Patent Description:
Intravascular ultrasound (IVUS) imaging is widely used in interventional cardiology as a diagnostic tool for assessing a diseased vessel, such as an artery, within the human body to determine the need for treatment, to guide the intervention, and/or to assess its effectiveness. An IVUS device including one or more ultrasound transducers is passed into the vessel and guided to the area to be imaged. The transducers emit ultrasonic energy in order to create an image of the vessel of interest. Ultrasonic waves are partially reflected by discontinuities arising from tissue structures (such as the various layers of the vessel wall), red blood cells, and other features of interest. Echoes from the reflected waves are received by the transducer and passed along to an IVUS imaging system. The imaging system processes the received ultrasound echoes to produce a cross-sectional image of the vessel where the device is placed.

Phased array (also known as synthetic-aperture) IVUS catheters are a type of IVUS device commonly used today. Phased array IVUS catheters carry a scanner assembly that includes an array of ultrasound transducers positioned and distributed around its perimeter or circumference along with one or more integrated circuit controller chips mounted adjacent to the transducer array. The controllers select individual acoustic elements (or groups of elements) for transmitting a pulse of acoustic energy and for receiving the ultrasound echo signal corresponding to the transmitted ultrasound energy. By stepping through a sequence of transmit-receive pairs, the phased array IVUS system can synthesize the effect of a mechanically scanned ultrasound transducer but without moving parts (hence the solid-state designation). Since there is no rotating mechanical element, the transducer array can be placed in direct contact with the blood and vessel tissue with minimal risk of vessel trauma and without a need for an additional housing between the rotating element and the vessel lumen.

IVUS catheters must be stiff enough to be pushable, so that a clinician can advance them through the tortuous pathways of human vasculature. However, to facilitate navigation through these tortuous pathways, the catheters must also be flexible. It can be challenging to design IVUS catheters that meet both of these requirements simultaneously.

For example, document <CIT> discloses guide wires that include a distal coil filled with a flexible adhesive.

Disclosed herein is an intraluminal imaging device (e.g., an intravascular ultrasound or IVUS imaging device) advantageously providing both pushability and flexibility for navigation through vasculature. The device includes a flexible elongate member (e.g., a catheter) with a proximal portion and a distal portion, and an imaging assembly disposed at the distal portion for obtaining intraluminal image data. The distal portion of the flexible elongate member comprises a flexible region, proximal to the imaging assembly, that is more flexible than the proximal portion, and is filled with an adhesive whose hardness helps to define the flexibility of the region, and is surrounded by an outer polymer layer. The outer polymer layer includes an opening for injecting the adhesive, after which the opening is filled with a plug of material (e.g., a second adhesive). The proximal region of the flexible elongate member includes a polymer-coated metal shaft that is cut in a spiral configuration to provide both flexibility and pushability. A guidewire lumen extends from the proximal portion the distal portion of the flexible elongate member through a guidewire lumen defined by a polymer-coated braided metal layer.

One general aspect of the intraluminal imaging device includes a flexible elongate member configured to be positioned within a body lumen of a patient, where the flexible elongate member includes a proximal portion and a distal portion; and an imaging assembly disposed at the distal portion of the flexible elongate member and configured to obtain intraluminal image data while positioned within the body lumen. The distal portion of the flexible elongate member includes a region proximal to the imaging assembly, where the region includes a first hardness that is less than a second hardness of the proximal portion of the flexible elongate member such that the region is more flexible than the proximal portion. The region includes: an inner member; a first adhesive configured to provide the first hardness, where the first adhesive surrounds the inner member; a communication line configured to carry signals associated with the imaging assembly, where the communication line is embedded within the first adhesive; and an outer polymer layer surrounding the first adhesive.

Implementations may include one or more of the following features. In some embodiments, the outer polymer layer includes an opening filled with a second adhesive. In some embodiments, the second adhesive is fluorescent under ultraviolet (UV) light. In some embodiments, the flexible elongate member includes an outer member proximal to the region, where the outer member includes a metal shaft and a polymer coating surrounding the metal shaft. In some embodiments, the metal shaft is cut in a spiral configuration. In some embodiments, the inner member and the communication line extend within the outer member. In some embodiments, the flexible elongate member includes a catheter, and where the inner member defines a guidewire lumen. In some embodiments, a distal portion of the inner member and a proximal portion the imaging assembly are positioned within the polymer tube. In some embodiments, the imaging assembly includes: a flexible substrate; and a plurality of integrated circuits disposed on the flexible substrate, where the polymer tube extends over the plurality of integrated circuits. In some embodiments, the device further including a third adhesive positioned within the polymer tube. In some embodiments, the communication line includes an electrical conductor; where the imaging assembly includes: a support member; a flexible substrate positioned around the support member, where the electrical conductor is coupled to a proximal portion of the flexible substrate; and insulation positioned around the support member and configured to prevent contact between the proximal portion of the flexible substrate and the support member. In some embodiments, the inner member defines a guidewire lumen extending from the proximal portion of the flexible elongate member to the distal portion of the flexible elongate member. In some embodiments, the outer polymer layer includes an outer surface of the flexible elongate member in the region. In some embodiments, the inner member includes: a first polymer layer defining a guidewire lumen; a wire braid surrounding the first polymer layer; and a second polymer layer surrounding the first polymer layer. In some embodiments, the flexible elongate member includes a catheter, where the body lumen includes a blood vessel, where the imaging assembly includes a circumferential array of acoustic elements, and where the intraluminal image data includes intravascular ultrasound (IVUS) image data.

One general aspect includes an intravascular ultrasound (IVUS) imaging device. The device includes a catheter configured to configured to be positioned within a blood vessel of a patient, where the catheter includes a proximal portion and a distal portion; and a circumferential array of acoustic elements disposed at the distal portion of the catheter and configured to obtain IVUS image data while positioned within the blood vessel, where the distal portion of the catheter includes a region proximal to the circumferential array of acoustic elements, where the region includes a first hardness that is less than a second hardness of the proximal portion of the catheter such that the region is more flexible than the proximal portion, where the region includes: an inner member including: a first polymer layer defining a guidewire lumen; a wire braid surrounding the first polymer layer; and a second polymer layer surrounding the first polymer layer; an adhesive configured to provide the first hardness, where the adhesive surrounds the inner member; a plurality of electrical conductors in communication with the circumferential array of acoustic elements, where the plurality of electrical conductors are embedded within the adhesive; and a third polymer layer surrounding the adhesive and forming an outer surface of catheter in the region.

Disclosed herein is an intraluminal imaging device with stiff portions to facilitate pushing, flexible portions to facilitate navigation, and rigid portions to facilitate imaging within body lumens such as human blood vessels. The intraluminal imaging device comprises a flexible elongate member (e.g., a catheter) for use within a body lumen (e.g., a blood vessel) of a patient. The flexible elongate member has a proximal portion and a distal portion, and an imaging assembly located at the distal portion and configured to obtain intraluminal image data (e.g., IVUS image data). The distal portion of the flexible elongate member comprises a region, proximal to the imaging assembly, that is more flexible than the proximal portion. The region includes an inner member that comprises a guidewire lumen and that is surrounded by an adhesive whose hardness or durometer helps to define the flexibility of the region. The region also includes communication lines (e.g., wires, optical fibers, etc.) embedded within the adhesive, to carry signals associated with the imaging assembly. The region also includes an outer polymer layer surrounding the first adhesive, whose outer diameter defines the outer diameter of the region. The outer polymer layer includes an opening filled with a plug of material (e.g., a second adhesive) that may be fluorescent under ultraviolet (UV) light to facilitate inspection of the plug.

