Medical device delivery system

Abstract

A catheter includes a catheter body extending from a proximal end to a distal end. The catheter further includes a cup at the distal end. The cup defines an opening at a cup distal end. The cup is configured to receive an implantable medical device through the opening. The cup includes a flared tip configured to flex radially inward.

Description

MEDICAL DEVICE DELIVERY SYSTEM

[0001] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 588,619, filed October 6, 2023, the entire content of which is incorporated herein by reference.TECHNICAL FIELD

[0002] This disclosure relates generally to medical devices, and, more particularly, to systems for delivering medical devices.BACKGROUND

[0003] Implantable medical devices (IMDs) are typically implanted via surgical procedures. In some examples, a medical device delivery system may include a delivery catheter configured to navigate through vasculature or other anatomical structures of a patient’s body to reach a target site for the IMD. Delivery catheters may be long, flexible, and have a small diameter to minimize patient discomfort and facilitate maneuverability. They are often equipped with additional features like guidewires, balloons, or sheaths to aid in the delivery process. By using a delivery catheter, a clinician may more accurately and / or less invasively deploy an IMD, potentially improving device positioning and functionality, as well as recovery from the procedure.SUMMARY

[0004] In some examples, a delivery catheter includes: a catheter body extending from a proximal end to a distal end; and a cup at the distal end, wherein the cup defines an opening at a cup distal end, wherein the cup is configured to receive an implantable medical device through the opening, and wherein the cup includes a flared tip configured to flex radially inward.

[0005] In some examples, a medical device system includes: an implantable medical device; an introducer defining a lumen; and a delivery catheter including: a catheter body extending from a proximal end to a distal end; and a cup at the distal end, wherein the cup defines an opening at a cup distal end, wherein the cup is configured to receive the implantable medical device through the opening, wherein the cup includes a flared tip configured to flex radially inward, wherein the introducer is configured to receive at leasta portion of the delivery catheter, wherein an inner diameter of the lumen is less than an outer diameter of the flared tip, and wherein the inner diameter of the lumen constrains the outer diameter of the flared tip while the flared tip is positioned inside the lumen.

[0006] In some examples, a method includes: advancing an introducer of a medical device system within a patient; advancing a delivery catheter through a lumen of the introducer, wherein the delivery catheter includes: a catheter body extending from a proximal end to a distal end; and a cup at the distal end, wherein the cup defines an opening at a cup distal end, wherein the cup includes a flared tip configured to flex radially inward, wherein an inner diameter of the lumen is less than an outer diameter of the flared tip, and wherein the inner diameter of the lumen constrains the outer diameter of the flared tip while the flared tip is positioned inside the lumen; pressing the flared tip against tissue of a target site; and implanting an implantable medical device positioned in the cup to the tissue of the target site.

[0007] In some examples, a method includes: forming, as a first shot of an overmolding process, a cup of a delivery catheter, wherein the delivery catheter includes: a catheter body extending from a proximal end to a distal end, wherein the cup is positioned at the distal end, wherein the cup defines an opening at a cup distal end, wherein the cup is configured to receive an implantable medical device through the opening, and wherein the cup comprises a flared tip configured to flex radially inward; and forming, as a second shot of the overmolding process, a flared tip of the delivery catheter, wherein the flared tip is formed over the cup, and wherein the flared tip is configured to flex radially inward.

[0008] This summary is intended to provide an overview of the subject matter described in this disclosure. It is not intended to provide an exclusive or exhaustive explanation of the apparatus and methods described in detail within the accompanying drawings and description below. Further details of one or more examples are set forth in the accompanying drawings and the description below.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG. 1 is a conceptual drawing illustrating portions of patient anatomy including potential target sites for an implantable medical device (IMD).

[0010] FIG. 2 is a conceptual drawing illustrating an example implantable medical device (IMD).

[0011] FIGS. 3A-3B are conceptual diagrams illustrating an example implantable medical device (IMD) within a delivery cup in accordance with techniques of this disclosure.

[0012] FIG. 4 is an exploded perspective view illustrating an example configuration of a delivery cup in accordance with techniques of this disclosure.

[0013] FIG. 5 is a flow diagram illustrating an example technique for using a medical device system in accordance with techniques of this disclosure.

[0014] FIG. 6 is a flow diagram illustrating an example technique for manufacturing a medical device system in accordance with techniques of this disclosure.DETAILED DESCRIPTION

[0015] In general, this disclosure describes a medical device delivery system (“delivery system”) configured to deliver an implantable medical device (IMD) to a target site, such as the triangle of Koch (TOK), a coronary sinus ostium, right atrium, a left bundle branch, etc. Although described herein primarily in the context of targeting certain areas of the heart, the delivery system may be used to deliver an IMD to any target site, including tissue from other parts of the body.

[0016] In general, a delivery system may include a delivery catheter with a distal cup configured to receive the IMD. During an implant procedure, the distal cup may be pressed against a target site. However, the distal cup may inadvertently move (e.g., slip) relative to the target site, despite a clinician’s best efforts, because of insufficient friction between the distal cup and the target site. Thus, in accordance with techniques of this disclosure, the distal cup of the delivery catheter may include a tip configured to resist slipping. The tip may be formed from a soft, flexible material that is compliant (e.g., deformable by intended or expected forces during an implantation procedure). In some examples, the tip may be flared (when in an undeformed configuration), and when the distal cup is in an introducer of the delivery system, the introducer may apply a contactforce that deforms the tip radially inward. When the tip of the distal cup is no longer in the introducer such that the tip is not subject to a force applied by the introducer, the tip may return to its original shape, increasing the surface area of the tip. The larger area of contact may increase the frictional force between the tip and the surface of the target site, making it harder for the distal cup to slip. In this way, the techniques of this disclosure may improve device placement and in turn device functionality.

