# US 8,784,321 B2 · Imaging probe with combined ultrasound and optical means of imaging > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,784,321 B2 - Document ID: US8784321B2 - Status: Granted - Kind: B2 - Application number: 12/010,208 - Filed: 2008-01-22 - Published: 2008-07-24 - Granted: 2014-07-22 - Earliest claimed: 2007-01-19 - Assignees: Sunnybrook Health Sciences Centre - Applicants: Brian Courtney; Nigel Robert Munce; Amandeep Singh Thind; Victor Xiao Dong Yang; Francis Stuart Foster - Inventors: Brian Courtney; Nigel Robert Munce; Amandeep Singh Thind; Victor Xiao Dong Yang; Francis Stuart Foster - Web page: https://patentgrep.com/patent/US8784321B2 ## CPC - A61B 5/0035: {adapted for acquisition of images from more than one imaging mode, e.g. combining MRI and optical tomography} - A61B 1/00112: {Connection or coupling means} - A61B 1/00172: {with means for scanning} - A61B 1/00183: {for variable viewing angles} - A61B 5/0062: {Arrangements for scanning} - A61B 5/0066: {Optical coherence imaging} - A61B 5/0084: {for introduction into the body, e.g. by catheters (A61B5/1459 takes precedence)} - A61B 5/0095: {by applying light and detecting acoustic waves, i.e. photoacoustic measurements} - A61B 5/6852: {Catheters} - A61B 5/742: {using visual displays (displays for heart-related electrical signals, e.g. ECG, A61B5/339)} - A61B 8/12: in body cavities or body tracts, e.g. by using catheters - A61B 8/445: {Details of catheter construction} - A61B 8/4461: {Features of the scanning mechanism, e.g. for moving the transducer within the housing of the probe} - A61B 8/5238: {for combining image data of patient, e.g. merging several images from different acquisition modes into one image} - A61B 8/5292: {using additional data, e.g. patient information, image labeling, acquisition parameters} - G02B 23/2423: {of the distal end} - G10K 11/002: {Devices for damping, suppressing, obstructing or conducting sound in acoustic devices (G10K1/06 - G10K1/10 take precedence; for electro-mechanical transducers for communication H04R3/002)} - A61B 5/7207: {of noise induced by motion artifacts} - A61B 8/4281: {characterised by sound-transmitting media or devices for coupling the transducer to the tissue} - A61B 8/483: {involving the acquisition of a 3D volume of data} - A61B 8/543: {involving acquisition triggered by a physiological signal} - G02B 6/3604: {Rotary joints allowing relative rotational movement between opposing fibre or fibre bundle ends} - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - G10K: SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR ## Abstract The present invention provides an imaging probe for imaging mammalian tissues and structures using high resolution imaging, including high frequency ultrasound and optical coherence tomography. The imaging probes structures using high resolution imaging use combined high frequency ultrasound (IVUS) and optical imaging methods such as optical coherence tomography (OCT) and to accurate co-registering of images obtained from ultrasound image signals and optical image, signals during scanning a region of interest. ## Claims ### Claim 1 An imaging probe, comprising: a hollow shaft; an imaging conduit at least partially residing within said hollow shaft, said imaging conduit including a fiber optic and an electrical conductor, wherein said imaging conduit is connectable, at a proximal end thereof, to a hardware image processing system, a source of light, and an ultrasound signal generator; an imaging assembly mechanically coupled to said imaging conduit at a location remote from a proximal portion of said imaging conduit, said imaging assembly including: an optical emitter/collector including an optical deflecting element, wherein said optical deflecting element is in optical communication with a distal end of said fiber optic for directing light imaging energy out of said distal end of said fiber optic and directing reflected light energy signals into said distal end of said fiber optic; and an ultrasound transducer for emitting ultrasound imaging energy and receiving reflected ultrasound imaging energy signals, said ultrasound transducer comprising an acoustic substrate and a backing, wherein said ultrasound transducer is connected to said electrical conductor, and wherein at least a portion of said optical deflecting element resides within said backing; wherein said imaging assembly is configured to deliver the light imaging energy from said optical emitter/collector and the ultrasound imaging energy from said ultrasound transducer out of said hollow shaft; and wherein said ultrasound transducer and said optical deflecting element are positioned and oriented relative to each other to enable co-registration of the reflected light energy signals and the reflected ultrasound imaging energy signals during scanning of a region of interest. ### Claim 2 (depends on 1) The imaging probe according to claim 1 wherein said imaging conduit is connectable to a drive mechanism for imparting motion to said imaging conduit. ### Claim 3 (depends on 2) The imaging probe according to claim 2 wherein said imaging conduit is rotatable. ### Claim 4 (depends on 2) The imaging probe according to claim 2 further comprising said drive mechanism, wherein said drive mechanism is configured for providing reciprocating translational movement of said imaging conduit. ### Claim 5 (depends on 3) The imaging probe according to claim 3 wherein said optical deflecting element and said ultrasound transducer are positioned and oriented relative to each other so that the reflected light energy signals and reflected ultrasound imaging energy signals are received from the same direction. ### Claim 6 (depends on 3) The imaging probe according to claim 3 