Method and Apparatus for Multi-spectral Imaging and Analysis of Skin Lesions and Biological Tissues

• US 20100042004A1
• Filed: 08/11/2009
• Published: 02/18/2010
• Est. Priority Date: 08/12/2008
• Status: Active Grant

• Current Assignee: New Jersey Institute of Technology
• Original Assignee: New Jersey Institute of Technology
• Inventors: Dhawan, Atam Prakash
• Granted Patent: US 9,572,494 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 5/411 Detecting or monitoring allergy or intolerance reactions to an allergenic agent or substance
• CPC Class Codes: A61B 5/443 Evaluating skin constituents, e.g. elastin, melanin, water
• 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 5/7264 Classification of physiological signals or data, e.g. using neural networks, statistical classifiers, expert systems or fuzzy systems neural networks per se G06N3/00; expert systems per se G06N5/00
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems

Abstract

A multispectral nevoscope that uses specific wavelengths in the visible and infrared spectrum of electromagnetic radiation to transilluminate a skin-lesion or a biological tissue or specimen for imaging and maps multispectral 2-dimensional images into 3-dimensional virtual space for providing 3-D distributions of pre-defined parameters representing the characteristic properties (such as melanin, hemoglobin and deoxyhemoglobin, etc.) of a skin lesion. Methods are disclosed for analyzing and using the characteristic distributions of specific parameters for detection and management of skin-cancers, or characterization of a biological tissue or specimen.

Claims

1. A multispectral nevoscope for examining in situ a skin lesion of a patient, comprising:

(a) a housing having a central axis and a base with a central aperture for positioning over a portion of skin of a patient, the portion of skin including the lesion to be examined;

(b) a face plate positioned in register with the central aperture comprising an imaging area having plural illumination fiber channels operably connected to an illuminator-filter assembly and plural receiver fiber channels; and

(c) at least one transillumination device disposed proximal to the faceplate operable to transmit light in a converging ring into the skin of the patient in the region of the lesion to uniformly transilluminate the region of skin of the patient including the lesion.

2. The multispectral nevoscope of claim 1 wherein the transillumination device comprises at least one ring illuminator disposed on the face plate.

3. The multispectral nevoscope of claim 2 wherein the at least one ring illuminator comprises a first outer ring illuminator comprising at least one transillumination fiber channel having a first wavelength oriented at 45 degrees to produce a convergent beam for multispectral or specific wavelength-based background image excitation, and a second outer ring illuminator comprising at least one transillumination fiber channel having a second wavelength oriented at 45 degrees to produce a convergent beam for multispectral or specific wavelength-based background image excitation.

4. The multispectral nevoscope of claim 3 wherein the first wavelength is shorter than the second wavelength.

5. The multispectral nevoscope of claim 2 further comprising a source mask wherein the imaging area illumination fiber channels and receiver fiber channels are in positions in a matrix corresponding to the source mask.

6. The multispectral nevoscope of claim 1 further comprising a focusing lens and optionally a polarizer.

7. The multispectral nevoscope of claim 1 further comprising a multispectral filter.

8. The multispectral nevoscope of claim 1 wherein the face plate is removably attached to the housing and is operably connected to a removable lens and/or polarizer wherein the lens and/or polarizer provides an interface to the imaging area.

9. The multispectral nevoscope of claim 1 wherein at least one of the plural receiver fiber channels is operably connected to a CCD image sensor.

10. The multispectral nevoscope of claim 1 comprising a device for recording images of the transilluminated skin lesion.

11. The multispectral nevoscope of claim 10 comprising a mask to receive the light from fibers not used for illumination, a focusing lens and/or polarizer operably linked to the mask and a CCD sensor to record images.

19. A system comprising a multispectral nevoscope according to claim 1 comprising a computing device operable to classify images collected by the multispectral nevoscope.

20. The system according to claim 19 wherein the computing device employs software operable to classify images using an adaptive fuzzy c-means clustering algorithm to provide an optimal set of classifiable clusters of correlated features extracted from white-light and multispectral nevoscope images.

12. A method of reconstructing skin lesion images comprising collecting image information about absorption and scattering properties of chromophores of skin layers and a lesion, retrieving information regarding the distribution of melanin and blood in the skin layers and lesion, and applying a shape-based multi-constrained algorithm to the collected and retrieved information.

13. The method according to claim 12 wherein the multi-constrained algorithm comprises a linearized forward model evaluated by Monte Carlo simulation in terms of typical optical properties of normal skin, generating a Jacobian matrix, applying a genetic algorithm to generate predicted shape, performing a sampling function, applying the Jacobian matrix to the result of the sampling function to generate a predicted result.

14. The method according to claim 12 wherein the retrieved blood information relates to hemoglobin.

15. The method according to claim 12 wherein the retrieved information relates to oxyhemoglobin and deoxyhemoglobin.

16. The method according to claim 12 wherein malignant melanoma is represented by shapes of its melanin part and blood part and these parameters are grouped into genetic algorithms.

17. The method according to claim 12 comprising using visible light and near-infrared wavelengths in the range of 400 nm to 1000 nm to obtain reflectance-based absorption measurements with different levels of depth of penetration to estimate volumes of chromophores selected from the group melanin, oxy-hemoglobin and deoxyhemoglobin.

18. The method according to claim 17 wherein the wavelengths are in the range of preferably 500 nm to 960 nm.