[0017] FIG. 1 is a conceptual diagram illustrating a portion of an example medical device system 10 configured to implant a relatively compact implantable medical device 100 (“IMD 100”) at a target site. In some examples, as illustrated in FIG. 1, the target site 107 may include an appendage or triangle of Koch region of a right atrium (RA) of the heart 104 of a patient. In some examples, as illustrated in FIG. 1, the target site 107 may include a coronary sinus ostium (not shown in FIG. 1), or to a left bundle branch (not shown in FIG. 1) on a right septal wall of a patient’s heart. In some examples, target site may include other portions of heart 104, such as an interventricular septum, or other locations within a body of the patient. Medical device system 10 may include a delivery catheter 170 configured to house and controllably deploy IMD 100.

[0018] Delivery catheter 170 may include a catheter body 169 extending from a proximal end to a distal end. A clinician may maneuver IMD 100 to target site. For example, with IMD 100 loaded within a cup 180 disposed at a distal end of catheter body 169 of delivery catheter 170, the clinician may guide delivery catheter 170 up through the inferior vena cava (IVC) and into the RA of heart 104, and place a tip 172 of cup 180 against the septum of the heart 104. In some examples, other pathways or techniques may be used to guide delivery catheter into other target sites within the body of the patient. For example, the superior vena cava (SVC) may be used to gain access to the heart. The inner diameter of at least a portion of cup 180 may be larger than an outer diameter of catheter body 169. At least that portion of cup 180 may extend longitudinally by a sufficient length to house IMD 100.

[0019] FIG. 2 is a perspective diagram illustrating IMD 200. IMD 200 includes a housing 202 that defines a hermetically sealed internal cavity. Housing 202 may be formed from a conductive material including titanium or titanium alloy, stainless steel, MP35N (a non-magnetic nickel-cobalt-chromium-molybdenum alloy), platinum alloy or other bio-compatible metal or metal alloy, or other suitable conductive material. In someexamples, Housing 202 is formed from a non-conductive material including ceramic, glass, sapphire, silicone, polyurethane, epoxy, acetyl co-polymer plastics, polyether ether ketone (PEEK), a liquid crystal polymer, other biocompatible polymer, or other suitable non-conductive material.

[0020] Housing 202 extends between a distal end 203 and a proximal end 207 along longitudinal axis 210. In some examples, housing can be cylindrical or substantially cylindrical but may be other shapes, e.g., prismatic, or other geometric shapes. Housing 202 may include a delivery tool interface member 208, e.g., at proximal end 207, for engaging with a delivery tool during implantation of IMD 200. At distal end 203, housing202 may define a face 205 of Housing 202. Face 205 may define a distal end major surface. Face 205 may be orthogonal to longitudinal axis 210. In some examples, face 205 may be slanted, e.g., face 205 may define a reference plane that is not orthogonal to longitudinal axis 210.

[0021] IMD 200 may include a ramp 213. Ramp 213 may be configured to promote contact between an electrode (e.g., second electrode 214 described below) and wall tissue of the chamber of heart 10 without penetration of the wall tissue of the chamber by the electrode. Ramp 213 may further be configured to separate the electrode from distal end203 by a fixed distance.

[0022] Ramp 213 may extend from a first end 214A that is fixedly attached to housing 202 at or near distal end 203 (e.g., attached to face 205), to a second end 214B that is more distal to first end 214A. Ramp 213 may be disposed radially outwards of first electrode212 relative to longitudinal axis 210. Ramp 213 may extend around at least a portion of a perimeter of Housing 202. Ramp 213 may extend up to 180 degrees around longitudinal axis 210 and along the perimeter of housing 202. Ramp 213 may be integrally formed as a part of the manufacturing of at least a portion of housing 202 (e.g., as a part of the manufacturing of a header defining distal end 203 and face 205 of housing 202). Ramp213 may be formed via a molding process, via additive manufacturing, or the like. In some examples ramp 213 is formed separately and affixed to face 205 of housing 202 afterwards. Ramp 213 may define a partial helix, e.g., wound in a same direction and / or in different directions as a helix and / or coil defined by first electrode 212. Ramp 213 may be formed at least partially of an electrically conductive material, such as titanium, platinum, iridium, tantalum, or alloys thereof, and / or of electrically nonconductive material(s). Atleast portions of ramp 213 may be coated with an electrically insulating coating, e.g., a parylene, polyurethane, silicone, epoxy, or other insulating coating.

[0023] First electrode 212 may include one or more coatings (e.g., electrically insulative coating(s)) configured to define a first electrically active region 216, or first electrode 212 may otherwise define first electrically active region 216. In some examples, first electrically active region 216 may be more proximate to the second, e.g., distal, end of first electrode 212. In the example of FIG. 2, first electrically active region 216 includes the distal end of electrode 212. Second electrode 214 may include one or more coatings configured to define a second electrically active region 217 on an outer surface of electrode 214. In some examples, as illustrated in FIG. 2, second electrical active region 217 forms a ring around a therapeutic substance dispensing device 215. Second electrode 214 may include, but is not limited to, a button electrode, a spring electrode, or any other suitable type or shape of electrode.

