Distortion reduction for intraluminal ultrasound imaging and related devices, systems and methods - Patents.com

Abstract

An intraluminal imaging device and a method for assembling an intraluminal imaging device are provided. For example, the intraluminal imaging device can include a flexible, elongate catheter body and a rigid imaging assembly coupled to a distal portion of the elongate catheter body. A distal portion of an inner member is disposed within the lumen of the imaging assembly, and the flexible, elongate member has a strain relief layer disposed about the inner member. The distal portion of the strain relief layer is disposed radially between the inner member and the imaging assembly, and a proximal end of the strain relief layer is disposed distal to the proximal end of the inner member, forming a transition region. The transition region can prevent bending or kinking of the flexible, elongate catheter body when the intraluminal imaging device is navigating tortuous regions of a patient's anatomy.

Description

[Technical field]

[0001] The present disclosure relates generally to intraluminal medical imaging, and more particularly to a distal structure of an intraluminal imaging device. For example, the distal structure may include a strain relief layer disposed over an elongate member and partially within the lumen of an imaging assembly to facilitate robust operation of the intravascular imaging device. [Background technology]

[0002] Intravascular ultrasound (IVUS) imaging is widely used in interventional cardiology as a diagnostic tool to evaluate diseased blood vessels, such as arteries, within the human body to determine the need for treatment, guide intervention, and / or evaluate its effectiveness. An IVUS device, including one or more ultrasound transducers, is passed into the blood vessel and guided to the area to be imaged. The transducers emit ultrasound energy to create an image of the blood vessel of interest. The ultrasound waves are partially reflected by discontinuities resulting from tissue structures (e.g., various layers of the blood vessel wall), red blood cells, and other features of interest. Echoes from the reflected waves are received by the transducers and sent to an IVUS imaging system. The imaging system processes the received ultrasound echoes to generate a cross-sectional image of the blood vessel in which the device is placed.

[0003] Solid-state (also known as synthetic aperture) IVUS catheters are one of two types of IVUS devices in common use today, the other being rotational IVUS catheters. Solid-state IVUS catheters carry a scanner assembly that includes an array of ultrasound transducers distributed around its periphery, with one or more integrated circuit controller chips mounted adjacent to the transducer array. The controller selects individual acoustic elements (or groups of elements) for transmitting ultrasound pulses and receiving ultrasound echo signals. By stepping through a series of transmit-receive pairs, solid-state IVUS systems can compound the effect of mechanically scanned ultrasound transducers, but have no moving parts (hence the solid-state designation). Solid-state scanners can be wired directly to imaging systems using simple electrical cables and standard detachable electrical connectors, rather than the complex rotating electrical interface required for rotational IVUS devices. Summary of the Invention [Problem to be solved by the invention]

[0004] It is difficult to manufacture a solid-state IVUS device that can effectively traverse the anatomical structures within the human body. In this regard, an IVUS device may include various structures that have different mechanical properties (e.g., stiffness) at different portions along the length of the device, such as a relatively rigid scanner assembly and a relatively flexible elongated catheter body. These differences in mechanical properties can result in bending or kinking, especially when the IVUS device is traversing tortuous regions of the vasculature. [Means for solving the problem]

[0005]

[0005] Embodiments of the present disclosure provide an improved intraluminal imaging device, as well as a method of assembling an improved intraluminal imaging device. For example, in one embodiment, the intraluminal imaging device includes a flexible elongated catheter body and a rigid imaging assembly coupled to a distal portion of the elongated catheter body. The distal end of the elongated catheter body is disposed within the lumen of the imaging assembly. A strain relief layer is disposed about the distal end of the elongated catheter body that is inserted into the lumen of the imaging assembly such that the distal portion of the strain relief layer is radially between the elongated catheter body and the imaging assembly. A proximal portion of the strain relief layer extends on the elongated catheter body proximal to the imaging assembly, providing a transition region from the rigid imaging assembly to the flexible elongated catheter body. The proximal transition region of the imaging assembly can prevent bending or kinking of the flexible elongated catheter body when the intraluminal imaging device is navigating tortuous regions of a patient's anatomy.

[0006] In one embodiment of the present disclosure, an intraluminal ultrasound imaging system includes a flexible elongate member configured to be disposed within a body lumen of a patient, the flexible elongate member having an inner member, an imaging assembly having ultrasound scanner circuitry disposed about the lumen, the imaging assembly coupled to the flexible elongate member, a distal portion of the inner member disposed within the lumen of the imaging assembly, the flexible elongate member having a strain relief layer disposed about the inner member, the distal portion of the strain relief layer disposed radially between the inner member and the imaging assembly, and a proximal end of the strain relief layer disposed distal to the proximal end of the inner member.

[0007] In some embodiments, the strain relief layer comprises a heat shrink material. The heat shrink material can include a polyether block amide tube. In some embodiments, the flexible elongate member comprises an outer member disposed over a proximal portion of the inner member and a proximal portion of the strain relief layer. In some embodiments, the imaging assembly comprises a support member defining a lumen of the imaging assembly, and the ultrasound scanner circuit comprises a flexible substrate disposed about the support member. The ultrasound scanner circuit can comprise a conductor interface portion disposed about the strain relief layer. In some embodiments, the strain relief layer has a length between 5 mm and 15 mm. The strain relief layer can, in some embodiments, comprise a wall thickness between 0.025 mm and 0.032 mm. In some embodiments, the strain relief layer is thermally bonded to the inner member. In some embodiments, the strain relief layer is bonded to the inner member using an adhesive. In some embodiments, the imaging assembly is an intravascular ultrasound (IVUS) assembly, and the flexible elongate member comprises a catheter.

[0008] In accordance with another embodiment of the present disclosure, a method for assembling an intraluminal ultrasound imaging device includes forming a flexible elongate member configured to be disposed within a body lumen of a patient, where forming the flexible elongate member includes disposing a strain relief tube about an inner member such that a proximal end of the strain relief tube is disposed distal to a proximal end of the inner member, and fixedly coupling the strain relief tube to the inner member. The method further includes coupling an ultrasonic imaging assembly to the flexible elongate member. Coupling the ultrasonic imaging assembly includes disposing a distal portion of the inner member and a distal portion of the strain relief tube through a lumen of the ultrasonic imaging assembly.

