Balance Sheets (Unaudited) (USD $)	Oct. 31, 2011	Apr. 30, 2011
Current assets
Cash	$ 724,058	$ 667,897
Accounts receivable, trade (Net of allowance for doubtful accounts of $500 at July 31, 2011 and April 30, 2011)	144,002	150,748
Inventories	100,099	86,662
Prepaid expenses	15,890	25,315
Total current assets	984,049	930,622
Equipment and leasehold improvements
Equipment	203,120	198,906
Leasehold improvements	20,022	20,022
[PropertyPlantAndEquipmentGross]	223,142	218,928
Less accumulated depreciation and amortization	(209,186)	(204,557)
Total equipment and leasehold improvements, net	13,956	14,371
Other assets
Patents less accumulated amortization	13,297	13,825
Pending patents	141,004	137,622
Deposits	5,947	5,947
Total other assets	160,248	157,394
[Assets]	1,158,253	1,102,387
Current Liabilities
Accounts payable	21,309	15,249
Accrued compensation and payroll taxes	10,727	24,631
Other accrued expenses	8,398	5,692
Accrued vacation	25,913	16,244
Total current liabilities	66,347	61,816
Deferred income taxes	28,534	28,534
Shareholders equity
Common stock, no par value: 20,000,000 authorized shares issued: 14,935,511 shares outstanding at July 31, 2011 and April 30, 2011	660,988	660,988
Receivable from Affiliate	(19,699)	(19,699)
Retained earnings	422,083	370,748
Total Shareholders Equity	1,063,372	1,012,037
[LiabilitiesAndStockholdersEquity]	$ 1,158,253	$ 1,102,387