Delivery system for implanting a medical device - Patents.com

Abstract

The present invention relates to a delivery system 2 for implanting a medical device 1, the delivery system 2 comprising a delivery catheter 20 having an inner lumen 201, a mandrel 23 received within the inner lumen of the delivery catheter and movable relative to the delivery catheter, and an anchoring member 21 including a first end 211, a second end 212, and a positive locking member 213 fixed to the second end 212. To improve automated manufacturing, the delivery system further comprises an adapter piece 22, 32, 42 having a longitudinal axis L and including a proximal end face 221, 321, 421 and a side face 220, 320, 420, the adapter piece 22, 32, 42 forming a fixed connection between a distal end 231 of the mandrel and a first end of the anchoring member, the adapter piece being displaceable between a first position inside the inner lumen of the delivery catheter and a second position in which the adapter piece is disposed outside the inner lumen of the delivery catheter by moving the mandrel relative to the delivery catheter, and in the first position of the adapter piece, the second end of the anchoring member extends beyond the proximal end face of the adapter piece along a side of the adapter piece substantially parallel to the longitudinal axis such that the positive locking member is adjacent the proximal end face of the adapter piece, thereby achieving a locked connection with the adapter piece. Furthermore, the present invention is directed to respective assemblies comprising the medical device 1 and the delivery system 2, as well as to a method for releasing the medical device 1 from the delivery system 2.

Description

[Technical field]

[0001] The present invention is directed to a delivery system for implanting a medical device within a patient's body. Such a medical device may be a pacemaker, for example a leadless pacemaker. The present invention is further directed to an assembly including the delivery system and a method for releasing the medical device from the delivery system. [Background technology]

[0002] A delivery system for implanting a medical device, such as a leadless pacemaker, in a patient's body typically includes a delivery catheter to which the medical device is connected for guiding the medical device to an implantation location. During implantation, once the medical device reaches the implantation location, it is detached from the delivery catheter and remains at the implantation location, and the delivery catheter is removed from the patient's body.

[0003] When using such a delivery system to implant a medical device, it must be ensured that the medical device is firmly connected to the delivery catheter during the implantation procedure until the implantation location is reached, since accidental dislodging may cause difficulties. Furthermore, the delivery system must ensure that the medical device can be released from the delivery system at the target location, i.e., the implantation location. However, some medical devices require testing before release to ensure that the medical device functions properly.

[0004] Such tests can be so-called pull tests and / or electrical tests, where the pull test is performed by exerting a pulling force on the medical device to check whether it is sufficiently fixed to the tissue of the patient's body. The electrical test uses electromagnetic fields to provide information on whether the medical procedure, e.g., proper pacing action and electrical signal reception of a leadless pacemaker, is performed in the desired manner. In such tests, the medical device needs to be at least partially detached from the delivery system to give the medical device itself free space for movement. Release of the medical device from the delivery system should only be performed if the test is successfully completed. In other situations, if the test is not successful, it must be ensured that the medical device can be realigned or even completely removed.

[0005] A delivery system suitable for implantation according to the above is disclosed in document WO 2020 / 043481 A1. The known system comprises an adapter piece movable together with the mandrel in a delivery catheter of the delivery system, which is used to fix a medical device to said delivery system via a fastening member in a first position and to release the medical device in a second position, the adapter piece being arranged inside the delivery catheter in the first position and outside the delivery catheter in the second position. The known delivery system is suitable for implantation of a medical device, but the adapter piece in particular and therefore the entire delivery system have some disadvantages. The adapter piece of the known system has a complex design, so that the system is not suitable for automated manufacturing and assembly. Furthermore, the connection of the mandrel as well as the connection of the fastening member offset from the center of the adapter piece can lead to an undesirable tilting of the adapter piece when pulling as well as when pushing the mandrel. A further disadvantage of the known adapter piece is that, due to its shape and size, relatively large frictional forces are generated when the adapter piece moves within the delivery catheter, which may hinder pull testing. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2020 / 043481A1 Summary of the Invention [Problem to be solved by the invention]

[0007] It is therefore an object of the present invention to provide an improved delivery system and assembly with respect to the above-mentioned shortcomings of the prior art, and further to define an easy and reliable method for releasing a medical device from such a delivery system. [Means for solving the problem]

[0008] The above problems are solved by a delivery system according to claim 1, an assembly according to claim 13 and a method for releasing a medical device from a delivery system according to claim 15.

