CN116635103A

CN116635103A - Echo multilayer medical device

Info

Publication number: CN116635103A
Application number: CN202180081313.2A
Authority: CN
Inventors: E·C·施密特; J·J·皮施拉尔
Original assignee: Medtronic Inc
Current assignee: Medtronic Inc
Priority date: 2020-12-21
Filing date: 2021-12-21
Publication date: 2023-08-22

Abstract

A medical device having an echogenic region is provided herein that facilitates the use of ultrasound to guide the medical device to a selected location within a patient. The medical device includes a first layer having a first polymer. The first layer defines an elongate body extending along a longitudinal axis from a proximal end to a distal end and defines a longitudinally extending cavity within the elongate body. The medical device further includes a second layer having a second polymer. The second layer is disposed on and radially adjacent to the first layer and defines the echogenic region. The echogenic region comprises a second polymer and an echogenic metal or ceramic material dispersed in the second polymer. The echo region is detectable using ultrasound imaging.

Description

Echo multilayer medical device

The present application claims priority from U.S. patent application Ser. No. 17/645,218, filed 12/20 in 2021, which claims the benefit of U.S. provisional patent application Ser. No. 63/128,504, filed 21 in 12/2020, each of which is incorporated herein by reference in its entirety.

Technical Field

The present disclosure relates to medical devices that include an elongate member that is introducible into a patient.

Background

The medical device may be advanced into the vasculature of a patient to introduce an Implantable Medical Device (IMD) or therapeutic agent to a treatment site. IMDs may be configured for delivery to selected locations within a patient using such catheters, such as different chambers of the patient's heart. Medical imaging devices and techniques, such as fluoroscopy, may be used to assist in positioning the medical device within a patient to deliver an IMD.

Disclosure of Invention

The use of fluoroscopic imaging techniques to assist in positioning medical devices includes several drawbacks such as radiation exposure of patients and clinicians, clinician personal protective equipment requirements such as lead vests or working skirts, lack of visibility of soft tissue when x-rays are used, and the need for large, expensive fluoroscopic or other medical imaging equipment. The disclosed medical devices include echogenic regions that enable a clinician to use other imaging devices and techniques, such as ultrasound, to assist in positioning the medical device at a selected location within a patient to deliver an IMD or therapeutic agent. As one example, the medical device may include at least one echogenic region located near a distal tip of the medical device. The at least one echogenic region may be used to determine the location of the distal tip of the medical device relative to a selected location, such as a particular region of the patient's heart. Once positioned at the selected location, an IMD (such as, for example, a medical electrical lead) may be advanced to the selected location through a lumen of the medical device.

In some examples, the medical device may include a first layer defining an elongate body extending along a longitudinal axis from a proximal end to a distal end and defining a lumen extending longitudinally within the elongate body. The medical device may also include a second layer disposed on and radially adjacent to the first layer. At least a portion of the second layer defines an echogenic region. The echogenic region may comprise echogenic metallic or ceramic material dispersed in a second layer. The echo region may be configured to diffusely scatter sound waves.

In some examples, the kit may include a first medical device and a second medical device. The first medical device may include a first layer defining an elongate body extending along a longitudinal axis from a proximal end to a distal end and defining a longitudinally extending lumen within the elongate body. The medical device may also include a second layer disposed on and radially adjacent to the first layer. At least a portion of the second layer defines an echogenic region. The echogenic region may comprise echogenic metallic or ceramic material dispersed in a second layer. The echo region may be configured to diffusely scatter sound waves. The second medical device may be sized to extend from the distal tip delivery of the elongate body and configured for at least one of therapy delivery or sensing.

In some examples, a method may include advancing a first medical device toward a selected location within a patient. The first medical device may include a first layer defining an elongate body extending along a longitudinal axis from a proximal end to a distal end and defining a longitudinally extending lumen within the elongate body. The first layer may comprise a first polymer. The medical device may also include a second layer disposed on and radially adjacent to the first layer. The second layer may comprise a second polymer. At least a portion of the second layer defines an echogenic region. The echogenic region may comprise a second polymer and an echogenic metal or ceramic material dispersed in the second polymer. The echo region may be configured to diffusely scatter sound waves. The method may also include identifying at least one of a location, orientation, or trajectory of the distal portion of the first medical device relative to the selected location based on the acoustic waves reflected by the echogenic member. The method may also include advancing a second medical device through the lumen and out from the distal tip of the elongate body to a selected position for at least one of therapy delivery or sensing.

In some examples, a method of assembling a medical device may include forming a first layer defining an elongate body extending along a longitudinal axis from a proximal end to a distal end and defining a cavity extending longitudinally within the elongate body. The first layer may comprise a first polymer. The method may further include forming a second layer disposed on and radially adjacent to the first layer. The second layer may comprise a second polymer. At least a portion of the second layer defines an echogenic region. The echogenic region may comprise a second polymer and an echogenic metal or ceramic material dispersed in the second polymer. The echo region may be configured to diffusely scatter sound waves.

The details of one or more examples are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims.

Drawings

Fig. 1A is a conceptual side view of an example medical device having an echogenic region.

Fig. 1B is a conceptual side view of the medical device shown in fig. 1A in an expanded configuration.

Fig. 2 is a conceptual diagram illustrating an example medical device having two echogenic regions and a handle assembly.

Fig. 3 is a conceptual diagram illustrating the right side of a heart in which a distal portion of an example medical device having an echogenic region is disposed.

Fig. 4 is a flow chart illustrating an example method for manufacturing an example medical device.

Fig. 5 is a flowchart illustrating an example method of delivering an example IMD to a selected location using an example medical device.

Detailed Description

The present disclosure describes example systems, devices, and techniques for positioning an echogenic medical device at a selected location within a patient to deliver another medical device or therapeutic agent (described below primarily in the context of delivery of a medical device) to the selected location. Typically, the patient may be a human patient. However, in other examples, the patient may be a non-human patient. The selected location may generally include any location within the patient where stimulation, sensing, or drug delivery is desired. In some examples, the selected location may include tissue suitable for ablation, such as ablation using cold, heat, electrical energy, or radiation. In some examples, the selected location includes cardiac tissue, coronary veins, or tissue suitable for pacing that is not dead, damaged, or otherwise operational within general anatomical specifications. In some examples, the medical device may include a medical electrical lead, such as a bradycardia lead (brady lead) or a tachycardia lead (tachy lead); site-selective medical electrical leads, such as a his bundle or a spacer pacing lead; implantable Medical Devices (IMDs), such as implantable pacing devices; or left bundle branch medical electrical lead.

