Methods and Systems for Imaging Skin Using Polarized Lighting

• US 20100245823A1
• Filed: 03/24/2010
• Published: 09/30/2010
• Est. Priority Date: 03/27/2009
• Status: Active Grant

• Current Assignee: BrighTex Bio-Photonics LLC
• Original Assignee: BrighTex Bio-Photonics LLC
• Inventors: Chhibber, Ashutosh, Chhibber, Rajeshwar, Sharma, Shefali
• Granted Patent: US 8,373,859 B2
• Time in Patent Office: Days
• US Class Current: 356/366
• 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 5/442 Evaluating skin mechanical properties, e.g. elasticity, hardness, texture, wrinkle assessment
• 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: H04N 23/50 Constructional details
• CPC Class Codes: H04N 23/56 provided with illuminating means

Abstract

An imaging system for imaging skin includes a light source to illuminate a subject and a first polarizer to polarize light provided by the light source to illuminate the subject. The imaging system also includes a photodetector to acquire an image of the subject as illuminated by the light source and an adjustable second polarizer, coupled to the photodetector, to provide an adjustable degree of polarization of light received by the photodetector.

Claims

1. An imaging system for imaging skin, comprising:

a light source to illuminate a subject;

a first polarizer to polarize light provided by the light source to illuminate the subject;

a photodetector to acquire an image of the subject as illuminated by the light source; and

an adjustable second polarizer, coupled to the photodetector, to provide an adjustable degree of polarization of light received by the photodetector.

2. The imaging system of claim 1, wherein the first polarizer is a linear polarizer.

3. The imaging system of claim 1, wherein the second polarizer is an elliptical polarizer.

4. The imaging system of claim 1, wherein the second polarizer is a circular polarizer.

5. The imaging system of claim 1, wherein the light source comprises a flash bulb.

6. The imaging system of claim 1, wherein the light source comprises one or more LEDs.

7. The imaging system of claim 1, further comprising a lens, situated between the second polarizer and the photodetector, to focus light onto the photodetector.

8. The imaging system of claim 7, wherein the lens is a zoom lens to provide variable image resolution.

9. The imaging system of claim 8, further comprising zoom lens control circuitry coupled to the zoom lens to provide automatic adjustment of the variable image resolution.

10. The imaging system of claim 1, wherein the photodetector is configured to provide a variable image aspect ratio.

11. The imaging system of claim 1, wherein:

the photodetector is situated within a housing; and

the light source is coupled to the housing.

12. The imaging system of claim 11, further comprising a light shield, extending outward from the housing, to shield the subject from ambient light.

13. The imaging system of claim 1, further comprising an imaging box, wherein the light source, photodetector, and first and second polarizers are installed in the imaging box.

14. The imaging system of claim 1, further comprising:

memory, coupled to the photodetector, to store the acquired image; and

a display, coupled to the memory, to display the acquired image.

15. The imaging system of claim 1, further comprising a knob to rotate the second polarizer, wherein a degree of rotation of the second polarizer corresponds to the degree of polarization provided by the second polarizer.

16. The imaging system of claim 1, further comprising a motor to rotate the second polarizer, wherein a degree of rotation of the second polarizer corresponds to the degree of polarization provided by the second polarizer.

17. The imaging system of claim 16, further comprising polarizer control circuitry, coupled to the motor, to control the degree of rotation of the second polarizer.

18. The imaging system of claim 17, further comprising:

memory;

a display;

one or more processors; and

one or more programs stored in the memory and configured for execution by the one or more processors, the one or more programs including;

instructions to rotate the second polarizer to a specified setting; and

instructions to use the photodetector to acquire an image of the subject with the second polarizer at the specified setting.

19. A method of generating a sub-surface skin image, comprising:

illuminating a subject with polarized light having a first polarization;

setting an adjustable polarizer to a first setting to admit light having the first polarization onto a photodetector and otherwise reject light;

with the adjustable polarizer in the first setting, using the photodetector to acquire a first image of the illuminated subject;

setting the adjustable polarizer to a second setting to at least partially reject light having the first polarization and to at least partially admit light having polarization distinct from the first polarization onto the photodetector;

with the adjustable polarizer in the second setting, using the photodetector to acquire a second image of the illuminated subject; and

subtracting the first image from the second image to generate a third image of the subject.

20. The method of claim 19, further comprising:

performing computerized analysis of the third image to determine a skin color of the subject; and

using the skin color to automatically select a recommended cosmetic product.

21. The method of claim 20, further comprising:

transmitting instructions to an automated cosmetic formulation system to produce the recommended cosmetic product.

22. The method of claim 19, further comprising:

performing computerized analysis of the third image to identify a skin feature in the third image; and

performing an automated comparison of the identified skin feature to a corresponding skin feature in a stored historical image.

23. The method of claim 19, further comprising:

calibrating the photodetector; and

correcting the first and second images in accordance with the calibration.

24. A computer-implemented method of processing and displaying images of skin, comprising:

receiving a first image of a subject, the first image having been acquired at an optical apparatus with the subject illuminated with light having a first polarization and the optical apparatus configured to receive light having the first polarization and to otherwise reject light;

receiving a second image of the subject, the second image having been acquired at the optical apparatus with the subject illuminated with light having the first polarization and the optical apparatus configured to at least partially reject light having the first polarization and to at least partially receive light having polarization distinct from the first polarization;

subtracting the first image from the second image to generate a third image of the subject; and

displaying the third image.

25. A system for processing and displaying images of skin, comprising:

memory;

a display;

one or more processors; and

one or more programs stored in the memory and configured for execution by the one or more processors, the one or more programs including;

instructions to receive a first image of a subject, the first image having been acquired at an optical apparatus with the subject illuminated with light having a first polarization and the optical apparatus configured to receive light having the first polarization and to otherwise reject light;

instructions to receive a second image of the subject, the second image having been acquired at the optical apparatus with the subject illuminated with light having the first polarization and the optical apparatus configured to at least partially reject light having the first polarization and to at least partially receive light having polarization distinct from the first polarization;

instructions to subtract the first image from the second image to generate a third image of the subject; and

instructions to display the third image.

26. A computer readable storage medium storing one or more programs configured to be executed by a computer system to process and display images of skin, the one or more programs comprising:

instructions to receive a first image of a subject, the first image having been acquired at an optical apparatus with the subject illuminated with light having a first polarization and the optical apparatus configured to receive light having the first polarization and to otherwise reject light;

instructions to receive a second image of the subject, the second image having been acquired at the optical apparatus with the subject illuminated with light having the first polarization and the optical apparatus configured to at least partially reject light having the first polarization and to at least partially receive light having polarization distinct from the first polarization;

instructions to subtract the first image from the second image to generate a third image of the subject; and

instructions to display the third image.