Method and apparatus for calibrating an optical probe

• US 5,902,246 A
• Filed: 03/21/1997
• Issued: 05/11/1999
• Est. Priority Date: 03/26/1996
• Status: Expired due to Fees

• Current Assignee: Lifespex, Inc.
• Original Assignee: Lifespex, Inc.
• Inventors: Schulze, Arthur E., McHenry, Peter
• Primary Examiner(s): Smith, Ruth S.
• Application Number:
  US08/823,044
• Time in Patent Office: 781 Days
• Field of Search: 600/310, 600/476, 600/477, 600/478, 356/39-42, 356/243, 250/458.1, 250/252.1
• US Class Current: 600/476
• CPC Class Codes: A61B 2560/0233 Optical standards
• CPC Class Codes: A61B 5/1459 invasive, e.g. introduced into the body by a catheter A61B5/1464 takes precedence
• CPC Class Codes: A61B 5/1495 Calibrating or testing of in-vivo probes

Abstract

An optical body cavity probe (110, 310, 1200, 1300) is provided with a disposable flexible comformable sheath (120) having an optical window (220), or a disposable rigid sheath (320, 1210, 1310) having an optical window (420). The electronic system includes optical sources for generating the illuminating electromagnetic energy, filters or spectrum analyzers for isolating returned wavelengths of interest, and a computer for processing the returned wavelengths of interest to determine the tissue properties of interest as well as to calibrate the system. For calibration purposes, a removable calibration body (510, 910, 1010, 1220, 1330, 1430) bearing a fluorescence pattern resides on the outside of the optical window (500, 900, 1000, 1210, 1310, 1420) so as to be in the field of view of the probe when the sheath is installed over the probe. The calibration body is maintained in contact with the optical window during a calibration sequence using an adhesive, an endcap, shrink wrap material, or other suitable means. After the system is calibrated, the calibration body is removed and discarded and the investigation is begun. Once the investigation is completed, the sheath containing the optical window is removed, if present, and discarded.

Claims

1. A self-calibrating autofluorescence tissue probe apparatus comprising:

an optical probe having a reusable section and a disposable section, the disposable section having an optical window that is transparent to optical energy at first and second wavelengths, the optical window being a rigid body;

a substrate coupled to the optical probe and removably disposed in a field of view of the optical window, the substrate being rigid and disposed against the optical window; and

a fluorescent material that is excitable by optical energy at the first wavelength to become fluorescent at the second wavelength, the fluorescent material being supported by the substrate in the field of view of the optical window;

wherein the optical window is a lens having a contoured external surface and the substrate has a contoured inside surface adjacent and matching the contoured external surface of the optical window.

2. A self-calibrating autofluorescence tissue probe apparatus comprising:

an optical probe having a reusable section and a disposable section, the disposable section having an optical window that is transparent to optical energy at first and second wavelengths and comprising a flexible sheath comformable with at least a portion of the reusable section of the optical probe, the optical window being a rigid optical body integral with the flexible sheath and the substrate being disposed on the rigid optical body;

a substrate coupled to the optical probe and removably disposed in a field of view of the optical window; and

a fluorescent material that is excitable by optical energy at the first wavelength to become fluorescent at the second wavelength, the fluorescent material being supported by the substrate in the field of view of the optical window.

3. A self-calibrating autofluorescence tissue probe apparatus comprising:

an optical probe having a reusable section and a disposable section, the reusable section of the optical probe comprising a rigid optical window at a distal end thereof, and the disposable section having an optical window that is transparent to optical energy at first and second wavelengths and comprising a flexible sheath comformable with at least a portion of the reusable section of the optical probe, the optical window being integral with the sheath and having a first surface and a second surface opposing the first surface, the first surface being disposed against the rigid optical window of the reusable section of the optical probe and the substrate being disposed on the second surface;

a substrate coupled to the optical probe and removably disposed in a field of view of the optical window; and

a fluorescent material that is excitable by optical energy at the first wavelength to become fluorescent at the second wavelength, the fluorescent material being supported by the substrate in the field of view of the optical window.