In this disclosure, example systems, devices, and techniques will be described with reference to delivering medical electrical leads to selected locations in the heart. However, it should be understood that the example systems, devices, and techniques of the present disclosure are not limited to delivering medical electrical leads to cardiac tissue. For example, the example systems, devices, and techniques described herein may be used to deliver medical electrical leads to coronary veins, epicardial tissue, or other locations. Additionally, the example systems, devices, and techniques described herein may be used to deliver medical electrical leads for neurostimulation therapy (e.g., spinal cord stimulation), deep brain stimulation, stimulation of one or more muscles, muscle groups, or organs, and stimulation of the patient's tissue in general. Additionally, in some examples, the example systems, devices, and techniques described herein may be used to deliver medical devices for dispensing drugs or other beneficial agents from implanted or external drug delivery devices. Further, in some examples, the example systems, devices, and techniques described herein may be used to deliver medical devices for ablating tissue using, for example, cold, heat, electrical energy, or radiation. Briefly, the example systems, devices, and techniques described herein may be used for application in delivering various medical electrical leads or catheters for delivering therapy to a patient or for patient sensing.

To overcome the drawbacks of some medical imaging techniques, such as fluoroscopy, ultrasound may be used to guide a medical device (e.g., a medical balloon, tube, or delivery catheter) to a selected location within a patient as discussed above. For example, echogenic particles may be incorporated into a medical balloon to provide echogenicity and/or radiopacity. The use of echogenic particles can result in a medical balloon having a lower burst pressure than a medical balloon without the particle additive. The consequences of lower burst pressure can result in weaker support structures and may shorten the life and reduce the reliability of the medical balloon or prevent the use of the balloon in high pressure applications such as angioplasty and stent deployment. The present disclosure relates to systems and techniques for facilitating delivery of echogenic medical devices to selected locations using ultrasound while providing a strong support structure that resists bursting and tearing.

Fig. 1A is a schematic and conceptual side view of an example medical device 10 having an echogenic region 24. The medical device 10 includes multiple layers such that the echogenic region 24 of the medical device 10 is a multi-layer echogenic region that resists bursting and tearing. As shown in fig. 1, the medical device 10 includes a first layer 12 and a second layer 14.

The first layer 12 defines an elongate body 16 extending along a central longitudinal axis A-A from a proximal end 18 of the elongate body 16 to a distal end 20 of the elongate body 16. The second layer 14 is disposed radially adjacent the first layer 12 and defines a cavity 22 extending longitudinally within the elongate body 16. The cavity 22 may be configured to receive a medical electrical lead or IMD. For example, the lumen 22 may be sized to deliver a medical electrical lead through the entire length of the lumen 22. In some examples, the elongate body 16 may include a plurality of lumens, each lumen extending along and/or parallel to the central longitudinal axis A-A. At least a portion of the second layer 14 defines an echogenic region 24 positioned closer to the distal end 20 of the elongate body 16 than the proximal end 18 of the elongate body 16.

The elongate body 16 may have any suitable dimensions, which may depend on the medical procedure intended for use with the medical device 10. For example, the elongate body 16 may have any suitable length, such as, but not limited to, about 20 centimeters (cm) to about 150cm, such as about 75cm, about 90cm, or about 135cm (e.g., precisely these lengths or about these lengths as allowed by manufacturing tolerances).

In some examples, the outer diameter of the elongate body 16 can be about 2 french to about 12 french, such as about 3 french or about 6 french. The measurement term French (Fr or F for short) is three times the diameter of the device measured in millimeters (mm). Thus, 6 french has a diameter of about 2mm (e.g., about 1.8 mm), 5 french has a diameter of about 1.67mm,4 french has a diameter of about 1.33mm, and 3 french has a diameter of about 1mm. The term "about" as used herein with respect to dimensions may refer to an exact value such as when used to describe a numerical value, "about" or "approximately" refers to a range within the numerical value resulting from manufacturing tolerances and/or within 1%, 5% or 10% of the numerical value. For example, a length of about 10mm refers to a length of 10mm, or in various examples 10mm +/-0.1mm, +/-0.5mm, or +/-1mm, within the limits allowed by manufacturing tolerances.

The echogenic region 24 can be positioned at any suitable distance from the distal tip 20 of the elongate body 16 to enable a clinician to determine the relative positioning of the distal tip 20. In some examples, the echogenic region 24 may be in a range of about 0mm proximal of the distal tip 20 (e.g., the distal tip of the echogenic region 24 may be flush or nearly flush with respect to the distal tip 20 of the elongate body 16 within manufacturing tolerances) to about 2mm. In other examples, the echogenic region 24 may be greater than 2mm proximal of the distal tip 20. In some examples, the echogenic region 24 may be located elsewhere on the medical device 10, such as, for example, adjacent preformed curves or articulating portions of the medical device 10.

The first layer 12 of the medical device 10 may be formed of any suitable polymer. In some examples, the first layer 12 may include one or more of the following: acrylonitrile-butadiene styrene (ABS), polyamide (e.g., nylon, polyamide 6 (PA 6) or polyamide 66 (PA 66), polycarbonate (PC), polyethylene (e.g., high Density Polyethylene (HDPE) or Low Density Polyethylene (LDPE)), poly (methyl methacrylate) (PMMA), polyoxymethylene (POM), polypropylene (PP), polystyrene (PS), polybutylene terephthalate (PBT), styrene acrylonitrile resin (SAN), thermoplastic elastomer (TPE) (e.g., polyether block amide (PEBA)), polyphenylene Sulfide (PPs), polyetheretherketone (PEEK), polyurethane, polyester, or combinations thereof Is a blend, copolymer or co-extrusion. In some examples, TPE (or PEBA) may include a compound with a trade name(Paris, france, arkema) or +.>(Essen, germany, winning Industrial Co., ltd. (Evonik Industries, essen, germany)).

The second layer 14 of the medical device 10 may be made of a variety of materials, including the same materials as the first layer 12. In some examples, the first layer 12 and the second layer 14 may be made of the same material and may have substantially the same density (e.g., identical except for manufacturing tolerances). In other examples, the first layer 12 and the second layer 14 may be made of different materials and may have different densities. For example, the first layer 12 may be made of a first polymer and the second layer 14 may be made of a second polymer. The first polymer may have a first density of about 0.7g/cm ³ To about 5.5g/cm ³ And the second polymer may have a second density of about 0.7g/cm ³ To about 5.5g/cm ³ Within a range of (2).

Additionally, in some examples, the first layer 12 and the second layer 14 may have substantially the same radial thickness (e.g., the same except for manufacturing tolerances), where the radial thickness is measured in a direction orthogonal to the central longitudinal axis A-A. In other examples, the first layer 12 and the second layer 14 have different radial thicknesses. For example, the first radial thickness of the first layer 12 may be in the range of about 0.001mm to about 2mm, and the second radial thickness of the second layer 14 may be in the range of about 0.001mm to about 2 mm. The radial thickness of each of the first layer 12 and the second layer 14 may depend on the intended use of the medical device 10.