wherein said optical deflecting element and said ultrasound transducer are positioned and oriented relative to each other to enable imaging of the region of interest with a time delay between obtaining the reflected ultrasound imaging energy signals and the reflected light energy signals, where the path scanned by a first beam of imaging energy is followed in a predominant manner by a second beam of imaging energy, where the first beam of imaging energy is one of a beam of light imaging energy and a beam of ultrasound imaging energy, and where the second beam of imaging energy is the other of the beam of light imaging energy and the beam of ultrasound imaging energy , where said predominant manner is such that during a delay interval starting at an initial time point a beam axis of the second beam of imaging energy does not align itself further from an initial axis of the first beam of imaging energy, wherein the delay interval ends when the beam axis of the second beam of imaging energy is aligned with said initial axis. ### Claim 7 (depends on 3) The imaging probe according to claim 3 wherein said optical emitter/collector includes an optical focusing element for focusing light emitted from said distal end of said fiber optic to the region of interest being imaged and for collecting light reflected therefrom. ### Claim 8 (depends on 7) The imaging probe according to claim 7 wherein the light imaging energy is used to enable imaging by optical coherence tomography. ### Claim 9 (depends on 7) The imaging probe according to claim 7 wherein said ultrasound transducer and said optical emitter/collector are positioned and oriented relative to each other such that when rotating said imaging conduit, a region imaged by said ultrasound transducer at a first point in time is imaged by said optical emitter/collector at a second point in time, and wherein said optical focusing element is positioned so that an outer surface thereof is closer to the region that is being imaged at the second point in time than a primary emitting surface of said ultrasound transducer at the first point in time. ### Claim 10 (depends on 3) The imaging probe according to claim 3 wherein said ultrasound transducer has a surface from which the ultrasound imaging energy is emitted, and wherein said ultrasound transducer has an optically transmissive channel located therein and wherein said optical deflecting element resides along said optically transmissive channel to transmit the light imaging energy via said optically transmissive channel through said surface such that the light imaging energy is collinear with the ultrasound imaging energy. ### Claim 11 (depends on 3) The imaging probe according to claim 3 wherein said ultrasound transducer has a surface from which ultrasound signals are emitted, and wherein said optical deflecting element is mounted with respect to said ultrasound transducer to emit light at a pre-selected angle with respect to the direction in which the ultrasound imaging energy is emitted such that the ultrasound imaging energy and the light imaging energy image the region of interest at different times. ### Claim 12 (depends on 11) The imaging probe according to claim 11 wherein said pre-selected angle is selected from the group consisting of 90 degrees, 135 degrees and 180 degrees. ### Claim 13 (depends on 3) The imaging probe according to claim 3 wherein said optical emitter/collector is a first optical emitter/collector, said imaging assembly including a second optical emitter/collector configured to emit light at a pre-selected angle with respect to the first optical emitter/collector, so that light imaging energy emitted by the first optical emitter/collector and light imaging energy emitted by said second optical emitter/collector scan the region of interest. ### Claim 14 (depends on 13) The imaging probe according to claim 13 wherein at least a portion of said second optical emitter/collector resides within said backing. ### Claim 15 (depends on 3) The imaging probe according to claim 3 wherein said imaging assembly includes a reflective member mounted to reflect the light imaging energy from said optical emitter/collector and ultrasound signals from said ultrasound transducer, and wherein said reflective member is a movable member for delivering an energy beam along an energy beam path from said movable member out of said hollow shaft at a variable imaging angle with respect to a rotational axis of said imaging assembly, wherein said movable member is mounted so that the variable imaging angle is varied by adjusting an angular velocity of said imaging assembly about said rotational axis. ### Claim 16 (depends on 15) The imaging probe according to claim 15 wherein said reflective member comprises an acoustically reflective surface and an optically reflective surface, wherein said acoustically reflective surface and said optically reflective surface are provided in separate layers. ### Claim 17 (depends on 16) The imaging probe according to claim 16 wherein said acoustically reflective surface is contoured to focus the ultrasound imaging energy. ### Claim 18 (depends on 16) The imaging probe according to claim 16 wherein said optically reflective surface is acoustically transparent. ### Claim 19 (depends on 15) The imaging probe according to claim 15 wherein said movable member is pivotally mounted in said imaging assembly along a pivot axis perpendicular to said rotational axis of said imaging assembly. ### Claim 20 (depends on 3) The imaging probe according to claim 3 wherein the light imaging energy is visible light. ### Claim 21 (depends on 3) The imaging probe according to claim 3 wherein the light imaging energy is infrared light. ### Claim 22 (depends on 3) The imaging