[0024] First and second electrodes 212 and 214 may be formed of an electrically conductive material, such as titanium, platinum, iridium, tantalum, stainless steel or alloys thereof. First and second electrodes 212 and 214 may be coated with an electrically insulating coating, e.g., a parylene, polyurethane, silicone, epoxy, or other insulating coating, to reduce the electrically conductive active surface area of first and second electrodes 212 and 214, and thereby define first and second electrically active regions 216 and 217. Defining first and second electrically active regions 216 and 217 by covering portions with an insulating coating may increase the electrical impedance of first and second electrodes 212 and 214 and thereby reduce the current delivered during a pacing pulse that captures the cardiac tissue. A lower current drain conserves the power source, e.g., one or more rechargeable or non-rechargeable batteries, of IMD 200.

[0025] In some examples, first and second electrodes 212 and 214 may have an electrically conducting material coating on first and second electrically active regions 216 and 217 to define the active regions. For example, first and second electrically active regions 216 and 217 may be coated with titanium nitride (TiN). First and second electrodes 212 and 214 may be made of substantially similar material or may be made of different material from one another.

[0026] In the example of FIG. 2, first electrode 212 takes the form of a helix or a coil. First electrode 212 may be an elongated body defining a helix. In some examples, a helixis an object having a three-dimensional shape like that of a wire wound uniformly in a single layer around a cylindrical or conical surface or mandrel such that the wire would be in a straight line if the surface were unrolled into a plane. First electrode 212 may extend from face 205 from a proximal end 220 to a distal end, e.g., defining first electrically active region 216. Proximal end 220 may be a location along first electrode 212 where first electrode 212 extends distally past distal end 203 of IMD 200.

[0027] Second electrode 214 is disposed on distal end 203 and may include a button electrode, e.g., as illustrated in FIG. 2, or any other suitable type or shape of electrode. In some examples, IMD 200 may have a plurality of second electrodes 214 (e.g., two or more second electrodes 214) disposed on distal end 203 of Housing 202. The plurality of second electrodes 214 may be equally spaced around a circumference of distal end 203. At least one of the plurality of second electrodes 214 may be disposed on ramps (e.g., on two or more ramps 212). In some examples, each of the plurality of second electrodes 214 may be disposed on ramps. Each ramp 213 may include a single second electrode 214 or two or more second electrodes 214. In some examples, second electrode 214 may be disposed at a predetermined angle away from first end of first electrode 212.

[0028] First and second electrodes 212 and 214 may vary in size and shape in order to enhance tissue contact of first and second electrically active regions 216 and 217. For example, first electrodes 212 may have a round cross-section or could be made with a flatter cross-section (e.g., oval or rectangular) based on tissue contact specifications. In some examples, second electrode 214 may have an outer surface that varies in size and shape (e.g., an oval outer surface, an outer surface with a larger diameter, or the like) in order to enhance tissue contact of second electrically active region 217.

[0029] The size and shape of first electrode 212 may be determined at least in part by stiffness requirements. For example, stiffness requirements may vary based on the expected implantation requirements, including the tissue into which the electrodes are implanted or contact, as well as how long IMD 200 is intended to be implanted.

[0030] First electrode 212 may extend from housing distal end 203 approximately 3 mm to 12 mm in various examples. In some examples, first electrode 212 may extend a distance from distal end 203 by at least 3 millimeters (mm), at least 3 mm but less than 20 mm, less than 15 mm, less than 10 mm, or less than 8 mm in various examples. The diameter of an elongated body defining first electrode 212 may be 2 mm or less, e.g., maybe 1 mm or less, may be 0.6 mm or less. An outer diameter of the helix or coil defined by first electrode 212 may be 4 mm or less.

[0031] The distal end of first electrode 212 can have a conical, hemi-spherical, or slanted edge distal tip with a narrow tip diameter, e.g., less than 1 mm, for penetrating into and through tissue layers. In some examples, the distal end of first electrode can be a sharpened or angular tip or sharpened or beveled edges, but the degree of sharpness may be constrained to avoid a cutting action that could lead to lateral displacement of the distal end of first electrode 212 and undesired tissue trauma. In some examples, first electrode 212 may have a maximum diameter at its base that interfaces with housing distal end 203. In such examples, the outer diameter of the helix defined by first electrode 212 may decrease from housing distal end 203 to the distal end of first electrode 212. In some examples, the diameter of first electrode 212 may vary from housing distal end 203 to the distal end of first electrode 212. The varying diameter may cause first electrode 212 to resist rotation within the tissue of heart 104.

[0032] The outer dimensions of first electrode 212 can be substantially straight and cylindrical, with first electrode 212 being rigid in some examples. In some examples, first electrode 212 may have flexibility in lateral directions, being non-rigid to allow some flexing with heart motion. In a relaxed state, when not subjected to any external forces, first electrode 212 can be configured to maintain a distance between first electrically active region 216 and housing distal end 203.

