Method and apparatus for detecting Barrett's metaplasia of the esophagus

• US 6,035,229 A
• Filed: 06/17/1997
• Issued: 03/07/2000
• Est. Priority Date: 07/14/1994
• Status: Expired due to Fees

• Current Assignee: Washington Research Foundation (University of Washington)
• Original Assignee: Washington Research Foundation (University of Washington)
• Inventors: Myers, John A., Taniguchi, Darik, Martin, Roy W., Silverstein, Fred E.
• Primary Examiner(s): Nasser, Robert L.
• Application Number:
  US08/878,227
• Time in Patent Office: 994 Days
• Field of Search: 600/473-478, 600/117, 600/341-3
• US Class Current: 600/473
• CPC Class Codes: A61B 1/00009 of image signals during a use of endoscope
• CPC Class Codes: A61B 1/00082 Balloons
• CPC Class Codes: A61B 1/00165 with light-conductive means, e.g. fibre optics A61B1/07 takes precedence
• CPC Class Codes: A61B 1/0607 for annular illumination
• CPC Class Codes: A61B 1/0638 providing two or more wavelengths
• CPC Class Codes: A61B 1/07 using light-conductive means, e.g. optical fibres
• CPC Class Codes: A61B 1/2733 Oesophagoscopes
• 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 5/0084 for introduction into the body, e.g. by catheters A61B5/1459 takes precedence
• CPC Class Codes: A61B 5/4233 oesophagus

Abstract

A system for detecting Barrett'"'"'s metaplasia utilizes an illumination and imaging probe at the end of a catheter. The probe illuminates the wall of the esophagus and returns reflected light to be processed to provide a visual indication of the color of the esophageal wall. The position of the probe along the length of the esophagus is also measured to allow a medical practitioner to determine the location of the transition from the pink stomach lining to the white esophageal lining.

Claims

1. A system for use in detecting Barrett'"'"'s metaplasia of the esophagus, comprising:

a flexible catheter;

a probe mounted at a distal end of said flexible catheter, said probe having an illuminator and a light receiving device each of which are directed radially outwardly to illuminate the wall of an esophagus into which said probe has been inserted and receive light from the esophageal wall;

a position measuring device measuring the position of said probe along the length of said esophagus; and

a light sensing device coupled to said light receiving device, said light sensing device providing an indication of the color of the esophageal wall whereby Barrett'"'"'s metaplasia of the esophagus can be detected based on a colorimetric change in the esophagus as sensed through said sensing device at a location along the length of the esophageal wall indicated by said position measuring device.

2. The system of claim 1 wherein said light from said illuminator is free of any significant red components.

3. The system of claim 2 wherein said light from said illuminator is green.

4. The system of claim 2 wherein said light from said illuminator is blue.

5. The system of claim 1 wherein said light from said illuminator is red, blue, and green.

6. The system of claim 1 wherein said illuminator and said light receiving device are each directed radially outward in a plurality of directions to illuminate said esophageal wall and receive light from a plurality of circumferential locations on said esophageal wall.

7. The system of claim 6 wherein said illuminator comprises a first fiber optic waveguide extending through said catheter from a proximal end of said catheter to a light opening in said probe, and a light source external to said catheter directing illuminating light into said fiber optic waveguide.

8. The system of claim 7 wherein said light receiving device comprises a second fiber optic waveguide extending from an image port in said probe to a viewing device at the proximal end of said catheter, said viewing device providing an output signal indicative of a characteristic of said light.

9. The system of claim 8 wherein said viewing device includes a filter receiving said light from said second fiber optic waveguide, and a light detector positioned adjacent said filter to receive light passing therethrough, said light detector generating said output signal as a function of the amplitude of light received by said light detector so that said output signal is indicative of the intensity of light corresponding to the wavelength of said filter.

10. The system of claim 8 wherein said light receiving device receives light from a limited range of radial directions at the same time, and wherein said catheter further includes a hollow flexible drive cable surrounding said first fiber optic waveguide, and wherein said system further includes scan means for rotating the proximal end of said drive cable so that said probe is rotated about the longitudinal axis of said catheter to scan an esophagus into which said probe has been inserted.

11. The system of claim 10 wherein said probe further includes a flexible transparent balloon surrounding said probe, and wherein said catheter further includes an outer sheath loosely surrounding said drive cable to form a lumen between said drive cable and sheath, said lumen communicating with the interior of said balloon so that said balloon can be inflated by injecting pressurized fluid into the proximal end of said lumen.

12. The system of claim 10 wherein said scan means comprise a motor mechanically coupled to said drive cable, and a rotary encoder to provide an indication of the rotational position of said probe.

13. The system of claim 1 wherein said position measuring device comprises a wheel having its periphery frictionally engaging said catheter, said wheel being positioned with the rotational axis of said wheel perpendicular to the longitudinal axis of said catheter so that said wheel rotates responsive to axial movement of said catheter, and a rotary encoder coupled to Said wheel to provide a signal indicative of the axial position of said catheter.

14. The system of claim 1 wherein said sensing device comprises a visual display coupled to said probe and said position measuring device, said visual display providing a visual image of said esophageal wall.

15. The system of claim 14 whereing said visual display shows the length of said esophageal wall along one axis of a visual display screen, and the circumference of said esophageal wall along an orthagonal axis of said visual display screen.

16. A system for use in detecting Barrett'"'"'s metaplasia of the esophagus, comprising:

a flexible catheter;

a probe mounted at a distal end of the flexible catheter, the probe having an illuminator and a light-receiving device each of which are directed radially outwardly to illuminate the wall of an esophagus into which the probe has been inserted and receive light from the esophageal wall, the probe further including a flexible transparent balloon surrounding the probe, and wherein the catheter further includes a fluid passage communicating with the interior of the balloon so that the balloon can be inflated by injecting pressurized fluid into the fluid passage at a proximal end thereof,

a position-measuring device measuring the position of the probe along the length of the esophagus; and

a light-sensing device coupled to the light-receiving device, the light-sensing device providing an indication of the color of the esophageal wall whereby Barrett'"'"'s metaplasia of the esophagus can be detected based on a colorimetric change in the esophagus as sensed through the sensing device at a location along the length of the esophageal wall indicated by the position-measuring device.

17. A system for use in detecting Barrett'"'"'s metaplasia of the esophagus, comprising:

a flexible catheter;

a probe mounted at a distal end of the flexible catheter, the probe having an illuminator and a light-receiving device each of which are directed radially outwardly to illuminate the wall of an esophagus into which the probe has been inserted and receive light from the esophageal wall;

a position-measuring device measuring the position of the probe along the length of the esophagus, the position-measuring device comprising a magnetic field generator adapted to be mounted at a stationery position relative to the position of the esophagus, and a magnetic field sensor mounted on the catheter so that the relative position between the magnetic field generator and the magnetic field sensor corresponds to the position of the probe along the length of an esophagus into which the probe has been inserted; and

a light-sensing device coupled to the light-receiving device, the light sensing device providing an indication of the color of the esophageal wall whereby Barrett'"'"'s metaplasia of the esophagus can be detected based on a calorimetric change in the esophagus as sensed through the sensing device at a location along the length of the esophageal wall indicated by the position-measuring device.