[0009] In some embodiments, the method further includes disposing an outer member over the proximal portion of the inner member and the proximal portion of the strain relief tube. In some embodiments, fixedly coupling the strain relief tube comprises thermally coupling the strain relief tube and the inner member. In some implementations, fixedly coupling the strain relief tube comprises applying heat to the strain relief tube to shrink the strain relief tube around the inner member. In some implementations, fixedly coupling the strain relief tube comprises disposing a heat shrink tube around the strain relief tube and applying heat to the heat shrink tube to shrink the heat shrink tube around the strain relief tube. In some embodiments, the ultrasound imaging assembly includes scanner circuitry disposed about a support member defining a lumen of the ultrasound imaging assembly, and disposing a distal portion of the inner member and a distal portion of the strain relief tube through a lumen of the imaging assembly comprises disposing a distal portion of the inner member and a distal portion of the strain relief tube through a lumen of the support member.

[0010] In some embodiments, the method includes the steps of disposing an outer member over a proximal portion of the inner member and a proximal portion of the strain relief tube; disposing a scanner circuit conductor interface portion about an outer surface of the strain relief tube, wherein disposing a proximal portion of the strain relief tube and an outer member of the proximal portion of the strain relief tube comprises disposing the outer member over the scanner circuit conductor interface portion; Further includes:

[0011] Further aspects, features, and advantages of the present disclosure will become apparent from the following detailed description.

[0012] Exemplary embodiments of the present disclosure will now be described with reference to the accompanying drawings. [Brief description of the drawings]

[0013] [Figure 1] 1 is a schematic diagram of an endoluminal imaging system according to an aspect of the present disclosure. [Diagram 2]FIG. 2 is a schematic perspective view of the top of a scanner assembly in a flat configuration, according to an aspect of the present disclosure. [Diagram 3] FIG. 3 is a schematic perspective view of the scanner assembly shown in FIG. 2 in a wrapped configuration around a support member, according to an embodiment of the present disclosure. [Figure 4] FIG. 4 is a schematic cross-sectional side view of the scanner assembly shown in FIG. 3 according to an embodiment of the present disclosure. [Diagram 5] 1 is a schematic cross-sectional side view of a transition region of a scanner assembly, according to an aspect of the present disclosure. [Figure 6A] FIG. 6 is a schematic cross-sectional view of the scanner assembly shown in FIG. 5 taken along line 6-6, in accordance with an embodiment of the present disclosure. [Figure 6B] FIG. 6 is a schematic cross-sectional view of the scanner assembly shown in FIG. 5 taken along line 6-6, in accordance with an embodiment of the present disclosure. [Figure 7] 1 is a flow diagram of a method for assembling an intravascular imaging device according to an aspect of the present disclosure. [Figure 8A] 1A-1D are side views of an intravascular imaging device at various points in an assembly process, according to aspects of the present disclosure. [Figure 8B] 1A-1D are side views of an intravascular imaging device at various points in an assembly process, according to aspects of the present disclosure. [Figure 8C] 1A-1D are side views of an intravascular imaging device at various points in an assembly process, according to aspects of the present disclosure. [Figure 8D] 1A-1D are side views of an intravascular imaging device at various points in an assembly process, according to aspects of the present disclosure. [Figure 8E] 1A-1D are side views of an intravascular imaging device at various points in an assembly process, according to aspects of the present disclosure. [Figure 9] 1 is a schematic cross-sectional side view of a transition region of a scanner assembly having a flexible distal tip with a proximal extension, according to an aspect of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] For purposes of facilitating an understanding of the principles of the present disclosure, reference will now be made to the embodiments shown in the drawings, and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the present disclosure is intended. Any changes and further modifications to the described apparatus, systems, and methods, and any further applications of the principles of the present disclosure, as would normally occur to one skilled in the art to which the present disclosure pertains, are fully contemplated and included within the present disclosure. For example, while the focusing system is described with respect to cardiovascular imaging, it will be understood that it is not intended to be limited to this application. The system is equally well suited to any application requiring imaging within a confined cavity. In particular, it is fully contemplated that features, components, and / or steps described with respect to one embodiment may be combined with features, components, and / or steps described with respect to other embodiments of the present disclosure. However, for the sake of brevity, multiple iterations of these combinations will not be described separately.

[0015] 1 is a schematic diagram of an endoluminal imaging system 100 according to an embodiment of the present disclosure. The endoluminal imaging system 100 can be an ultrasound imaging system. In some cases, the system 100 can be an intravascular ultrasound (IVUS) imaging system. The system 100 may include an endoluminal imaging device 102, such as a catheter, guidewire, or guide catheter, a patient interface module (PIM) 104, a processing system or console 106, and a monitor 108. The endoluminal imaging device 102 can be an ultrasound imaging device. In some cases, the device 102 can be an IVUS imaging device, such as a solid-state IVUS device.

[0016] At a high level, the IVUS device 102 emits ultrasonic energy from a transducer array 124 included in a scanner assembly 110 mounted near the distal end of the catheter device. The ultrasonic energy is reflected by tissue structures in a medium, such as a blood vessel 120 or another body cavity surrounding the scanner assembly 110, and ultrasonic echo signals are received by the transducer array 124. In this regard, the device 102 can be sized, shaped, or otherwise configured to be placed within a patient's body cavity. The PIM 104 transfers the received echo signals to a console or computer 106, where an ultrasound image (including flow information) is reconstructed and displayed on a monitor 108. The console or computer 106 can include a processor and memory. The computer or computing device 106 can be operable to facilitate the features of the IVUS imaging system 100 described herein. For example, the processor can execute computer readable instructions stored on a non-transitory tangible computer readable medium.

