PORTABLE RAMAN DIAGNOSTIC SYSTEM

• US 20120035442A1
• Filed: 06/23/2011
• Published: 02/09/2012
• Est. Priority Date: 08/05/2010
• Status: Active Grant

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Barman, Ishan, Dasari, Ramachandra, Feld, Michael, Feld, David, Feld, Jonathan, Dingari, Narahara Chari, Kong, Chae-Ryon, Hearn, Alison
• Granted Patent: US 9,662,047 B2
• Time in Patent Office: Days
• US Class Current: 600/316
• CPC Class Codes: A61B 2560/0223 of calibration, e.g. protocols for calibrating sensors
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/1455 using optical sensors, e.g. spectral photometrical oximeters
• CPC Class Codes: A61B 5/4312 Breast evaluation or disorder diagnosis A61B5/0091 takes precedence
• CPC Class Codes: A61B 5/444 Evaluating skin marks, e.g. mole, nevi, tumour, scar
• CPC Class Codes: G01J 3/0208 using focussing or collimating elements, e.g. lenses or mirrors; performing aberration correction
• CPC Class Codes: G01J 3/0216 using light concentrators or collectors or condensers
• CPC Class Codes: G01J 3/0218 using optical fibers
• CPC Class Codes: G01J 3/0272 Handheld
• CPC Class Codes: G01J 3/44 Raman spectrometry; Scattering spectrometry ; Fluorescence spectrometry
• CPC Class Codes: G01N 21/65 Raman scattering
• CPC Class Codes: G01N 2201/129 Using chemometrical methods
• CPC Class Codes: Y02A 90/10 Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation

Abstract

The present invention further relates to the selection of the specific filter combinations, which can provide sufficient information for multivariate calibration to extract accurate analyte concentrations in complex biological systems. The present invention also describes wavelength interval selection methods that give rise to the miniaturized designs. Finally, this invention presents a plurality of wavelength selection methods and miniaturized spectroscopic apparatus designs and the necessary tools to map from one domain (wavelength selection) to the other (design parameters). Such selection of informative spectral bands has a broad scope in miniaturizing any clinical diagnostic instruments which employ Raman spectroscopy in particular and other spectroscopic techniques in general.

Claims

1. A method for measuring glucose concentration comprising:

illuminating a region of tissue having a glucose concentration to be measured with light having a plurality of wavelengths;

detecting a plurality of Raman spectral regions with light from the tissue in response to the illuminating wavelengths of light; and

analyzing the spectral data to determine a concentration of an analyte in the region of tissue.

2. The method of claim 1 further comprising illuminating the region of tissue with a fiber optic probe having an optical concentration.

3. The method of claim 2 wherein the optical concentrator comprises a compound parabolic concentrator.

4. The method of claim 2 wherein the optical concentrator comprise a compound hyperbolic concentrator.

5. The method of claim 1 further comprising illuminating the region of tissue with a fiber optic probe having a light delivery fiber and a plurality of light collection optical fibers, the light delivery fiber having a first light filter and the plurality of light collection optical fibers having a second filter.

6. The method of claim 1 further comprising using a light source that emits illuminating light that illuminates the region of tissue with a plurality of wavelength bands.

7. The method of claim 6 further comprising using a tunable light filter to control the wavelength of illuminating light.

8. The method of claim 1 further comprising processing spectral data with a computer to select the plurality of Raman spectral regions.

9. The method of claim 8 wherein the processing step comprises using a nonlinear representation of spectral data to select the plurality of Raman spectral regions.

10. The method of claim 8 wherein the nonlinear representation comprises support vector regression.

11. The method of claim 8 further comprising forming a regression vector to determine glucose concentration.

12. The method of claim 9 wherein the step of using a non-linear representation comprises a physiological lag component of a glucose concentration measurement.

13. The method of claim 9 wherein the step of using a non-linear representation comprises a tissue turbidity component.

14. The method of claim 1 further comprising detecting the plurality of Raman spectral regions with a single photodetetor.

15. A device for measuring glucose concentration within a body comprising:

a light source system for illuminating a region of tissue with a plurality of wavelengths;

an optical system to deliver and collect light from the region of tissue in response to the illuminating light; and

a detector that detects a plurality of spectral regions of Raman shifted light collected by the optical system.

16. The device of claim 15 wherein the light source system comprises a tuneable laser.

17. The device of claim 15 wherein the light source system further comprises an acousto optic modulator to control the wavelength of illuminating light.

18. The device of claim 15 further comprising a phase modulator.

19. The device of claim 15 wherein the detector comprises a photodetector.

20. The device of claim 15 further comprising a data processor connected to the detector, data processor being programmed to process Raman spectral data.

21. The device of claim 20 wherein the processor is programmed to apply a non-linear representation to the data.

22. The device of claim 21 wherein the representation comprises support vector regression.

23. The device of claim 15 wherein the detector comprises a tunable filter.

24. The device of claim 15 further comprising a compound optical concentrator coupled to a fiber optic device.