Detecting chemical components from spectroscopic observations
View Patent ↗Embodiments disclosed herein may include methods and systems capable of estimating the underlying concentrations of chromophores in a sample. The photon scattering and absorption model may be based on Laplace and stable distributions, which may reveal that measurements in diffuse reflectance may follow a Beer-Lambert and Kohlrausch-Williams-Watts (KWW) product. This Beer-Lambert portion of the product may dominate in high absorption sample areas, while the KWW portion of the product may dominate in low absorption sample areas.
1. A medical device, comprising:
a monitor adapted to receive a physiologic signal from a patient; and
a processor capable of determining physiological characteristics of the patient based at least in part on the physiologic signal by applying a mixed Beer-Lambert/Kohlrausch-Williams-Watts Model (KWW) algorithm for photon diffusion to the physiologic signal.
2. The medical device of claim 1 , wherein the processor is capable of determining an absorption rate of a sample area of the patient from the physiologic signal.
3. The medical device of claim 2 , wherein the processor is capable of applying a predicted KWW model of diffuse reflectance when the absorption rate is determined to fall below a threshold value.
4. The medical device of claim 1 , comprising a memory device capable of storing the threshold value as a value determined by the processor based at least in part upon the physiologic signal.
5. The medical device of claim 2 , wherein the processor is capable of storing a predicted Beer-Lambert model of diffuse reflectance when the absorption rate is
determined to be above a threshold value.
6. The medical device of claim 5 , comprising a memory device capable of storing the threshold value as a preprogrammed value.
7. The medical device of claim 1 , wherein the processor is capable of determining concentrations of chromophores in a sample area of the patient based at least in part upon the mixed Beer-Lambert/KWW algorithm.
8. The medical device of claim 1 , comprising a sensor capable of emitting electromagnetic radiation into a tissue sample of the patient, and detecting the scattered and/or reflected light from the tissue sample.
9. The medical device of claim 8 , wherein the sensor is capable of generating the physiologic signal corresponding to the scattered and/or reflected light detected, and directing the physiologic signal to the monitor.
10. A method of calculating physiological characteristics of a patient, comprising:
obtaining a physiologic signal from a patient;
calculating physiological characteristics of the patient based at least in part on the physiologic signal by applying a mixed Beer-Lambert/Kohlrausch-Williams-Watts Model (KWW) algorithm for photon diffusion to the physiologic signal.
11. The method of claim 10 , comprising determining an absorption rate of a sample of the patient from the physiologic signal.
12. The method of claim 11 , comprising applying a predicted KWW model of diffuse reflectance when the absorption rate is determined to fall below a threshold value.
13. The method of claim 12 , comprising calculating the threshold value based at least in part upon the physiologic signal.
14. The method of claim 11 , comprising applying a predicted Beer-Lambert model of diffuse reflectance when the absorption rate is determined to be above a threshold value.
15. The method of claim 14 , comprising storing the threshold value as a preprogrammed value.
16. The method of claim 10 , wherein calculating physiological characteristics of a sample comprises utilizing the mixed Beer-Lambert/KWW algorithm to determine concentrations of chromophores in a sample area of the patient.
17. The method of claim 10 , wherein obtaining a physiologic signal comprises: emitting electromagnetic radiation into a tissue sample of the patient; detecting the scattered and/or reflected light from the tissue sample; generating the physiologic signal corresponding to the scattered and/or
reflected light detected and
directing the physiologic signal to the monitor.