 2021		12,307,157