Disposable electronic diagnostic instrument

Claim 1

A disposable diagnostic instrument calibrated for use with a test strip to which a blood sample is applied, comprising: a. an instrument housing having keying guides defining a location as which said strip is placed, and defining a test reading aperture on said strip on which one or more drops of blood to be tested are inoculated, said test reading aperture defining a test area; b. a sensor switch located adjacent said keying guide and contacted by the strip in response to the strip being inserted into the guide, and a control circuit, the switch connected to the control circuit for activation of the instrument by providing power to the instrument in order to operate the instrument c. a light source positioned to emit radiation of desired wavelengths towards said test area and a photodetector positioned to detect radiation reflected by said test areas said light source and photodetector capable of analyzing said blood sample at said desired wavelengths to determine the amount of cholesterol in said blood sample; d. a display mounted on said instrument housing for displaying instrumental prompt icons and cholesterol level readings; e. a first control circuit, said first control circuit capable of performing self-diagnostic testing of said instrument to determine the capability of said photodetector to read said light source within a desired range; f. a second control circuit, said second control circuit controlling the operation of said light source, analyzing the output signal of said photodetector, and controlling the operation of said display; wherein said instrument measures the change in reflectance of said strip in response to a test solution being applied to said strip, and wherein said keying guides include at least one lateral edge guide for engaging a lateral edge of strip and an angled fore guide for engaging an angled fore edge of said strip.