[0017] The PIM 104 facilitates communication of signals between the IVUS console 106 and the scanner assembly 110 included in the IVUS device 102. This communication includes (1) providing commands to the integrated circuit controller chips 206A, 206B shown in FIG. 2 included in the scanner assembly 110 to select the particular transducer array element or acoustic element to be used for transmission and (2) providing a transmit trigger signal to the integrated circuit controller chips 206A, 206B included in the scanner assembly 110 to activate transmitter circuitry to generate an electrical pulse that excites the selected transducer array element, and (3) accepting amplified echo signals received from the selected transducer array element via an amplifier included in the integrated circuit controller chip 126 of the scanner assembly 110. In some embodiments, the PIM 104 performs pre-processing of the echo data before relaying the data to the console 106. In an example of such an embodiment, the PIM 104 performs amplification, filtering, and / or aggregation of the data. In one embodiment, the PIM 104 also provides high and low voltage DC power to support operation of the device 102 , including the circuitry within the scanner assembly 110 .

[0018] The IVUS console 106 receives echo data from the scanner assembly 110 via the PIM 104 and processes the data to reconstruct an image of tissue structures within the medium surrounding the scanner assembly 110. The console 106 outputs the image data such that an image of the blood vessel 120, such as a cross-sectional image of the blood vessel 120, is displayed on the monitor 108. The blood vessel 120 may represent both natural and artificial fluid-filled or surrounded structures. The blood vessel 120 may be within a patient's body. The blood vessel 120 may be a blood vessel as an artery or vein of the patient's vascular system, including the cardiovascular system, peripheral vascular system, neurovascular system, renal vascular system, and / or any other suitable lumen within the body. For example, device 102 may be used to inspect any number of anatomical locations and tissue types, including, but not limited to, organs including the liver, heart, kidneys, gallbladder, pancreas, lungs, ducts, intestines, brain, dural sac, nervous system structures including the spinal cord and peripheral nerves, urinary tract, and valves, ventricles or other parts of the blood vessels of the heart, and / or other systems of the body. In addition to natural structures, device 102 may be used to inspect artificial structures, such as, but not limited to, heart valves, stents, shunts, filters, and other devices.

[0019] In some embodiments, the IVUS device includes some features similar to conventional solid-state IVUS catheters, such as the EagleEye® catheter available from Volcano, Inc. and those disclosed in U.S. Patent No. 7,846,101, which is incorporated herein by reference in its entirety. For example, the IVUS device 102 includes a scanner assembly 110 near the distal end of the device 102 and a transmission wire bundle 112 extending along the longitudinal body of the device 102. The transmission wire bundle or cable 112 can include multiple conductors, including one, two, three, four, five, six, seven, or more conductors 218 (FIG. 2). It is understood that any suitable gauge wire can be used for the conductors 218. In one embodiment, the cable 112 can include a four-conductor transmission line configuration, for example, having 41 AWG gauge wire. According to one embodiment, the cable 112 can include a seven-conductor transmission line configuration, for example, utilizing 44 AWG gauge wire. In some embodiments, 43 AWG gauge wire can be used.

[0020] The transmission line bundle 112 terminates at a PIM connector 114 at the proximal end of the device 102. The PIM connector 114 electrically couples the transmission line bundle 112 to the PIM 104 and physically couples the IVUS device 102 to the PIM 104. In one embodiment, the IVUS device 102 further includes a guidewire exit port 116. Thus, in some cases, the IVUS device is a rapid exchange catheter. The guidewire exit port 116 allows a guidewire 118 to be inserted toward the distal end to guide the device 102 through a blood vessel 120.

[0021] FIG. 2 is a schematic top view of a portion of a flexible assembly 200 according to an embodiment of the present disclosure. For purposes of this disclosure, the flexible assembly 200 may be referred to as an ultrasonic scanner circuit. The flexible assembly 200 includes a transducer array 124 formed in a transducer region 204 and a transducer control logic die 206 (including dies 206A and 206B) formed in a control region 208 with a transition region 210 disposed therebetween. The transducer array 124 includes an array of ultrasonic transducers 212. The transducer control logic die 206 is mounted on a flexible substrate 214 on which the transducers 212 were previously integrated. The flexible substrate 214 is shown in a flat configuration in FIG. 2. Although six control logic dies 206 are shown in FIG. 2, any number of control logic dies 206 may be used. For example, one, two, three, four, five, six, seven, eight, nine, ten, or more control logic dies 206 may be used.

[0022] The flexible substrate 214 on which the transducer control logic die 206 and transducer 212 are attached provides structural support and interconnects for electrical coupling. The flexible substrate 214 may be configured to include a film layer of flexible polyimide material, such as KAPTON® (a trademark of DuPont). Other suitable materials include polyester film, polyimide film, polyethylene naphthalate film, or polyetherimide film, liquid crystal polymers, other flexible printed semiconductor substrates, and products such as Upilex® (a trademark of Ube Industries) and Teflon® (a trademark of DuPont). In the flat configuration shown in FIG. 2, the flexible substrate 214 has a generally rectangular shape. As shown and described herein, the flexible substrate 214 is configured to be optionally wrapped around the support member 230 (FIG. 3). Thus, the thickness of the film layer of the flexible substrate 214 is generally related to the degree of curvature of the final assembled flexible assembly 110. In some embodiments, the film layer is between 5 μm and 100 μm, and in some particular embodiments, between 5 μm and 25.1 μm, for example, 6 μm.

[0023] The transducer control logic die 206 is a non-limiting example of a control circuit. The transducer region 204 is disposed on a distal portion 221 of the flexible substrate 214. The control region 208 is disposed on a proximal portion 222 of the flexible substrate 214. The transition region 210 is disposed between the control region 208 and the transducer region 204. The dimensions (e.g., lengths 225, 227, 229) of the transducer region 204, the control region 208, and the transition region 210 can vary in different embodiments. In some embodiments, the lengths 225, 227, 229 can be substantially similar, or the length 227 of the transition region 210 can be shorter than the lengths 225 and 229, and the length 227 of the transition region 210 can be longer than the lengths 225, 229 of the transducer region and the controller region, respectively.

[0024] The control logic die 206 is not necessarily homogeneous. In some embodiments, a single controller is shown as the master control logic die 206A and includes a communication interface for the cable 142, which may function as an electrical conductor, e.g., electrical conductor 112, between the processing system, e.g., the processing system 106, and the flexible assembly 200. Thus, the master control circuit may include control logic to decode adjustment signals received via the cable 142, transmit control responses on the cable 142, amplify echo signals, and / or transmit echo signals on the cable 142. The remaining controller is the slave controller 206B. The slave controller 206B may include control logic to drive the transducers 212 to emit ultrasonic signals and select the transducers 212 to receive echoes. In the illustrated embodiment, the master controller 206A does not directly control any of the transducers 212. In other embodiments, the master controller 206A drives the same number of transducers 212 as the slave controllers 206B, or drives a reduced set of transducers 212 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.