probe according to claim 3 further comprising a rotary encoder mechanism coupled to said imaging assembly for detecting rotational motion of said imaging assembly. ### Claim 23 (depends on 3) The imaging probe according to claim 3 wherein said optical emitter/collector and said ultrasound transducer are positioned and oriented relative to each other so that the ultrasound imaging energy and the light imaging energy are transmitted in a collinear direction from said optical emitter/collector and said ultrasound transducer. ### Claim 24 (depends on 3) The imaging probe according to claim 3 wherein said optical emitter/collector and said ultrasound transducer are positioned and oriented relative to each other such that the space occupied by an acoustic beam emitted from said ultrasound transducer overlaps the space occupied by an optical beam emitted from said optical emitter/collector and wherein the orientation of said optical beam from said optical emitter/collector is parallel to the orientation of said acoustic beam emitted from said ultrasound transducer. ### Claim 25 (depends on 3) The imaging probe according to claim 3 further comprising said hardware image processing system, wherein said hardware image processing system is configured to process ultrasound images and optical images obtained from ultrasound imaging and optical imaging during scanning of the region of interest and to co-register the ultrasound images and optical images and to display co-registered images. ### Claim 26 (depends on 3) The imaging probe according to claim 3 wherein at least a portion of said optical deflecting element is embedded within said backing. ### Claim 27 (depends on 3) The imaging probe according to claim 3 wherein one or more optical elements of said optical emitter/collector extend beyond an outer surface of said ultrasound transducer. ### Claim 28 (depends on 3) The imaging probe according to claim 3 wherein said imaging assembly is configured such that the light imaging energy delivered from said optical emitter/collector and the ultrasound imaging energy emitted from said ultrasound transducer propagate without further reflection prior to reaching an inner surface of said hollow shaft. ### Claim 29 (depends on 3) The imaging probe according to claim 3 wherein said imaging assembly is configured such that the light imaging energy delivered from said optical emitter/collector and the ultrasound imaging energy emitted from said ultrasound transducer propagate without encountering an additional reflective element prior to reaching an inner surface of said hollow shaft. ### Claim 30 (depends on 3) The imaging probe according to claim 3 wherein said optical emitter/collector is configured to deliver the light imaging energy and wherein said ultrasound transducer is configured to emit the ultrasound imaging energy in a direction that is oriented away from a rotational axis of said imaging assembly. ### Claim 31 (depends on 3) The imaging probe according to claim 3 wherein an outer diameter of a distal portion of said hollow shaft in which the imaging assembly can reside is less than approximately 2 mm. ### Claim 32 (depends on 3) The imaging probe according to claim 3 wherein said optical emitter/collector and said ultrasound transducer are configured for side-viewing and wherein said optical emitter/collector and said ultrasound transducer are tilted for reducing reflections from said hollow shaft. ### Claim 33 An imaging probe, comprising: a hollow shaft; an imaging conduit at least partially residing within said hollow shaft, said imaging conduit including a fiber optic and an electrical conductor, wherein said imaging conduit is connectable, at a proximal end thereof, to a hardware image processing system, a source of light, and an ultrasound signal generator; an imaging assembly mechanically coupled to said imaging conduit at a location remote from a proximal portion of said imaging conduit, said imaging assembly including: an optical emitter/collector including an optical deflecting element, wherein said optical deflecting element is in optical communication with a distal end of said fiber optic for directing light imaging energy out of said distal end of said fiber optic and directing reflected light energy signals into said distal end of said fiber optic; and an ultrasound transducer for emitting ultrasound imaging energy and receiving reflected ultrasound imaging energy signals, said ultrasound transducer including an acoustic substrate and a backing, wherein said ultrasound transducer is connected to said electrical conductor; wherein said ultrasound transducer includes an optically transmissive channel having a first portion and a second portion, wherein said first portion resides at least partially within said backing, and wherein said second portion is in optical communication with said first portion, said second portion extending through said acoustic substrate of said ultrasound transducer and through an emitting surface of said ultrasound transducer, and wherein said optical deflecting element resides along said optically transmissive channel for deflecting an optical beam between said first portion and said second portion; wherein said imaging assembly is configured to deliver the light imaging energy from said optical emitter/collector and the ultrasound imaging energy from said ultrasound transducer out of said hollow shaft; and wherein said ultrasound transducer and said optical deflecting element are positioned and oriented relative to each other to enable co-registration of the reflected light energy signals and the reflected ultrasound imaging energy signals during scanning of a region of interest. ### Claim 34 (depends on 33) The imaging probe according to claim 