Blood glucose reflectance meter including a null prompting means and a device for providing a constant brightness light

Abstract

A portable blood glucose monitoring meter that employs an analog circuit in conjunction with a manually rotatable dial that varies the resistance of a potentiometer to locate a null position that balances the measure taken of the blood glucose-induced changes in the chemistries of disposable test strips. The dial supports a replaceable, pre-printed, man-readable calibration disk. The calibration disk displays in man-readable format blood glucose concentrations in milligrams per milliliter calibrated to the specific batch-lot chemistries of the disposable test strips used with the meter. A patient places a replaceable batch-lot calibration disk upon the dial, and inserts a corresponding test strip bearing a drop of capillary blood into the meter. The patient then manually adjusts the dial until prompting arrows indicate a null position. If the dial has rotated past the null position, an opposing arrow will illuminate indicating a need to rotate the dial in the opposite direction. The procedure is repeated until a null position is found. At the null position, the prompting arrows illuminate simultaneously. The concentration of the patient's blood glucose in milligrams per milliliter is then read directly from the number appearing on the calibration disk at the null point.

Dependencies are inferred from the claim text.