[0033] Distal end of first electrode 212 can pierce through one or more tissue layers to position first electrically active region 216 within a desired tissue layer, e.g., the ventricular myocardium 208 or interventricular septum. Accordingly, first electrode 212 extends a distance from housing distal end 203 corresponding to the expected pacing site depth and may have a relatively high compressive strength along its longitudinal axis, which may be substantially similar to or coincident with longitudinal axis 210, to resist bending in a lateral or radial direction when a longitudinal, axial, and / or rotational force is applied, e.g., to the proximal end 207 of housing 202 to advance IMD 200 into the tissue at target site 107. By resisting bending in a lateral or radial direction, first electrode 212 can maintain a spacing between a plurality of windings of first electrode 212 when first electrode 212 is a helix electrode. The spacing may be a pre-determined pitch of first electrode 212 and may vary from distal end 203 to the distal end of first electrode 212.First electrode 212 may be longitudinally non-compressible. First electrode 212 may also be elastically deformable in lateral or radial directions when subjected to lateral or radial forces, however, to allow temporary flexing, e.g., with tissue motion, but returns to its normally straight position when lateral forces diminish. In some examples, when first electrode 212 is not exposed to any external force, or to only a force along its longitudinal axis (substantially similar to or coincident with longitudinal axis 210), first electrode 212 retains a straight, linear configuration as shown.

[0034] All, substantially all, or a portion of housing 202 may function as an electrode 218, e.g., an anode, during pacing and / or sensing. In some examples, electrode 218 can circumscribe a portion of housing 202 at or near proximal end 207. Electrode 218 can fully or partially circumscribe housing 202. FIG. 2 shows electrode 218 extending as a singular band. Electrode 218 can also include multiple segments spaced a distance apart along a longitudinal axis 210 of housing 202 and / or around a perimeter of housing 202. In some examples, electrode 218 may be disposed on face 205 or on another ramp 213 disposed on face 205. For example, electrode 214 may be disposed on a first ramp 213 and electrode 218 may be disposed on a second ramp 213.

[0035] When housing 202 is formed from a conductive material, such as a titanium alloy, portions of housing 202 may be electrically insulated by a non-conductive material, such as a coating of parylene, polyurethane, silicone, epoxy or other biocompatible polymer, or other suitable material. For the portions of housing 202 without the non- conductive material, one or more discrete areas of housing 202 with conductive material can be exposed to define electrode 218.

[0036] When housing 202 is formed from a non-conductive material, such as a ceramic, glass or polymer material, an electrically-conductive coating or layer, such as a titanium, platinum, stainless steel, alloys thereof, a conductive material may be applied to one or more discrete areas of housing 202 to form electrode 218.

[0037] In some examples, electrode 218 may be a component, such as a ring electrode, that is mounted or assembled onto housing 202. Electrode 218 may be electrically coupled to internal circuitry of IMD 200 via electrically-conductive housing 202 or an electrical conductor when housing 202 is a non-conductive material. In some examples, electrode 218 is located proximate to proximal end 207 of housing 202 and can be referred to as a proximal housing -based electrode. Electrode 218 can also be located at other positionsalong housing 202, e.g., located proximately to distal end 203 or at other positions along longitudinal axis 210.

[0038] In some examples, second electrode 214 or electrode 218 may be paired with first electrode 212 for sensing ventricular signals and delivering ventricular pacing pulses. In some examples, second electrode 214 may be paired with electrode 218 or first electrode 212 for sensing atrial signals and delivering pacing pulses to atrial tissue (e.g., to the atrial myocardium) in target site 107. In other words, electrode 218 may be paired, at different times, with first electrode 212 and / or second electrode 214 for either ventricular or atrial functionality, respectively, in some examples. In some examples, first and second electrodes 212 and 214 may be paired with each other, with different polarities, for atrial and ventricular functionality.

[0039] In some examples, second electrode 214 may be configured as an atrial cathode electrode for delivering pacing pulses to the atrial tissue, e.g., at target site 107 in combination with electrode 218. Second electrode 214 and electrode 218 may also be used to sense atrial P-waves for use in controlling atrial pacing pulses (delivered in the absence of a sensed P-wave) and for controlling atrial-synchronized ventricular pacing pulses delivered using first electrode 212 as a cathode and electrode 218 as the return anode.

[0040] A distal end of first electrode 212 can be configured to rest within a ventricular myocardium of the patient, and second electrode 214 and ramp 213 can be configured to contact an atrial endocardium of the patient. IMD 200 may include more or fewer electrodes than two electrodes. In some examples, IMD 200 may include one or more second electrodes 214 along housing distal end 203. For example, IMD 200 may include two or three electrodes configured for atrial functionality like second electrode 214, and the three electrodes may be substantially similar or different from one another. Spacing between a plurality of second electrodes 214 may be at an equal or unequal distance. Second electrode(s) 214 may be individually selectively coupled to sensing and / or pacing circuitry enclosed by housing 202 for use as an anode with first electrode 212 or as an atrial cathode electrode, or may be electrically common and not individually selectable. IMD 200 may include one or more fixation members configured to secure IMD 200 to a target site. In some examples, the fixation member may include first electrode 212.

[0041] In some examples IMD 200 includes one or more therapeutic substance dispensing devices 215, e.g., on face 205, within a recess defined by second electrode 214,on ramp 213. The therapeutic substance (e.g., a steroid) may mitigate inflammation of patient tissue resulting from interaction with the IMD. Therapeutic substance dispensing devices 215 may be configured to elute one or more steroids to tissue in proximity to therapeutic substance dispensing devices 215 over time. In some examples, therapeutic substance dispensing devices 215 comprise one or more monolithic controlled release devices (MCRDs).