The echogenic region 24 of the second layer 14 may include embedded echogenic particles 28. In some examples, echogenic particles 28 may include echogenic materials or echogenic metal or ceramic materials, such as one or more of tungsten, tantalum, platinum, gold, stainless steel, aluminum, titanium, aluminum oxide, magnesium oxide, silica glass, silica, tungsten carbide, silicon carbide, titanium dioxide, titanium carbide, or titanium nitride. In some examples, the average diameter of the echogenic particles 28 may be in a range of about 0.1 micrometers (μm) to about 50 μm. The echogenic particles 28 embedded in the echogenic region 24 are configured to enhance the acoustic impedance and the diffuse scattering characteristics of the echogenic region 24, and the average diameter of the echogenic particles 28 can be selected to achieve a balance between diffuse scattering and device manufacturability. For example, where the second layer is formed by a coating process, the selected diameter of echogenic particles 28 may help ensure a low particle settling rate. Additionally, echogenic particles 28 of selected diameters may help to enhance mechanical properties of medical device 10, such as enhancing burst pressure and tensile strength of medical device 10. Instead of or in addition to the echogenic regions 24 of the second layer 14, the first layer 12 may have echogenic regions (not shown) that may optionally be similar in configuration, material composition, and/or location to any of the various disclosed embodiments of the echogenic regions 24.

In some examples, the selected density of the echogenic region 24 is about 1.0 grams per cubic centimeter (g/cm) ³ ) To about 16.0g/cm ³ Such as about 1.0g/cm ³ To about 4.0g/cm ³ 、1.5g/cm ³ To about 3.0g/cm ³ 、2.0g/cm ³ To about 3.5g/cm ³ Within a range of (2). The density of the echogenic region 24 may be selected such that the difference between the densities of the echogenic region 24 and the first layer 12 is about 0cm ³ /g to about 15g/cm ³ Within a range of (2). In addition, the selected specific acoustic impedance of the echo region 24 is also in the range of about 2 megarayls (MRayl) to about 90 MRayl. The density of the echogenic area 24 and the specific acoustic impedance of the echogenic area 24 may be selected to achieve a balance between a high specific acoustic impedance and a low particle settling rate or density mismatch between the first layer and the second layer.

The echo region 24 may be configured to diffusely scatter sound waves, such as sound waves having frequencies greater than about 20,000 hertz (Hz), such as greater than about 1 megahertz, such as in the range of about 1MHz to about 20 MHz.

In some examples, the first layer 12 defines an outermost surface of the medical device 10, while the second layer 14 defines an innermost surface of the medical device 10. However, in some examples, the medical device 10 may include one or more additional layers. Additionally or alternatively, one or more coatings or surface treatments, such as, but not limited to, lubricating coatings, lubricating surface treatments, or therapeutic agents, may be applied to the first layer 12 and/or the second layer 14. By having multiple layers, such as both the first layer 12 and the second layer 14, the medical device 10 provides a strong support structure that resists bursting and tearing.

In some examples, the medical device 10 may include an expandable portion 25 controllable between a collapsed configuration and an expanded configuration. In the collapsed configuration, the diameter of the echogenic region 24 may be small enough to pass through the vasculature of the patient, such as equal to or less than about 28Fr (9.333 mm), or less than about 9.5mm. In the expanded configuration, the size and/or shape of the echogenic region 24 may be selected to improve visualization of the echogenic region 24 using ultrasound. In some examples, the diameter of the echogenic region 24 in the expanded configuration may be in the range of about 1mm to about 30mm, such as about 2mm to about 15 mm. The diameter of the echogenic region 24 may be selected to facilitate imaging of the medical device 10 and/or to facilitate maneuvering through the vasculature or heart of a patient. In the collapsed configuration, the expandable portion 25 may remain relatively adjacent the central longitudinal axis A-A, such as the diameter of the expandable portion 25 may be substantially similar to the diameter of other portions of the elongate body 16. In this way, the expandable portion 25 may not affect the introduction of the medical device 10 through the vasculature of the patient. In the expanded configuration, the expandable portion 25 may be configured to anchor the medical device 10 to a target site. In addition, the expandable portion 25 may be configured to improve visualization in the heart or other portion of the body to provide a larger target to pick up ultrasound. Fig. 1B is a schematic and conceptual side view of medical device 10 in an expanded configuration. In other examples, the medical device 10 may not include the expandable portion 25.

As shown in fig. 1B, the echogenic region 24 is located at an expandable portion 25 of the medical device 10. By including the echogenic region 24 at the expandable portion 25, the medical device 10 can be configured to provide a larger ultrasound target (e.g., relative to a non-expandable portion of the medical device 10). The larger ultrasound target may enable the clinician to more accurately visualize and thereby guide the medical device 10 to a selected location within the patient.

The medical device 10 further includes a hub 26 connected to the proximal end 18 of the elongate body 16 that can allow the elongate body 16 to be maneuvered, advanced or retracted, and can provide a port for communication with a lumen defined by the elongate body 16. For example, the hub 26 may include an inflation arm that is connectable to a source of inflation fluid to deliver inflation fluid to inflate a portion of the elongate body 16 or to deflate a portion of the elongate body 16 by withdrawing inflation fluid. In some examples, the hub 26 may include an adapter 32 to receive a guidewire (not shown) through a guidewire lumen in the elongate body 16. In some examples, the elongate body 16 may comprise a catheter body, such as a balloon catheter, and the hub 26 may comprise a catheter hub. In some examples, instead of a guidewire catheter, the medical device 10 may include a rapid exchange balloon catheter system.

The elongate body 16 may be advanced to a target site, for example, through a body lumen (such as a patient's blood vessel). In some examples, the distal tip 20 of the elongate body 16 may be introduced into the vasculature of a patient through an incision or opening, followed by the shaft of the elongate body 16. The elongate body 16 can be advanced through a body lumen, for example, over a guidewire introduced through the adapter 32 of the hub 26. The elongate body 16 may remain in a collapsed or partially expanded configuration as the elongate body 16 is advanced through the vasculature. For example, when the elongate body 16 is advanced sufficiently such that the echogenic region 24 is adjacent the target site, inflation fluid may be delivered to inflate a portion of the elongate body 16 into an expanded configuration at the target site.

In some examples, the medical device may include more than one echo region. Fig. 2 is a conceptual diagram illustrating an example medical device 100 including a first layer 112 and a second layer 114, where the second layer 114 defines echogenic areas 124A and 124B (collectively, "echogenic areas 124"). The medical device 100 may be the same or substantially similar to the medical device 10 discussed above with respect to fig. 1A and 1B, except for the differences described herein.

The first layer 112 defines an elongate body 116 extending from a proximal end 118 to a distal end 120. The elongate body 116 may include any suitable length from an access site (such as a femoral access site or a radial access site) to a selected location of the heart. The elongate body 116 may include a proximal portion 138 near the proximal end 118 and a distal portion 140 near the distal end 120. The elongate body 116 has a flexibility that allows the distal portion 140 to deflect when the elongate body 116 is maneuvered within the vasculature of a patient. The proximal portion 138 may be coupled to a handle assembly 142 having a control member 144. The proximal portion 138 extends along a longitudinal axis C-C. In some examples, the proximal portion 138 may include a stabilizing sheath surrounding the proximal portion 138 and configured to transfer a force (such as torque) at the handle assembly 142 to the distal portion 140.

