Optical coherence tomography / acoustic radiation force imaging probe

• US 7,999,945 B2
• Filed: 07/18/2008
• Issued: 08/16/2011
• Est. Priority Date: 07/18/2007
• Status: Active Grant

• Current Assignee: George Washington University
• Original Assignee: George Washington University
• Inventors: Zara, Jason Michael
• Primary Examiner(s): Toatley; Gregory J
• Assistant Examiner(s): Richey; Scott M
• Application Number:
  US12/175,985
• Publication Number:
  US 20090116032A1
• Time in Patent Office: 1,124 Days
• Field of Search: 356/451, 356/456, 356/479, 356/497, 356/502, 356/477, 602/22
• US Class Current: 356/479
• CPC Class Codes: A61B 5/0066 Optical coherence imaging
• CPC Class Codes: A61B 5/0073 by tomography, i.e. reconstruction of 3D images from 2D projections A61B5/0066 takes precedence
• CPC Class Codes: A61B 5/0097 by applying acoustic waves and detecting light, i.e. acoustooptic measurements
• CPC Class Codes: A61B 5/6852 Catheters
• 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: A61B 8/485 involving measuring strain or elastic properties
• CPC Class Codes: G01N 2021/1787 Tomographic, i.e. computerised reconstruction from projective measurements

Abstract

A combined system and method synchronizes optical coherence tomography and acoustic radiation force for simultaneously imaging and mechanically displacing tissue in a patient as a detection and analytic tool. An endoscope is provided which has a piezoelectric element and an OCT scanner. The piezoelectric element generates the acoustic force to displace the tissue. The OCT scanner images the tissue and the system determines the mechanical displacement of the tissue. Cancer and arterial plaques can be recognized from the mechanical displacement of the tissue.

Claims

1. A combined system which synchronizes optical coherence tomography and acoustic radiation force for simultaneously imaging and mechanically displacing interior body tissue in a patient, which comprises:

an endoscopic probe;

a piezoelectric transducer located inside the endoscopic probe for delivering acoustic radiation force to a target area of the interior body tissue to mechanically displace the interior body tissue;

an optical coherence tomography device having a light source located inside the endoscopic probe to provide infrared light, a movable mirror located inside the endoscopic probe to receive the infrared light from said light source, an actuator device located inside the endoscopic probe to move said movable mirror to direct the infrared light from the light source to scan across the target area to illuminate the interior body tissue before and during delivery of the acoustic radiation force by said piezoelectric transducer, and a lens located inside the endoscopic probe to receive images of the target area of the tissue before and during the delivery of the acoustic radiation force as the infrared light scans across the target area of the interior body tissue, and

a controller for determining a displacement of the target area of the interior body tissue resulting from the delivery of the acoustic radiation force.

2. A method of obtaining mechanical properties of interior body tissue in a patient, comprising simultaneously imaging said interior body tissue using optical coherence tomography while subjecting said interior body tissue to mechanical displacement using acoustic radiation force, and determining a displacement of the interior body tissue resulting from the delivery of the acoustic radiation force.

3. A method of detecting cancer within interior body tissue in a patient, comprising simultaneously imaging said interior body tissue using optical coherence tomography while subjecting said interior body tissue to mechanical displacement using acoustic radiation force, and comparing the imaging and displacement data to known values of healthy and unhealthy tissue properties.

4. A method of detecting whether interior arterial plaque in a patient is solid or liquid filled, comprising simultaneously imaging said interior arterial plaque using optical coherence tomography while subjecting said target tissue to mechanical displacement using acoustic radiation force, and comparing the imaging and displacement data to control data.

5. A system comprising:

an acoustic radiation force component which is operationally synchronized with an optical coherence tomography component, the acoustic radiation force component comprising an acoustic source and an acoustic detector, the acoustic source and detector being operably connected to a power source, the power source being operably connected to a function generator, and the function generator being operably connected to a controller having data acquisition, storage and analysis capability, the controller having the capability to process acquired acoustic data, make determinations of at least one of acoustic emission properties, induced and intrinsic tissue displacements and relate the determination of at least one of acoustic emission properties, induced and intrinsic tissue displacement with at least one physiological tissue condition of a target tissue, the controller being operably connected to a display device for displaying information relating to the at least one physiological tissue condition, and

the optical coherence tomography component comprising an apparatus for optical coherence tomography comprising a low coherent light source;

an optical fiber interferometer, including a beam-splitter, a sampling and reference optical fiber arms, and a photodetector, which are mutually optically coupled, a data processing and displaying unit, a reference mirror being placed at the end of said reference arm, the output of said photodetector being connected with said data processing and displaying unit, and a source of control voltage, whereas the output of said data processing and displaying unit of said optical fiber interferometer is the output of said apparatus for optical coherence tomography;

at least one of said arms comprising an in-depth scanner having a capability of changing the optical length of said arm by at least several tens of operating wavelengths of said light source, said in-depth scanner being controlled by a source of control voltage, said sampling arm including a flexible part, which is made capable of being introduced into an instrumental channel of an endoscope or borescope and being provided with an optical fiber probe;

said optical fiber probe being designed miniature and including a lens system.

6. A system of claim 5, wherein a part of said sampling arm of said interferometer, including said part that is made capable of being introduced into an instrumental channel of an endoscope or borescope, is detachably connected with a main part of said sampling arm.

7. A system as claimed in claim 5, wherein said changeable part of said sampling arm of said interferometer is disposable.

8. A system as claimed in claim 5, wherein the distal part of said optical fiber probe is made with changeable tips.