33 wherein at least a portion of said optically transmissive channel includes an acoustic damping layer. ### Claim 35 (depends on 34) The imaging probe according to claim 34 wherein said acoustic damping layer includes a compliant material for reducing the transmission of stresses generated by said acoustic substrate to optical elements residing within said optically transmissive channel. ### Claim 36 (depends on 33) The imaging probe according to claim 33 wherein at least a portion of said optically transmissive channel includes an electrically insulating layer. ### Claim 37 (depends on 33) The imaging probe according to claim 33 further comprising an optical focusing element, wherein at least a portion of said optical focusing element resides within said optically transmissive channel. ### Claim 38 (depends on 37) The imaging probe according to claim 37 wherein said optical focusing element resides within said acoustic substrate within said second portion of said optically transmissive channel. ### Claim 39 (depends on 38) The imaging probe according to claim 38 wherein said optical focusing element extends beyond an outer surface of said ultrasound transducer. ### Claim 40 (depends on 37) The imaging probe according to claim 37 wherein said optical deflecting element is a prism having a path length suitable for acting as an optical spacer for said optical focusing element. ### Claim 41 (depends on 37) The imaging probe according to claim 37 wherein said optically transmissive channel includes an optical spacer residing therein, wherein said optical spacer is located along an optical beam path between said distal end of said fiber optic and said optical focusing element. ### Claim 42 (depends on 37) The imaging probe according to claim 37 wherein said optical focusing element resides within said second portion of said optically transmissive channel. ### Claim 43 (depends on 33) The imaging probe according to claim 33 wherein a distal portion of said second portion of said optically transmissive channel includes an optically transmissive window. ### Claim 44 (depends on 43) The imaging probe according to claim 43 wherein a region within said optically transmissive channel that is unoccupied by an optical component is filled with a gas or fluid. ### Claim 45 (depends on 33) The imaging probe according to claim 33 wherein a distal portion of said fiber optic is embedded within said first portion of said optically transmissive channel. ### Claim 46 (depends on 33) The imaging probe according to claim 33 wherein at least a portion of the backing is interposed between said first portion of said optically transmissive channel and said acoustic substrate. ### Claim 47 (depends on 33) The imaging probe according to claim 33 wherein at least a portion of said backing is provided behind said first portion of said optically transmissive channel, on a side opposite to that of said acoustic substrate. ### Claim 48 (depends on 33) The imaging probe according to claim 33 wherein said first portion of said optically transmissive channel is adjacent to said acoustic substrate. ### Claim 49 An imaging probe, comprising: a hollow shaft; an imaging conduit at least partially residing within said hollow shaft, said imaging conduit including a fiber optic and an electrical conductor, wherein said imaging conduit is connectable, at a proximal end thereof, to a hardware image processing system, a source of light, and an ultrasound signal generator; an imaging assembly mechanically coupled to said imaging conduit at a location remote from a proximal portion of said imaging conduit, said imaging assembly including: an optical emitter/collector including an optical deflecting element, wherein said optical deflecting element is in optical communication with a distal end of said fiber optic for directing light imaging energy out of said distal end of said fiber optic and directing reflected light energy signals into said distal end of said fiber optic; an ultrasound transducer for emitting ultrasound imaging energy and receiving reflected ultrasound imaging energy signals, wherein said ultrasound transducer is connected to said electrical conductor, said ultrasound transducer including an acoustic substrate and a backing, wherein at least a portion of said optical emitter/collector resides within a channel provided in said backing, and further including a deflecting feature configured to deflect ultrasound energy that would otherwise be reflected towards said acoustic substrate by said portion of said optical emitter/collector that resides within said channel; wherein said imaging assembly is configured to deliver the light imaging energy from said optical emitter/collector and the ultrasound imaging energy from said ultrasound transducer out of said hollow shaft; wherein said ultrasound transducer and said optical deflecting element are positioned and oriented relative to each other to enable co-registration of the reflected light energy signals and the reflected ultrasound imaging energy signals during scanning of a region of interest. ### Claim 50 (depends on 49) The imaging probe according to claim 49 wherein an external surface of said channel is shaped to deflect ultrasound energy in one or more directions that are not oriented towards said acoustic substrate. ### Claim 51 (depends on 49) The imaging probe according to claim 49 wherein said deflecting feature is an acoustically reflective element that is configured to deflect ultrasound energy in one or more directions that are not incident upon said acoustic substrate. ### Claim 52 (depends on 51) The imaging probe according to claim 51 wherein said acoustically reflective element is positioned adjacent to at least a portion of said channel.