[0025] To electrically interconnect the control logic die 206 and the transducer 212, according to one embodiment, the flexible substrate 214 includes conductive traces 216 formed in a film layer that convey signals between the control logic die 206 and the transducer 212. In particular, the conductive traces 216 that provide communication between the control logic die 206 and the transducer 212 extend along the flexible substrate 214 in the transition region 210. In some cases, the conductive traces 216 can also facilitate electrical communication between the master controller 206A and the slave controller 206B. The conductive traces 216 can also provide a set of conductive pads that contact the conductors 218 of the cable 142 when the conductors 218 of the cable 142 are mechanically and electrically coupled to the flexible substrate 214. Suitable materials for the conductive traces 216 include copper, gold, aluminum, silver, tantalum, nickel, and tin, and may be deposited on the flexible substrate 214 by processes such as sputtering, plating, and etching. In one embodiment, the flexible substrate 214 includes a chrome adhesion layer. The width and thickness of the conductive traces 216 are selected to provide suitable conductivity and resilience when the flexible substrate 214 is rolled. In this regard, an exemplary range of thickness for the conductive traces 216 and / or conductive pads is 1-5 μm. For example, in one embodiment, 5 μm conductive traces 216 are separated by 5 μm spaces. The width of the conductive traces 216 on the flexible substrate may be further determined by the width of the conductors 218 that are coupled to the traces / pads.

[0026] The flexible substrate 214 may include a conductor interface 220 in some embodiments. The conductor interface 220 may be a location on the flexible substrate 214 where the conductors 218 of the cable 142 are coupled to the flexible substrate 214. For example, the bare conductors of the cable 142 are electrically coupled to the flexible substrate 214 at the conductor interface 220. The conductor interface 220 may be a tab extending from the body of the flexible substrate 214. In this regard, the body of the flexible substrate 214 may collectively refer to the transducer region 204, the controller region 208, and the transition region 210. In the illustrated embodiment, the conductor interface 220 extends from a proximal portion 222 of the flexible substrate 214. In other embodiments, the conductor interface 220 may be located on other portions of the flexible substrate 214, such as the distal portion 221, or the flexible substrate 214 may lack the conductor interface 220. A dimension of the tab or conductor interface 220, such as width 224, can be less than a dimension of the body of the flexible substrate 214, such as width 226. In some embodiments, the substrate forming the conductor interface 220 is made of the same material as the flexible substrate 214 and / or is similarly flexible. In other embodiments, the conductor interface 220 is made of a different material and / or is relatively more rigid than the flexible substrate 214. For example, the conductor interface 220 can be made of a plastic, thermoplastic, polymer, rigid polymer, etc., including polyoxymethylene (e.g., Delrin®), polyetheretherketone (PEEK), nylon, liquid crystal polymer (LCP), and / or other suitable materials.

[0027] 3 shows a perspective view of the device 102 with the scanner assembly 110 in a rolled configuration. In some examples, the assembly 110 is transitioned from a flat configuration (FIG. 2) to a rolled or more cylindrical configuration (FIG. 3). For example, in some embodiments, techniques such as those disclosed in one or more of U.S. Patent No. 6,776,763, entitled "ULTRASONIC TRANSDUCER ARRAY AND METHOD OF MANUFACTURING THE SAME," and U.S. Patent No. 7,226,417, entitled "HIGH RESOLUTION INTRAVASCULAR ULTRASOUND SENSING ASSEMBLY HAVING A FLEXIBLE SUBSTRATE," each of which is incorporated herein by reference in its entirety, are utilized.

[0028] In some embodiments, the transducer elements 212 and / or the controller 206 can be arranged in an annular configuration, such as a circular or polygonal configuration, around the longitudinal axis 250 of the support member 230. It is understood that the longitudinal axis 250 of the support member 230 can also be referred to as the longitudinal axis of the scanner assembly 110, the flexible elongated member 121, and / or the device 102. For example, the cross-sectional profile of the imaging assembly 110 at the transducer elements 212 and / or the controller 206 can be a circle or a polygon. Any suitable annular polygon shape can be implemented, including, for example, a pentagon, hexagon, heptagon, octagon, nonagon, decagon, etc., based on the number of controllers / transducers, the flexibility of the controllers / transducers, etc. In some examples, multiple transducer controllers 206 may be used to control multiple ultrasound transducer elements 212 to obtain imaging data associated with the blood vessel 120.

[0029] The support member 230 may be referred to as a unitary body in some examples. The support member 230 may be constructed from a metallic material, such as stainless steel, or a non-metallic material, such as a plastic or polymer, as described in U.S. Provisional Application No. 61 / 985,220, filed April 28, 2014, entitled "Pre-Doped Solid Substrate for Intravascular Devices," which is incorporated herein by reference in its entirety. The support member 230 may be a ferrule having a distal flange or portion 232 and a proximal flange or portion 234. The support member 230 may be tubular in shape and define a lumen 236 extending longitudinally therethrough. The lumen 236 may be sized and shaped to receive the guidewire 118. The support member 230 may be manufactured using any suitable process. For example, the support member 230 can be machined and / or electrochemically machined or laser milled, such as by removing material from a blank to form the support member 230, or can be formed, such as by an injection molding process.