The flexible elongate member also includes, proximal to the adhesive-filled region, an outer member comprising a metal shaft surrounded by a polymer coating. The metal shaft is cut in a spiral configuration to provide flexibility, while the inner member and the communication lines extend through a lumen within the outer member.

The imaging assembly of the device includes a circumferential array of acoustic elements for gathering intravascular ultrasound (IVUS) image data. A distal portion of the inner member and a proximal portion of the imaging assembly are positioned within a polymer tube, which extends over a portion of a flexible substrate of the imaging assembly (e.g., over one or more weld legs that join the communication lines to the flexible substrate and/or over a plurality of integrated circuits on the flexible substrate). The flexible substrate is wrapped around a support member (e.g., a metallic ferrule). A third adhesive may be positioned within the polymer tube, and an insulating material (which may also be an adhesive) is positioned around the support member and configured to prevent electrical contact (e.g., shorting) between the proximal portion of the flexible substrate and the support member.

The inner member comprises a guidewire lumen extending from the proximal portion the distal portion of the flexible elongate member. The wall of the guidewire lumen is defined by a first polymer layer, which is surrounded by a wire braid layer, which is surrounded by a second polymer layer. The second polymer layer defines the outer surface of the inner member.

<FIG> is a diagrammatic schematic view of an ultrasound imaging system <NUM>, according to aspects of the present disclosure. The ultrasound imaging system <NUM> can be an intraluminal imaging system. In some instances, the system <NUM> can be an intravascular ultrasound (IVUS) imaging system. The system <NUM> may include an intraluminal imaging device <NUM> such as a catheter, guide wire, or guide catheter, a patient interface module (PIM) <NUM>, a processing system or console <NUM>, and a monitor <NUM>. The intraluminal imaging device <NUM> can be an ultrasound imaging device. In some instances, the device <NUM> can be IVUS imaging device, such as a solid-state IVUS device.

At a high level, the IVUS device <NUM> emits ultrasonic energy, or ultrasound signals, from a transducer array <NUM> included in scanner assembly <NUM> mounted near a distal end of the catheter device. The ultrasonic energy is reflected by tissue structures in the medium, such as a vessel <NUM>, or another body lumen surrounding the scanner assembly <NUM>, and the ultrasound echo signals are received by the transducer array <NUM>. In that regard, the device <NUM> can be sized, shaped, or otherwise configured to be positioned within the body lumen of a patient. The PIM <NUM> transfers the received echo signals to the console or computer <NUM> where the ultrasound image (possibly including flow information) is reconstructed and displayed on the monitor <NUM>. The processing system <NUM> can include a processor and a memory. The processing system <NUM> can be operable to facilitate the features of the IVUS imaging system <NUM> described herein. For example, the processing system <NUM> can execute computer readable instructions stored on the non-transitory tangible computer readable medium.

The PIM <NUM> facilitates communication of signals between the processing system <NUM> and the scanner assembly <NUM> included in the IVUS device <NUM>. This communication includes the steps of: (<NUM>) providing commands to integrated circuit controller chip(s) 206A, 206B, illustrated in <FIG>, included in the scanner assembly <NUM> to select the particular transducer array element(s), or acoustic element(s), to be used for transmit and receive, (<NUM>) providing the transmit trigger signals to the integrated circuit controller chip(s) 206A, 206B included in the scanner assembly <NUM> to activate the transmitter circuitry to generate an electrical pulse to excite the selected transducer array element(s) <NUM>, and/or (<NUM>) accepting amplified echo signals received from the selected transducer array element(s) <NUM> via amplifiers included on the integrated circuit controller chip(s) <NUM> of the scanner assembly <NUM>. In some embodiments, the PIM <NUM> performs preliminary processing of the echo data prior to relaying the data to the console <NUM>. In examples of such embodiments, the PIM <NUM> performs amplification, filtering, and/or aggregating of the data. In an embodiment, the PIM <NUM> also supplies high- and low-voltage DC power to support operation of the device <NUM> including circuitry within the scanner assembly <NUM>.

The processing system <NUM> receives the echo data from the scanner assembly <NUM> by way of the PIM <NUM> and processes the data to reconstruct an image of the tissue structures in the medium surrounding the scanner assembly <NUM>. The console <NUM> outputs image data such that an image of the vessel <NUM>, such as a cross-sectional image of the vessel <NUM>, is displayed on the monitor <NUM>. Vessel <NUM> may represent fluid filled or surrounded structures, both natural and man-made. The vessel <NUM> may be within a body of a patient. The vessel <NUM> may be a blood vessel, as an artery or a vein of a patient's vascular system, including cardiac vasculature, peripheral vasculature, neural vasculature, renal vasculature, and/or or any other suitable lumen inside the body. For example, the device <NUM> may be used to examine any number of anatomical locations and tissue types, including without limitation, organs including the liver, heart, kidneys, gall bladder, pancreas, lungs; ducts; intestines; nervous system structures including the brain, dural sac, spinal cord and peripheral nerves; the urinary tract; as well as valves within the blood, chambers or other parts of the heart, and/or other systems of the body. In addition to natural structures, the device <NUM> may be used to examine man-made structures such as, but without limitation, heart valves, stents, shunts, filters and other devices.

In some embodiments, the IVUS device includes some features similar to traditional solid-state IVUS catheters, such as the EagleEye® catheter available from Koninklijke Philips N. and those disclosed in <CIT>. For example, the IVUS device <NUM> includes the scanner assembly <NUM> near a distal end of the device <NUM> and a transmission line bundle <NUM> extending along the longitudinal body of the device <NUM>. The transmission line bundle or cable <NUM> can include a plurality of conductors, including one, two, three, four, five, six, seven, or more conductors <NUM> (<FIG>). Further, in some embodiments, the IVUS device <NUM> includes a plurality of transmission line bundles each comprising a plurality of conductors of varying size (e.g., gauge), insulation, and/or other structural and electrical characteristics. It is understood that any suitable gauge wire can be used for the conductors <NUM>. In an embodiment, the cable <NUM> can include a four-conductor transmission line arrangement with, e.g., <NUM> AWG gauge wires. In an embodiment, the cable <NUM> can include a seven-conductor transmission line arrangement utilizing, e.g., <NUM> AWG gauge wires. In some embodiments, <NUM> AWG gauge wires can be used.

The transmission line bundle <NUM> passes through or connects to a cable <NUM> that terminates in a PIM connector <NUM> at a proximal end of the device <NUM>. The PIM connector <NUM> electrically couples the transmission line bundle <NUM> to the PIM <NUM> and physically couples the IVUS device <NUM> to the PIM <NUM>. In an embodiment, the IVUS device <NUM> further includes a guide wire exit port <NUM>. Accordingly, in some instances the IVUS device is a rapid-exchange catheter. The guide wire exit port <NUM> allows a guide wire <NUM> to be inserted towards the distal end in order to direct the device <NUM> through the vessel <NUM>.

In an embodiment, the processing system <NUM> generates flow data by processing the echo signals from the IVUS device <NUM> into Doppler power or velocity information. The processing system <NUM> may also generate B-mode data by applying envelope detection and logarithmic compression on the conditioned echo signals. The processing system <NUM> can further generate images in various views, such as 2D and/or 3D views, based on the flow data or the B-mode data. The processing system <NUM> can also perform various analyses and/or assessments. For example, the processing system <NUM> can apply virtual histology (VH) techniques, for example, to analyze or assess plaques within a vessel (e.g., the vessel <NUM>). The images can be generated to display a reconstructed color-coded tissue map of plaque composition superimposed on a cross-sectional view of the vessel.

