Raman Imaging Systems and Methods

Patent metadata

Field	Value
Publication number	US-2018303347-A1
Application number	US-201515530266-A
Country	US
Kind code	A1
Filing date	Jun 18, 2015
Priority date	Jun 18, 2014
Publication date	Oct 25, 2018
Grant date	—

Abstract

Systems and methods for biocompatible tissue characterization using Raman imaging are provided. The systems and methods utilize Raman systems tuned to monitor spectral wavelengths characteristic of target types of tissue to monitor constituents of that tissue in biological systems and samples. The Raman systems may be tuned to monitor the Raman signature for the formation of the chemical bonds that join phosphorous and oxygen (PO) atoms, such that the formation of hydroxyapatite may be monitored and used to determine the presence of bone formation in a sample, such as, for example, biological tissue.

First claim

What is claimed is:

1 . A biocompatible imaging Raman system comprising:
a sample containing therein at least one substance emitting at least one Raman signal over at least one unique wavelength when the substance is excited; an illumination source in radiative alignment with the sample, the illumination source illuminating the sample over at least one excitation wavelength to excite the sample thereby stimulating the emission of the at least one Raman signal from the substance; an imager in optical alignment with the sample, the imager being tuned to a detection wavelength capturing a signal containing at least the at least one Raman signal from the substance along with a background emission; one or both of the excitation wavelength of the illumination source and the detection wavelength of the imager being tunable over at least two wavelengths, wherein at least one of the at least two wavelengths includes the at least one Raman signal and at least one of the at least two wavelengths omits the at least one Raman signal such that only the background emissions are captured by the imager; and a signal processor for subtracting the signal containing the at least one Raman signal from the signal omitting the at least one Raman signal to obtain a data set containing only the at least one Raman signal.

2 . The imaging Raman system of claim 1 , wherein the illumination source is one of either coherent or non-coherent and is selected from the group consisting of a laser diode and a light emitting diode, and wherein the imager is selected from the group consisting of PMT, CCD, iCCD, EMCCD and CMOS imagers.

3 . The imaging Raman system of claim 1 , wherein the substance is hydroxyapatite and the at least one Raman signal arises from the excitation of the phosphorous-oxygen bonds within the hydroxyapatite.

4 . The imaging Raman system of claim 1 , wherein the excitation wavelength of the illumination source is tunable over at least two wavelengths.

5 . The imaging Raman system of claim 1 , wherein the detection wavelength of the imager is tunable over at least two wavelengths.

6 . The imaging Raman system of claim 5 , wherein the imager incorporates one or more filters for tuning the detection wavelength.

7 . The imaging Raman system of claim 6 , wherein the filters are one of either illumination rejection or narrow pass-band filters.

8 . The imaging Raman system of claim 1 , wherein the sample contains at least two distinct Raman signals.

9 . The imaging Raman system of claim 1 , wherein the illumination source comprises an array of radiative emitters arranged to simultaneously illuminate a target area, and wherein the imager has a field of view sufficiently large to capture the entire target area in a single capturing step.

10 . A method of performing biocompatible imaging Raman comprising:
providing a sample containing therein at least one substance emitting at least one Raman signal over at least one unique wavelength when the substance is excited; illuminating the sample over at least one excitation wavelength to excite the sample to stimulate the emission of the at least one Raman signal from the substance; imaging the sample at a detection wavelength capturing a signal containing at least the at least one Raman signal from the substance along with a background emission; tuning one of either the excitation wavelength of the illumination source or the detection wavelength of the imager over at least a second wavelength that omits the at least one Raman signal such that the at least one Raman signal from the substance is not captured; reimaging the sample at the second wavelength to obtain a signal lacking the Raman signal; and subtracting the signal containing the at least one Raman signal from the signal lacking the at least one Raman signal to obtain a data set containing only the at least one Raman signal.

11 . The method of claim 10 , wherein the tuning comprises altering the excitation wavelength such that the at least one Raman signal from the substance radiates at a wavelength different from the detection wavelength.

12 . The method of claim 10 , wherein the tuning comprises altering the detection wavelength such that the unique wavelength of the Raman signal and the detection wavelength differ.

13 . The method of claim 12 , wherein altering the detection wavelength includes using one or more wavelength filters.

14 . The method of claim 13 , wherein the filters are one of either illumination rejection or narrow pass-band filters.

15 . The method of claim 10 , wherein the sample contains at least two Raman signals over at least two distinct wavelengths, and wherein the method further comprises imaging, tuning and reimaging to capture each of the at least two distinct Raman signals separately.

16 . The method of claim 15 , wherein the at least two Raman signals arise from at least two distinct substances.

17 . The method of claim 10 , wherein the illumination source is provided by one of either coherent or non-coherent and is selected from the group consisting of a laser diode and a light emitting diode, and wherein the imaging is provided by an imager selected from the group consisting of a PMT, CCD, iCCD, EMCCD and CMOS imagers.

18 . The method of claim 10 , wherein the substance is hydroxyapatite and the at least one Raman signal arises from the excitation of the phosphorous-oxygen bonds within the hydroxyapatite.

19 . The method of claim 10 , wherein the illuminating comprises simultaneously illuminating a target area; and
wherein the imaging comprises capturing the entire target area in a single capturing step.

Assignees

• Univ California

Inventors

• Grundfest Warren S
• Stafsudd Oscar M
• Papour Asael
• Taylor Zachary

Classifications

• A61B5/445

  Evaluating skin irritation or skin trauma, e.g. rash, eczema, wound, bed sore · CPC title

• A61B5/7282

  Event detection, e.g. detecting unique waveforms indicative of a medical condition (cough events A61B5/0823; seizures A61B5/4094; sleep apnoea A61B5/4818) · CPC title

• A61B5/0075 Primary

  by spectroscopy, i.e. measuring spectra, e.g. Raman spectroscopy, infrared absorption spectroscopy (A61B5/0071 takes precedence) · CPC title

• G01J3/44

  Raman spectrometry; Scattering spectrometry {; Fluorescence spectrometry} · CPC title

• A61B5/4504

  Bones (A61B5/4547 takes precedence) · CPC title