[0030] 4, shown therein is a schematic cross-sectional side view of a distal portion of an intraluminal imaging device 102 including a flexible substrate 214 and a support member 230, according to an embodiment of the present disclosure. The support member 230 may be referred to as a unitary body in some examples. The support member 230 may be constructed of a metallic material, such as stainless steel, or a non-metallic material, such as a plastic or polymer, as described in U.S. Provisional Application No. 61 / 985,220, filed April 28, 2014, entitled "Pre-Doped Solid Substrate for Intravascular Devices," which is incorporated herein by reference in its entirety. The support member 230 may be a ferrule having a distal portion 262 and a proximal portion 264. The support member 230 may define a lumen 236 extending along a longitudinal axis LA. The lumen 236 communicates with the inlet / outlet port 116 and is sized and shaped to receive a guidewire 118 (FIG. 1). The support member 230 can be manufactured according to any suitable process. For example, the support member 230 can be machined and / or electrochemically machined or laser milled, such as by removing material from a blank to form the support member 230, or can be formed, such as by an injection molding process. In some embodiments, the support member 230 can be integrally formed as a unitary structure, while in other embodiments, the support member 230 can be formed from different components, such as the ferrules and stands 242, 244, that are fixedly coupled to one another. In some cases, the support member 230 and / or one or more components thereof can be fully integrated with the inner member 256. In some cases, the inner member 256 and the support member 230 can be joined as one piece, for example, in the case of a polymeric support member.

[0031] Vertically extending stands 242, 244 are provided at the distal and proximal portions 262, 264 of the support member 230, respectively. The stands 242, 244 lift and support the distal and proximal portions of the flexible substrate 214. In this regard, a portion of the flexible substrate 214, such as the transducer portion 204 (or transducer region 204), can be spaced apart from a central body portion of the support member 230 that extends between the stands 242, 244. The stands 242, 244 can have the same or different outer diameters. For example, the distal stand 242 can have a larger or smaller outer diameter than the proximal stand 244 and can have special features for rotational alignment and control chip placement and connection. To improve acoustic performance, any cavities between the flexible substrate 214 and the surface of the support member 230 are filled with a backing material 246. A liquid backing material 246 can be introduced between the flexible substrate 214 and the support member 230 via the passages 235 in the stands 242, 244. In some embodiments, suction can be applied via the passages 235 of one of the stands 242, 244 while the liquid backing material 246 is supplied between the flexible substrate 214 and the support member 230 via the passages 235 of the other of the stands 242, 244. The backing material can be cured to allow it to solidify and set. In various embodiments, the support member 230 includes more than two stands 242, 244, includes only one of the stands 242, 244, or includes no stands. In this regard, the support member 230 can have an increased diameter distal portion 262 and / or an increased diameter proximal portion 264 sized and shaped to lift and support the distal and / or proximal portions of the flexible substrate 214.

[0032] The support member 230 can be substantially cylindrical in some embodiments. Other shapes of the support member 230 are also contemplated, including geometric, non-geometric, symmetrical, asymmetrical, cross-sectional profiles. As the term is used herein, the shape of the support member 230 can refer to the cross-sectional profile of the support member 230. Different portions of the support member 230 can be various shapes in other embodiments. For example, the proximal portion 264 can have an outer diameter that is greater than the outer diameter of the distal portion 262, or the central portion extending between the distal portion 262 and the proximal portion 264. In some embodiments, the inner diameter of the support member 230 (e.g., the diameter of the lumen 236) can correspondingly increase or decrease as the outer diameter changes. In other embodiments, the inner diameter of the support member 230 remains the same despite the change in outer diameter.

[0033] The proximal inner member 256 and the proximal outer member 254 are coupled to a proximal portion 264 of the support member 230. The proximal inner member 256 and / or the proximal outer member 254 can comprise flexible elongated members. The proximal inner member 256 can be received within the proximal flange 234 and extend through a portion of the length of the lumen 236 of the support member 230. The proximal outer member 254 is adjacent to and in contact with the flexible substrate 214. The distal member 252 is coupled to a distal portion 262 of the support member 230. For example, the distal member 252 is disposed about the distal flange 232. The distal member 252 can be adjacent to and in contact with the flexible substrate 214 and the stand 242. The distal member 252 can be the most distal component of the intraluminal imaging device 102. The distal tip member 252 has a proximal extension portion 268 that extends into the lumen and overlaps the inner member 256. In some embodiments, the inner member 256 can extend beyond the distal portion 262 of the support member 230. In some embodiments, the proximal extension portion 268 of the distal tip member 252 can extend proximal to the proximal portion 264 of the support member 230. The proximal extension portion 268 can form a lap joint with the inner member 256 using thermal bonding and / or adhesives.

[0034] Due to the difference in mechanical properties between the rigid support member 230 and the relatively flexible inner and outer members 256, 254, the transition between the support member 230 and the inner and outer members 256, 254 may be subject to significant stress. This concentrated stress may result in kinking of the inner and outer members 256, 254 which may adversely affect the structural integrity and performance of the device 102. Replacing the relatively flexible material of the inner and / or outer members 256, 254 with a more rigid material may adversely affect the maneuverability and / or durability of the device. Additionally, it is desirable to maintain a low, substantially uniform outer profile of the device 102 along its length. Thus, the strain relief layer 270 is disposed around the proximal inner member 256 and within the proximal flange 234 such that the strain relief layer 270 overlaps the inner member 256 within the proximal flange 234. Thus, strain relief layer 270 is disposed radially between inner member 256 and support member 330 at the proximal portion of support member 330 .

[0035] The strain relief layer 270 may comprise a flexible material such as polyether block amide heat shrink tubing. For example, the strain relief layer 270 may comprise Pebax® 6333 SA01 tubing manufactured by Arkema. However, any suitable flexible material may be used, including high density polyethylene (HDPE), nylon, PET, PTFE, HDPE, and LDPE. The inner member 256 may comprise the same material as the strain relief layer 270 or a different material. In one embodiment, the inner member comprises Alathon® H5618 HDPE manufactured by Lyondell. In another embodiment, the inner member 256 comprises a combination or blend of different materials, such as HDPE and one or more polyolefins. For example, in some embodiments, the inner member comprises a combination of Alathon® H5618 HDPE and Orevac® 18307 manufactured by Arkema. However, any suitable flexible material may be used, including all types of nylon, PET, and polypropylene.

[0036] In this regard, the stiffness and / or thickness of the material used for strain relief layer 270 can be selected to provide a stiffness transition between the rigid support member 230 and the relatively flexible inner and outer members 256, 254. In this manner, strain relief layer 270 can prevent kinking of the flexible inner and outer members 256, 254, particularly in the transition region immediately proximal to support member 230. The thickness of strain relief layer 270 can range from about 0.013 mm to about 0.051 mm, including values ​​such as 0.025 mm and 0.032 mm.