In some examples, handle assembly 142 may include hub 126, adjustable handle 150, and/or control member 144. Hub 126 may be configured to provide access to the lumen of elongate body 116. For example, the hub 126 may provide access to a lumen fluidly coupled to the echogenic region 124 including the inflatable balloon. In this way, the clinician may use a fluid to inflate and/or deflate the echogenic region 124, for example via a syringe. In some examples, the handle assembly 142 may include a flush assembly configured to be coupled to a syringe to purge air, for example, from a lumen of the medical device 100. The adjustable handle assembly 142 may be configured to manipulate (e.g., rotate) the deflection of the distal portion 140. The control member 144 may include one or more controls 148 coupled to one or more pull wires 146. One or more controls 148 are operable to control the length of the pull wire 146 extending through the elongate body 116.

The echogenic region 124 is positioned on a distal portion 140 of the elongate body 116. In some examples, the echogenic region 124 is configured to controllably expand from a collapsed configuration to an expanded configuration and diffusely scatter sound waves. Echo zone 124A is positioned near distal tip 120. For example, the echogenic region 124A may be positioned a distance in the range of about 0mm to about 2mm proximal to the distal tip 120. Echo zone 124B is proximal to echo zone 124A. For example, the echogenic region 124B may be spaced apart from the echogenic region 124A by a distance in the range of about 1mm to about 30mm, such as about 5mm to about 25mm or about 10mm to about 20 mm. In some examples, echo regions 124A and 124B may be directly adjacent. In examples where the echogenic areas 124A and 124B are immediately adjacent, the volumes of the inflated echogenic areas 124A and 124B (e.g., the largest diameter of the inflated configuration) may be separated by a distance in the range from about 1mm to about 30mm, such as about 5mm to about 25mm or about 10mm to about 20 mm.

In some examples, the echogenic areas 124 spaced apart a selected distance may enable a clinician to determine an orientation and/or trajectory of the medical device 100 relative to surrounding soft tissue. For example, by visualizing two echogenic areas 124 in the ultrasound plane, the clinician may determine that at least the distal portion 140 comprising echogenic areas 124 is oriented in the plane. This enables a determination that at least the orientation and/or trajectory of the distal portion 140 is in the plane of the surrounding anatomy of the patient indicated by the ultrasound. Determining the orientation and/or trajectory of the distal portion 140 may facilitate traversing the heart valve or creating a penetration between heart chambers, such as from the right atrium to the left ventricle or from the right ventricle to the left ventricle. Using the echogenic regions to determine the orientation and/or trajectory of the medical device 100 relative to surrounding anatomy may increase the clinician's confidence and speed in navigating the patient's vasculature as compared to other medical imaging techniques with reduced soft tissue visibility, such as fluoroscopy.

The first echo region and the second echo region may be similar or dissimilar in size and shape. For example, as shown in fig. 2, the echo region 124A may be smaller and more spherical than the echo region 124B. This difference in size and/or shape may enable a clinician to distinguish between echo regions 124A and 124B. Distinguishing the echo regions 124A and 124B may enable the orientation and/or trajectory of the distal portion 140 to be determined. In some examples, the distance between the echo regions 124 may be based on the size and/or shape of the echo regions 124. For example, an ultrasound image showing the overall diameter of the echo region 124A may indicate that the echo region 124A is centered in the plane of the surrounding anatomy indicated by the ultrasound image. When the ultrasound image shows that a portion of the echogenic region 124B is smaller than the total diameter of the echogenic region 124B, the clinician can determine that the orientation and/or trajectory of the medical device 100 is above or below the ultrasound image plane. In some examples, a smaller echo region may enhance resolution aligned with the ultrasound plane as compared to a larger echo region. In some examples, a larger echo region may be easier to track than a smaller echo region. In this manner, the size and spacing of the echogenic areas 124 can be selected to improve visualization of the medical device 100 (e.g., distal portion 140) using ultrasound, which can improve determination of the trajectory and orientation of the distal portion 140 relative to surrounding tissue as compared to other medical imaging techniques, such as fluoroscopy.

Although described as including two echogenic regions 124, in some examples, the medical device 100 may include three or more echogenic regions positioned on the distal portion 140 of the medical device 100 to enable a clinician to determine the location, orientation, and/or trajectory of selected portions of the medical device 100, including, for example, the distal tip 120, the preformed curved segment 152, or the articulating segment 154. For example, the distal portion 140 may include an articulating section 154 and a preformed curved section 152 distal to the articulating section 154. In this way, the shape of the distal portion 140 may be controllable. For example, the pull wire 146 may be configured to controllably bend the articulating segment 154 along the first curvilinear portion 156 in the first geometric plane, such as by actuating the control member 144. In some examples, the amount of actuation of control member 144 may control the degree of curvature of articulating section 154. For example, the degree of curvature of articulating segment 154 may be controlled to a range between about 0 degrees and about 240 degrees, such as between about 45 degrees and about 180 degrees or between about 85 degrees and about 100 degrees. In some examples, the length of the hinge segment 154 defining the first curvilinear portion 156 may be in the range of about 5cm to about 20cm, such as about 12cm to about 15 cm. In some examples, the radius 158 of the first curved portion 156 may be between about 5mm and about 60mm, such as in a range between about 10mm and about 30mm or between about 15mm and about 20mm when hinged. By controlling the degree of curvature, the articulating segment 154 may enable the first curvilinear portion 156 to be adjusted to accommodate changes in the positioning of a selected location or differences in the size of the dilated heart as compared to an average size heart.

The pull wire 146 may enable control of the degree of curvature of the articulating section 154 from the handle assembly 142. For example, the proximal end 162 of the pull wire 146 may be coupled to the control member 144. The pull wire 146 may extend from the control member 144 to a distal tip 164 of the pull wire 146 that is anchored to the elongate body 116 distal to the articulating section 154. For example, a drawstring 160 may be used to anchor the distal tip 164 to the elongate body 116. The pull strap 160 can include any suitable structure configured to anchor the distal tip 164 of the pull wire 146 to the elongate body 116 distal to the articulating section 154. In some examples, the pull strap 160 may include a radiopaque marker, gold, platinum iridium, other noble metals or alloys thereof, stainless steel, other materials configured to withstand deflection forces from the actuation pull wire 146 that may include sputtered noble metals, or combinations thereof. In some examples, the pull wire 146 comprises a single pull wire. In other examples, the pull wire 146 may include a plurality of pull wires. In examples where the pull wire 146 includes a plurality of pull wires, each of the plurality of pull wires may be configured to control deflection of the distal portion 140 in one or more directions. The pull wire 146 may comprise any suitable material and construction. In some examples, the diameter of the pull wire 146 may be about 0.009 inches (0.23 mm) and may be formed of medical grade stainless steel. In some examples, the pull wire 146 may include a coating, for example, a fluoropolymer such as Polytetrafluoroethylene (PTFE). By anchoring the distal end 164 of the pull wire 146, actuation of the control member 144 in a proximal direction, for example, to shorten the length of the pull wire 146 extending through the elongate body, may result in a controllable bending of the articulating section 154 in the geometric plane. Actuation of the control member 144 in a distal direction, for example, to lengthen the length of the pull wire 146, may cause the articulating section 154 to controllably return to a rest state, e.g., an unflexed or less flexed configuration.