In an embodiment, the processing system <NUM> can apply a blood flow detection algorithm to determine the movement of blood flow, for example, by acquiring image data of a target region (e.g., the vessel <NUM>) repeatedly and determining the movement of the blood flow from the image data. The blood flow detection algorithm operates based on the principle that signals measured from vascular tissue are relatively static from acquisition to acquisition, whereas signals measured from blood flow vary at a characteristic rate corresponding to the flow rate. As such, the blood flow detection algorithm may determine movements of blood flow based on variations in signals measured from the target region between repeated acquisitions. To acquire the image data repeatedly, the processing system <NUM> may control to the device <NUM> to transmit repeated pulses on the same aperture.

While the present disclosure describes embodiments related to intravascular ultrasound (IVUS) imaging using an intravascular catheter or guidewire, it is understood that one or more aspects of the present disclosure can be implemented in any suitable ultrasound imaging system, including a synthetic aperture ultrasound imaging system, a phased array ultrasound imaging system, or any other array-based ultrasound imaging system. For example, aspects of the present disclosure can be implemented in intraluminal ultrasound imaging systems using an intracardiac (ICE) echocardiography catheter and/or a transesophageal echocardiography (TEE) probe, and/or external ultrasound imaging system using an ultrasound probe configured for imaging while positioned adjacent to and/or in contact with the patient's skin. The ultrasound imaging device can be a transthoracic echocardiography (TTE) imaging device in some embodiments.

An ultrasound transducer array of the ultrasound imaging device includes an array of acoustic elements configured to emit ultrasound energy and receive echoes corresponding to the emitted ultrasound energy. In some instances, the array may include any number of ultrasound transducer elements. For example, the array can include between <NUM> acoustic elements and <NUM> acoustic elements, including values such as <NUM> acoustic elements, <NUM> acoustic elements, acoustic elements, <NUM> acoustic elements, <NUM> acoustic elements, <NUM> acoustic elements, <NUM> acoustic elements, <NUM> acoustic elements, <NUM> acoustic elements, and/or other values both larger and smaller. In some instances, the transducer elements of the array may be arranged in any suitable configuration, such as a linear array, a planar array, a curved array, a curvilinear array, a circumferential array, an annular array, a phased array, a matrix array, a one-dimensional (1D) array, a <NUM>. x dimensional array (e.g., a <NUM>. 5D array), or a two-dimensional (2D) array. The array of transducer elements (e.g., one or more rows, one or more columns, and/or one or more orientations) can be uniformly or independently controlled and activated. The array can be configured to obtain one-dimensional, two-dimensional, and/or three-dimensional images of patient anatomy.

The ultrasound transducer elements may include piezoelectric/piezoresistive elements, piezoelectric micromachined ultrasound transducer (PMUT) elements, capacitive micromachined ultrasound transducer (CMUT) elements, and/or any other suitable type of ultrasound transducer elements. The ultrasound transducer elements of the array are in communication with (e.g., electrically coupled to) electronic circuitry. For example, the electronic circuitry can include one or more transducer control logic dies. The electronic circuitry can include one or more integrated circuits (IC), such as application specific integrated circuits (ASICs). In some embodiments, one or more of the ICs can include a microbeamformer (µBF). In other embodiments, one or more of the ICs includes a multiplexer circuit (MUX).

<FIG> is a schematic diagram of a processor circuit <NUM>, according to embodiments of the present disclosure. The processor circuit <NUM> may be implemented in the processing system <NUM> and/or the imaging device <NUM> of <FIG>. As shown, the processor circuit <NUM> may include a processor <NUM>, a memory <NUM>, and a communication module <NUM>. These elements may be in direct or indirect communication with each other, for example via one or more buses.

The processor <NUM> may include a central processing unit (CPU), a digital signal processor (DSP), an ASIC, a controller, an FPGA, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein.

The memory <NUM> may include a cache memory (e.g., a cache memory of the processor <NUM>), random access memory (RAM), magnetoresistive RAM (MRAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read only memory (EPROM), electrically erasable programmable read only memory (EEPROM), flash memory, solid state memory device, hard disk drives, other forms of volatile and non-volatile memory, or a combination of different types of memory. In an embodiment, the memory <NUM> includes a non-transitory computer-readable medium. The instructions <NUM> may include instructions that, when executed by the processor <NUM>, cause the processor <NUM> to perform the operations described herein with reference to the processing system <NUM> and/or the imaging device <NUM> (<FIG>). Instructions <NUM> may also be referred to as code. The terms "instructions" and "code" should be interpreted broadly to include any type of computer-readable statement(s). For example, the terms "instructions" and "code" may refer to one or more programs, routines, sub-routines, functions, procedures, etc. "Instructions" and "code" may include a single computer-readable statement or many computer-readable statements.

The communication module <NUM> can include any electronic circuitry and/or logic circuitry to facilitate direct or indirect communication of data between the processor circuit <NUM>, the imaging device <NUM>, and/or the display <NUM>. In that regard, the communication module <NUM> can be an input/output (I/O) device. In some instances, the communication module <NUM> facilitates direct or indirect communication between various elements of the processor circuit <NUM> and/or the processing system <NUM> (<FIG>).

<FIG> is a diagrammatic top view of a portion of a flexible assembly <NUM>, according to aspects of the present disclosure. The flexible assembly <NUM> includes a transducer array <NUM> formed in a transducer region <NUM> and transducer control logic dies <NUM> (including dies 206A and 206B) formed in a control region <NUM>, with a transition region <NUM> disposed therebetween.

The transducer control logic dies <NUM> are mounted on a flexible substrate <NUM> into which the transducers <NUM> have been previously integrated. The flexible substrate <NUM> is shown in a flat configuration in <FIG>. Though six control logic dies <NUM> are shown in <FIG>, any number of control logic dies <NUM> may be used. For example, one, two, three, four, five, six, seven, eight, nine, ten, or more control logic dies <NUM> may be used.

The flexible substrate <NUM>, on which the transducer control logic dies <NUM> and the transducers <NUM> are mounted, provides structural support and interconnects for electrical coupling. The flexible substrate <NUM> may be constructed to include a film layer of a flexible polyimide material such as KAPTON™ (trademark of DuPont). Other suitable materials include polyester films, polyimide films, polyethylene napthalate films, or polyetherimide films, liquid crystal polymer, other flexible printed semiconductor substrates as well as products such as Upilex® (registered trademark of Ube Industries) and TEFLON® (registered trademark of E. In the flat configuration illustrated in <FIG>, the flexible substrate <NUM> has a generally rectangular shape. As shown and described herein, the flexible substrate <NUM> is configured to be wrapped around a support member <NUM> (<FIG>) in some instances. Therefore, the thickness of the film layer of the flexible substrate <NUM> is generally related to the degree of curvature in the final assembled flexible assembly <NUM>. In some embodiments, the film layer is between <NUM> and <NUM>, with some particular embodiments being between <NUM> and <NUM>, e.g., <NUM>.

The transducer control logic dies <NUM> is a non-limiting example of a control circuit. The transducer region <NUM> is disposed at a distal portion <NUM> of the flexible substrate <NUM>. The control region <NUM> is disposed at a proximal portion <NUM> of the flexible substrate <NUM>. The transition region <NUM> is disposed between the control region <NUM> and the transducer region <NUM>. Dimensions of the transducer region <NUM>, the control region <NUM>, and the transition region <NUM> (e.g., lengths <NUM>, <NUM>, <NUM>) can vary in different embodiments. In some embodiments, the lengths <NUM>, <NUM>, <NUM> can be substantially similar or, the length <NUM> of the transition region <NUM> may be less than lengths <NUM> and <NUM>, the length <NUM> of the transition region <NUM> can be greater than lengths <NUM>, <NUM> of the transducer region and controller region, respectively.

