Apparatus for non-invasive measurement of glucose in blood

A non-invasive blood glucose measuring apparatus, for measuring a glucose level in an object of measurement, comprising:

• a. an irradiation source, for irradiating a narrow-band wavelength light into said object of measurement containing a blood vessel, comprising:
• i. a light-emitting source, for emitting a single narrow-band wavelength light beam of a narrow spectral shape;
• ii. an output polarizer, for polarizing said emitted narrow-band wavelength light beam into a single linearly polarized light beam;
• iii. a limiting aperture diaphragm, for irradiating the linearly polarized light into said object of measurement, in orthogonally to the illuminated surface of said object of measurement;
• b. an optical detector, for collecting and processing some of the light, irradiated by said irradiating source, which is back-scattered from the object of measurement, comprising:
• i. a Light Receiving Tube (LRT), for collecting some of said back-scattered light, which is essentially normal to the plane of the surface of said object of measurement, where said LRT, which is adapted to be in contact with the surface of said object of measurement at a point spatially separated, by a fixed distance, from the irradiation point of said irradiating source, where said collected back-scattered light comprises at least part of the back-scattered beam that has propagated through said blood vessel, which serves as an optical waveguide, between said light-emitting source and said LRT;
• ii. a beam splitter, for splitting said collected back-scattered light from the object of measurement, into two separate light beams;
• iii. two polarizers, for polarizing said two separate light beams into two orthogonally polarized beams;
• iv. two detector-amplifiers for detecting and amplifying the intensities of said two orthogonally polarized beams, where each of said detector-amplifiers detects and amplifies the intensity of one orthogonally polarized beam;
• c. sampling means, for sampling said orthogonally polarized beams, provided by said detector-amplifiers, for converting the data of said orthogonally polarized beams into sampled digital codes;
• and
• d. a computing unit for computing the glucose level in said object of measurement, based on a polarization angle, by processing said digital codes of said sampled orthogonally polarized beams, sensed by said detector-amplifiers, and by averaging said sampled digital codes, the computing unit comprising:
• an adaptive filter, for enhancing the cardiac pulse waveform for determining the polarization angle of said light back-scattered light from said object.