In some examples, the shape of the distal portion 140 may include a preformed curve. For example, the preformed curve segment 152 defines the second curve 153 in a second geometric plane. The second geometric plane may be similar to or different from the first geometric plane. For example, the first geometric plane and the second geometric plane may be offset by a certain offset angle. In some examples, the offset angle, e.g., the angle of the first geometric plane relative to the second geometric plane, may be in a range of about 10 degrees to about 80 degrees, such as about 30 degrees to about 60 degrees or about 40 degrees to about 50 degrees.

In some examples, the preformed curve segment 152 may be flexible enough to deform into a substantially straight configuration when delivered through the vasculature of a patient. The spring force of the preformed curved section 152 may be sufficient to restore the preformed shape of the second curved portion 153 when positioned in the patient's heart. In some examples, the second curvilinear portion 153 of the preformed curvilinear segment 152 can be formed by, for example, heat setting. In some examples, the degree of curvature of the preformed curve segment 152 may be between about 10 degrees and about 180 degrees, such as in the range between about 30 degrees and about 140 degrees. In some examples, the length of the preformed curve segment 152 defining the second curve 153 is between about 6mm and about 10cm, such as in a range between about 1cm and about 5cm or between about 1cm and about 2 cm. In some examples, the radius 155 of the second curvilinear portion 153 is in a range between about 1mm and about 20mm, such as between about 2mm and about 10 mm. The degree of curvature of the preformed curved section 152 may enable the distal tip 120 to be oriented substantially perpendicular to the tissue at the selected location.

In some examples, the distal portion 140 may include one or more substantially straight portions. For example, the elongate body 116 may include a substantially straight portion 166 distal to the articulating section 154 and proximal to the preformed curved section 152, and/or a substantially straight portion 168 distal to the preformed curved section 152 and including the distal tip 120. In some examples, the length of substantially straight portions 166 and/or 168 may be between about 1mm and about 15mm, such as in the range between about 0.5mm and about 9 mm. In some examples, the echo region 124 may be positioned on one or more of the substantially straight portions 166 or 168.

Fig. 3 is a conceptual diagram illustrating a distal portion 240 of an example medical device 200 positioned to the right of a heart 270. The medical device 200 may be the same or substantially similar to the medical device 10 or the medical device 100 described above with reference to fig. 1-2.

The medical device 200 includes an echogenic region 224 positioned on a distal portion 240 (e.g., near the distal tip 220) of the medical device 200. The echogenic region 224 is configured to facilitate guiding the medical device 200 to a selected location within the heart 270 using ultrasound.

As shown in fig. 3, the heart 270 has an anterior sidewall that peels back to present a portion of the intrinsic conduction system of the heart 270 and the chambers of the Right Atrium (RA) 271 and Right Ventricle (RV) 272. Related elements of the intrinsic conduction system of the heart 270 may include a Sinus (SA) node 273, an Atrioventricular (AV) node 274, a bundle of his 275, a right bundle branch 276, and a Purkinje fiber 277. The SA node 273 is shown as being proximate to the Superior Vena Cava (SVC) 279 in the RA 271. The electrical pulse beginning at SA node 273 rapidly travels through the tissue of RA 271 and the left atrial tissue (not shown) to AV node 274. At AV node 274, the pulse slows to create a delay before passing through the his bundle 275, which branches into a right bundle branch 276 and a left bundle branch (not shown) in the ventricular septum 278 and then into purkinje fibers 277 near the RV apex 16. The flow of electrical pulses produces an ordered sequence of atrial and ventricular contractions and relaxation to effectively pump blood through the heart 270.

The intrinsic conduction system of heart 270 may no longer operate within the general anatomical specifications due to disease, injury, or natural imperfections. In some examples, a cardiac pacemaker system may be implanted within a patient such that implantable medical electrical leads or electrodes carried by a leadless Implantable Medical Device (IMD) may be placed in the atrial appendage 281. The electrodes stimulate the RA 271 downstream of the SA node 273 and the stimulation pulses travel to the AV node 274, the bundle of his 275 and the purkinje fibers 277 to restore the physiological contractions of the heart. However, if the patient's AV node 274 is defective, pacing in the atrial appendage 281 will be ineffective because the pacing site is located upstream of the AV node 274, such as an atrioventricular block. For these or other reasons, the patient may have implanted a cardiac pacemaker system such that the medical electrical lead is positioned at the RV apex 16, his bundle 275 (as shown in fig. 1A), a selected location of the ventricular septum, or a suitable location in the left atrium or left ventricle. Navigation medical device 200 delivers an electrical lead or leadless Implantable Medical Device (IMD) to a selected location within a patient's body, requiring medical imaging to visualize the position of medical device 200 relative to the anatomy of heart 270. In some examples, medical device 200 may be inserted into heart 270 using an intravenous approach through SVC 279 into RA 271. In some examples, the medical device 200 may be directed through the tricuspid valve 280 to the RA 272. In some examples, the medical device 200 may penetrate from the right atrium, through the atrial septum and the ventricular septum to the left ventricle, or through the right ventricle and the ventricular septum to the left ventricle. To overcome the drawbacks of some medical imaging techniques, such as fluoroscopy, ultrasound may be used to guide the medical device 200 to a selected location within the heart 270, as discussed above.

Due to the nature of ultrasound imaging, it may be difficult to use ultrasound to position the medical device 200. For example, the field of view of the ultrasound image may include a two-dimensional (2D) plane having a thickness in the range of about 2 millimeters (mm) to about 6 mm. Because of, for example, the thinness of the 2D plane of the ultrasound image relative to the volume of the heart 270 and/or relative movement of the medical device 200 as it advances to a selected location, it may be difficult for a clinician to maintain the medical device 200 in view, for example, during movement caused by a heartbeat. Furthermore, the resolution of ultrasound imaging may make it difficult to distinguish features having diameters less than about 1mm to about 2 mm. Furthermore, in order to visualize a structure using ultrasound, the structure must reflect (e.g., scatter) at least a portion of the emitted ultrasonic sound waves back to the ultrasound transducer. As used herein, visualizing a structure using ultrasound means detecting the structure by receiving a signal at an ultrasound transducer indicative of the reflection of ultrasound waves emitted from the ultrasound transducer and processing the signal to generate an image indicative of the structure. In some examples, a smooth surface of a medical device (such as medical device 200) may produce geometric scattering of ultrasonic sound waves rather than diffuse scattering of ultrasonic sound waves. Geometric scattering may reduce visualization of the medical device at angles away from perpendicular. For these reasons, it may be difficult for a clinician to orient the ultrasound transducer to visualize the medical device 200, determine which portion of the medical device 200 (or medical device to be delivered) is within the field of view of the ultrasound, or both.

