Apparatus and Method for Measuring Photodamage to Skin

• US 20080080755A1
• Filed: 09/28/2007
• Published: 04/03/2008
• Est. Priority Date: 10/02/2006
• Status: Active Grant

• Current Assignee: Johnson & Johnson Consumer Inc. (Johnson & Johnson)
• Original Assignee: Johnson & Johnson Consumer Companies Incorporated (Johnson & Johnson)
• Inventors: Cula, Gabriela, Kollias, Nikiforos, Payonk, Gregory
• Granted Patent: US 7,558,416 B2
• Time in Patent Office: Days
• US Class Current: 382/128
• 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: G01J 3/50 using electric radiation detectors

Abstract

An apparatus and method for assessing photodamage has a digital imaging system for recording blue light imagining and in particular the green signal response intensity of the skin of a person, which is indicative of elastotic material and photodamage. Because the image data has a numerical intensity value, which may be expressed in RGB or L*a*b* colorspace, the image data taken from one image can be numerically compared to that of one or more other images and the image data is amenable to numerical and statistical analysis. Comparison to population profiles/image data permits an individual'"'"'s image data to be characterized numerically, such as by a relative score or percentile rating. The image data can also be used to ascertain the degree of variation over a surface such as the face, with wider variation being indicative of greater photodamage.

Claims

1. A method for detecting photodamage to skin, comprising the steps of:

(A) exposing skin to light in the approximate wavelength range of 380 nm to 430 nm;

(B) measuring the green response.

2. The method of claim 1, wherein the green response is at least partially attributable to elastotic material beneath the outer surface of the skin.

3. The method of claim 2, further including the step of identifying a plurality of regions of interest on the skin imaged;

taking at least one image of a plurality of the regions of interest; and

comparing the resultant green response recorded in the images for the plurality of regions.

4. The method of claim 3, wherein variations of green response from region to region is interpreted as indicative of photodamage.

5. The method of claim 4, wherein the variation of green response from region to region is quantified by calculating the standard deviation thereof.

6. The method of claim 2, further including repeating steps (A) and (B) a plurality of times for skin of different persons who form a statistically significant group to establish a group model.

7. The method of claim 6, further comprising the steps of identifying a group model which is predictive for an individual and comparing the green response of the individual to the predictive group model.

8. The method of claim 7, wherein the relationship between the green response of the individual and the green response of the group model is expressed as a percentile rank.

9. The method of claim 6, wherein the persons are selected for inclusion in a group based upon at least one of the following:

race, skin pigmentation, geographic location of residence and extent of sun exposure.

10. The method of claim 6, further including the step of performing said steps (A) and (B) in a plurality of different seasons which have significantly different levels of solar radiation.

11. The method of claim 6, further including the steps of identifying a plurality of regions of interest on the skin, then for each person in the group, taking at least one image for each of the regions of interest and comparing the resultant green response stored in the images for the plurality of regions.

12. The method of claim 2, wherein the green response is recorded in image data and further including the step of converting an imaging colorspace to L*a*b* colorspace, and using the a* axis in measuring the green response.

13. The method of claim 2, further including the step of performing steps (A) and (B) a plurality of times yielding corresponding green responses, from which a trend in the person'"'"'s photodamage may be discerned.

14. The method of claim 13, wherein the trend may be used to assess the person'"'"'s response to treatment of the photodamage.

15. The method of claim 2, wherein the green response is recorded in digital imaging data and further including the step of isolating the green response of elastotic material from the green response of skin pigment.

16. The method of claim 15, wherein the step of isolation includes capturing images in white light and in blue light then normalizing image data from an image taken in white light and image data from an image taken in blue light, wherein the respective white and blue light images are of an area of skin having substantially the same pigment and elastotic material characteristics.

17. The method of claim 3, wherein at least one of the plurality of regions is selected to be a low horn, low porphyrin area.

18. The method of claim 17, wherein the at least one region is a area of skin on the cheek under the eye.

19. An apparatus for detecting photodamage to a person'"'"'s skin, comprises:

a digital camera;

a computer;

a source of light;

a filter passing light of 380 nm to 430 nm, said passed light usable for illuminating the person'"'"'s skin for generating a green response, said camera recording the green response in a plurality of pixel intensity values, said computer programmed to allow the green response attributable to skin pigment to be differentiated from the green response due to elastotic material.

20. A method for detecting photodamage to skin, comprising the steps of:

(A) selecting a plurality of persons on the basis of skin similarity;

(B) identifying a plurality of facial regions having different sun-exposure probability;

(C) for each of said plurality of persons, exposing each of the plurality of skin regions to light in the approximate wavelength range of 380 nm to 430 nm and capturing a plurality of digital images with a digital camera, each digital image having green response data;

(D) converting the green response data to a* equivalents in L*a*b* colorspace, said green response data being at least partially attributable to the elastotic material beneath the surface of the skin, the presence of elastotic material being indicative of photodamage;

(E) quantitatively analyzing the green response data to ascertain at least one of the mean of the green response data for all images and the standard deviation between regions for the plurality of persons;

(F) comparing at least one of the mean and the standard deviation of the green response data of an individual to the quantitatively analyzed green response data of Step (E) to show how the individual'"'"'s photodamage compares to that of the plurality of other persons, thereby giving a relative measure of photodamage.