Device for the detection and characterization of biological tissue

• US 7,613,505 B2
• Filed: 07/28/2004
• Issued: 11/03/2009
• Est. Priority Date: 07/28/2003
• Status: Active Grant

• Current Assignee: Sopro
• Original Assignee: Sopro
• Inventors: Mazuir, Alain, Dieras, Francis
• Primary Examiner(s): Winakur; Eric F
• Assistant Examiner(s): Fernandez; Katherine L
• Application Number:
  US10/565,589
• Publication Number:
  US 20060227216A1
• Time in Patent Office: 1,924 Days
• Field of Search: 607/91, 348/207.99, 600/437, 600/473, 600/476
• US Class Current: 600/476
• CPC Class Codes: A61B 5/0088 for oral or dental tissue
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/10024 Color image
• CPC Class Codes: G06T 2207/30036 Dental; Teeth
• CPC Class Codes: G06T 5/10 using non-spatial domain filtering
• CPC Class Codes: G06T 5/94 based on local image properties, e.g. for local contrast enhancement
• CPC Class Codes: G06T 7/0012 Biomedical image inspection
• CPC Class Codes: G06T 7/42 using transform domain methods

Abstract

Method for detection and location of a difference in density and/or structure and/or chemical composition of a biological tissue (7) which is subjected to continuous illumination in a first determined band of frequencies, causing the former to generate a phenomenon of fluorescence, autofluorescence or luminescence in a second band of frequencies. The method includes the following stages: the biological tissue thus illuminated is visually captured by color video elements provided with image sensors with a mosaic of pixels provided with additional color filters; for each image point thus obtained 1) information relating to the energy received by each pixel is collected in order to reconstitute an image of the biological tissue (7), b) amplification occurs for the signal corresponding to the energy received in the second frequency band in order to characterize the biological tissue (7) difference or to cause the image thus obtained to appear.

Claims

1. A method for detecting and locating the difference in density and/or structure and/or chemical composition of a biological tissue which is subjected to continuous illumination in a first determined band of frequencies, able to cause the tissue to generate a phenomenon of fluorescence, autofluorescence or luminescence in a second band of frequencies, comprising:

capturing an image of the biological tissue illuminated in this way, using colour video means provided with image sensors with a mosaic of pixels provided with filters of complementary colours, the filters having a greater range of reaction compared to filters of primary colours,

for each point of the image so obtained;

a) collecting data related to the energy received by each pixel, so as to reconstitute the image of the biological tissue, and

b) amplifying, pixel by pixel, the signal corresponding to the energy received in the second band of frequencies so as to characterize the said difference of the biological tissue in the image obtained, by acting on signals as received by at least two neighbouring pixels provided with filters of different colours, an amount of amplification of the signal corresponding to the energy received in the second band of frequencies by said at least two neighbouring pixels.

2. The method as claimed in claim 1, wherein the data collected in the second band of frequencies is processed so as to characterize the structure difference obtained in a colour other than the colour naturally corresponding to this second zone of frequencies.

3. The method as claimed in claim 2, wherein radiations are added to the band of frequencies of the illumination spectrum that are able to modify the fluorescence spectrum to shift the fluorescence band of parasite fluorescence.

4. The method as claimed in claim 1, wherein radiations are added to a band of frequencies of the illumination spectrum that are able to modify the fluorescence spectrum to shift a fluorescence band of parasite fluorescence.

5. The method as claimed in claim 1, wherein said complementary colours are cyan, magenta and yellow.

6. The method as claimed in claim 1, wherein said mosaic of pixels is further provided with a green filter.

7. The method as claimed in claim 6, wherein said tissue is a tooth and the fluorescence of deteriorated parts being in the red, for each point of the image, said amplification is realized by acting on signals as received by at least two corresponding neighbouring pixels provided with filters of different colours, said amplification comprising amplifying the energy received by a corresponding yellow pixel when said corresponding neighbouring pixels provided with filters of yellow and green are such that the yellow pixel receives energy while the green pixel does not receive energy, and in not amplifying the energy received by the corresponding yellow pixel when said corresponding neighbouring pixels provided with filters of yellow and green are such that the yellow pixel receives energy while the green pixel is saturated.

8. The method as claimed in claim 1, wherein said first band of frequencies includes a visible part, for each point of the image, said data related to the energy received by each pixel collected so as to reconstitute the image of the biological tissue, are derived from illumination in visible light and from fluorescence produced by said tissue.

9. The method as claimed in claim 1, wherein while translating data for display of each point of the image on a RGB video monitor, said amplifying is realized by providing each red, blue, or green components of at least one point of the image, in addition with data collected so as to reconstitute the image of the biological tissue with a sum of amplified energy as received by at least two neighbouring pixels provided with filters of different colours.

10. The method as claimed in claim 9, wherein said tissue is a tooth and the fluorescence of deteriorated parts being in the red, for each point of the image, said amplification is realized by acting on signals as received by at least two corresponding neighbouring pixels provided with filters of different colours, said amplification comprising amplifying the energy received by a corresponding yellow pixel when said corresponding neighbouring pixels provided with filters of yellow and green are such that the yellow pixel receives energy while the green pixel does not receive energy, and in not amplifying the energy received by the corresponding yellow pixel when said corresponding neighbouring pixels provided with filters of yellow and green are such that the yellow pixel receives energy while the green pixel is saturated.

11. The method as claimed in claim 1, wherein the action on signals as received by at least two neighbouring pixels provided with filters of different colours is realized with consultation of the energy received on another neighbouring pixel.

12. A device for detecting and locating the difference in density and/or structure and/or chemical composition of a biological tissue, comprising:

means able to illuminate the biological tissue continuously with a light located in a first determined band of frequencies, so as to cause the tissue to generate a phenomenon of fluorescence in a second band of frequencies,

colour video means provided with image sensors with a mosaic of pixels provided with filters of complementary colours, the filters having a greater range of reaction compared to filters of primary colours,

capture and calculation means which, for each point of the image so obtained, are able to collect data related to the energy received by each pixel so as to reconstitute the image of the biological tissue, and

means for amplifying, pixel by pixel, the signal corresponding to the energy received in the second band of frequencies so as to characterize said difference of the biological tissue in the image obtained, by acting on at least two neighbouring signals as received by at least two pixels provided with filters of different colours, an amount of amplification of the signal corresponding to the energy received in the second band of frequencies by said at least two neighbouring pixels.

13. The device as claimed in claim 12, wherein the device further comprises processing means to process data collected in the second band of frequencies, so as to characterize the structure difference obtained in a colour other than the colour naturally corresponding to this second zone of frequencies.

14. The device as claimed in claim 12, wherein the act on signals as received by at least two neighbouring pixels provided with filters of different colours is realized with consultation of the energy received on another neighbouring pixel.