[0042] In some examples, IMD 200 includes one or more therapeutic substance dispensing devices 215 configured to elute one or more steroids to tissue proximate to first electrode 212. Therapeutic substance dispensing devices 215 may be disposed within a recess defined by second electrode 214. In some examples, therapeutic substance dispensing devices 215 may be disposed at a center of face 205, e.g., within recess defined by housing 202, and / or on ramp 213, e.g., between first end 214A and second end 214B. In some examples, first electrode 212 may deliver a therapeutic substance. For example, first electrode 212 may be coated with the therapeutic substance or include therapeutic substance dispensing devices 215.

[0043] FIGS. 3A-3B illustrate a system 30 that includes an IMD 300, a delivery catheter 370, which may be an example configuration of delivery catheter 170 of FIG. 1, and an introducer 390. As shown in FIG. 3A, delivery catheter 370 is positioned within introducer 390, and IMD 300 is positioned within a cup 380 of delivery catheter 370. Cup 380 may hold IMD 300 during the implant process, and a body 373 of delivery catheter 370 may guide cup 380 during the implant process. In the example of FIGS. 3A-3B, cup 380 is extended distally beyond introducer 390 when delivery catheter 370 and introducer 390 are positioned inside of the heart of a patient. However, in some examples, cup 380 may be extended distally beyond introducer 390 when introducer 390 is positioned just inside of the heart (e.g., such that only a distalmost portion of introducer 390 is just inside of the heart).

[0044] A distal end of cup 380 may define an opening configured to receive IMD 300. In some examples, delivery catheter 370 is a deflectable catheter. In some examples, the rate of deflection or curving may be predetermined. Cup 380 may include a tip 382 configured to resist slipping. Tip 382 may or may not be flared, but is generally described herein as flared. For example, tip 382 may extend radially outward as cup 380 extends in a distal direction. Tip 382 may be formed from a soft (e.g., a low durometer value), flexiblematerial that is compliant (e.g., easily deformed), such as a thermoplastic elastomer (e.g., Pebax 3533), silicone, polyurethane, polyethylene, etc. In some examples, a distal portion of tip 382 may be rounded in order to distribute the contact force between tip 382 and tissue at a target site 307 over a larger area. Thus, rounding tip 382 may avoid the risk of discomfort or trauma associated with sharp edges. Tip 382 may have a same or similar cross-sectional profile or shape to cup 380, e.g., round or oval.

[0045] In general, a delivery catheter having a small diameter may be desirable. For example, a smaller diameter catheter may allow for a less invasive surgical procedure, e.g., due to allowing use of a smaller introducer, reducing trauma to surrounding tissues and reducing scarring. Further, a small diameter catheter may be more maneuverable and can navigate through vasculature and other anatomical structures with greater precision, reducing the risk of vessel damage or blockages. As a result, a smaller diameter catheter may generally be more comfortable for patients and reduce risk of complications such as bleeding, vessel rupture, or vessel wall damage.

[0046] For at least the above reasons, constricting or otherwise reducing the maximum diameter of tip 382 when cup 380 is in an introducer 390 may be advantageous. For example, as shown in FIG. 3 A, tip 382 may be configured to deform radially inward when inside introducer 390. When tip 382 is inside introducer 390, introducer 390 may apply a contact force that deforms the tip radially inward. Thus, the inner diameter of introducer 390 may constrain the largest outer diameter of cup 380 as a whole, including the outer diameter of tip 382. When tip 382 is no longer in introducer 390 (e.g., as shown in FIG. 3B), tip 382 may no longer be subject to a contact force by introducer 390. As consequence, tip 382 may return to its original, flared shape, increasing the surface area of tip 382. The larger area of contact may increase the frictional force between tip 382 and the target site, making it harder for cup 380 to slip relative to target site 307.

[0047] In general, system 30 including tip 382 may be used in conjunction with an IMD including any type of fixation member. That said, tip 382 may work particularly well with a helical fixation member 383 because helical fixation member 383 does not need to be compressed or bent to fit inside cup 380. Accordingly, when helical fixation member 383 advances distally toward and / or through tip 382, the helical fixation member may not be biased to expand radially outward, which otherwise may cause contact between helical fixation member 383 and tip 382. Reducing contact between helical fixation member 383and tip 382 in this way may increase the longevity of tip 382 and reduce the risk of complications.

[0048] During surgery, a clinician may use visualization to effectively navigate the complex anatomical structures within the patient’s body. For example, clear visualization may provide information about the surgical site, enabling the clinician to accurately identify and differentiate between various tissues and structures. This visual clarity may ensure precision and accuracy in performing surgical maneuvers, such as the placement of implants or devices. Thus, visualization may enhance patient safety and contribute to the overall success of an implantation procedure.

[0049] To this end, tip 382 may include features that facilitate visualization during surgery. For example, tip 382 may include or otherwise be formed from and / or with radiopaque additive material (e.g., tungsten carbide) that is visible under imaging techniques such as X-rays, fluoroscopy, CT scans, etc. The radiopaque material may allow for precise placement and alignment of IMD 300 relative to anatomical structures, such as the target site. For example, the radiopaque material may provide real-time feedback regarding the positioning of IMD 300 within the body. In some examples, tip 382 may be darkly radiopaque, and the rest of cup 380 may be lightly radiopaque such that tip 382 and the rest of cup 380 are visually distinguishable.