The echogenic region 224 may facilitate the use of ultrasound to direct the medical device 200 to a selected location within the heart 270 by increasing the size and diffuse reflection of at least a portion of the medical device 200. The medical device 200 may comprise a flexible biocompatible material such as, for example, silicone or polyurethane. In some examples, the medical device 200 may include a preformed curve. For example, upon advancing into RA 271, medical device 200 may begin to resume its preformed curve. In some examples, the medical device 200 is a steerable catheter. In some examples, the medical device 200 is a guidable catheter and includes a lumen for receiving a guidewire to assist in advancing the medical device 200 at least a portion of a distance to a selected location within the heart 270. In some examples, the medical device 200 includes features that allow it to effectively transfer forces applied to the proximal end of the medical device 200 into movement of the distal end 220 of the medical device 200, for example, via a handle assembly (not shown). For example, the distal portion 240 may include a plurality of curves proximal to the distal tip 220 to facilitate guiding the distal tip 220 to a selected location. In some examples, the plurality of curves may be formed from an articulating section that is adjustable, for example, by a pull wire that may be manipulated by a control member at the handle assembly, a preformed curved section, or other feature configured to shape the length of the distal portion 240.

The medical devices described herein may be assembled by any suitable technique. Fig. 4 is a flow chart illustrating an example method for assembling an example medical device having an echogenic region. The medical device may be the same or substantially similar to medical device 10, 100, and/or 200 discussed above with respect to fig. 1-3. Although fig. 4 is described with respect to medical device 10, in other examples, the method of fig. 4 may be used to assemble other medical devices having echogenic regions.

The technique shown in fig. 4 includes forming a first layer 12 (302). As described above, the first layer 12 can define an elongate body 16 extending along a longitudinal axis A-A from a proximal end 18 of the elongate body 16 to a distal end 20 of the elongate body 16, and can define a cavity 22 extending longitudinally within the elongate body 16. The first layer 12 of the medical device 10 may be formed of any suitable polymer. The cavity 22 may be configured to receive a medical electrical lead including at least one electrode and/or IMD.

The technique shown in fig. 4 also includes forming a second layer 14 (304). As described above, the second layer 14 may be disposed on and radially adjacent to the first layer 12. The second layer 14 may be secured to the first layer 12 by, for example, adhesive, thermal welding, or ultrasonic welding. In some examples, the second layer 14 may be coated on the first layer 12, for example, by dip coating or spray coating. Conversely, the first layer 12 may be coated on the second layer 14.

A portion of the second layer 14 may define an echogenic region 24. The echogenic region 24 of the second layer 14 may have an embedded echogenic metallic or ceramic material, such as echogenic particles 28. In some examples, echogenic particles 28 may include one or more of tungsten, tantalum, platinum, gold, stainless steel, aluminum, titanium, aluminum oxide, magnesium oxide, silica glass, silica, tungsten carbide, silicon carbide, titanium dioxide, titanium carbide, or titanium nitride. For example, the second layer 14 may be a silicon adhesive layer containing echogenic particles 28, and may be dip coated onto the first layer 12. In one example, the echogenic particles 28 may include lightweight low density particles (e.g., aluminum particles) to help lengthen the particle suspension time.

The first layer 12 may be formed by any suitable technique, such as, for example, heating and inflating the first polymer within a mold. The second layer 14 may be formed by inserting a second polymer into the formed first layer 12 and heating and inflating the second polymer in a similar manner. As described above, this process may be repeated to form additional layers, such as a third layer.

In some examples, the first layer 12 and the second layer 14 may be extruded sequentially prior to inflation within the die. For example, the first layer 12 may be formed of a polymeric material and may be extruded prior to inflation within the balloon mold. The balloon mold may be heated to an elevated temperature to soften the polymeric material of the first layer 12 for the molding process. The softened polymeric material of the first layer 12 may then be inflated to expand the softened polymeric material within the cavity of the balloon mold such that the polymeric material conforms to the shape of the cavity to form the desired shape. The second layer 14 may comprise the same polymeric material as the first layer 12 and may be extruded sequentially prior to inflation within the balloon mold. The polymeric material of the second layer 14 may then be heated and inflated to bond it to the first layer 12. In some examples, an initial sequential extrusion may be performed to form three or more layers prior to inflation within the balloon mold.

In some examples, the second polymer is placed over the first polymer prior to shaping the two polymers to form the first layer 12 and the second layer 14. In such examples, the first polymer and the second polymer may be sequentially extruded tubes. The first polymer and the second polymer may be laminated together before, during, or after forming.

In some examples, the first layer 12 and the second layer 14 may be coextruded prior to inflation within the die. For example, the first layer 12 may be formed of a first polymeric material and the second layer 14 may be formed of a second polymeric material, and the first layer 12 and the second layer 14 may be co-extruded prior to inflation within the balloon mold. The balloon mold may be heated and the first layer 12 and the second layer 14 may be inflated to form the multi-layer echogenic area 24. Co-extruding the first layer 12 and the second layer 14 may help bond the first layer 12 formed of the first polymeric material to the second layer 14 formed of the second polymeric material. In some examples, an initial coextrusion may be performed to form three or more layers prior to inflation within the balloon mold.

In some examples, the echogenic region 24 of the medical device 10 may further include an innermost layer configured to be bonded to a shaft (e.g., a catheter shaft) of the elongate body 16 of the medical device 10. The innermost layer may be made of a material compatible with bonding the innermost layer to the shaft of the elongate body 16. In some examples, the innermost layer may be made of a different material than the materials of the first layer 12 and the second layer 14.

In some examples, the technique may include applying an echogenic coating to one layer 12 and/or second layer 14. For example, the first layer 12 and/or the second layer 14 may be dip coated in an echogenic coating, or the echogenic coating may be injected into the first layer 12 and/or the second layer 14 after the first layer 12 and/or the second layer 14 are formed. The echogenic medical device 10 having the first layer 12 and the second layer 14 is configured to be deployed to a selected location using ultrasound while having a strong support structure that resists bursting and tearing. The medical devices described herein may be used to deliver medical electrical leads or IMDs using any suitable technique. Fig. 5 is a flow chart illustrating an example method of delivering a medical electrical lead to a selected location using an example medical device having an echogenic region. The medical device may be the same or substantially similar to medical device 10, 100, and/or 200 discussed above with respect to fig. 1-3. Although fig. 5 is described with respect to medical device 100, in other examples, the method of fig. 5 may be used to assemble other medical devices having echogenic regions.

