Method of and apparatus for investigating tissue histology

• US 20050251049A1
• Filed: 06/13/2005
• Published: 11/10/2005
• Est. Priority Date: 11/19/1996
• Status: Active Grant

• Current Assignee: MedX Health Corporation
• Original Assignee: Astron Clinica Ltd. (Boston Scientific Corporation)
• Inventors: Cane, Michael Roger, Cotton, Symon D'Oyly, Beadman, Michael Andrew
• Granted Patent: US 7,647,085 B2
• Time in Patent Office: Days
• US Class Current: 600/476
• 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 5/0075 by spectroscopy, i.e. measuring spectra, e.g. Raman spectroscopy, infrared absorption spectroscopy A61B5/0071 takes precedence
• CPC Class Codes: A61B 5/1072 measuring distances on the body, e.g. measuring length, height or thickness A61B5/1076 takes precedence
• CPC Class Codes: A61B 5/1075 for measuring dimensions by non-invasive methods, e.g. for determining thickness of tissue layer A61B8/0858 takes precedence
• CPC Class Codes: A61B 5/443 Evaluating skin constituents, e.g. elastin, melanin, water
• 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: G01N 21/314 with comparison of measurements at specific and non-specific wavelengths dual wavelength spectrometry G01J3/427
• CPC Class Codes: G01N 21/35 using infrared light G01N21/39 takes precedence
• CPC Class Codes: G01N 21/359 using near infrared light

Abstract

Apparatus for monitoring the presence of one or more chromophores in a tissue sample, comprises a light source for projecting light to illuminate an area of such tissue sample, a photo-receptor for receiving light remitted by the illuminated area of tissue, and spectroscopic analyser means for monitoring the remitted light, a comparator having means for comparing variations in the intensity and spectral characteristics of the remitted light with respect to the intensity and spectral characteristics of the projected light at different wavelengths and with a record of the intensity and spectral characteristics of light remitted by a reference sample of such tissue and means for emitting a control signal in response to any such variations. Methods of analyzing tissue histology, especially skin histology, are discussed, and a mathematical model is proposed for the analysis and comparison of the remitted light with a reference sample.

Claims

17-1. Apparatus according to claim 1, further comprising a light guide of which a least part is flexible provided for conducting light between said light source, said tissue sample and said photo-receptor.

18-2. Apparatus according to claim 17, wherein said light guide comprises an endoscope.

26. A method of monitoring the presence of individual chromophores in a sample of tissue, comprising:

storing records of the spectral characteristics of light re-emitted by reference samples of tissue of known structure containing identified chromophores;

illuminating an area of a tissue sample with different wavelengths of light using a light source;

receiving light re-emitted by the illuminated area of tissue at a photo-receptor;

comparing the spectral characteristics of re-emitted light received by said photo-receptor with said records to identify the record including spectral characteristics most closely matching the characteristics of said re-emitted light received by said photo-receptor; and

outputting as an identification of the individual chromophores present in the area of the illuminated tissue sample from which re-emitted light is received by said photo-receptor an identification of the chromophores associated with said spectral characteristics by said record.

27. A method according to claim 26, wherein said records comprise records of the spectral characteristics of light remitted by reference samples of epithelial or epithelial and sub-epithelial tissue.

28. A method according to claim 27, wherein said records comprise records of the spectral characteristics of light remitted by reference samples of skin.

29. A method according to claim 26, wherein said records comprise records of the spectral characteristics of light remitted by reference samples of normal healthy tissue.

30. A method according to claim 26, wherein said records comprise records of calculated estimated spectral characteristics of light re-emitted by samples of tissue containing identified chromophores.

31. A method according to claim 26, further comprising the steps of:

deriving data relating to the presence, depth, and concentration of chromophores; and

creating and displaying a map thereof.

32. A method according to claim 26, comprising:

deriving data relating to the presence, depth, and concentration of any chromophore selected from the group consisting of;

melanin, blood, hemoglobin, oxy-hemoglobin, bilirubin, tattoo pigments or dyestuffs, keratin, collagen and hair.

33. A method according to claim 26 which further comprising:

passing projected light and/or the remitted light through one or more filters and spectroscopically analyzing the remitted light such that the result of the analysis is independent of the presence of a predetermined chromophore in the tissue.

34. A method according to claim 33 wherein said light source and photo-receptor are arranged to project and detect light at wavelengths which are substantially unaffected by the presence of said predetermined chromophore.

35. A method according to claim 33 further comprising:

processing data indicative of the spectral characteristics of re-emitted light received by said photo-receptor to generate signals which are indicative of the presence of chromophores which are substantially independent of the variation in spectral characteristics arising due to the presence of said predetermined chromophores; and

comparing said processed data with said records to identify the record having the most closely corresponding spectral data.

36. A method according to claim 33 wherein said predetermined chromophore comprises a chromophore selected from melanin, blood and tattoo pigments.

37. A method according to claim 26, further comprising:

determining the depth of papillary dermis of a tissue sample being monitored on the basis of the spectral characteristics of said received re-emitted light; and

identifying the presence of individual chromophores within the area of the illuminated issue sample from which re-emitted light is received utilizing the spectral characteristics of said received re-emitted light and said determined depth of papillary dermis.