[0009] In particular, the problem is solved by a delivery system for implanting a medical device, comprising a delivery catheter, an adapter piece, a mandrel, and an anchoring member. The delivery catheter comprises an inner lumen, and the mandrel is received within the inner lumen of the delivery catheter and is movable relative to the delivery catheter. Furthermore, the anchoring member comprises a first end, a second end, and a positive locking member secured to the second end. Moreover, the adapter piece has a longitudinal axis and includes a proximal end face and a side face, and the adapter piece forms a fixed connection between a distal end of the mandrel and the first end of the anchoring member. By moving the mandrel relative to the delivery catheter, the adapter piece can be displaced between a first position within the inner lumen of the delivery catheter and a second position in which the adapter piece is disposed outside the inner lumen of the delivery catheter. In the first position of the adapter piece, the second end of the anchoring member extends substantially parallel along a side of the adapter piece, i.e., parallel or at a small angle (less than 20°) to the longitudinal axis, beyond the proximal end face of the adapter piece such that the positive locking member abuts the proximal end face, thereby providing a locked connection with the adapter piece. In the first position, the adapter piece is at least partially disposed within the internal lumen of the delivery catheter.

[0010] The delivery system according to the present invention includes a delivery catheter disposed proximally relative to an implantable medical device, which is directed toward a health care practitioner (HCP) during surgery. The distal end of the delivery catheter, which may be provided with an end cap, is connected to the medical device as long as the adapter piece is in its first position. For example, the delivery catheter may include a flexible material to be guided into the patient's heart through the superior vena cava to access the right ventricle via the right atrium.

[0011] The mandrel, the adapter piece, the anchoring member, and the positive locking member can form a pushing catheter that is disposed within the inner lumen of the delivery catheter.

[0012] The mandrel is disposed proximally from the adapter piece and extends to the proximal end of the delivery catheter and is secured to the adapter piece by its distal end. The mandrel, which may be formed, for example, of a stiff but bendable wire having a round or angular cross section, pushes or pulls the adapter piece, thereby coupling the medical device to the anchoring member at the desired location. The mandrel may be pushed or pulled, either manually or automatically, by a handle provided at the proximal end of the delivery catheter.

[0013] The adapter piece serves to control the establishment and release of the connection between the medical device and the delivery system, and provides the connection until release. The position of the adapter piece relative to the delivery catheter is critical to its control function. The position of the adapter piece is adjusted by pushing or pulling a mandrel fixedly connected to the adapter piece. The proximal end face of the adapter piece extends substantially perpendicular or inclined to its longitudinal axis. The proximal end face may be formed by a flat or curved surface. The side surface extends at least partially or completely parallel to the longitudinal axis and between the proximal end face and the distal end face of the adapter piece. The distal end face is located opposite the proximal end face along the longitudinal direction of the adapter piece. The side surface forms an outer surface intermediate the proximal end face and the distal end face of the adapter piece. For example, in a substantially cylindrical adapter piece, the side surface is located between the proximal and distal end faces of the adapter piece, and the cylindrical side surface is radially offset from the longitudinal axis of the adapter piece. The length of the adapter piece is its extension in a direction parallel to its longitudinal axis, or in other words, its dimension between the proximal and distal end faces.

[0014] In the connected state, i.e. in the first position of the adapter piece relative to the delivery catheter, the anchoring member located at the distal end of the adapter piece forms a loop, which extends through the opening of the connecting member of the medical device such that the medical device is coupled to the delivery system. The anchoring member is thus a flexible member configured to form the required loop. The loop starts at the distal end of the adapter piece, where the first end of the anchoring member is fixed to the adapter piece, and ends at the positive locking member (i.e. at the second end of the anchoring member). In the connected state, the proximal end face of the adapter piece and the positive locking member form a positive / interlock connection, and the proximal end face of the adapter piece and the inner surface of the delivery catheter prevent the movement of the positive locking member in the distal direction relative to the adapter piece. In other words, the intermediate space between the side of the adapter piece and the inner surface of the delivery catheter is very small such that the positive locking member is captured at the proximal end face of the adapter piece. Thus, the outer diameter of the positive locking member is greater than the intermediate distance between the side of the adapter piece and the inner surface of the delivery catheter. However, this intermediate distance is selected such that, at least in a portion of the circumference of the adapter piece, the anchoring member extends along the side of the adapter piece in a different section than the positive locking member and along the inner surface of the delivery catheter substantially parallel to the longitudinal axis of the adapter piece. In a second position of the adapter piece, where the adapter piece is disposed outside the inner lumen of the delivery catheter, the inner surface of the delivery catheter no longer forms any restrictive surface for distal movement of the positive locking member, and the second end of the anchoring member carrying the positive locking member can move freely relative to the adapter piece, thereby opening the loop and releasing the medical device from the delivery system. In the second position, the second end of the anchoring member is no longer pinched or jammed between the inner surface of the delivery catheter and the side of the adapter piece, and therefore the positive locking connection between the second end of the anchoring member and the adapter piece is released.Thus, the connection between the adapter piece and the second end of the anchoring member is generally released by a simple uniaxial movement of the adapter piece from the first position to the second position, i.e. by pushing the mandrel in the distal direction, whereas a similar uniaxial movement is also sufficient to connect the second end of the anchoring member with the adapter piece during manufacture or in preparation for surgery, for example by pulling the adapter piece in the proximal direction with the mandrel to reach the first position.