The technique shown in fig. 5 includes advancing the medical device 100 toward a selected location within the patient (312). In some examples, after advancing the medical device 100 toward the selected location, the technique may include actuating the control member 144, e.g., via the one or more controls 148, to cause the pull wire 146 to controllably bend the articulating segment 154 into the first curvilinear portion 156.

In some examples, the technique may include expanding the echogenic region 124 from a collapsed configuration to an expanded configuration. In some examples, expanding the echogenic region 124 may include injecting a fluid (such as saline) into the echogenic region 124 via one or more lumens of the medical device 100. In some examples, expanding the echogenic region 124 may include actuating the control member 144, e.g., via one or more controls 148, to cause the pull wire 146 to expand the echogenic region 124.

The technique shown in fig. 5 also includes identifying at least one of a location, orientation, or trajectory of the distal portion of the catheter relative to the selected location based on acoustic waves reflected by the echogenic region 124 (314). In some examples, the identifying may include imaging the at least one echo region 124 by an ultrasound imaging device. For example, imaging may include capturing a plurality of images of the surrounding anatomy and the at least one echogenic region 124. Each image of the plurality of images may include a different angle of the ultrasound transceiver relative to the medical device 100 and/or surrounding anatomy. In some examples, the identifying may include determining a location, orientation, and/or trajectory of the distal portion 140 (e.g., distal tip 120) relative to surrounding anatomy based on the ultrasound image. For example, determining the location, orientation, and/or trajectory of the distal portion 140 may include comparing the size and/or shape of the echogenic region 124 to known sizes and/or shapes of one or more cross-sectional geometries of the echogenic region 124. In some examples, determining the location, orientation, and/or trajectory of the distal portion 140 may include comparing the size and/or shape of the first echogenic region 124A with the size and/or shape of the second echogenic region 124B. In some examples, after determining the location, orientation, and/or trajectory of the distal portion 140, the technique may include further advancing, repositioning, or redirecting the distal portion 140, and repeatedly imaging the at least one echogenic region 124.

The technique shown in fig. 6 also includes, after identifying the selected location, advancing a medical electrical lead or IMD through the lumen and out of the distal tip 120 of the elongate body 116 to the selected location (316). For example, the technique may include advancing a medical electrical lead out of the distal end 120 of the medical device 100 and controlling the fixation member, e.g., via a lead body of the medical electrical lead, controllable at or near a handle assembly of the medical device 100, to knob the fixation member into tissue at a selected location.

The following clauses illustrate example subject matter described herein.

Clause 1. A medical device comprising: a first layer defining an elongate body extending along a longitudinal axis from a proximal end to a distal end and defining a cavity extending longitudinally within the elongate body, wherein the first layer comprises a first polymer; and a second layer disposed on and radially adjacent to the first layer, wherein the second layer comprises a second polymer, wherein at least a portion of the second layer defines an echogenic region comprising: a second polymer; and an echogenic metal or ceramic material dispersed in the second polymer, and wherein the echogenic region is configured to diffusely scatter sound waves.

Clause 2. The medical device of clause 1, wherein the medical device comprises at least one of a medical balloon, a medical tube, or a catheter.

Clause 3 the medical device of clause 1 or 2, wherein the echogenic metal or ceramic material comprises at least one of tungsten, tantalum, platinum, gold, stainless steel, aluminum, titanium, aluminum oxide, magnesium oxide, silica glass, silica, tungsten carbide, silicon carbide, titanium dioxide, titanium carbide, or titanium nitride.

Clause 4 the medical device of any of clauses 1-3, wherein the first polymer has a density of about 0.7g/cm ³ To about 5.5g/cm ³ Within a range of (2).

Clause 5 the medical device of any of clauses 1-4, wherein the second polymer has a density of about 0.7g/cm ³ To about 5.5g/cm ³ Within a range of (2).

Clause 6 the medical device of any of clauses 1 to 5, wherein the echogenic metallic or ceramic material has a density of about 1g/cm ³ To about 20g/cm ³ Within a range of (2).

Clause 7. The medical device of any of clauses 1-6, wherein the specific acoustic impedance of the echogenic metallic or ceramic material is in the range of about 10MRayl to about 110 MRayl.

Clause 8 the medical device of any of clauses 1-7, wherein the difference between the density of the echogenic region and the density of the first polymer is about 0g/cm ³ To about 15g/cm ³ Within a range of (2).

The medical device of any one of clauses 1-8, wherein the radial thickness of the first layer is in the range of about 0.001mm to about 2 mm.

The medical device of any one of clauses 1-9, wherein the radial thickness of the second layer is in the range of about 0.001mm to about 2 mm.

The medical device of any one of clauses 1-10, further comprising a third layer radially adjacent to the second layer, wherein the third layer comprises a third polymer.

The medical device of any one of clauses 1-11, wherein the echogenic material comprises a plurality of particles, wherein an average diameter of the plurality of particles is in a range of about 0.1 μm to about 50 μm.

Clause 13 the medical device of any of clauses 1-13, wherein the sound waves comprise ultrasonic sound waves having a frequency in the range of about 1MHz to about 20 MHz.

Clause 14, a kit, comprising: a first medical device, the first medical device comprising: a first layer defining the elongate body extending along a longitudinal axis from a proximal end to a distal end and defining a cavity extending longitudinally within the elongate body, wherein the first layer comprises a first polymer; and a second layer disposed on and radially adjacent to the first layer, wherein the second layer comprises a second polymer, wherein at least a portion of the second layer defines an echogenic region comprising: a second polymer; and an echogenic metal or ceramic material dispersed in the second polymer, and wherein the echogenic region is configured to diffusely scatter sound waves; and a second medical device sized to extend from the distal tip delivery of the elongate body and configured for at least one of therapy delivery or sensing.

Clause 15 the kit of clause 14, wherein the first medical device comprises at least one of a medical balloon, a medical tube, or a catheter.

Clause 16 the kit of clauses 14 or 15, further comprising a fluid, wherein the echogenic region is configured to be inflated with the fluid.

The kit of any of clauses 14-16, wherein the second medical device comprises at least one of a medical electrical lead or an implantable medical device.

Clause 18 the kit of any of clauses 14 to 17, wherein the second layer further comprises a second echogenic region adjacent to the first echogenic region.

The kit of any of clauses 14-18, wherein the first medical device further comprises a handle assembly configured to controllably expand the first medical device from the collapsed configuration to the expanded configuration.

The kit of any of clauses 14 to 19, wherein the second medical device comprises at least one of a medical electrical lead or an implantable medical device.