4. A self-calibrating autofluorescence tissue probe apparatus comprising:

an optical probe having a reusable section and a disposable section, the disposable section having an optical window that is transparent to optical energy at first and second wavelengths and comprising a rigid sheath in removable engagement with at least a portion of the reusable section of the optical probe, the optical window being a rigid optical body integral with the sheath and the substrate being disposed on the rigid optical body;

a substrate coupled to the optical probe and removably disposed in a field of view of the optical window; and

a fluorescent material that is excitable by optical energy at the first wavelength to become fluorescent at the second wavelength, the fluorescent material being supported by the substrate in the field of view of the optical window.

5. A self-calibrating autofluorescence tissue probe apparatus comprising:

an optical probe having a reusable section and a disposable section, the reusable section of the optical probe comprising a rigid optical window at a distal end thereof, and the disposable section having an optical window that is transparent to optical energy at first and second wavelengths and comprising a rigid sheath in removable engagement with at least a portion of the reusable section of the optical probe, the optical window being integral with the sheath and having a first surface and a second surface opposing the first surface, the first surface being disposed against the rigid optical window of the reusable section of the optical probe and the substrate being disposed on the second surface;

a substrate coupled to the optical probe and removably disposed in a field of view of the optical window; and

a fluorescent material that is excitable by optical energy at the first wavelength to become fluorescent at the second wavelength, the fluorescent material being supported by the substrate in the field of view of the optical window.

6. A self-calibrating autofluorescence tissue probe apparatus comprising:

an optical probe having a reusable section and a disposable section, the disposable section having an optical window that is transparent to optical energy at first and second wavelengths;

a substrate coupled to the optical probe and removably disposed in a field of view of the optical window;

an optical mask disposed about the substrate and the optical window; and

a fluorescent material that is excitable by optical energy at the first wavelength to become fluorescent at the second wavelength, the fluorescent material being supported by the substrate in the field of view of the optical window.

7. A self-calibrating autofluorescence cervical tissue probe comprising:

a generally cylindrical elongated optical probe having an optical window at one end that is transparent to optical energy at plural illuminating wavelengths and at plural return wavelengths;

a generally circular substrate coupled to the optical probe and removably disposed in a field of view of the optical window;

fluorescent material that is excitable by optical energy at the illuminating wavelengths to become fluorescent at the return wavelengths, the fluorescent material being supported by the substrate in a field of view of the optical window;

a single-use material supported by the substrate in the field of view of the optical window; and

an optical mask disposed about the substrate and the optical window.

8. An apparatus as in claim 7 wherein the fluorescent material comprises fluorescent microspheres disposed on the substrate.

9. An apparatus as in claim 8 wherein the fluorescent microspheres are coated with a variety of fluorophores having respective excitation wavelengths.

10. An apparatus as in claim 7 wherein the fluorescent material comprises a fluorescent dye that is disposed on the substrate.

11. An apparatus as in claim 7 wherein the fluorescent material comprises a mixture of fluorescent dyes that are disposed on the substrate and have respective excitation wavelengths.

12. A method for calibrating a tissue analysis system that includes an optical probe having an optical window transparent to a return wavelength, the optical window having a field of view, the method comprising:

positioning a calibration body in the field of view of the optical window;

illuminating the calibration body at an illuminating wavelength to excite material distributed in the calibration body, the excited material emitting energy at a return wavelength in a predetermined pattern across a region of the calibration body;

detecting the energy at the return wavelength through the optical window in accordance with a set of scaling factors;

deciding whether the predetermined pattern is present from the energy detected in the detecting step; and

in the event that the predetermined pattern is found to be not present in the deciding step, adjusting the set of scaling factors and repeating the illuminating, detecting, and deciding steps.

13. A method as in claim 12 wherein the illuminating step is performed through the optical window, the optical window being transparent to the illuminating wavelength.

14. A method as in claim 12 further comprising the step of indicating a defect in the event that the predetermined pattern is found to be not present in the deciding step after a predetermined number of repetitions of the deciding step.