[0037] Although embodiments of the present disclosure are described in the context of IVUS imaging, it will be understood that the present disclosure is applicable to other types of intraluminal imaging and / or treatment devices. For example, the present disclosure contemplates an intraluminal device (guidewire, catheter, or guide member) configured for any suitable purpose (e.g., sensing or treatment) in addition to or instead of IVUS imaging. The described embodiments provide a particular structural configuration of components that facilitates a gradual transition in stiffness from a rigid component (e.g., imaging assembly, treatment device) and an elongated flexible component (e.g., catheter, guidewire, guide member). In that regard, the embodiments and concepts described herein are applicable to any intraluminal device having a sharp transition between a flexible component and a rigid component. In particular, the embodiments and concepts of the present disclosure can be used in various intraluminal diagnostic devices, such as optical coherence tomography (OCT) devices, intravascular photoacoustic imaging (IVPA) devices, forward-looking IVUS (FL-IVUS) devices, intravascular pressure sensing devices, blood flow measurement devices, temperature sensing devices, etc. Additionally, embodiments of the present disclosure are applicable to a variety of endoluminal treatment devices, such as ablation devices, atherectomy devices, drug coated balloon delivery devices, scoring balloon delivery devices, cutting tools, radiofrequency devices, suction devices, stent delivery devices, and / or other suitable devices.

[0038] Figure 5 is a schematic cross-sectional view illustrating a transition region of an intravascular device 302 that includes a strain relief layer 370 about a proximal inner member 356. In some aspects, the intravascular device 302 shown in Figure 5 can include similar or identical components as the device 102 shown in Figure 4. For example, the device 302 shown in Figure 5 includes a flex circuit 314 or flexible substrate disposed about a support member 330 that includes a proximal flange 334, and a proximal inner member 356 and a strain relief layer 370 disposed partially within the proximal flange 334.

[0039] The strain relief layer 370 comprises heat shrink tubing applied around the inner member 356. The inner member 356 and strain relief layer 370 are inserted into the lumen 336 of the support member 330 such that the strain relief layer 370 extends partially into the support member 330. The interface portion 320 of the flex circuit 314 is disposed over and bonded to the strain relief layer 370. Finally, the proximal outer member 354 is disposed over the inner member 356 and strain relief layer 370 and bonded to the support member 330 and / or the flex circuit 314 at the proximal portion 322 of the support member flex circuit 314. In some embodiments, the outer member 354 is bonded to the proximal portion of the flex circuit 314 using at least one of an interference fit, an adhesive, or a thermal bond.

[0040] The strain relief layer 370 is disposed within the support member 330 such that a proximal portion of the strain relief layer 370 extends proximally to the proximal flange 334 of the support member 330 and a distal portion of the strain relief layer extends into the support member 330. As described further below, in an exemplary embodiment, the distal portion of the strain relief layer 370 that extends into the support member 330 is shorter than the proximal portion of the strain relief layer 370 that extends proximally outside the support member 330. For example, the proximal portion may be about 8-9 mm, while the distal portion is 1-2 mm. However, the length of the strain relief layer can be longer or shorter, such as between 2 mm and 20 mm, including values ​​such as 5 mm, 8 mm, 12 mm, or 15 mm in some embodiments. Additionally, the amount of the length of the strain relief layer disposed within support member 330 can be greater or less than 1 to 2 mm, such as 0.5 mm, 2.5 mm, 3.0 mm, 3.5 mm, or any other suitable fraction of the length of the strain relief layer. Adjusting the percentage of the strain relief layer that extends proximally of support member 330 can advantageously improve or optimize the strain relief properties of strain relief layer 370.

[0041] FIG. 6A is a cross-sectional view taken along line 6-6 of the device 302 shown in FIG. 5 according to one embodiment of the disclosure. The cross-sectional view shows a strain relief layer 370 disposed around the inner member 356, which is disposed inside the support member 330 or hypotube. In the embodiment of FIG. 6A, the strain relief layer 370 is in direct physical contact with the inner member 356 and is fixedly bonded to the inner member 356 without the use of an adhesive. For example, the strain relief layer 370 can have a heat shrink tube disposed around the inner member 356 and then shrunk by applying heat to create a physical connection between the strain relief layer and the inner member. The inner member 356 and the strain relief layer 370 are disposed inside the support member 330 such that the strain relief layer 370 is in direct physical contact with the support member 330. The flex circuit 314 is disposed around the support member 330 as shown in FIG. 5.

[0042] The device 302 has a first diameter or width 380, measured as the diameter of the flex circuit 314. In an exemplary embodiment, the first diameter is less than 0.04 inches to allow the device 302 to navigate tortuous regions of the vasculature. However, the first diameter can range between 0.03 inches and 0.11 inches, including values ​​such as 0.033, 0.039, 0.0455, 0.107 inches, and the like. The inner member has a second width or diameter 382. In an exemplary embodiment, the second width 382 is about 0.015 inches. However, the second diameter can range between 0.010 inches and 0.035 inches, including values ​​such as 0.02 inches, 0.025 inches, and 0.030 inches. In some embodiments, the ratio of the first diameter 380 to the second diameter 382 can be 4:1, 3:1, 2:1, or any other suitable ratio in which the first diameter 380 is greater than the second diameter 382. Additionally, the strain relief layer 370 has a wall thickness 384. In an exemplary embodiment, the wall thickness 384 is approximately 0.001 inches. However, in other embodiments, the wall thickness 384 can be between approximately 0.00025 inches and 0.002 inches, including values ​​such as 0.0005, 0.00125, and 0.0015 inches. It should be understood that the above dimensions are exemplary and can be modified as needed to achieve the desired mechanical performance and physical characteristics of the device.

