Digital light processing hyperspectral imaging apparatus and method

Patent metadata

Field	Value
Publication number	US-9622662-B2
Application number	US-201313776087-A
Country	US
Kind code	B2
Filing date	Feb 25, 2013
Priority date	Aug 10, 2008
Publication date	Apr 18, 2017
Grant date	Apr 18, 2017

Abstract

A hyperspectral imaging system having an optical path. The system including an illumination source adapted to output a light beam, the light beam illuminating a target, a dispersing element arranged in the optical path and adapted to separate the light beam into a plurality of wavelengths, a digital micromirror array adapted to tune the plurality of wavelengths into a spectrum, an optical device having a detector and adapted to collect the spectrum reflected from the target and arranged in the optical path and a processor operatively connected to and adapted to control at least one of: the illumination source; the dispersing element; the digital micromirror array; the optical device; and, the detector, the processor further adapted to output a hyperspectral image of the target. The dispersing element is arranged between the illumination source and the digital micromirror array, the digital micromirror array is arranged to transmit the spectrum to the target and the optical device is arranged in the optical path after the target.

First claim

What is claimed is:

1. A method of obtaining a hyperspectral image of a target comprising the steps of:
generating a light beam;
dispersing said light beam with a dispersing element;
separating said dispersed light beam into a first complex spectrum using a spatial light modulator;
illuminating said target with said first complex spectrum, wherein said first complex spectrum subsequently reflects off of said target as a first reflected light beam;
collecting said first reflected light beam;
directing said collected first reflected light beam to a detector to capture a first spectral image data;
separating said dispersed light beam into a second complex spectrum using said spatial light modulator;
illuminating said target with said second complex spectrum, wherein said second complex spectrum subsequently reflects off of said target as a second reflected light beam;
collecting said second reflected light beam;
directing said collected second reflected light beam to said detector to capture a second spectral image data; and,
forming said hyperspectral image from said first and second spectral image data,
wherein said detector comprises:
a plurality of pixels,

wherein said step of forming a hyperspectral image comprises the steps of:
calculating a spectra ratio for each of said plurality of pixels;
filtering said spectra ratios with a data smoothing filter to create a filtered data set;
normalizing said filtered data set to create a normalized data set; and,
deconvoluting said normalized data set and scaling said normalized data set to create a grey scale or color encoded image, wherein said grey scale or color encoded image is said hyperspectral image, and

wherein the step of calculating a spectra ratio for each of said plurality of pixels comprises:

RD
ij

=

Log
10

⁡

(

BKG
ij

-

DF
ij

SD
ij

-

DF
ij

)

where: RD ij is a ratioed data for each pixel i at wavelength j
BKG ij is a reflectance of a 100% reflectance standard
DF ij is a dark field
SD ij is a reflectance from the sample; and,

wherein the step of normalizing said filtered data set to create a normalized data set comprises:

ND
ij

=

(

RD
ij

-

min
⁡

(

RD
ij

)

max
⁡

(

RD
ij

)

-

min
⁡

(

RD
ij

)

)

where: ND ij is a normalized spectrum at each pixel
RD ij is the ratioed data.

2. The method according to claim 1 , wherein said first and second reflected light beams each comprises reflected, luminescence, fluorescence, autofluorescence, Raman scattered, transmitted, scattered, absorbed, or emitted electromagnetic radiation.

3. The method according to claim 1 , wherein said detector further comprises:
a processor comprising an image data acquisition software adapted to tune said spatial light modulator, trigger said detector for collection of said first and second spectral image data formatted as a hyperspectral image cube and process said hyperspectral image cube for visualization;
a digital signal process algorithm for analyzing chemometrics of said target; and,
a display device adapted to display said hyperspectral image.

4. The method according to claim 1 , wherein said first and second complex spectrum each comprise a plurality of wavelengths of said light beam and respective portions of each of said plurality of wavelengths each comprise an intensity.

5. The method according to claim 1 , wherein the target comprises an organ selected from the group consisting of: skin, an eye; a kidney; a gall bladder; a liver; a lung; a stomach; a bowel; and, a brain.

6. The method according to claim 1 , wherein the target comprises a physiological process selected from the group consisting of: angiogenesis; an antigen binding to an antibody; a drug uptake; a vascular change; wound healing; oxygenation of a retina; optic nerve oxygenation; kidney oxygenation.

7. The method according to claim 1 , wherein the target comprises a disease state selected from the group consisting of: a burn; diabetic retinopathy; cancer progression; sickle cell; diabetes; anemia; diabetic retinopathy; macular degeneration; raynauds; an ulcer; autoimmune retinitis; infectious retinitis; infiltrative neoplastic conditions; ocular trauma injuries; necrotic tissue; and, wound infections.

8. The method according to claim 1 , wherein the target comprises a physiological substance selected from the group consisting of: water; oxyhemoglobin; deoxyhemoglobin; carboxyhemoglobin; lipids; metabolites; macular pigments; retinal photoreceptor pigments; retinal pigment epithelium; cholesterol; glucose; proteins in central nervous system fluid; proteins in saliva; semen; and, disease biomarkers.

9. The method according to claim 1 , wherein at least one step of said method is performed in combination with an endoscope, a laparoscope, a surgical microscope or a fundus camera.

10. The method according to claim 1 , wherein deconvoluting said normalized data set is performed using a least squares fit on said normalized data set to create a fitted normalized data set.

11. The method according to claim 1 , wherein said gray scale or color encoded image comprises a chemically encoded image, said chemically encoded image comprising a quantitative assessment of the target.

12. A method of performing a surgical procedure selected from the group consisting of: a cholecystectomy; an amputation; a

Assignees

• Univ Texas

Inventors

• Zuzak Karel J
• Cadeddu Jeffrey A
• Ufret-Vincenty Rafael
• Francis Robert P
• Livingston Edward

Classifications

• A61B5/4064

  Evaluating the brain (for intracranial pressure A61B5/031; for cerebral blood gases A61B5/14553; using EEG A61B5/369) · CPC title

• G01N21/39

  using tunable lasers · CPC title

• G01J2003/1282

  Spectrum tailoring · CPC title

• A61B5/0084

  for introduction into the body, e.g. by catheters (A61B5/1459 takes precedence) · CPC title

• G01J2003/1213

  Filters in general, e.g. dichroic, band · CPC title