Method and apparatus for quantifying tissue histology
Method of analysing at least one parameter of a body component is provided. The method includes illuminating the component or body with light of at least a first and second waveband, receiving light of at least said first and second wavebands remitted by the component at a photoreceptor or photoreceptors, and analysing the light received at the photoreceptor(s) to provide a ratio between the amount of light remitted of the first waveband and the amount of light remitted of the second waveband, and from this calculating the component parameter.
1. An apparatus for determining a distribution of chromophores and/or a thickness of structural layers in a sample of epithelial tissue, the apparatus comprising:
a polarized light source configured to illuminate said sample of epithelial tissue with polarized light having wavelengths falling within a first, second, and third predetermined wavebands;
a polarizing filter positioned so as to filter light remitted from said sample of epithelial tissue, said polarizing filter configured to filter out light polarized in a manner generated by said polarized light source;
an image generator configured to detect filtered remitted light from said sample of epithelial tissue and generate image data indicative of the intensity of filtered remitted light received by said image generator having wavelengths falling within said first, second and third predetermined wavebands;
a ratio determination module configured to process said image data generated by said image generator to determine for positions within images represented by said image data, a first ratio corresponding to a ratio of light received by said image generator having wavelengths within said second waveband relative to light having wavelengths within said first waveband, and a second ratio corresponding to a ratio of light received by said image generator having wavelengths within said third waveband relative to light having wavelengths within said first waveband;
a concentration determination module configured to determine for positions within said images represented by said image data by said image generator, concentrations of chromophores and/or the thickness of structural layers of said epithelial tissue at said positions in a sample of epithelial tissue represented by said image data utilizing said first and said second ratios determined for said positions by said ratio determination module; and
an output module configured to output data representing the determined concentrations of chromophores and/or thickness of structural layers for said positions of said sample of epithelial tissue as determined by said concentration determination module.
2. The apparatus in accordance with claim 1 wherein said image generator comprises a digital camera.
3. The apparatus in accordance with claim 1 wherein said first waveband comprises a waveband corresponding to red light.
4. The apparatus in accordance with claim 1 wherein said second waveband comprises a waveband corresponding to green light.
5. The apparatus in accordance with claim 1 wherein said third waveband comprises a waveband corresponding to blue light.
6. The apparatus in accordance with claim 1 wherein said first waveband comprises a waveband centered on a wavelength of 700 nm.
7. The apparatus in accordance with claim 1 wherein said second waveband comprises a waveband centered on a wavelength of 560 nm.
8. The apparatus in accordance with claim 1 wherein said third waveband comprises a waveband centered on a wavelength of 473 nm.
9. The apparatus in accordance with claim 1 wherein one of said first, second or third wavebands comprises infrared light.
10. The apparatus in accordance with claim 1 wherein said concentration determination module comprises a look up table associating pairs of said first and second ratios generated by said ratio determination module with items of data identifying concentrations of blood and melanin, wherein the blood and melanin when illuminated with polarized light are liable to remit cross polarized light having wavelengths falling within said first, second and third wavebands at said first and second ratios.
11. The apparatus in accordance with claim 10 wherein said pairs of first and second ratios and said concentrations of blood and melanin comprise ratios and concentrations determined by analyzing samples of epithelial tissue.
12. The apparatus in accordance with claim 10 wherein said pairs of first and second ratios and said concentrations of blood and melanin comprise ratios and concentrations determined utilizing a mathematical model of an expected remittance of illuminated light by said samples of epithelial tissue having differing concentrations of blood and melanin.
13. The apparatus in accordance with claim 1 wherein said concentration determination module is configured to determine values representative of concentrations of blood and melanin by applying a predetermined mathematical function to said first and second ratios for said positions as determined by said ratio determination module.
14. The apparatus in accordance with claim 1 wherein said concentration determination module comprises a look up table associating pairs of said first and second ratios generated by said ratio determination module with items of data identifying concentrations of blood and tissue thickness, wherein the blood and tissue thickness when illuminated with polarized light are liable to remit cross polarized light having wavelengths falling within said first, second and third wavebands at said first and second ratios.
15. The apparatus in accordance with claim 14 wherein said pairs of said first and second ratios and said concentrations of blood and tissue thickness comprise ratios and concentrations determined by analyzing said samples of epithelial tissue.
16. The apparatus in accordance with claim 14 wherein said pairs of first and second ratios and said concentrations of blood and melanin comprise ratios and concentrations determined utilizing a mathematical model of an expected remittance of illuminated light by said samples of epithelial tissue having differing concentrations of blood and tissue thickness.
17. The apparatus in accordance with claim 1 wherein said concentration determination module is configured to determine values representative of concentrations of blood and tissue thickness by applying a predetermined mathematical function to said first and second ratios for said positions as determined by said ratio determination module.
18. The apparatus in accordance with claim 1 wherein said polarized light source configured to illuminate said sample of epithelial tissue with polarized light comprises:
a light source; and
a polarizing filter arranged to polarize light generated by said light source.
19. The apparatus in accordance with claim 18 wherein said light source is configured to illuminate said sample of epithelial tissue sequentially with light having wavelengths falling within different ones of said first, second and third predetermined wavebands.