Fiber optic multitasking probe

• US 6,514,277 B1
• Filed: 06/11/1999
• Issued: 02/04/2003
• Est. Priority Date: 06/11/1999
• Status: Expired due to Fees

• Current Assignee: Photonics Research Ontario
• Original Assignee: Photonics Research Ontario
• Inventors: Walsh, David, Lilge, Lothar
• Primary Examiner(s): Shay, David M.
• Application Number:
  US09/329,998
• Time in Patent Office: 1,334 Days
• Field of Search: 606/7, 606/10-18, 600/310-344, 600/407, 600/473-476, 600/478, 607/88, 607/89, 422/82.05, 422/82.08, 422/82.11
• US Class Current: 607/88
• CPC Class Codes: A61N 5/0601 Apparatus for use inside the body
• CPC Class Codes: A61N 5/062 Photodynamic therapy, i.e. excitation of an agent
• CPC Class Codes: G01N 21/6428 Measuring fluorescence of fluorescent products of reactions or of fluorochrome labelled reactive substances, e.g. measuring quenching effects, using measuring "optrodes" in vivo A61B5/00; immunoassay G01N33/53
• CPC Class Codes: G01N 21/7703 using reagent-clad optical fibres or optical waveguides using measurement of total internal reflection or attenuated total reflection G01N21/552; optical fibres or waveguides per se G02B
• CPC Class Codes: G01N 2201/0846 Fibre interface with sample, e.g. for spatial resolution
• CPC Class Codes: G01N 2201/088 Using a sensor fibre

Abstract

A multitasking optical fiber probe for collecting dosimeter information from more than one position in a sample. The basic principle of the present invention involves using one or more different sensor zones along the length of the fiber each with a different photoactive constituent having a sufficiently unique emission spectra (spectral or temporal) to enable deconvolution of the emission spectra by the computer and therefore correlation of the detected parameter with the position of the sensor zone along the length of the optical fiber. In the broadest form of the invention the probe is embodied by only one sensor zone located at some point along the length of the fiber spaced away from the end face of the fiber. Probes are provided in which multiple sensor zones are disposed along the length of the fiber and photoactive constituents with sufficiently unique emission spectra (intensity and/or spectral shape which convey the optical information) are used in the different sensor zones so that the different spectra can be deconvoluted so that the contributions from the various etch zones can be distinguished. More than one different photoactive constituent could be incorporated into a single sensor zone for measuring several factors in the vicinity of the sensor zone. In photodynamic therapy applications the probe is isotropic in response and can be employed for all light (300 to 900nm) based medical diagnostics and therapeutics. As an extension the probe can include photosensitiser and molecular oxygen concentrations dosimetry to be used for photodynamic therapy (PDT) treatment monitoring, dosimetry and planning utilizing a mathematical model describing tissue response to PDT.

Claims

1. An optical fiber probe apparatus for measuring dosimetric parameters, comprising;

an optical fiber including at least two sensor zones spaced along a length of said optical fiber, each sensor zone including an effective photoactive constituent having an emission spectrum distinguishable in time domain or spectral domain from emission spectra of photoactive constituents in all other sensor zones, each photoactive constituent emitting light responsive to preselected factors external to the optical fiber interacting with said photoactive constituent with some of the light emitted by each photoactive constituent being coupled into said optical fiber.

2. The optical fiber probe apparatus according to claim 1 wherein the sensor zones are defined by diffusing the photoactive constituent into the optical fiber at spaced locations along the length of the optical fiber.

3. The optical fiber probe apparatus according to claim 1 including an optical controller, wherein a proximal end portion of the optical fiber is connected to said optical controller, said sensor zones being spaced from a distal end portion of the optical fiber, and wherein said optical controller includes a spectrophotometer means optically coupled to said optical fiber, said spectrophotometer means being connected to processing means for deconvoluting emission spectrum from the photoactive constituent in each of said at least two sensor zones to measure said dosimetric parameters along the length of the fiber.

4. The optical fiber probe apparatus according to claim 3 wherein said optical controller includes an effective light source for excitation of photoactive constituents comprising photoluminescent phosphor compounds.

5. The optical fiber probe apparatus according to claim 4 including computer control means connected to the spectrophotometer means and the light source for controlling the spectrophotometer means and an output of the light source and for deconvoluting the emission spectra from the photoactive constituents in each sensor zone and for analyzing light coupled into said optical fiber from a distal end face thereof.

6. The optical fiber probe apparatus according to claim 5 wherein the optical fiber probe is produced from a physiologically compatible material for insertion into mammalian tissue, wherein the computer control means deconvolutes optical data transmitted from the sensor zones to obtain dosimetric parameters in a mammalian tissue along the length of the optical fiber probe.

7. The optical fiber probe apparatus according to claim 6 wherein the dosimetric parameters include

fluence rates calculated from emission spectra from the sensor zones in which the photoactive constituent is a fluorophore,

pO₂ calculated from emission spectra from the sensor zones in which the photoactive constituent is a photoluminescent phosphor, and

photosensitizer concentration calculated from fluorescence radiation incident on said distal end face emitted by photosensitizers.

8. The optical fiber probe apparatus according to claim 1 wherein the photoactive constituent in the at least one sensor zone is selected from the group consisting of fluorophore compounds each having a fluorescent emission spectrum, photoluminescent phosphor compounds each having a phosphorescent emission spectrum, chemiluminescent compounds each having a chemiluminescent emission spectrum, scintillator compounds each having a scintillator emission spectrum, and any combination thereof.