Clause 21, a method comprising: forming a first layer defining an elongate body extending along a longitudinal axis from a proximal end to a distal end and defining a cavity extending longitudinally within the elongate body, wherein the first layer comprises a first polymer; and forming a second layer disposed on and radially adjacent to the first layer, wherein the second layer comprises a second polymer, wherein at least a portion of the second layer defines an echogenic region comprising: a second polymer; and an echogenic metal or ceramic material dispersed in the second polymer, and wherein the echogenic region is configured to diffusely scatter sound waves.

Clause 22 the method of clause 21, further comprising: forming a third layer radially adjacent to the second layer, wherein the third layer comprises a third polymer.

Clause 23 the method of clause 21, further comprising: extruding the first polymer through a die; shaping the first polymer to form the first layer; extruding the second polymer through the first layer; and shaping the second polymer to form the second layer.

Clause 24 the method of clause 21, further comprising: coextruding the first polymer and the second polymer through a die; and shaping the first polymer and the second polymer to form the first layer and the second layer.

Clause 25, a method comprising: advancing a first medical device toward a selected location within a patient, wherein the first medical device comprises: a first layer defining an elongate body extending along a longitudinal axis from a proximal end to a distal end and defining a cavity extending longitudinally within the elongate body, wherein the first layer comprises a first polymer; and a second layer disposed on and radially adjacent to the first layer, wherein the second layer comprises a second polymer, wherein at least a portion of the second layer defines an echogenic region comprising: a second polymer; and an echogenic metal or ceramic material dispersed in the second polymer, and wherein the echogenic region is configured to diffusely scatter sound waves; identifying at least one of a location, orientation, or trajectory of the distal portion of the first medical device relative to a selected location based on acoustic waves reflected by the echogenic region; and advancing a second medical device through the lumen and out from the distal end of the elongate body to the selected position for at least one of therapy delivery or sensing.

The method of clause 26, wherein identifying at least one of the location, the orientation, or the trajectory of the distal portion comprises: imaging the echo region by an ultrasonic imaging device; and determining at least one of the location, the orientation, or the trajectory of the distal portion relative to the anatomy of the patient surrounding the distal portion of the medical device based on the ultrasound image.

Clause 27 the method of clause 25 or 26, further comprising expanding the echogenic region from the collapsed configuration to the expanded configuration.

Clause 28, a method comprising: forming a first layer defining an elongate body extending along a longitudinal axis from a proximal end to a distal end and defining a cavity extending longitudinally within the elongate body, wherein the first layer comprises a first polymer; and forming a second layer disposed on and radially adjacent to the first layer, wherein the second layer comprises a second polymer, wherein at least a portion of the second layer defines an echogenic region comprising: a second polymer; and an echogenic metal or ceramic material dispersed in the second polymer, and wherein the echogenic region is configured to diffusely scatter sound waves.

Clause 29 the method of clause 28, further comprising: forming a third layer radially adjacent to the second layer, wherein the third layer comprises a third polymer.

Clause 30 the method of clause 28, further comprising: extruding the first polymer through a die; shaping the first polymer to form the first layer; extruding the second polymer through the first layer; and shaping the second polymer to form the second layer.

Clause 31 the method of clause 30, further comprising placing the second polymer over the first polymer before shaping the first polymer to form the first layer and shaping the second polymer to form the second layer.

Clause 32 the method of clause 28, further comprising: coextruding the first polymer and the second polymer through a die; and shaping the first polymer and the second polymer to form the first layer and the second layer.

Various examples of the present disclosure have been described. Any combination of the described systems, operations, or functions is contemplated. These and other examples are within the scope of the following claims.

Claims

1. A medical device, comprising:

A first layer defining an elongate body extending along a longitudinal axis from a proximal end to a distal end and defining a cavity extending longitudinally within the elongate body; and

a second layer disposed on and radially adjacent to the first layer,

wherein at least a portion of the second layer defines an echogenic region comprising echogenic metallic or ceramic material dispersed in the second layer,

wherein the echo region is configured to diffusely scatter sound waves.

2. The medical device of claim 1, wherein the medical device comprises at least one of a medical balloon, a medical tube, or a catheter.

3. The medical device of claim 1 or 2, wherein the echogenic metal or ceramic material comprises at least one of tungsten, tantalum, platinum, gold, stainless steel, aluminum, titanium, aluminum oxide, magnesium oxide, silica glass, silica, tungsten carbide, silicon carbide, titanium dioxide, titanium carbide, or titanium nitride.

4. The medical device of any one of claims 1-3, wherein the first layer comprises a first polymer, the second layer comprises a second polymer, and the echogenic metal or ceramic material is dispersed in the second polymer.

5. The medical device of claim 4, wherein the first polymer has a density of about 0.7g/cm ³ To about 5.5g/cm ³ Within a range of (2).

6. The medical device of claim 4 or 5, wherein the second polymer has a density of about 0.7g/cm ³ To about 5.5g/cm ³ Within a range of (2).

7. The medical device of any one of claims 4-6, wherein a difference between the density of the echogenic region and the density of the first polymer is about 0g/cm ³ To about 15g/cm ³ Within a range of (2).

8. The medical device of any one of claims 4-7, further comprising a third layer radially adjacent to the second layer, wherein the third layer comprises a third polymer.

9. The medical device of any one of claims 1-8, wherein the echogenic metal or ceramic material has a density of about 1g/cm ³ To about 20g/cm ³ Within a range of (2).

10. The medical device of any one of claims 1-9, wherein the echogenic metallic or ceramic material has a specific acoustic impedance in a range of about 10MRayl to about 110 MRayl.

11. The medical device of any one of claims 1-10, wherein the radial thickness of the first layer is in a range of about 0.001mm to about 2 mm.

12. The medical device of any one of claims 1-11, wherein the radial thickness of the second layer is in the range of about 0.001mm to about 2 mm.

13. The medical device of any one of claims 1-12, wherein the echogenic material comprises a plurality of particles, wherein an average diameter of the plurality of particles is in a range of about 0.1 μιη to about 50 μιη.

14. The medical device of any one of claims 1-13, wherein the acoustic waves of the echo region configured to diffusely scatter comprise ultrasonic acoustic waves having a frequency in a range of about 1MHz to about 20 MHz.

15. The medical device of any one of claims 1-14, wherein the first layer defines an outermost surface of the medical device.

16. The medical device of any one of claims 1-15, wherein the second layer defines an innermost surface of the medical device.

17. The medical device of any one of claims 1-16, wherein the second layer is disposed on an inner surface of the first layer.

18. The medical device of any one of claims 1-17, wherein the echogenic region is expandable with an adjacent portion of the first layer.

19. A kit, comprising:

the first medical device of any one of claims 1-18; and

a second medical device sized to deliver a protrusion from the distal tip of the elongate body and configured for at least one of therapy delivery or sensing.

20. The kit of claim 19, wherein the first medical device comprises at least one of a medical balloon, a medical tube, or a catheter.