15. A method for calibrating a tissue analysis system that includes an optical probe having an optical window transparent to first and second sets of return wavelengths, the optical window having a field of view, the method comprising:

positioning a calibration body in the field of view of the optical window;

illuminating the calibration body at a first illuminating wavelength to excite material distributed in the calibration body, the excited materials emitting energy at the first set of return wavelengths in a first predetermined pattern across a region of the calibration body;

illuminating the calibration body through the optical window at a second illuminating wavelength to excite material distributed in the calibration body, the excited material emitting energy at the second set of return wavelengths in a second predetermined pattern across a region of the calibration body;

detecting the energy at the first and second sets of return wavelength through the optical window in accordance with, respectively, first and second sets of scaling factors;

deciding whether the first and second predetermined patterns are present from the energy detected in the detecting step; and

in the event that the predetermined pattern is found to be not present in the deciding step, adjusting the first and second sets of scaling factors and repeating the illuminating, detecting, and deciding steps.

16. A method as in claim 15 wherein the illuminating step is performed through the optical window, the optical window being transparent to the first and second illuminating wavelengths.

17. A method as in claim 15 further comprising the step of indicating a defect in the event that any one of the first and second predetermined patterns is found to be not present in the deciding step after a predetermined number of repetitions of the deciding step.

18. A method for calibrating a tissue analysis system that includes an optical probe having an optical window transparent to a return wavelength, the optical window having a field of view, the method comprising:

positioning a calibration body in the field of view of the optical window;

applying optical energy to the calibration body, the optical energy interacting with material distributed in the calibration body to return energy at a return wavelength in a predetermined pattern across a region of the calibration body;

detecting the energy at the return wavelength through the optical window in accordance with a set of scaling factors;

deciding whether the predetermined pattern is present from the energy detected in the detecting step; and

in the event that the predetermined pattern is found to be not present in the deciding step, adjusting the set of scaling factors and repeating the applying, detecting, and deciding steps.

19. A method as in claim 18 wherein the applying step is performed through the optical window.

20. A method as in claim 18 further comprising the step of indicating a defect in the event that the predetermined pattern is found to be not present in the deciding step after a predetermined number of repetitions of the deciding step.

21. A disposable sheath for use with a reusable optical body cavity probe section, comprising:

an elongated member of a length and cross-section suitable for insertion into the body cavity;

an optical window having a field of view disposed in the elongated member, the optical window comprising a rigid lens; and

a body removably disposed in the field of view of the optical window and containing fluorescent material distributed in a predetermined pattern across a region of the body, the fluorescent material being excitable by optical energy at a first wavelength to become fluorescent at a second wavelength in a predetermined pattern across the body region.

22. A disposable sheath for use with a reusable optical body cavity probe section, comprising:

an elongated member of a length and cross-section suitable for insertion into the body cavity;

an optical window having a field of view disposed in the elongated member, the optical window comprising a flexible optical body; and

a body removably disposed in the field of view of the optical window and containing fluorescent material distributed in a predetermined pattern across a region of the body, the fluorescent material being excitable by optical energy at a first wavelength to become fluorescent at a second wavelength in a predetermined pattern across the body region.

23. A disposable sheath for use with a reusable optical body cavity probe section, comprising:

an elongated member of a length and cross-section suitable for insertion into the body cavity, the elongated member comprising a flexible sheath;

an optical window having a field of view disposed in the elongated member; and

a body removably disposed in the field of view of the optical window and containing fluorescent material distributed in a predetermined pattern across a region of the body, the fluorescent material being excitable by optical energy at a first wavelength to become fluorescent at a second wavelength in a predetermined pattern across the body region.

24. A disposable sheath for use with a reusable optical body cavity probe section, comprising:

an elongated member of a length and cross-section suitable for insertion into the body cavity;

an optical window having a field of view disposed in the elongated member; and

a body removably disposed in the field of view of the optical window and containing fluorescent material distributed in a predetermined pattern across a region of the body, the fluorescent material being excitable by optical energy at a first wavelength to become fluorescent at a second wavelength in a predetermined pattern across the body region;

wherein the elongated member is elongated along a major axis and the optical window passes optical energy in a direction generally transverse to the major axis of the elongated member.