[0043] FIG. 6B is a cross-sectional view of the device 302 shown in FIG. 5 taken along line 6-6 according to another embodiment of the present disclosure. In the embodiment shown in FIG. 6B, the strain relief layer 370 is bonded to the inner member 356 by an adhesive layer 372 disposed between the inner member 356 and the strain relief layer 370. In that regard, in some embodiments, the strain relief layer 370 comprises a flexible material that is not a heat shrink tube. The adhesive layer 372 can be applied to the inner member and / or the strain relief layer 370 before being disposed around the inner member 356. In an exemplary embodiment, the adhesive layer 372 comprises a flexible adhesive material to allow the catheter to bend and flex while navigating through tortuous regions of the vasculature. The adhesive layer 372 can include any suitable adhesive, including epoxies, UV light curing, and / or instant adhesives. In other embodiments, the strain relief layer 370 can be co-extruded with the inner member 356.

[0044] 7 and 8A-8E illustrate a method for assembling an intraluminal ultrasound imaging device including a strain relief layer. Specifically, FIG. 7 is a flow diagram illustrating various steps of a method 500 for assembling an intraluminal ultrasound imaging device. FIGS. 8A-8E illustrate the intraluminal ultrasound imaging device at various points in the assembly process. With reference to FIGS. 7 and 8A, in step 510, an inner member 456 is provided. The inner member 456 includes a flexible tube and a number of radiopaque marker bands 457 disposed around the circumference of the inner member 456. The inner member 456 may include a single extruded tube or may include multiple layers of one or more materials. The marker bands 457 are swaged onto the inner member 456 and are positioned approximately 10 mm apart from one another. In other embodiments, the spacing between the marker bands 457 may be greater or less, including approximately 5 mm, 8 mm, 12 mm, 15 mm, or 20 mm. 7 and 8B, in step 520, a strain relief layer 470 is disposed about the inner member 456. In an exemplary embodiment, the strain relief layer 470 comprises heat shrink tubing. The strain relief layer or tube 470 is positioned such that a proximal end of the strain relief tube 470 is distal to a proximal end of the inner member 456. In other words, the inner member 456 extends proximal to a proximal end of the strain relief tube 470. In the embodiment shown in FIG. 8B, the strain relief tube 470 is disposed over one of the marker bands 457. In other embodiments, the strain relief tube 470 is positioned such that it does not overlap the marker band 457.

[0045] In step 530, the strain relief tube 470 is secured to the inner member 456. In an exemplary embodiment, the strain relief tube 470 is secured to the inner member 456 by heat shrinking the strain relief tube 470 to the inner member 456. In this manner, the outer profile of the device can be reduced and the number of components required to assemble the intravascular imaging device can be minimized. In some embodiments, heat shrinking the strain relief tube 470 to the inner member 456 includes placing an additional heat shrink mold layer over the strain relief tube 470 and heat shrinking the strain relief tube 470 and the heat shrink mold layer onto the inner member 456. In some embodiments, the heat shrink mold layer is removed and discarded after heat shrinking the strain relief tube 470 to the inner member 456. In some embodiments, the heat shrink mold layer comprises polytetrafluoroethylene (PTFE) tubing. The heat shrink mold layer can facilitate a consistent and repeatable assembly process to maintain the outer profile of the device to a desired size. However, in other embodiments, the strain relief tube 470 is secured to the inner member 456 using a layer of adhesive. In some embodiments, the strain relief tube 470 is secured to the inner member 456 using a combination of heat shrink and adhesive.

[0046] 7 and 8C, in step 540, the inner member 456 and a distal portion of the strain relief tube 470 are placed through the lumen of the imaging assembly 402. In this manner, the strain relief tube 470 provides a rigid transition from the rigid imaging assembly 402 to the more flexible inner member 456. This transition can prevent kinking of the intravascular device as the device navigates tortuous regions of the vasculature, especially in the transition region proximal to the imaging assembly 402. To aid in the assembly process, the inner member 456 is placed around a processing mandrel 50 that is removed upon completion of the assembly process. The imaging assembly 402 has a flex circuit that is placed around a rigid support member, similar to the imaging device 302 shown in FIG. 5. The imaging assembly 402 also includes an interface portion 420 coupled to a plurality of communication lines. The communication lines can be attached to the interface portion 420 of the flex circuit 414 before or after the inner member 456 and strain relief tube 470 are inserted into the lumen of the imaging assembly 402 .

[0047] The lumen of the imaging assembly 402 is sized and shaped to receive the inner member 456 with the strain relief tube 470 disposed about the inner member 456. The inner member 456 and the strain relief tube 470 are disposed within the lumen of the imaging assembly 402 such that a portion, but not all, of the strain relief tube 470 extends distally within the lumen of the imaging assembly 402 and a portion of the strain relief tube 470 extends proximally outside of the imaging assembly 402. For example, as described above, the strain relief tube 470 may have a length of about 10 mm in one embodiment. In contrast, the inner member 456 may have a length that is significantly longer than the strain relief layer 470. For example, the length of the inner member may range from 10 inches to 60 inches, including values ​​such as 12 inches, 18 inches, 36 inches, and 48 inches.

[0048] 7 and 8D, in step 550, the outer member 454 is positioned over the inner member 456 and the strain relief tube 470 such that the distal end of the outer member 454 is adjacent to the proximal end of the imaging assembly 402 (shown in more detail in FIG. 8E). In some embodiments, prior to positioning the outer member 454 over the inner member 456 and the strain relief tube 470, the interface portion 420 of the imaging assembly 402 is wrapped around a portion of the strain relief tube 470 that is proximal to the lumen of the imaging assembly 402. The interface portion 420 can be wrapped around the strain relief tube 470 in a spiral or helical manner, as shown in FIG. 8D. In some embodiments, the interface portion 420 is wrapped around the strain relief tube 470 in a circular fashion. In other embodiments, the interface portion 420 is not wrapped around the strain relief tube 470, but instead lies flat against one side of the outer surface of the strain relief tube 470. In some embodiments, the interface portion 420 is secured to the strain relief tube 470 and / or the outer surface of the inner member 456 using an adhesive. The flexible distal tip 452 is coupled to the imaging device 402 such that the distal tip 452 extends distally from the distal end of the imaging device 420. Also, as shown in FIG. 5, the distal tip 452 may include a tubular member (e.g., 368) disposed within a lumen of the imaging assembly 402.