9. The optical fiber probe apparatus according to claim 8 wherein said preselected factors are selected from the group consisting of radiation incident on said photoactive constituent in preselected wavelength bands and preselected molecules present in a volume adjacent to each sensor zone.

10. The optical fiber probe apparatus according to claim 9 wherein the photoactive constituents in the two or more sensor zones are each selected from the group consisting of fluorophore compounds each having a fluorescent emission spectrum, photoluminescent phosphor compounds each having a phosphorescent emission spectrum, chemiluminescent compound compounds each having a chemiluminescent emission spectrum, scintillator compounds each having a scintillator emission spectrum, and any combination thereof.

11. The optical fiber probe apparatus according to claim 10 wherein the photoactive constituent in at least some of the sensor zones includes a preselected quantity of an effective fluorophore compound, wherein the fluorophore compound in each sensor zone has a fluorescence spectrum different from the fluorescence spectra of the fluorophore compounds in the other sensor zones.

12. The optical fiber probe apparatus according to claim 11 wherein the photoactive constituent in at least some of the sensor zones includes a preselected quantity of an effective photoluminescent phosphor compound, wherein the photoluminescent phosphor compound in each sensor zone has a phosphorescence lifetime different from the phosphorescence lifetimes of the photoluminescent phosphor compounds in the other sensor zones, and wherein the spectrophotometer includes an effective light source for activating excitation of photoactive constituents comprising photoluminescent phosphor compounds.

13. The optical fiber probe apparatus according to claim 12 wherein the sensor zones are defined by spaced circumferential slots formed in an outer cladding of said optical fiber, the photoactive constituents being contained in said slots.

14. A device for photodynamic therapy, comprising:

an elongate isotropic light source for emitting light for photodynamic therapy, the isotropic light source having a length and opposed ends;

a multitasking optical fiber probe adjacent to said elongate isotropic light source, the multitasking optical fiber probe including an elongate optical fiber with a plurality of sensor zones spaced along a length thereof, each sensor zone including an effective photoactive constituent having an emission spectrum distinguishable in time domain or spectral domain from emission spectra of photoactive constituents in all other sensor zones, each photoactive constituent emitting light responsive to said photoactive constituent interacting with preselected factors, the optical fiber having a length longer than the isotropic light source and extending beyond the opposed ends of said isotropic light source;

computer control means for controlling the isotropic light source and calculating preselected dosimetric parameters along the length of said optical fiber from light transmitted along said optical fiber probe.

15. The device according to claim 14 wherein the photoactive constituents in each of the plurality of sensor zones are selected from the group consisting of fluorophore compounds each having a fluorescent emission spectrum, photoluminescent phosphor compounds each having a phosphorescent emission spectrum, and any combination thereof.

16. The device according to claim 15 wherein the optical fiber has a distal end face adapted to couple said optical fiber to radiation incident on said distal end face.

17. The device according to claim 16 wherein the dosimetric parameters include

fluence rates calculated from emission spectra from the sensor zones in which the photoactive constituent is a fluorophore,

pO₂ calculated from emission spectra from the sensor zones in which the photoactive constituent is a photoluminescent phosphor, and

photosensitizer concentration calculated from fluorescence radiation incident on said distal end face emitted by photosensitizers.

18. The device according to claim 16 including at least two multitasking optical fiber probes, one being located on one side and extending beyond one of said opposed ends of the isotropic light source and the other being located on another side of the isotropic light source and extending beyond the other opposed end of the isotropic light source.

19. A device for treatment of Barrett'"'"'s esophoagus, comprising:

an elongate wire cage made of flexible wires, an elongate light source for photodynamic therapy adjustably extendable along a longitudinal axis of said elongate cage, said wire cage having an expandable diameter;

at least some of the flexible wires having a multitasking optical fiber probe attached thereto, each multitasking optical fiber probe including an elongate optical fiber with a plurality of sensor zones spaced along a length thereof, each sensor zone including an effective photoactive constituent having an emission spectrum distinguishable in time domain or spectral domain from emission spectra of photoactive constituents in all other sensor zones, each photoactive constituent emitting light responsive to said photoactive constituent interacting with preselected factors including radiation incident on said sensor zones and preselected molecules; and

computer control means for controlling the light source and calculating fluence rates along the length of said optical fiber from emission spectra from the photoactive constituents in the plurality of sensor zones.

20. The device according to claim 19 wherein the photoactive constituents in each of the plurality of sensor zones are selected from the group consisting of fluorophore compounds each having a fluorescent emission spectrum, photoluminescent phosphor compounds each having a phosphorescent emission spectrum, and any combination thereof.

21. The device according to claim 20 wherein the dosimetric parameters include

fluence rates calculated from emission spectra from the sensor zones in which the photoactive constituent is a fluorophore,

pO₂ calculated from emission spectra from the sensor zones in which the photoactive constituent is a photoluminescent phosphor, and

photosensitizer concentration calculated from fluorescence radiation incident on a distal end face of the optical fiber emitted by photosensitizers.

22. The device according to claim 20 wherein said wire cage includes a bulbous distal end portion for anchoring the cage at a gastro-esphageal-junction of a patient.

23. The device according to claim 22 including a gastroscope, wherein the wire cage is contained in a passageway in the gastroscope, including adjustment means for moving the wire cage in and out of the gastroscope, wherein when the wire cage is moved out of the gastroscope and into the lumen of the esophagus the cage expands the esophagus.

24. The device according to claim 23 wherein said wires are made out of superelastic metals.