Side-viewing optical acoustic sensors and their use in intravascular diagnostic probes

• US 20070291275A1
• Filed: 06/08/2007
• Published: 12/20/2007
• Est. Priority Date: 06/16/2006
• Status: Abandoned Application

• Current Assignee: Prescient Medical, Inc.
• Original Assignee: Prescient Medical, Inc.
• Inventors: Diamond, Paul
• Application Number:
  US11/808,374
• Publication Number:
  US 20070291275A1
• Time in Patent Office: Days
• US Class Current: 356/480
• CPC Class Codes: A61B 5/0084 for introduction into the body, e.g. by catheters A61B5/1459 takes precedence
• CPC Class Codes: A61B 5/0095 by applying light and detecting acoustic waves, i.e. photoacoustic measurements
• CPC Class Codes: A61B 5/6858 with a distal basket, e.g. expandable basket
• CPC Class Codes: A61B 8/12 in body cavities or body tracts, e.g. by using catheters catheters per se A61M25/00
• CPC Class Codes: G01N 21/1702 with opto-acoustic detection, e.g. for gases or analysing solids

Abstract

One aspect of the invention provides side-sensing optical fiber-based optical acoustic sensors that are well suited to catheter-based intravascular diagnostic applications. Another aspect of the invention provides intravascular probes, such as catheters, that include a side-sensing optical acoustic sensor according to the invention and means for photoacoustically generating an acoustic signal, such as ultrasound, from a target tissue. Still another aspect of the invention provides a method for evaluating at least a section of a blood vessel, such as an artery, and in particular identifying, locating and/or characterizing atherosclerotic lesions within the blood vessel. A related embodiment provides a method for identifying, locating and/or characterizing lipid-rich atherosclerotic lesions such as vulnerable plaques.

Claims

1. A side-sensing optical acoustic probe, comprising:

an optical fiber having a proximal end and a distal end and a central axis;

a light redirecting element having a sensing-side face and a fiber-side face, the light directing element being in optical communication with distal end of the fiber via the fiber-side face; and

a side-facing Fabry-Perot interferometer element in optical communication with the light redirecting element via the sensing-side face of the light redirecting element.

2. The probe of claim 1, wherein the light redirecting element is a prism.

3. The probe of claim 2, wherein the light redirecting element is a 45-degree prism.

4. The probe of claim 1, wherein the light redirecting element comprises a mirror face.

5. The probe of claim 4, wherein the light redirecting element comprises a 45-degree mirror face.

6. The probe of claim 1, wherein the Fabry-Perot interferometer element consists essentially of a thin-film.

7. The probe of claim 6, wherein the thin-film is polymeric.

8. The probe of claim 1, wherein the Fabry-Perot interferometer element is an optical etalon Fabry-Perot interferometer.

9. The probe of claim 8, wherein the Fabry-Perot interferometer element consists essentially of two mirror elements separated by a transparent layer element.

10. The probe of claim 8, further comprising a protective outer coating over the Fabry-Perot interferometer element.

11. The probe of claim 9, further comprising a protective outer coating over the Fabry-Perot interferometer element.

12. The probe of claim 1, wherein the distal end of the optical fiber is directly or indirectly joined to the fiber-side face of the light redirecting element.

13. The probe of claim 1, wherein Fabry-Perot interferometer element is directly or indirectly disposed on the sensing-side face of the light redirecting element.

14. The probe of claim 13, wherein the distal end of the optical fiber is directly or indirectly joined to the fiber-side face of the light redirecting element.

15. The probe of claim 1, further comprising a photoacoustic excitation channel for inducing ultrasound in a side-disposed target.

16. The probe of claim 15, wherein the photoacoustic excitation channel comprises a separate excitation optical fiber in optical communication with the same or a different light redirector.

17. A diagnostic guidewire comprising:

a guidewire body; and

at least one optical probe according to claim 1 at least substantially disposed within the guidewire body.

18. An intravascular catheter comprising:

an intravascular catheter body; and

at least one optical probe according to claim 1 at least substantially disposed within the guidewire body.