Method and apparatus for detection of caries
View Patent ↗A method for obtaining an image of tooth tissue directs incident light toward a tooth, wherein the incident light excites a fluorescent emission from the tooth tissue. Fluorescence image data is obtained from the fluorescent emission. Back-scattered reflectance image data is obtained from back-scattered light from the tooth tissue. The fluorescence and back-scattered reflectance image data are combined to form an enhanced image of the tooth tissue for caries detection.
1. A method for detection of caries of a tooth comprising:
directing incident light toward the tooth, wherein the incident light excites a fluorescent emission from the tooth;
capturing an image of the tooth with a camera wherein
fluorescence image data is captured on a first color plane of the image; and
back-scattered reflectance image data is captured on a second color plane of the image; and
subtracting, by a processor, a portion of the back-scatter reflectance image data captured in the second color plane from a portion of the fluorescence image data captured in the first color plane to form an enhanced image of the tooth.
2. The method of claim 1 further comprising applying a thresholding operation to the enhanced image of the tooth.
3. The method of claim 1 wherein the first color plane of the image is a green color plane.
4. The method of claim 1 wherein the second color plane of the image is a blue color plane.
5. The method of claim 1 wherein capturing the image further comprises switching one or more spectral filters into position to filter light from the tooth.
6. The method of claim 1 wherein capturing the back-scattered reflectance image data comprises using a polarizer.
7. The method of claim 1 wherein capturing the back-scattered reflectance image data comprises using a wire grid polarizer or a wire grid polarizing beamsplitter.
8. The method of claim 1 wherein capturing the back-scattered reflectance image data comprises using a polarizer and an analyzer.
9. The method of claim 1 wherein directing incident light comprises using multiple light sources.
10. The method of claim 1 wherein the fluorescence image data and the back-scattered reflectance image data are captured in a single exposure.
11. The method of claim 1 wherein the incident light is provided through an optical fiber or fiber array.
12. The method of claim 1 wherein the incident light is provided from a laser or light-emitting diode source.
13. The method of claim 1 wherein directing incident light further comprises directing light through a diffuser.
14. The method of claim 1 , the method further comprising:
multiplying at least one of the fluorescence image data and reflectance image data by a scalar coefficient.
15. The method of claim 1 wherein directing the incident light comprises directing light toward a polarization beamsplitter.
16. A method for detection of caries of a tooth, comprising:
directing incident light toward the tooth, wherein the incident light excites a fluorescent emission from the tooth;
capturing an image of the tooth with a camera wherein fluorescence image data is captured on a first color plane of the image, and back-scattered reflectance image data is captured on a second color plane of the image; and
combining, by a processor, a portion of the back-scatter reflectance image data captured in the second color plane and a portion of the fluorescence image data captured in the first color plane to form an enhanced image of the tooth, wherein the combining comprises:
multiplying at least one pixel value in the fluorescence image data by a first coefficient to form a first value;
multiplying at least one pixel value in the back-scatter reflectance image data by a second coefficient to form a second value; and
subtracting the second value from the first value.