[0015] Since the positive locking of the positive locking member is realized by the proximal end face of the adapter piece, no further special structure for positive locking is required on the side of the adapter piece. Therefore, a simple design / form can be selected for the adapter piece. Examples for such designs are described in detail below. The simple design allows for cost-effective automated manufacturing and assembly, e.g. by turning, milling, and / or drilling.

[0016] The accommodation of the positive locking member at the proximal end of the adapter piece further allows the adapter piece to be constructed such that the frictional surface between the adapter piece and the distal end of the anchoring member that interacts with the inner surface of the delivery catheter is reduced, resulting in reduced interference with pull testing. Additionally, the connection of the adapter piece to the mandrel and to the first end of the anchoring member can be more centered than in the prior art, so that the entire adapter piece can move more centered within the delivery catheter.

[0017] After the medical device has reached its implantation location, the connection between the delivery catheter and the medical device can be released by moving, e.g., pushing, the adapter piece from its first position to its second position as explained above. However, if tests such as pull tests and / or electrical tests are to be performed before full release, the adapter piece can also be displaced to a so-called intermediate position such that the medical device is released from the end cap, but the adapter piece still remains inside the inner lumen of the delivery catheter. In this (first) position of the adapter piece, the connection between the medical device and the delivery catheter via the anchoring member still remains in force by positive locking.

[0018] Similar to the electrical test, a pull test can also be performed at the intermediate position. The pull test checks for proper fixation of the medical device to the tissue by the anchoring members at the target location by pulling the medical device proximally through the delivery system, for example using a mandrel. Additionally, an electrical test can be performed to ensure that electrical stimulation by electrodes placed on the medical device functions properly. If during the test it is found that the medical device must be repositioned, the adapter piece can be retracted again into the delivery catheter by pulling the mandrel, and the adapter piece with the mandrel, proximally so that the medical device again engages with the end cap of the delivery catheter. The medical device can then be realigned to the new implantation location. In one embodiment, the adapter piece can only be moved to the second position, i.e., the medical device can only be released from the delivery system after the test is successful.

[0019] During manufacture, the distal end of the mandrel is fixedly connected to the adapter piece, for example by welding. Furthermore, the first end of the anchoring member is fixedly connected to the adapter piece, for example also by welding or by crimping, as described in more detail below. The adapter piece thus forms a fixed connection between the distal end of the mandrel and the first end of the anchoring member. In one embodiment, a borehole may be provided on the proximal end face of the adapter piece and / or at the distal end of the adapter piece to receive the mandrel and / or the first end of the anchoring member. Alternatively or additionally, the distal end of the mandrel and / or the first end of the anchoring member may be directly connected to the end face of the adapter piece. Regardless of the type of connection of the adapter piece with the mandrel or with the first end of the anchoring member, a central connection, in particular a connection at the center of the mandrel, prevents the adapter piece from tilting when pressing and / or pulling forces are applied to the adapter piece via the mandrel.

[0020] After connection of the distal end of the mandrel and of the first end of the anchoring member with the adapter piece, the anchoring member can be connected to a medical device, i.e., to a connecting member of the medical device.

[0021] In one embodiment, the adapter piece is rotationally symmetrical with respect to its longitudinal axis. In the context of the present invention, rotationally symmetrical means that the adapter piece has an axis of rotation, i.e. a longitudinal axis, around which a rotation about an angle different from 360° causes the rotating body to coincide with the rotating body in the starting position. Due to the rotationally symmetrical design of the adapter piece, the manufacturing is considerably simplified. In this way, the symmetrical design allows for manufacturing by common machining processes, such as, for example, turning and milling. An exemplary adapter piece can be a rotationally symmetrical cylinder, optionally with rounded edges, chamfered edges, crushed edges. Furthermore, due to the symmetrical design of the adapter piece, the friction surface between the side of the adapter piece and the inner surface of the inner lumen of the delivery catheter is configured to be flat when viewed in the circumferential direction of the adapter piece. This allows for a flat distribution of frictional forces between the adapter piece and the delivery catheter when the adapter piece is placed in the inner lumen of the delivery catheter, which can, for example, prevent the adapter piece from tilting undesirably.

