Microchip Technology Inc.

Darren Edward Noel Wenn

James E Bartling

Aaron Joel Mach

A blood glucose meter comprises a blood sample test strip, a constant current source, a precision timer, a digital processor and memory, and an analog measurement circuit, e.g., voltage comparator, analog-to-digital converter (ADC), etc., that eliminates the complex analog front end and other related circuits of present technology glucose meters. When a blood sample is applied to the blood sample test strip a charge, Q, develops from the reaction between an enzyme in the test strip and the blood sample. The constant current source injects a constant current value, I, into the charge, Q, on the blood sample test strip over a precisely measured time determined by when the excess charge, Q, has been removed from the test strip. The amount of charge, Q, is determined by Q=I*T, the charge, Q, is then converted into a blood glucose level for display.

Glucose measurement using a current source

Temperature is determined by measuring the time it takes to charge a capacitor with a resistive temperature sensor. A clock, time counter, a voltage comparator and voltage reference are used in determining a coarse time measurement. The time measurement resolution is enhanced with the addition of a constant current source charging another timing capacitor within a single clock pulse time to provide a fine time measurement.

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High Wycombe, United Kingdom

Darren Edward Noel Wenn