The control logic dies <NUM> are not necessarily homogenous. In some embodiments, a single controller is designated a master control logic die 206A and contains the communication interface for the transmission line bundle <NUM>, which may serve as an electrical communication bus between a processing system, e.g., processing system <NUM>, and the flexible assembly <NUM>. Accordingly, the master control circuit may include control logic that decodes control signals received over the transmission line bundle <NUM>, transmits control responses over the transmission line bundle <NUM>, amplifies echo signals, and/or transmits the echo signals over the transmission line bundle <NUM>. The remaining controllers are slave controllers 206B. The slave controllers 206B may include control logic that drives a transducer <NUM> to emit an ultrasonic signal and selects a transducer <NUM> to receive an echo. In the depicted embodiment, the master controller 206A does not directly control any transducers <NUM>. In other embodiments, the master controller 206A drives the same number of transducers <NUM> as the slave controllers 206B or drives a reduced set of transducers <NUM> as compared to the slave controllers 206B. In an exemplary embodiment, a single master controller 206A and eight slave controllers 206B are provided with eight transducers assigned to each slave controller 206B.

To electrically interconnect the control logic dies <NUM> and the transducers <NUM>, in an embodiment, the flexible substrate <NUM> includes conductive traces <NUM> formed in the film layer that carry signals between the control logic dies <NUM> and the transducers <NUM>. In particular, the conductive traces <NUM> providing communication between the control logic dies <NUM> and the transducers <NUM> extend along the flexible substrate <NUM> within the transition region <NUM>. In some instances, the conductive traces <NUM> can also facilitate electrical communication between the master controller 206A and the slave controllers 206B. The conductive traces <NUM> can also provide a set of conductive pads that contact the conductors <NUM> of the transmission line bundle <NUM> when the conductors <NUM> of the transmission line bundle <NUM> are mechanically and electrically coupled to the flexible substrate <NUM>. Suitable materials for the conductive traces <NUM> include copper, gold, aluminum, silver, tantalum, nickel, and tin, and may be deposited on the flexible substrate <NUM> by processes such as sputtering, plating, and etching. In an embodiment, the flexible substrate <NUM> includes a chromium adhesion layer. The width and thickness of the conductive traces <NUM> are selected to provide proper conductivity and resilience when the flexible substrate <NUM> is rolled. In that regard, an exemplary range for the thickness of a conductive trace <NUM> and/or conductive pad is between <NUM>-<NUM>. For example, in an embodiment, <NUM> conductive traces <NUM> are separated by <NUM> of space. The width of a conductive trace <NUM> on the flexible substrate may be further determined by the width of the conductor <NUM> to be coupled to the trace/pad.

The flexible substrate <NUM> can include a conductor interface <NUM> in some embodiments. The conductor interface <NUM> can be a location of the flexible substrate <NUM> where the conductors <NUM> of the transmission line bundle <NUM> are coupled to the flexible substrate <NUM>. For example, the bare conductors of the transmission line bundle <NUM> are electrically coupled to the flexible substrate <NUM> at the conductor interface <NUM>. The conductor interface <NUM> can be a tab extending from the main body of flexible substrate <NUM>. In that regard, the main body of the flexible substrate <NUM> can refer collectively to the transducer region <NUM>, controller region <NUM>, and the transition region <NUM>. In the illustrated embodiment, the conductor interface <NUM> extends from the proximal portion <NUM> of the flexible substrate <NUM>. In other embodiments, the conductor interface <NUM> is positioned at other parts of the flexible substrate <NUM>, such as the distal portion <NUM>, or the flexible substrate <NUM> may lack the conductor interface <NUM>. A value of a dimension of the tab or conductor interface <NUM>, such as a width <NUM>, can be less than the value of a dimension of the main body of the flexible substrate <NUM>, such as a width <NUM>. In some embodiments, the substrate forming the conductor interface <NUM> is made of the same material(s) and/or is similarly flexible as the flexible substrate <NUM>. In other embodiments, the conductor interface <NUM> is made of different materials and/or is comparatively more rigid than the flexible substrate <NUM>. For example, the conductor interface <NUM> can be made of a plastic, thermoplastic, polymer, hard polymer, etc., including polyoxymethylene (e.g., DELRIN®), polyether ether ketone (PEEK), nylon, Liquid Crystal Polymer (LCP), and/or other suitable materials.

<FIG> illustrates a perspective view of the device <NUM> with the scanner assembly <NUM> in a rolled configuration. In some instances, the assembly <NUM> is transitioned from a flat configuration (<FIG>) to a rolled or more cylindrical configuration (<FIG>). For example, in some embodiments, techniques are utilized as disclosed in one or more of <CIT>, titled "ULTRASONIC TRANSDUCER ARRAY AND METHOD OF MANUFACTURING THE SAME" and <CIT>, titled "HIGH RESOLUTION INTRAVASCULAR ULTRASOUND SENSING ASSEMBLY HAVING A FLEXIBLE SUBSTRATE".

In some embodiments, the transducer elements <NUM> and/or the controllers <NUM> can be positioned in in an annular configuration, such as a circular configuration or in a polygon configuration, around a longitudinal axis <NUM> of a support member <NUM>. It will be understood that the longitudinal axis <NUM> of the support member <NUM> may also be referred to as the longitudinal axis of the scanner assembly <NUM>, the flexible elongate member <NUM>, and/or the device <NUM>. For example, a cross-sectional profile of the imaging assembly <NUM> at the transducer elements <NUM> and/or the controllers <NUM> can be a circle or a polygon. Any suitable annular polygon shape can be implemented, such as a based on the number of controllers/transducers, flexibility of the controllers/transducers, etc., including a pentagon, hexagon, heptagon, octagon, nonagon, decagon, etc. In some examples, the plurality of transducer controllers <NUM> may be used for controlling the plurality of ultrasound transducer elements <NUM> to obtain imaging data associated with the vessel <NUM>.

The support member <NUM> can be referenced as a unibody in some instances. The support member <NUM> can be composed of a metallic material, such as stainless steel, or non-metallic material, such as a plastic or polymer as described in <CIT>, ('<NUM> Application). The support member <NUM> can be a ferrule having a distal flange or portion <NUM> and a proximal flange or portion <NUM>. The support member <NUM> can be tubular in shape and define a lumen <NUM> extending longitudinally therethrough. The lumen <NUM> can be sized and shaped to receive the guide wire <NUM>. The support member <NUM> can be manufactured using any suitable process. For example, the support member <NUM> can be machined and/or electrochemically machined or laser milled, such as by removing material from a blank to shape the support member <NUM>, or molded, such as by an injection molding process.