[0050] As shown in FIG. 3A, tip 382 may be joined to distal end 372 of cup 380. Securely joining tip 382 to distal end 372 may be critical for ensuring the proper functioning and longevity of cup 380. For example, a weak or loose joint may eventually lead to separation of tip 382 and distal end 372. Furthermore, it may be important to join tip 382 and distal end 372 in a cost-effective manner that helps to reduce assembly time, eliminate the need for additional operations or equipment, simplify the overall manufacturing process, etc.

[0051] FIG. 4 is an exploded diagram of a cup 480 and tip 482, which may be an example configuration of cup 380 and tip 382 of FIG. 3 A. As shown in FIG. 4, cup 480 and tip 482 of a delivery catheter 470 may be joined using a mechanically interlocking joint (e.g., a lap joint). That is, cup 480 and tip 482 may be configured to mechanically interlock to prevent separation under load. For example, a first mating surface 484 of cup 480 may define a set (e.g., one or more) of features such as protrusions, tabs, hooks, bumps, etc., and second mating surface 486 of tip 482 may define a corresponding set offeatures such as recesses, ridges, cutouts, notches, holes, grooves, etc. Conversely, second mating surface 486 may define a set of features such as protrusion, tabs, hooks, bumps, etc., and second mating surface 486 may define a set of corresponding features such as recesses, ridges, cutouts, notches, holes, grooves, etc.

[0052] In any case, first mating surface 484 and second mating surface 486 may be configured to engage when cup 480 and tip 482 are assembled. For example, when cup 480 and tip 482 are fitted together, first mating surface 484 (e.g., a protrusion) may slide into second mating surface 486 (e.g., a recess), creating a strong and secure connection. Mechanically interlocking first mating surface 484 and second mating surface 486 may increase the stability and strength in the joint, reducing the risk of joint failure as well as reliance on adhesives or fasteners.

[0053] To facilitate the radial compression of a tip 482 (e.g., due to contact with the inner surface of an introducer), distal end 472 may be configured to flex in a radial direction. For example, distal end 472 may define one or more notches 488 or cutouts configured to increase a deformability of distal end 472 by introducing areas of reduced material strength and increased flexibility. For example, notches 488 may act as stress concentrators, causing distal end 472 to deform more readily at the base or edges of notches 488. In other words, the material of cup 480 surrounding notches of 488 can more easily yield and deform under applied loads, resulting in increased flexibility.

[0054] In some examples, cup 480 and tip 482 may be formed using overmolding (e.g., two-shot molding, multi-material injection molding, etc.). As used herein, overmolding may refer to a manufacturing process in which a single component is created by combining two or more different materials during the injection molding process. The “first shot” of overmolding may refer to the initial material or substrate that is molded as the base or core component. The “second shot” of overmolding may refer to a subsequent material that is molded to cover or encapsulate the first shot.

[0055] In some examples, cup 480 may be the first shot, and tip 482 may be the second shot. For example, cup 480 may be the substrate serving as the base or core onto which tip 482 is molded. The material for tip 482 may be heated and injected to cover or encapsulate distal end 472 of cup 480. Cup 480 and tip 482 may then bond together as tip 482 cools and solidifies. In some examples, the surface of cup 480 may be rough to aid adhesion of tip 482 to cup 480. Overmolding cup 480 and tip 482 may offer variousadvantages, including enhanced functionality, improved aesthetics, and increased comfort or safety. Overmolding may also simplify assembly by eliminating the need for separate parts and subsequent assembly processes, reducing production time and costs.

[0056] FIG. 5 is a flow diagram illustrating an example technique for implanting an implantable medical device using a delivery catheter according to aspects of this disclosure. The example technique of FIG. 5 is described in the context of IMD 300 and catheter-370 of FIG. 3 but may be applicable to other embodiments of the IMD and / or catheter disclosed herein, or to other medical devices.

[0057] During an implant procedure, a clinician may advance introducer 390 through an access site proximate to target site 307, such as the TOK (500). For example, the clinician may advance introducer 309 such that the distalmost portion of introducer 390 is just inside the heart of the patient. The clinician may insert delivery catheter 370 into a lumen of introducer 390. For example, the clinician may manually radially compress tip 382 to fit tip 382 inside the lumen of introducer 390. When tip 382 is positioned inside the lumen of introducer 390, the inner surface defining the lumen may impart or otherwise exert a contact force on tip 382 to constrain an outer diameter of tip 382.

[0058] The clinician may advance delivery catheter 370 (e.g., by translating delivery catheter 370 relative to introducer 390) to target site 307 with IMD 300 disposed in cup 380 (502). During delivery of IMD 300 to target site 307 via delivery catheter 370, the clinician may advance delivery catheter 370 such that tip 382 is distal to introducer 390 (504). When tip 382 is distal to introducer 390, tip 382 may return to its original dimensions (e.g., a flared configuration). A clinician may advance cup 380 into contact with tissue of target site 307 prior to engaging fixation members of IMD 300 with tissue of target site 307 (506). Due to being flared, tip 382 may offer a larger area of contact that increases the frictional force between tip 382 and tissue at the target site, making it harder for the distal cup to slip. In this way, tip 382 may improve placement of IMD 300.

[0059] Once IMD 300 is properly positioned, the clinician may implant IMD 300 to the target site (508). In some examples, the target site with the catheter includes the TOK, the coronary sinus ostium, the left bundle branch on a right septal wall, other regions of the heart, other places in the body, etc. To implant IMD 300, the clinician may rotate helical fixation member 383 such that helical fixation member 383 engages the tissues and becomes embedded therein.