[0049] 8E shows an enlarged plan view of the assembled intravascular ultrasound imaging device shown in FIG. 8D. As shown in FIG. 8E, the outer member 454 has a proximal portion 490 and a distal portion 492. The proximal portion 490 has a first outer diameter D1 and the distal portion 492 has a larger second outer diameter D2. In some embodiments, the larger second outer diameter D2 of the distal portion of the outer member 454 can be formed by flaring, gauging, or otherwise modifying the distal portion 492 of the outer member 454. In this regard, the distal portion 492 may also have an inner diameter larger than the inner diameter of the proximal portion 490. The larger inner diameter of the distal portion 492 may allow space for additional thickness created by the wrapped interface portion 420 of the imaging assembly 402. The smaller inner diameter of the proximal portion 490 is large enough to accommodate at least the inner member 456 and the communication lines 412 that extend proximally along the inner member 456 to the proximal portion of the intravascular ultrasound imaging device. In some embodiments, the outer member 454 is secured to the inner member 456, the strain relief tube 470, and / or the imaging device using an adhesive. In other embodiments, the outer member 454 is coupled to the imaging assembly 402 using an interference fit. However, the present application contemplates any suitable means for coupling the outer member to the inner member, the strain relief tube, and / or the imaging assembly 402.

[0050] 9 is a schematic cross-sectional view illustrating a transition region of an intravascular device 302 including a strain relief layer 470 about a proximal inner member 456, according to one embodiment of the present disclosure. In the embodiment of FIG. 9, a proximal extension 468 of a flexible distal tip member (e.g., tip member 252) extends through the lumen 336 of the support member 330, proximal to the proximal flange 334 of the support member 330. The proximal end of extension 468 may extend further proximally in some embodiments. The proximal inner member 456 and attached strain relief layer 470 are disposed within the lumen of the proximal extension 468 such that the strain relief layer 470 extends at least partially into the lumen 336 of the support member 330.

[0051] Those skilled in the art will appreciate that the above-described devices, systems, and methods can be modified in various ways. Thus, those skilled in the art will appreciate that the embodiments encompassed by the present disclosure are not limited to the specific exemplary embodiments described above. In that regard, while exemplary embodiments have been shown and described, a wide range of modifications, changes, and substitutions are contemplated in the foregoing disclosure. It is understood that such modifications can be made to the above without departing from the scope of the present disclosure. Thus, it is appropriate that the appended claims be broadly construed in a manner consistent with the present disclosure.

Claims

1. a flexible elongate member configured to be disposed within a body lumen of a patient, the flexible elongate member having an inner member; an imaging assembly coupled to the flexible elongate member, the imaging assembly having an ultrasound scanner circuit disposed about a lumen, a distal portion of the inner member disposed within the lumen of the imaging assembly; In an intraluminal ultrasound imaging device having the flexible elongate member further comprising a strain relief tube disposed about the inner member, a distal portion of the strain relief tube being radially disposed between the inner member and the imaging assembly, and a proximal end of the strain relief tube being disposed distal to a proximal end of the inner member. Ultrasound imaging device.

2. The ultrasound imaging device of claim 1 , wherein the strain relief tube comprises a heat shrink material.

3. The ultrasound imaging device of claim 2 , wherein the heat shrink material comprises a polyether block amide tubing.

4. The ultrasound imaging device of claim 1 , wherein the flexible elongate member comprises an outer member disposed over a proximal portion of the inner member and a proximal portion of the strain relief tube.

5. The ultrasound imaging device of claim 1 , wherein the imaging assembly includes a support member defining the lumen of the imaging assembly, and the ultrasound scanner circuitry includes a flexible substrate disposed about the support member.

6. 6. The ultrasound imaging device of claim 5, wherein the ultrasound scanner circuitry includes a conductor interface portion disposed about the strain relief tube.

7. The ultrasonic imaging device of claim 1 , wherein the strain relief tube has a length of between 5 mm and 15 mm.

8. The ultrasound imaging device of claim 7 , wherein the strain relief tube has a wall thickness of 0.025 mm to 0.032 mm.

9. The strain relief tube is i) thermally coupled to the inner member; or ii) bonded to the inner member using an adhesive; 2. The ultrasound imaging device according to claim 1.

10. The ultrasound imaging device of claim 1 , wherein the imaging assembly is an intravascular ultrasound (IVUS) assembly and the flexible elongated member comprises a catheter.

11. 1. A method of assembling an intraluminal ultrasound imaging device, comprising: forming a flexible elongate member configured to be placed within a body lumen of a patient, disposing a strain relief tube about the inner member such that a proximal end of the strain relief tube is disposed distal to a proximal end of the inner member; and fixedly coupling the strain relief tube to the inner member; and coupling an ultrasonic imaging assembly to the flexible elongate member, the coupling comprising disposing a distal portion of the inner member and a distal portion of the strain relief tube through a lumen of the ultrasonic imaging assembly; The method according to claim 1,

12. The method of claim 11 , further comprising disposing an outer member over a proximal portion of the inner member and a proximal portion of the strain relief tube.

13. The method of claim 11 , wherein fixedly coupling the strain relief tube comprises thermally coupling the strain relief tube and the inner member.

14. The method of claim 13 , wherein the step of fixedly coupling the strain relief tube comprises applying heat to the strain relief tube to cause the strain relief tube to shrink around the inner member.

15. 15. The method of claim 14, wherein the step of fixedly coupling the strain relief tube comprises the steps of: placing a heat shrink tube around the strain relief tube; and applying heat to the heat shrink tube to shrink the heat shrink tube around the strain relief tube.

16. 12. The method of claim 11 , wherein the ultrasonic imaging assembly has a scanner circuit disposed about a support member that defines the lumen of the ultrasonic imaging assembly, and the step of positioning the distal portion of the inner member and the distal portion of the strain relief tube through the lumen of the imaging assembly comprises the step of positioning the distal portion of the inner member and the distal portion of the strain relief tube through the lumen of the support member.

17. placing an outer member over a proximal portion of the inner member and a proximal portion of the strain relief tube; disposing a conductor interface portion of the scanner circuitry around an exterior surface of the strain relief tube; and placing the outer member over the proximal portion of the inner member and the proximal portion of the strain relief tube comprises placing the outer member over the conductor interface portion of the scanner circuitry.

17. The method of claim 16.

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