<FIG> is a diagrammatic cross-sectional side view of a distal portion of the intraluminal imaging device <NUM>, including the flexible substrate <NUM> and the support member <NUM>, according to aspects of the present disclosure. The support member <NUM> can be referenced as a unibody in some instances. The support member <NUM> can be composed of a metallic material, such as stainless steel, or non-metallic material, such as a plastic or polymer as described in <CIT>. The support member <NUM> can be a ferrule having a distal portion <NUM> and a proximal portion <NUM>. The support member <NUM> can define a lumen <NUM> extending along the longitudinal axis LA. The lumen <NUM> is in communication with the entry/exit port <NUM> and is sized and shaped to receive the guide wire <NUM> (<FIG>). The support member <NUM> can be manufactured according to any suitable process. For example, the support member <NUM> can be machined and/or electrochemically machined or laser milled, such as by removing material from a blank to shape the support member <NUM>, or molded, such as by an injection molding process. In some embodiments, the support member <NUM> may be integrally formed as a unitary structure, while in other embodiments the support member <NUM> may be formed of different components, such as a ferrule and stands <NUM>, <NUM>, that are fixedly coupled to one another. In some cases, the support member <NUM> and/or one or more components thereof may be completely integrated with inner member <NUM>. In some cases, the inner member <NUM> and the support member <NUM> may be joined as one, e.g., in the case of a polymer support member.

Stands <NUM>, <NUM> that extend vertically are provided at the distal and proximal portions <NUM>, <NUM>, respectively, of the support member <NUM>. The stands <NUM>, <NUM> elevate and support the distal and proximal portions of the flexible substrate <NUM>. In that regard, portions of the flexible substrate <NUM>, such as the transducer portion or region <NUM>, can be spaced from a central body portion of the support member <NUM> extending between the stands <NUM>, <NUM>. The stands <NUM>, <NUM> can have the same outer diameter or different outer diameters. For example, the distal stand <NUM> can have a larger or smaller outer diameter than the proximal stand <NUM> and can also have special features for rotational alignment as well as control chip placement and connection. To improve acoustic performance, any cavities between the flexible substrate <NUM> and the surface of the support member <NUM> are filled with a backing material <NUM>. The liquid backing material <NUM> can be introduced between the flexible substrate <NUM> and the support member <NUM> via passageways <NUM> in the stands <NUM>, <NUM>. In some embodiments, suction can be applied via the passageways <NUM> of one of the stands <NUM>, <NUM>, while the liquid backing material <NUM> is fed between the flexible substrate <NUM> and the support member <NUM> via the passageways <NUM> of the other of the stands <NUM>, <NUM>. The backing material can be cured to allow it to solidify and set. In various embodiments, the support member <NUM> includes more than two stands <NUM>, <NUM>, only one of the stands <NUM>, <NUM>, or neither of the stands. In that regard the support member <NUM> can have an increased diameter distal portion <NUM> and/or increased diameter proximal portion <NUM> that is sized and shaped to elevate and support the distal and/or proximal portions of the flexible substrate <NUM>.

The support member <NUM> can be substantially cylindrical in some embodiments. Other shapes of the support member <NUM> are also contemplated including geometrical, non-geometrical, symmetrical, non-symmetrical, cross-sectional profiles. As the term is used herein, the shape of the support member <NUM> may reference a cross-sectional profile of the support member <NUM>. Different portions the support member <NUM> can be variously shaped in other embodiments. For example, the proximal portion <NUM> can have a larger outer diameter than the outer diameters of the distal portion <NUM> or a central portion extending between the distal and proximal portions <NUM>, <NUM>. In some embodiments, an inner diameter of the support member <NUM> (e.g., the diameter of the lumen <NUM>) can correspondingly increase or decrease as the outer diameter changes. In other embodiments, the inner diameter of the support member <NUM> remains the same despite variations in the outer diameter.

A proximal inner member <NUM> and a proximal outer member <NUM> are coupled to the proximal portion <NUM> of the support member <NUM>. The proximal inner member <NUM> and/or the proximal outer member <NUM> can include a flexible elongate member. The proximal inner member <NUM> can be received within a proximal flange <NUM>. The proximal outer member <NUM> abuts and is in contact with the flexible substrate <NUM>. A distal member <NUM> is coupled to the distal portion <NUM> of the support member <NUM>. For example, the distal member <NUM> is positioned around the distal flange <NUM>. The distal member <NUM> can abut and be in contact with the flexible substrate <NUM> and the stand <NUM>. The distal member <NUM> can be the distal-most component of the intraluminal imaging device <NUM>.

One or more adhesives can be disposed between various components at the distal portion of the intraluminal imaging device <NUM>. For example, one or more of the flexible substrate <NUM>, the support member <NUM>, the distal member <NUM>, the proximal inner member <NUM>, and/or the proximal outer member <NUM> can be coupled to one another via an adhesive.

The conductor interface <NUM> is positioned at a proximal end of the substrate <NUM>, and provides a point of electrical contact for the transmission line bundle <NUM>. As described above, the transmission line bundle <NUM> may comprise a plurality of conductors configured to carry signals to and from the electrical components positioned on the substrate. The conductors of the transmission line bundle <NUM> are sized, shaped, and otherwise configured to be positioned within the space <NUM> between the proximal outer member <NUM> and the proximal inner member <NUM>.

As described above, space available within the spaces provided in the elongate body of the catheter (e.g., within the proximal outer member <NUM>) may be limited. One approach to positioning the conductors of the transmission line bundle <NUM> within the limited spaces of the catheter is to use a single group of small-gauge wires or ribbons spanning an entire length of the catheter from the scanner assembly to the PIM. The conductors of the bundle <NUM> may be bundled together to form one or more twisted pairs, twisted quads, twisted groups, or other arrangements of conductors. In some embodiments, one or more of the conductors is non-twisted, such that it runs parallel with one or more conductors or twisted groups of conductors.

It will be understood that, while the embodiments described below include IVUS imaging catheters, the present disclosure contemplates that the described structural features and/or arrangements may be used in other types of intraluminal devices, including sensing catheters, guide catheters, imaging probes, sensing probes, or any other suitable type of device.

<FIG> is a diagrammatic side view of an intraluminal imaging device <NUM>, in accordance with at least one embodiment of the present disclosure. The device <NUM> includes a flexible elongate member <NUM>, which includes a working length L (e.g., <NUM> centimeters, although other working lengths, both longer and shorter, may be used instead or in addition) and a gauge or diameter D (e.g., <NUM> French, although other diameters both larger and smaller may be used instead or in addition). The flexible elongate member includes a distal portion <NUM>, a hydrophilic coating <NUM>, and a scanner assembly <NUM>. The device <NUM> also includes a proximal assembly <NUM> that includes a Y-connector <NUM>. The Y-connector <NUM> includes a strain relief <NUM>, and a guidewire lumen exit port <NUM> from which the guidewire <NUM> (as shown for example in <FIG>) can emerge after being inserted into a guidewire lumen entry port <NUM> (located in the distal portion <NUM> of the flexible elongate member <NUM>) and threaded through the guidewire lumen <NUM> (as shown for example in <FIG>). The Y-connector <NUM> also includes the cable <NUM>, which connects the device <NUM> to a Patient Interface Module <NUM> (as shown for example in <FIG>).

<FIG> is a diagrammatic, cross-sectional side view of an example flexible elongate member <NUM>, in accordance with at least one embodiment of the present disclosure. The flexible elongate member includes a distal member or flexible tip <NUM> and a scanner assembly <NUM>. Proximal of the scanner assembly <NUM> is a region <NUM> (e.g., a more flexible region to assist navigation of the flexible elongate member)) and a region <NUM> (e.g., a stiffer region to assist pushing of the flexible elongate member).