[0060] FIG. 6 is a flow diagram illustrating an example technique for manufacturing a delivery catheter according to aspects of this disclosure. The example technique of FIG. 6 is described in the context of delivery catheter 470 of FIG. 4 but may be applicable to other embodiments of the catheter disclosed herein, or to other medical devices.

[0061] In some examples, delivery catheter may be manufactured using the overmolding process. Overmolding may involve combining two or more materials to create a single, integrated component with improved functionality, durability, and comfort. The overmolding process may create a seamless bond between the materials, which may be further enhanced by the mechanical features described herein.

[0062] Cup 480 may be formed as the first shot of delivery catheter 470 (600). For example, the chosen material for cup 480 may be heated to a molten state and injected into a mold cavity under high pressure. After the material cools and solidifies within the mold cavities, cup 480 may be ejected from the mold.

[0063] Tip 482 may be formed as the second shot of delivery catheter 470 over cup 480 (602). For example, cup 480 may be placed into another mold cavity and serve as the core or substrate for tip 482. The material for tip 482 may be injected into the mold cavity, forming around cup 480. The materials may be bonded, creating a final integrated product.

[0064] In some examples, cup 480 and tip 482 may be joined using a mechanically interlocking joint (e.g., a lap joint). For example, first mating surface 484 of cup 480 may define a set of features such as protrusions, tabs, hooks, bumps, etc., and second mating surface 486 of tip 482 may define a corresponding set of features such as recesses, ridges, cutouts, notches, holes, grooves, etc. Conversely, second mating surface 486 may define a set of features such as protrusion, tabs, hooks, bumps, etc., and second mating surface 486 may define a set of corresponding features such as recesses, ridges, cutouts, notches, holes, grooves, etc.

[0065] First mating surface 484 and second mating surface 486 may be configured to engage when cup 480 and tip 482 are assembled. For example, when cup 480 and tip 482 are fitted together, first mating surface 484 (e.g., a protrusion) may slide into second mating surface 486 (e.g., a recess), creating a strong and secure connection. Mechanically interlocking first mating surface 484 and second mating surface 486 may increase the stability and strength in the joint, reducing the risk of joint failure as well as reliance on adhesives or fasteners.

[0066] To facilitate the radial compression of a tip 482 (e.g., due to contact with the inner surface of an introducer), distal end 472 may be configured to flex in a radial direction. For example, distal end 472 may define one or more notches 488 or cutouts configured to increase a deformability of distal end 472 by introducing areas of reduced material strength and increased flexibility. For example, notches 488 may act as stress concentrators, causing distal end 472 to deform more readily at the base or edges of notches 488. In other words, the material of cup 480 surrounding notches of 488 can more easily yield and deform under applied loads, resulting in increased flexibility.

[0067] The following examples are illustrative of the techniques described herein.

[0068] Example 1: A delivery catheter includes: a catheter body extending from a proximal end to a distal end; and a cup at the distal end, wherein the cup defines an opening at a cup distal end, wherein the cup is configured to receive an implantable medical device through the opening, and wherein the cup includes a flared tip configured to flex radially inward.

[0069] Example 2: The delivery catheter of example 1, wherein a first mating surface of the cup defines a first set of features, wherein a second mating surface of the flared tip defines a second set of features, and wherein the first set of features and the second set of features are configured to engage each other to mechanically interlock the cup and the flared tip.

[0070] Example 3: The delivery catheter of example 1 or 2, wherein the cup defines one or more notches configured to increase a deformability of the cup distal end.

[0071] Example 4: The delivery catheter of any of examples 1 to 3, wherein a distal portion of the flared tip is rounded.

[0072] Example 5: The delivery catheter of any of examples 1 to 4, wherein the flared tip includes radiopaque material.

[0073] Example 6: The delivery catheter of any of examples 1 to 5, wherein the flared tip is molded over the cup.

[0074] Example 7: The delivery catheter of any of examples 1 to 6, wherein the flared tip is formed from a thermoplastic elastomer.

[0075] Example 8: The delivery catheter of any of examples 1 to 7, wherein an inner diameter of at least a portion of the cup is larger than an outer diameter of the catheterbody, and wherein at least the portion of the cup extends longitudinally by a sufficient length to house the implantable medical device.

[0076] Example 9 : A medical device system includes: an implantable medical device; an introducer defining a lumen; and a delivery catheter including: a catheter body extending from a proximal end to a distal end; and a cup at the distal end, wherein the cup defines an opening at a cup distal end, wherein the cup is configured to receive the implantable medical device through the opening, wherein the cup includes a flared tip configured to flex radially inward, wherein the introducer is configured to receive at least a portion of the delivery catheter, wherein an inner diameter of the lumen is less than an outer diameter of the flared tip, and wherein the inner diameter of the lumen constrains the outer diameter of the flared tip while the flared tip is positioned inside the lumen.

[0077] Example 10: The medical device system of example 9, wherein the flared tip is configured to flex radially inward in response to a contact force exerted on the flared tip by an inner surface of the lumen.

[0078] Example 11: The medical device system of example 9 or 10, wherein a first mating surface of the cup defines a first set of features, wherein a second mating surface of the flared tip defines a second set of features, and wherein the first set of features and the second set of features are configured to engage each other to mechanically interlock the cup and the flared tip.

[0079] Example 12: The medical device system of any of examples 9 to 11, wherein the cup defines one or more notches configured to increase a deformability of the cup distal end.

