Claims
- 1. An apparatus for improving the accuracy of a noninvasive blood analysis measurement instrument, comprising:A.) first means for locating at least one sweet spot on the skin, said sweet spots having a significantly higher density of capillaries than the average of the surrounding skin area; B.) second means for controlling the measurement process performed by said noninvasive instrument such that it selectively probes sweet spots; whereby the tracking error is reduced and the signal-to-noise ratio is increased and full clinical usefulness can be achieved.
- 2. The apparatus of claim 1 wherein said noninvasive instrument comprises a near-infrared spectrometer.
- 3. The apparatus of claim 1 wherein said skin is the inner lower lip.
- 4. The apparatus of claim 3 wherein said sweet spots are located close to interface line 2.
- 5. The apparatus of claim 1 wherein the lateral size of said sweet spots is at least about 0.3 millimeter.
- 6. The apparatus of claim 1 wherein said first means comprise an imaging apparatus including a photodetector array selected form the group consisting of CCD arrays and CMOS arrays.
- 7. The apparatus of claim 6, said imaging apparatus further including a light source and optical means to illuminate an annular pattern with a dark center on said skin.
- 8. The apparatus of claim 1 wherein said second means comprise a monitor to display real-time images of the capillaries in said skin and a button that the user has to press to start the noninvasive measurement process.
- 9. The apparatus of claim 1 wherein said second means comprise real-time image analysis means to automatically detect sweet spots and indicator means to signal this event to the user.
- 10. The apparatus of claim 1 wherein said second means comprise a movable foil 50 to position said skin relative to said noninvasive instrument.
- 11. The apparatus of claim 1 wherein said first means comprise color measurement means to measure the color of a plurality of skin spots, each of said skin spots being at least several hundred micrometers in lateral size.
- 12. The apparatus of claim 1 wherein said first means comprise laser Doppler measurement means to measure the blood flow of a plurality of skin spots, each of said skin spots being at least several hundred micrometers in lateral size.
- 13. A method for improving the accuracy of a noninvasive blood analysis measurement instrument, comprising the steps of:A.) locating at least one sweet spot on the skin, said sweet spots having a significantly higher density of capillaries than the average of the surrounding skin area; B.) controlling the measurement process performed by said noninvasive instrument such that it selectively probes sweet spots; whereby the tracking error is reduced and the signal-to-noise ratio is increased and full clinical usefulness can be achieved.
- 14. The method of claim 13 wherein said noninvasive instrument comprises a near-infrared spectrometer.
- 15. The method of claim 13 wherein said skin is the inner lower lip.
- 16. The apparatus of claim 15 wherein said sweet spots are located close to interface line 2.
- 17. The method of claim 13 wherein said step of locating at least one sweet spot is comprised ofA.) forming an annular illumination pattern with a dark center on surface 9 of said skin; and B.) imaging an entrance field 21 located laterally within said dark center and at a shallow depth underneath said surface 9 onto a camera 20.
- 18. The method of claim 13 wherein said step of locating at least one sweet spot is comprised of measuring the color of a plurality of skin spots, each of said skin spots being at least several hundred micrometers in lateral size.
- 19. The method of claim 13 wherein said step of locating at least one sweet spot is comprised of measuring the laser Doppler signal from a plurality of skin spots, each of said skin spots being at least several hundred micrometers in lateral size.
- 20. A method for improving the accuracy of a noninvasive blood analysis measurement instrument, comprising the steps of:A.) providing means for limiting the lateral size of the skin volume probed by said noninvasive instrument to a predetermined value; B.) locating a sweet spot on the skin, said sweet spot having a significantly higher density of capillaries than the average of the surrounding skin area and a lateral size at least as large as said predetermined value; C.) positioning said skin relative to said noninvasive instrument such that the skin volume probed by said noninvasive instrument is overlapped by sweet spot area; and D.) starting a measurement on said noninvasive instrument; whereby the tracking error is reduced and the signal-to-noise ratio is increased and full clinical usefulness can be achieved.
- 21. The method of claim 20 wherein said step of providing means for limiting the lateral size comprises providing a fiber bundle guiding the measurement light.
- 22. The method of claim 20 wherein said step of positioning said skin comprises providing a movable foil 50 to move said skin relative to an optical window 45.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is entitled to the benefit of Provisional Patent Application Ser. No. 60/224,533 filed Aug. 11, 2000.
US Referenced Citations (5)
Provisional Applications (1)
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Number |
Date |
Country |
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60/224533 |
Aug 2000 |
US |