The scanner assembly <NUM> includes a flexible substrate or flex circuit <NUM>, a weld leg or conductor interface <NUM>, a sleeve or tube <NUM> (e.g., made of a polymer such as polyimide, polyamide, thermoplastic elastomer like PEBAX®, or PTFE), a tube extension or guidewire lumen extension <NUM> (e.g., made of a polymer such as polyimide, polyamide, thermoplastic elastomer like PEBAX®, or PTFE), and a microcable <NUM> comprising conductors, signal paths, or communication lines <NUM> (as shown for example in <FIG>), at least some of which are welded to one or more weld legs <NUM>. It should be understood that signal paths or communication lines <NUM> may be electrical conductors, fiber optic lines, or other types of signal paths. In that regard, the scanner assembly <NUM> can include acoustic imaging elements, optical imaging elements, photoacoustic imaging elements, etc. For example, scanner assembly <NUM> can be an IVUS imaging assembly, intracardiac echocardiography (ICE) imaging assembly, intravascular photoacoustic (IVPA) imaging assembly, optical coherence tomography (OCT) imaging assembly, etc..

In an example, the polymer tube <NUM> and tube extension <NUM> help to support and protect the weld leg <NUM>, microcable <NUM>, and the junctions therebetween, and/or to provide electrical insulation to the weld leg <NUM> (e.g., conductive traces of the weld leg), the conductors <NUM>, and any welds or joins between the weld leg and the conductors.

A portion of the polymer protection tube <NUM> may also extend into region <NUM>. The polymer tube <NUM> can be any suitable length, and the proximal and distal ends of the polymer tube can be positioned in a variety of locations. For example, a distal end of the tube <NUM> can extend partially or completely (longitudinally) over the integrated circuit region <NUM> of the scanner assembly <NUM>, or completely over the transition region <NUM> of the scanner assembly <NUM>, partially or completely over the transducer array <NUM> of the scanner assembly <NUM>. A proximal end of the tube <NUM> can extend into region <NUM> of the flexible elongate member <NUM>. The flexible substrate <NUM> may extend partially or completely along the length of the tube extension or guidewire lumen extension <NUM> on the proximal side of support member <NUM>.

Region <NUM> includes an inner member <NUM> (e.g., composed at least partly of braided metal wires), the microcable <NUM>, and an outer layer <NUM> (e.g., a flexible cylindrical tube of a polymer such as polyamide like Vestamid®), at least a portion of which is filled with a flexible adhesive <NUM>. In an example, the outer diameter of region <NUM> is the same as, and is defined by, the outer diameter of the outer layer <NUM>. Depending on the implementation, the durometer or hardness of the flexible adhesive <NUM> may be selected to adjust the flexibility of region <NUM>, while also enhancing the resistance of region <NUM> to kinking or buckling as the flexible elongate member is pushed through the tortuous pathways of human vasculature. In some embodiments, portions of the inner member <NUM>, adhesive <NUM>, and outer layer <NUM> may also extend into the scanner assembly <NUM>.

Region <NUM> includes the inner member <NUM>, microcable <NUM>, and an outer member <NUM>. In an example, the outer member <NUM> comprises a tube or shaft <NUM> composed of metal wires or ribbons enclosed in or covered by a smooth coating or sheath <NUM> of a biocompatible polymer (e.g., polyimide, polyamide, thermoplastic elastomer like PEBAX®, or PTFE). The metal wires or ribbons can be segments of a metal tube or shaft <NUM> that are cut in a spiral configuration comprising one, two, three, or more spirals. In other embodiments, the metal wires or ribbons may be embedded in or surrounded by the polymer <NUM>, or else outer member <NUM> may be composed entirely of polymer or entirely of metal, or of other materials, depending on the implementation. In an example, the outer member <NUM> is flexible enough to navigate the tortuous pathways of human vasculature, but stiff enough, and resistant enough to buckling or kinking, that the flexible elongate member <NUM> may be readily pushed forward through the tortuous pathways. In an example, the outer diameter of region <NUM> is equal to, and defined by, the outer diameter of the outer member <NUM>. The polymer sheath <NUM> may for example be thermally bonded to the outer layer <NUM>, forming a smooth surface of constant diameter.

Cut plane <NUM>-<NUM> shows a cross-sectional plane through the flexible elongate member <NUM>, which is shown in greater detail in <FIG>. Cut plane <NUM>-<NUM> shows a cross-sectional plane through the flexible elongate member <NUM>, which is shown in greater detail in <FIG>.

<FIG> is a diagrammatic, cross-sectional side view of a distal portion <NUM> of an example flexible elongate member <NUM>, in accordance with at least one embodiment of the present disclosure. The distal portion <NUM> includes the scanner assembly <NUM> and distal member or flexible tip <NUM>. The scanner portion <NUM> includes the flexible substrate or flex circuit <NUM>, one or more weld legs or conductor interface <NUM> (e.g., one, two, three, or more weld legs), the protection sleeve or protection tube <NUM>, the tube extension <NUM>, and the microcable <NUM>. The scanner assembly <NUM> also includes the inner member <NUM> and the outer layer <NUM>, at least a portion of which is filled with the flexible adhesive <NUM>. The distal portion <NUM> also includes adhesive fillets <NUM> and <NUM>, which may for example form smooth, biocompatible transition regions between the outer surfaces of the flexible substrate <NUM>, outer layer <NUM>, and distal tip <NUM>. In an example, fillets <NUM> and <NUM> are formed with a UV-curable adhesive that provides mechanical joint stability and prevents fluid ingress.

Cut plane <NUM>-<NUM> shows a cross-sectional plane through the distal portion <NUM> of the flexible elongate member <NUM>, which is shown in greater detail in <FIG>. Cut plane <NUM>-<NUM> shows a cross-sectional plane through the distal portion <NUM> of the flexible elongate member <NUM>, which is shown in greater detail in <FIG>. Cut plane <NUM>-<NUM> shows a cross-sectional plane through the distal portion <NUM> of the flexible elongate member <NUM>, which is shown in greater detail in <FIG>.

<FIG> is a is a diagrammatic, cross-sectional perspective view of a distal portion <NUM> of an example flexible elongate member <NUM>, in accordance with at least one embodiment of the present disclosure. The distal portion <NUM> includes the scanner assembly <NUM> and distal member or flexible tip <NUM>. The scanner portion <NUM> includes the flexible substrate or flex circuit <NUM>, one or more weld legs or conductor interfaces <NUM>, the sleeve or tube <NUM>, the tube extension <NUM>, and the microcable <NUM>. The scanner assembly <NUM> also includes the inner member <NUM> and the outer layer <NUM>, at least a portion of which is filled with the flexible adhesive <NUM>.

<FIG> is a is a diagrammatic, cross-sectional side view of a scanner assembly <NUM> of an example flexible elongate member <NUM>, in accordance with at least one embodiment of the present disclosure. In an example, the scanner assembly <NUM> includes the flexible substrate <NUM>, upon which are formed a transducer array <NUM> comprising acoustic elements <NUM> (shown for example in <FIG>) in a transducer region <NUM>, and transducer control logic dies or controller chips <NUM> formed in a control region <NUM>, with a transition region <NUM> disposed therebetween.

In the example shown in <FIG>, the flexible substrate <NUM> is wrapped around a support member <NUM>. Cavities between the flexible substrate <NUM> and the surface of the support member <NUM> are filled with an acoustic backing material <NUM> (e.g., an adhesive, electrical insulator, or thermal insulator) to attenuate ultrasound energy propagating in undesired directions (e.g., radially inward). The flexible substrate <NUM> includes one or more conductor interfaces or weld legs <NUM>, where the conductors <NUM> of the transmission line bundle or microcable <NUM> are coupled to the flexible substrate <NUM>. In some embodiments, the support member <NUM> and/or one or more components thereof may be joined with inner the braided inner member <NUM> (e.g., by welding, soldering, adhesive, etc.).