[0080] Example 13: The medical device system of any of examples 9 to 12, wherein a distal portion of the flared tip is rounded.

[0081] Example 14: The medical device system of any of examples 9 to 13, wherein the flared tip includes radiopaque material.

[0082] Example 15: The medical device system of any of examples 9 to 14, wherein the flared tip is molded over the cup.

[0083] Example 16: The medical device system of any of examples 9 to 15, wherein the flared tip is formed from a thermoplastic elastomer.

[0084] Example 17: The medical device system of any of examples 9 to 16, wherein a fixation member of the implantable medical device includes a helical fixation member.

[0085] Example 18: The medical device system of any of examples 9 to 17, wherein an inner diameter of at least a portion of the cup is larger than an outer diameter of the catheter body, and wherein at least the portion of the cup extends longitudinally by a sufficient length to house the implantable medical device.

[0086] Example 19: A method includes: advancing an introducer of a medical device system within a patient; advancing a delivery catheter through a lumen of the introducer, wherein the delivery catheter includes: a catheter body extending from a proximal end to a distal end; and a cup at the distal end, wherein the cup defines an opening at a cup distal end, wherein the cup includes a flared tip configured to flex radially inward, wherein an inner diameter of the lumen is less than an outer diameter of the flared tip, and wherein the inner diameter of the lumen constrains the outer diameter of the flared tip while the flared tip is positioned inside the lumen; pressing the flared tip against tissue of a target site; and implanting an implantable medical device positioned in the cup to the tissue of the target site.

[0087] Example 20: The method of example 19, wherein the flared tip is configured to flex radially inward in response to a contact force exerted on the flared tip by an inner surface of the lumen.

[0088] Example 21: The method of example 19 or 20, wherein the target site is one of a triangle of Koch, a coronary sinus ostium, or a left bundle branch on a right septal wall.

[0089] Example 22: A method includes: forming, as a first shot of an overmolding process, a cup of a delivery catheter, wherein the delivery catheter includes: a catheter body extending from a proximal end to a distal end, wherein the cup is positioned at the distal end, wherein the cup defines an opening at a cup distal end, wherein the cup is configured to receive an implantable medical device through the opening, and wherein the cup comprises a flared tip configured to flex radially inward; and forming, as a second shot of the overmolding process, a flared tip of the delivery catheter, wherein the flared tip is formed over the cup, and wherein the flared tip is configured to flex radially inward.

[0090] Various aspects of the disclosure have been described. These and other aspects are within the scope of the following claims.

Claims

WHAT IS CLAIMED IS:

1. A delivery catheter comprises: a catheter body extending from a proximal end to a distal end; and a cup at the distal end, wherein the cup defines an opening at a cup distal end, wherein the cup is configured to receive an implantable medical device through the opening, and wherein the cup comprises a flared tip configured to flex radially inward.

2. The delivery catheter of claim 1, wherein a first mating surface of the cup defines a first set of features, wherein a second mating surface of the flared tip defines a second set of features, and wherein the first set of features and the second set of features are configured to engage each other to mechanically interlock the cup and the flared tip.

3. The delivery catheter of claim 1 or 2, wherein the cup defines one or more notches configured to increase a deformability of the cup distal end.

4. The delivery catheter of any of claims 1 to 3, wherein a distal portion of the flared tip is rounded.

5. The delivery catheter of any of claims 1 to 4, wherein the flared tip comprises radiopaque material.

6. The delivery catheter of any of claims 1 to 5, wherein the flared tip is molded over the cup.

7. The delivery catheter of any of claims 1 to 6, wherein the flared tip is formed from a thermoplastic elastomer.

8. The delivery catheter of any of claims 1 to 7, wherein an inner diameter of at least a portion of the cup is larger than an outer diameter of the catheter body, and wherein at least the portion of the cup extends longitudinally by a sufficient length to house the implantable medical device.

9. A medical device system comprising: an implantable medical device; an introducer defining a lumen; and a delivery catheter comprising: a catheter body extending from a proximal end to a distal end; and a cup at the distal end, wherein the cup defines an opening at a cup distal end, wherein the cup is configured to receive the implantable medical device through the opening, wherein the cup comprises a flared tip configured to flex radially inward, wherein the introducer is configured to receive at least a portion of the delivery catheter, wherein an inner diameter of the lumen is less than an outer diameter of the flared tip, and wherein the inner diameter of the lumen constrains the outer diameter of the flared tip while the flared tip is positioned inside the lumen.

10. The medical device system of claim 9, wherein the flared tip is configured to flex radially inward in response to a contact force exerted on the flared tip by an inner surface of the lumen.

11. The medical device system of claim 9 or 10, wherein a first mating surface of the cup defines a first set of features, wherein a second mating surface of the flared tip defines a second set of features, and wherein the first set of features and the second set of features are configured to engage each other to mechanically interlock the cup and the flared tip.

12. The medical device system of any of claims 9 to 11, wherein the cup defines one or more notches configured to increase a deformability of the cup distal end.

13. The medical device system of any of claims 9 to 12, wherein a distal portion of the flared tip is rounded.

14. The medical device system of any of claims 9 to 13, wherein a fixation member of the implantable medical device comprises a helical fixation member.

15. The medical device system of any of claims 9 to 14, wherein an inner diameter of at least a portion of the cup is larger than an outer diameter of the catheter body, and wherein at least the portion of the cup extends longitudinally by a sufficient length to house the implantable medical device.

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