Hyperspectral imaging in diabetes and peripheral vascular disease

• US 20070016079A1
• Filed: 04/04/2006
• Published: 01/18/2007
• Est. Priority Date: 04/04/2005
• Status: Active Grant

• Current Assignee: Hypermed Imaging Incorporated
• Original Assignee: Hypermed Imaging Incorporated
• Inventors: Brand, Derek, Freeman, Jenny, Panasyuk, Svetlana, Schomacker, Kevin, Hopmeier, Michael
• Granted Patent: US 8,374,682 B2
• Time in Patent Office: Days
• US Class Current: 600/476
• CPC Class Codes: A61B 5/0059 using light, e.g. diagnosis by transillumination, diascopy, fluorescence A61B5/0093, A61B5/1455, A61B5/02416 and A61B5/0261 take precedence
• CPC Class Codes: A61B 5/145 Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissuemeasuring of blood pressure or blood flow A61B5/02; non-radiation detecting or locating of foreign bodies in blood A61B5/06
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/412 Detecting or monitoring sepsis
• CPC Class Codes: A61B 5/444 Evaluating skin marks, e.g. mole, nevi, tumour, scar
• CPC Class Codes: A61B 5/445 Evaluating skin irritation or skin trauma, e.g. rash, eczema, wound, bed sore
• CPC Class Codes: A61B 5/7275 Determining trends in physiological measurement data; Predicting development of a medical condition based on physiological measurements, e.g. determining a risk factor
• CPC Class Codes: A61B 5/743 Displaying an image simultaneously with additional graphical information, e.g. symbols, charts, function plots
• CPC Class Codes: G01J 3/02 Details
• CPC Class Codes: G01J 3/0224 using polarising or depolarising elements
• CPC Class Codes: G01J 3/0272 Handheld
• CPC Class Codes: G01J 3/0283 using a charging unit
• CPC Class Codes: G01J 3/10 Arrangements of light sources specially adapted for spectrometry or colorimetry
• CPC Class Codes: G01J 3/12 Generating the spectrum; Monochromators
• CPC Class Codes: G01J 3/2823 Imaging spectrometer
• CPC Class Codes: G06T 7/0012 Biomedical image inspection
• CPC Class Codes: G16H 30/40 for processing medical images, e.g. editing
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems

Abstract

The invention is directed to methods and systems of hyperspectral and multispectral imaging of medical tissues. In particular, the invention is directed to new devices, tools and processes for the detection and evaluation of diseases and disorders such as, but not limited to diabetes and peripheral vascular disease, that incorporate hyperspectral or multispectral imaging.

Claims

1. A medical instrument comprising:

a first stage optic responsive to illumination of tissue;

a spectral separator;

one or more polarizers;

an imaging sensor;

a diagnostic processor;

a filter control interface;

a general purpose operating module to assess the state of tissue in diabetic subjects following a set of instructions; and

a calibrator.

2. The medical instrument of claim 1 further comprising a second stage optic responsive to illumination of tissue.

3. The medical instrument of claim 1 wherein the set of instructions comprises:

preprocessing hyperspectral information;

building a visual image;

defining a region of interest in tissue;

converting the visual image into units of optical density by taking a negative logarithm of each decimal base;

decomposing a spectra for each pixel into several independent components;

determining three planes for an RGB pseudocolor image;

determining a sharpness factor plane;

converting the ROB pseudo-color image to a hue-saturation-value/intensity image having a plane;

adjusting the hue-saturation-value/intensity image plane with the sharpness factor plane;

converting the hue-saturation-value/intensity image back to the RGB pseudo-color image;

removing outliers beyond a standard deviation and stretching image between 0 and 1;

displaying the region of interest in pseudo-colors; and

characterizing a metabolic state of the tissue of interest.

4. The medical instrument of claim 3 wherein the region of interest is one of a pixel, a specified region or an entire field of view.

5. The medical instrument of claim 3 wherein determining three planes for an RGB pseudo-color image comprises one or more characteristic features of the spectra.

6. The medical instrument of claim 3 wherein determining a sharpness factor plane comprises a combination of the images at different wavelengths.

7. The medical instrument of claim 3 wherein removing outliers beyond a standard deviation comprises three standard deviations.

8. The medical instrument of claim 3 wherein displaying the region of interest in pseudo-colors comprises one of performing one in combination with a color photoimage of a subject, in addition to a color photo image of a subject, and projecting onto the tissue of interest.

9. The medical instrument of claim 3 wherein defining the color intensity plane as apparent concentration of one or a mathematical combination of oxygenated Hb, deoxygenated Hb, and total Hb, oxygen saturation.

10. The medical instrument of claim 3 wherein defining the color intensity plane as reflectance in blue-green-orange region.

11. The medical instrument of claim 3 wherein adjusting the hue saturation comprises adjusting a color resolution of the pseudo-color image according to quality of apparent concentration of one or a mathematical combination of oxygenated Hb, deoxygenated Hb, and total Hb, oxygen saturation.

12. The medical instrument of claim 11 wherein adjusting the hue saturation farther comprises one or a combination of reducing resolution of hue and saturation color planes by binning the image, resizing the image, and smoothing the image through filtering higher frequency components out.

13. The medical instrument of claim 12 further interpolating the smoothed color planes on a grid of higher resolution intensity plane.

14. A method for assessing the state of tissue of a diabetic subject comprising:

preprocessing hyperspectral information;

building a visual image;

defining a region of interest in tissue;

converting the visual image into units of optical density by taking a negative logarithm of each decimal base;

decomposing a spectra for each pixel into several independent components;

determining three planes for an ROB pseudo-color image;

determining a sharpness factor plane;

converting the RGB pseudo-color image to a hue-saturation-value/intensity image having a plane;

adjusting the hue-saturation-value/intensity image plane with the sharpness factor plane;

converting the hue-saturation-value/intensity image back to the RGB pseudo-color image;

removing outliers beyond a standard deviation and stretching image between 0 and 1;

displaying the region of interest in pseudo-colors; and

characterizing a metabolic state of the tissue of interest.

15. The method of claim 14 wherein the region of interest is one of a pixel, a specified region or an entire field of view.

16. The method of claim 14 wherein determining three planes for an RGB pseudo-color image comprises one or more characteristic features of the spectra.

17. The method of claim 14 wherein determining a sharpness factor plane comprises a combination of the images at different wavelengths.

18. The method of claim 14 wherein removing outliers beyond a standard deviation comprises three standard deviations.

19. The method of claim 14 wherein displaying the region of interest in pseudo-colors comprises one of performing one in combination with a color photoimage of a subject, in addition to a color photo image of a subject, and projecting onto the tissue of interest.

20. The method of claim 14 wherein defining the color intensity plane as apparent concentration of one or a mathematical combination of oxygenated Hb, deoxygenated Hb, and total Hb, oxygen saturation.

21. The method of claim 14 wherein defining the color intensity plane as reflectance in blue-green-orange region

22. The method of claim 14 wherein adjusting the hue saturation comprises adjusting a color resolution of the pseudo-color image according to quality of apparent concentration of one or a mathematical combination of oxygenated Hb, deoxygenated Hb, and total Hb, oxygen saturation.

23. The method of claim 14 wherein adjusting the hue saturation further comprises one or a combination of reducing resolution of hue and saturation color planes by binning the image, resizing the image, and smoothing the image through filtering higher frequency components out.

24. The method of claim 14 further interpolating the smoothed color planes on a grid of higher resolution intensity plane.