The scanner assembly <NUM> also includes a protection sleeve or protection tube <NUM> spaced radially outward from the weld legs <NUM>, and a tube extension <NUM> spaced radially inward from the weld legs <NUM>. In an example, the tube <NUM> and tube extension <NUM> help to support and protect the connection between the microcable <NUM> and the one or more weld legs <NUM>. The microcable <NUM> may comprise one or more conductors or signal paths <NUM> (shown for example in <FIG>). The conductors or signal paths <NUM> can be twisted or straight, and each conductor <NUM> can for example be a bare wire surrounded by an insulating layer. In an example, the conductors <NUM> carry electrical signals from the console and/PIM to the imaging assembly (as shown for example in <FIG>). Extending longitudinally through the scanner assembly <NUM> (and in some embodiments, through the entirety of the flexible elongate member), interior to the inner member <NUM>, support member <NUM>, and distal member <NUM>, is a lumen <NUM>, through which the guidewire <NUM>, or other tools or materials, may be threaded or transported.

Spaced radially outward from the inner member <NUM> is the outer layer <NUM>, with the space between the inner member <NUM> and the outer member <NUM> filled with flexible adhesive <NUM>. In some embodiments, the outer layer <NUM> can be formed of polymer, or metal wires that are braided or spiraled together, or a combination of the two. The polymer can be a coating over the metal wires, or it may be polymer tubing.

In some embodiments, a portion of the flexible adhesive <NUM> extends between the polymer outer layer <NUM> and the polymer protection sleeve <NUM>, all the way to adhesive fillet <NUM>. In some embodiments, at least a portion of the space between the outer member <NUM> and the tube or sleeve <NUM> is filled with an adhesive <NUM>, which may be the same as, similar to, or different from adhesive <NUM> or backing material <NUM>. Similarly, at least a portion of the space between the flex circuit <NUM> (e.g., the weld legs <NUM>) and at least a portion of the polymer sleeve <NUM> is filled with an adhesive <NUM>, which may or may not be the same ad adhesive <NUM>.

Also visible are adhesive fillets <NUM> and <NUM>. In an example, adhesive fillets <NUM> and <NUM> are positioned on the outer surface of the flexible substrate <NUM>, where they may be directly exposed to the fluids and walls of the vessel <NUM>. Accordingly, they may comprise an adhesive that is smooth, low-friction, and biocompatible. This adhesive may be the same as, similar to, or different from adhesives <NUM>, <NUM>, or <NUM>.

The boundaries between the adhesives need not be straight as shown, but can be angled, irregular, or otherwise, and may be placed differently than shown herein. One adhesive may extend into the other adhesive region and vice versa, or adhesives may partially or completely bond or blend at the interfaces between them.

In some embodiments, space <NUM> inside the sleeve <NUM> is not filled (e.g., with adhesive). In such embodiments, the sleeve <NUM> is thereby advantageously permitted to flex, such as when the imaging device moves through tortuous vasculature. Because the sleeve <NUM> is coupled to the substrate <NUM> via the adhesive <NUM>, <NUM>, <NUM>, flexing of the sleeve <NUM> advantageously causes flexing of the substrate <NUM> as well.

<FIG> is a diagrammatic, cross-sectional perspective view of cut plane <NUM>-<NUM> of region <NUM> from <FIG>, in accordance with at least one embodiment of the present disclosure. Visible are the inner member <NUM>, the interior of which defines lumen <NUM>, and the microcable <NUM>. Inner member <NUM>, lumen <NUM>, and microcable <NUM> extend through regions <NUM> and <NUM>. In region <NUM>, an outer layer <NUM> is spaced radially outward from the inner member <NUM>, and the space between the inner member <NUM> and outer member <NUM> is at least partially filled with a flexible adhesive <NUM>, which may or may not also extend into portion <NUM>. In an example, outer layer <NUM> terminates at the boundary between region <NUM> and region <NUM>, where it is joined (e.g., by friction fitting, adhesive, or other means) to outer member <NUM> (which may, for example, be a metal tube that is spiral cut along at least a portion of its length, to render it flexible).

<FIG> is a diagrammatic, cross-sectional view of cut plane <NUM>-<NUM> of region <NUM> from <FIG>, in accordance with at least one embodiment of the present disclosure. Visible is the inner member <NUM>, the interior of which defines lumen <NUM>. Also visible are the outer layer <NUM> (made for example of a polymer such as Vestamid®, polyimide, polyamide, thermoplastic elastomer like PEBAX®, or PTFE), the microcable <NUM>, and the flexible adhesive <NUM>, which fills at least a portion of the space between the inner member <NUM> and outer layer <NUM>. In an example, the hardness or durometer of the flexible adhesive <NUM> helps to determine the flexibility of region <NUM> of the flexible elongate member. The hardness and/or flexibility of the region <NUM> can be a composite of and/or otherwise result from the individual hardnesses and/ flexibilities of the individual components in the region <NUM>. A particular adhesive <NUM> (with a given hardness and/or flexibility) can be selected by a manufacturer such that the region <NUM> has the desired composite hardness and/or flexibility. In that regard, manufacturing is advantageously made more efficient because implementation of a given adhesive <NUM> and/or changing from one adhesive <NUM> to another within the region <NUM> to achieve the desired hardness and/or flexibility may be logistically easier than changing other components within the region <NUM> to achieve the desired hardness and/or flexibility.

In the example shown in <FIG>, inner member <NUM> comprises an inner layer <NUM>, composed for example of a polymer such as <NUM>" PTFE film, that forms the wall of lumen <NUM>. Inner member <NUM> further comprises a middle layer <NUM> composed for example of mechanically flattened, braided, <NUM>" x <NUM>" SS304V wires with a combined ultimate tensile strength of <NUM>,<NUM> to <NUM>,<NUM> PSI, and a braid pitch of <NUM> ± <NUM> PPI. Inner member <NUM> further comprises an interface layer <NUM> that may for example be made of a polymer such as <NUM>" PEBAX <NUM> SA01 film. In the example shown in <FIG>, interface layer <NUM> forms the outer surface of inner member <NUM>, and is in circumferential contact with flexible adhesive <NUM>. In some embodiments, the interface layer <NUM> may include a slot, notch, or groove <NUM> for receiving the microcable <NUM>. Although the microcable <NUM> is shown fully surrounded by adhesive <NUM>, and not in contact with either the interface layer <NUM> or the outer layer <NUM>, it should be noted that the positioning of the microcable <NUM> may be different than shown here, and may vary over the length of the flexible elongate member, so that for example the microcable <NUM> may be in contact with either or both of the interface layer <NUM> or the outer layer <NUM>.

<FIG> is a diagrammatic, cross-sectional perspective view of cut plane <NUM>-<NUM> of region <NUM> from <FIG>, in accordance with at least one embodiment of the present disclosure. Visible are the outer member <NUM> (e.g., a spiral-cut shaft of spring steel coated with an outer layer of polymer), which is hollow and thus defines an outer lumen <NUM>. Disposed within the outer lumen are the inner member <NUM> and the microcable <NUM>, which may or may not be bonded to the inner member <NUM> (e.g., by adhesive, shrink tubing, or other means). The interior of the inner member <NUM> defines the guidewire lumen or inner lumen <NUM>, through which the guidewire <NUM> or other tools may be extended.

