Sample depth resolved noninvasive glucose concentration determination analyzer apparatus and method of use thereof
The invention comprises a method and apparatus for selecting optical pathways sampling a common tissue layer, such as the dermis, of a person for analysis in a noninvasive analyte property determination systemy, comprising the steps of: probing skin with a range of illumination zone-to-detection zone distances with at least two wavelength ranges, which optionally overlap, and selecting, using a metric, illumination zone-to-detection zone distances having mean optical pathways probing the common tissue layer, such as without the mean optical pathways entering the subcutaneous fat layer of the person. Optionally, the skin tissue layers are modulated and/or treated via tissue displacement before and/or during data collection.
1. A method for selecting signals corresponding to a common layer of skin of a person for a noninvasive sample constituent property determination, comprising the steps of:
providing an analyzer, said analyzer comprising: a first source system configured to provide first photons comprising a first mean illumination wavelength in a range of 1300 to 1900 nm, a second source system configured to provide second photons comprising a second mean illumination wavelength in the range of 1300 to 1900 nm, an optical probe housing, and multivariate analysis software, said optical probe housing comprising:
a first radial distance between a first illumination zone, optically coupled to said first source system, and a first detection zone in said optical probe housing,
a second radial distance between a second illumination zone, optically coupled to said second source system, and a second detection zone in said optical probe housing,
selecting a first current mean optical pathway of the first photons, between said first illumination zone and said first detection zone, probing a first maximum depth in a common layer, the common layer comprising a dermis layer of the skin, the first current mean optical pathway comprising a first absorbance; and
selecting a second current mean optical pathway of the second photons, between said second illumination zone and said second detection zone, probing a second maximum depth in the common layer of the dermis, the second current mean optical pathway comprising a second absorbance at least one hundred twenty percent of the first absorbance and less than two hundred percent of the first absorbance, the second radial distance at least three times the first radial distance.
2. The method of claim 1 , said step of selecting a first current mean optical pathway further comprising the step of:
measuring a first outer response from a first radially outwardly positioned detection zone relative to the first detection zone; and
observing a first increase in a first fat related signal of the first outer response relative to a first selected response related to a first measure of the common layer via the first detection zone.
3. The method of claim 2 , said step of selecting a second current mean optical pathway further comprising the step of:
measuring a second outer response from a second radially outwardly positioned detection zone relative to the second detection zone; and
observing a second increase in a second fat related signal of the second outer response relative to a second selected response related to a second measure of the common layer via the second detection zone.
4. The method of claim 1 , further comprising the steps of:
at a second point in time after said step of selecting the first current mean optical pathway, displacing the skin using a mechanical force by at least one-half of a millimeter; and
repeating said step of selecting the first current mean optical pathway to generate a first updated mean optical pathway corresponding to the common layer measured at an updated detection zone, an updated radial distance between the first illumination zone and the updated detection zone at least twenty percent larger than the first radial distance.
5. The method of claim 1 , further comprising the steps of:
at a second point in time after said step of selecting the first current mean optical pathway, displacing the skin using a mechanical force by at least one-tenth of a millimeter; and
repeating said step of selecting the first current mean optical pathway to generate a first updated mean optical pathway corresponding to the common layer measured at an updated detection zone, an updated radial distance between the first illumination zone and the updated detection zone at least twenty percent smaller than the first radial distance.
6. The method of claim 1 , said second absorbance comprising: at least one hundred fifty percent of the first absorbance and at least an absorbance of two.
7. The method of claim 1 , wherein the first detection zone overlaps at least eighty percent of the second detection zone.
8. The method of claim 1 , further comprising the steps of:
measuring a first set of signals using a first set of detectors configured at a first set of distances from the first illumination zone;
selecting a first signal from a first detector, of said first set of detectors, corresponding to the first mean optical pathway sampling the common layer;
measuring a second set of signals, using a second set of detectors configured at a second set of distances from the second illumination zone; and
selecting a second signal from said second set of detectors corresponding to the second mean optical pathway sampling the common layer.
9. The method of claim 8 , further comprising the step of:
a transducer physically displacing the skin of the subject during said step of measuring the first set of signals.
10. The method of claim 1 , further comprising the step of:
displacing the skin of the subject via mechanical motion of a first electromechanical transducer.
11. The method of claim 10 , said step of selecting the first current mean optical pathway of the first photons further comprising the step of:
using data generated during a time period of displacement of the skin by said step of displacing.
12. The method of claim 10 , further comprising the step of:
said step of selecting the first current mean optical pathway of the first photons occurring during a first displacement magnitude of the skin resultant from the step of displacing and said step of selecting the second current mean optical pathway of the second photons occurring during a second displacement magnitude of the skin resultant from the step of displacing, said second magnitude of displacement at least ten percent larger than said first magnitude of displacement.
13. The method of claim 10 , further comprising the step of:
displacing the skin of the subject via mechanical motion of a second electromechanical transducer.
14. The method of claim 10 , further comprising the step of:
affixing said optical probe housing to the skin between an elbow and a should of the subject; and
said analyzer communicating with a watch apparatus of the user.
15. The method of claim 1 , further comprising the step of:
displacing the skin of the subject during a step of measuring a first set of signals using a first set of detectors configured at a first set of distances from the first illumination zone; and
selecting a first signal from a first detector, of said first set of detectors, corresponding to the first mean optical pathway sampling the common layer.