Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($)	3 Months Ended		9 Months Ended
	Feb. 28, 2025	Feb. 29, 2024	Feb. 28, 2025	Feb. 29, 2024
Income Statement [Abstract]
Net sales	$ 1,119,000	$ 1,017,000	$ 4,562,000	$ 4,299,000
Cost of sales	(1,100,000)	(1,166,000)	(3,820,000)	(3,708,000)
Gross (loss) profit	19,000	(149,000)	742,000	591,000
Operating expenses:
Selling, general and administrative	1,012,000	1,508,000	3,544,000	4,204,000
Research and development	217,000	343,000	771,000	1,226,000
Total operating expenses	1,229,000	1,851,000	4,315,000	5,430,000
Loss from operations	(1,210,000)	(2,000,000)	(3,573,000)	(4,839,000)
Other income:
Interest and dividend income	43,000	86,000	140,000	317,000
Total other income	43,000	86,000	140,000	317,000
Loss before income taxes	(1,167,000)	(1,914,000)	(3,433,000)	(4,522,000)
Benefit (provision) for income taxes	4,000	(4,000)	4,000	(35,000)
Net loss	$ (1,163,000)	$ (1,918,000)	$ (3,429,000)	$ (4,557,000)
Basic net loss per common share	$ (0.06)	$ (0.11)	$ (0.18)	$ (0.27)
Diluted net loss per common share	$ (0.06)	$ (0.11)	$ (0.18)	$ (0.27)
Weighted average number of common and common equivalent shares:
Basic	19,186,282	16,821,646	18,616,979	16,821,646
Diluted	19,186,282	16,821,646	18,616,979	16,821,646
Other comprehensive income (loss), net of tax:
Foreign currency translation	$ (1,000)	$ 2,000	$ (11,000)	$ 8,000
Comprehensive loss	$ (1,164,000)	$ (1,916,000)	$ (3,440,000)	$ (4,549,000)