<FIG> is a diagrammatic, cross-sectional perspective view of cut plane <NUM>-<NUM> of scanner assembly <NUM> from <FIG>, in accordance with at least one embodiment of the present disclosure. Visible are portions of the scanner assembly <NUM> and region <NUM> of the flexible elongate member <NUM>. Extending through the visible portions of scanner assembly <NUM> and region <NUM> are the inner member <NUM> and microcable <NUM>, which in this example is adhered to an outer surface of the inner member <NUM> (e.g., with an adhesive). Also visible are the outer layer <NUM> and the flexible adhesive <NUM>, which fills at least a portion of the space between the inner member <NUM> and outer layer <NUM>. Additionally visible are the polymer tube or sleeve <NUM>, adhesive <NUM>, and weld legs <NUM> of the scanner assembly <NUM>, to which conductor <NUM> of the microcable <NUM> may be electrically and mechanically coupled (e.g., by welding or soldering).

<FIG> is a diagrammatic, cross-sectional perspective view of cut plane <NUM>-<NUM> of scanner assembly <NUM> from <FIG>, in accordance with at least one embodiment of the present disclosure. Visible is the outer layer <NUM>. Flexible adhesive <NUM> is disposed radially inward from the outer layer <NUM>, and may be in contact with the outer layer <NUM> along at least a portion of region <NUM> and at least a portion of scanner assembly <NUM>. Disposed radially inward from flexible adhesive <NUM> is inner member <NUM>, which may extend through the entirety of region <NUM> and at least a portion of scanner assembly <NUM>. A tube <NUM> (e.g., a polymer tube for protection of the weld legs <NUM>) is disposed radially inward from the outer layer <NUM> and radially outward from the inner member <NUM>, and radially outward from at least a portion of the flexible adhesive <NUM>. A tube extension <NUM> is disposed radially inward from tube <NUM> and radially outward from inner member <NUM>, such that at least a portion of tube extension <NUM> is in circumferential contact with at least a portion of inner member <NUM>. An additional adhesive <NUM> may be disposed between the tube <NUM> and the outer layer <NUM>. Also visible are two weld legs <NUM>, although other numbers of weld legs <NUM> may be employed.

<FIG> is a diagrammatic, cross-sectional perspective view of cut plane <NUM>-<NUM> of scanner assembly <NUM> from <FIG>, in accordance with at least one embodiment of the present disclosure. Flexible adhesive <NUM> is disposed radially inward from the outer layer <NUM>, and may be in contact with the outer layer <NUM> along at least a portion of region <NUM> and at least a portion of scanner assembly <NUM>. Disposed radially inward from flexible adhesive <NUM> is inner member <NUM>. A tube <NUM> is disposed radially inward from the outer layer <NUM> and radially outward from inner member <NUM>, and radially outward from at least a portion of the flexible adhesive <NUM>. A tube extension <NUM> is disposed radially inward from tube <NUM> and radially outward from inner member <NUM>. Adhesive <NUM> is disposed between the polymer tube <NUM> and the outer layer <NUM>. Also visible are microcable <NUM>, support member <NUM>, and various portions of the flex circuit <NUM>, including a weld leg <NUM> and control chips <NUM>.

<FIG> is a perspective view of an interface region <NUM> between regions <NUM> and <NUM> of an example flexible elongate member <NUM>, in accordance with at least one embodiment of the present disclosure. The outer member <NUM> of region <NUM> may have a similar or identical diameter to the outer layer <NUM> of region <NUM>, and may be fixedly coupled to the outer layer <NUM> of region <NUM> by a friction fit, an adhesive, or combinations thereof. Visible inside the outer layer <NUM> is inner member <NUM>, which is surrounded by adhesive <NUM>. In an example, the space between outer layer <NUM> and inner member <NUM> is filled with adhesive <NUM> by means of an aperture <NUM> (e.g., a hole drilled or poked into outer layer <NUM>) through which the adhesive <NUM> is injected in a liquid state (e.g., by a hypodermic needle). Depending on the implementation, after injection the adhesive <NUM> may harden or be cured, or may remain in a liquid or gel state. Aperture <NUM> is then plugged, either by hardening or curing of adhesive <NUM>, or by application and hardening/curing of another adhesive, or by welding of the polymer material of outer layer <NUM>, or by other means.

<FIG> is a diagrammatic, cross-sectional side view of the interface region <NUM> and region <NUM> from <FIG>, in accordance with at least one embodiment of the present disclosure. Visible are the outer member <NUM>, adhesive <NUM>, inner member <NUM>, inner lumen or guidewire lumen <NUM>, microcable <NUM>, and adhesive filling aperture, port, or opening <NUM>. Within the filling aperture <NUM> is a plug <NUM>, which may comprise the same material as adhesive <NUM>, or may comprise another adhesive, or may comprise the same or a similar material as outer member <NUM>. In an example, plug <NUM> is fluorescent, such that it may be examined under ultraviolet light (e.g., using a microscope).

<FIG> is a perspective view of an example flexible elongate member <NUM>, including scanner assembly <NUM>, distal tip <NUM>, region <NUM>, and a portion of region <NUM>, in accordance with at least one embodiment of the present disclosure. Also visible is plug <NUM> in aperture or opening <NUM>. In this example, plug <NUM> is fluorescing (e.g., emitting visible light) under the influence of an ultraviolet light source <NUM>, which may for example be a light-emitting diode, laser diode, or other blue, violet or ultraviolet light source. Fluorescence of the plug <NUM> facilitates inspection, such that for example a quality control technician may observe the plug <NUM> under a microscope (not pictured) to confirm that aperture <NUM> is properly plugged.

A person of ordinary skill in the art will recognize that the present disclosure advantageously provides an intraluminal imaging system that enables both pushability and flexibility for navigating an imaging assembly through human vasculature. The logical operations making up the embodiments of the technology described herein are referred to variously as operations, steps, objects, elements, components, regions, etc. Furthermore, it should be understood that these may occur in any order, unless explicitly claimed otherwise or a specific order is inherently necessitated by the claim language.

It should further be understood that the described technology may be employed in a variety of different applications, including but not limited to human medicine, veterinary medicine, education and inspection. All directional references e.g., upper, lower, inner, outer, upward, downward, left, right, lateral, front, back, top, bottom, above, below, vertical, horizontal, clockwise, counterclockwise, proximal, and distal are only used for identification purposes to aid the reader's understanding of the claimed subject matter, and do not create limitations, particularly as to the position, orientation, or use of the intraluminal imaging system. Connection references, e.g., attached, coupled, connected, and joined are to be construed broadly and may include intermediate members between a collection of elements and relative movement between elements unless otherwise indicated. As such, connection references do not necessarily imply that two elements are directly connected and in fixed relation to each other. The term "or" shall be interpreted to mean "and/or" rather than "exclusive or. " The word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. Unless otherwise noted in the claims, stated values shall be interpreted as illustrative only and shall not be taken to be limiting.

Claim 1:
An intraluminal imaging device, comprising:
a flexible elongate member comprising a catheter, the flexible elongate member configured to be positioned within a body lumen of a patient, wherein the flexible elongate member comprises a proximal portion and a distal portion; and
an imaging assembly disposed at the distal portion of the flexible elongate member and configured to obtain intraluminal image data while positioned within the body lumen,
wherein the distal portion of the flexible elongate member comprises a region proximal to the imaging assembly, wherein the region comprises a first hardness that is less than a second hardness of the proximal portion of the flexible elongate member such that the region is more flexible than the proximal portion, wherein the region comprises:
an inner member;
a first adhesive configured to provide the first hardness, wherein the first adhesive surrounds the inner member;
a communication line configured to carry signals associated with the imaging assembly; and
an outer polymer layer surrounding the first adhesive,
characterized in that the inner member defines a guidewire lumen, and the communication line is embedded within the first adhesive.