[0022] In one embodiment, the radial distance between the longitudinal axis and the side of the adapter piece varies along the circumferential direction of the adapter piece, the variation extending along at least a portion of the length of the adapter piece or along the entire length of the adapter piece. In one embodiment, the adapter piece can have a single groove or the like on its longitudinally extending side, in which the anchoring member can be located at the first position of the adapter piece. In another embodiment, the adapter piece can have a plurality of longitudinally extending ribs and grooves or notches, including curved edges on its side, forming a substantially star-shaped design in its cross section. This design can still be manufactured and assembled cost-effectively and provides a well-defined location for the anchoring member at the first position of the adapter piece.

[0023] In one embodiment, the surface of the inner lumen of the delivery catheter (i.e., the inner surface) and the adapter piece have one to six contact lines or contact surfaces. For example, a cylindrically shaped adapter piece has one contact surface with the inner surface of the delivery catheter. In another embodiment, a star-shaped adapter piece, in cross section, in which grooves or notches run parallel to the longitudinal axis of the adapter piece across the entire side, can have, for example, two to six contact surfaces or contact lines, each contact line representing a contact between a longitudinally extending rib of the adapter piece and the inner surface of the delivery catheter. The number of ribs in such a design is therefore determined by the number of degrees of rotation that define the rotational symmetry.

[0024] The frictional forces between the two components are influenced in particular by the size of the frictional surface, i.e. the contact line or surface between the adapter piece and the inner surface of the delivery catheter. In this embodiment, the reduction of the frictional surface is achieved by a suitable design, for example a star-shaped design. Alternatively or additionally, the dimensions of the adapter piece can be reduced. The total length of the adapter piece can be between 3 mm and 4 mm, preferably between 3 mm and 3.4 mm. Furthermore, the diameter of the adapter piece, or the maximum in-plane distance between two points of the sides of the adapter piece, can be between 1 mm and 2 mm, preferably between 1.1 mm and 1.6 mm. Furthermore, the adapter piece can be in contact with the inner surface of the delivery catheter over a portion of its longitudinal extent after being placed inside the inner lumen of the delivery catheter. The aforementioned method results in an increased trackability of the pushing catheter in the delivery catheter.

[0025] In one embodiment, the adapter piece has a through hole extending along or parallel to its longitudinal axis, which is configured to receive the distal end of the mandrel and / or the first end of the anchoring member. The mandrel and / or the first end of the anchoring member can be fixed inside the through hole of the adapter piece to form a permanent connection, for example by welding or gluing. The mandrel, which is first partially received inside the through hole and fixed (for example by welding), can serve as a stop surface for the subsequently inserted first end of the anchoring member. The configuration of the through hole along the longitudinal axis ensures the previously mentioned advantageous central fastening, in particular the fastening of the distal end of the mandrel, whereby the pressing and / or pulling forces act on the adapter piece in a central manner, thus preventing tilting. The production of the delicate adapter pieces is significantly easier and less labor-intensive due to the use of the through hole in the automated production, since it is not necessary to remove chips that may otherwise accumulate in the borehole. In another embodiment, the through holes may also be angled relative to the longitudinal axis.

[0026] In another embodiment, the through hole has an abutment surface extending perpendicularly to the longitudinal axis. The abutment surface can in particular be produced by first drilling a through hole with a smaller diameter and then drilling a bore hole with a larger diameter at the location of the smaller through hole, whereby a first section of the through hole with a larger diameter and a second section with a smaller diameter are formed. The abutment surface separates the first section and the second section from each other. The abutment surface thus formed can help to predefine the insertion depth of the mandrel and / or the anchoring member in the adapter piece. Furthermore, by using different bore hole diameters for different diameters of the mandrel and the first end of the anchoring member, a simple fastening of the mandrel and / or the first end of the anchoring member with the adapter piece can be provided. In one embodiment, the first section of the through hole with a larger diameter is arranged at the proximal end of the through hole and is adapted to receive the distal end of the mandrel.

[0027] In one embodiment, the adapter piece has a tubular section at its distal end, the tubular section configured to receive the first end of the anchoring member, the tubular section having a smaller outer diameter than the proximal section of the adapter piece. Thus, the outer diameter of the tubular section may be between 0.3 mm and 0.8 mm, preferably between 0.5 mm and 0.7 mm. The longitudinal length of the tubular section may be between 1.3 mm and 2 mm, preferably between 1.5 mm and 1.7 mm, and the proximal section may have the aforementioned diameter or maximum in-plane distance. Furthermore, the tubular section may have a borehole or through hole to receive the first end of the anchoring member. The through hole may also be configured to receive a portion of a mandrel in the proximal section of the adapter piece. Furthermore, the distal tubular section may be configured to be crimped such that, when received inside the tubular section, the first end of the anchoring member may be connected to the adapter piece by crimping. This is an advantageous and reliable fastening method, especially for multi-strand type anchoring members. The adapter piece may be a multi-piece component, but alternatively is a one-piece component.

[0028] As already indicated above, in one embodiment, the side of the adapter piece has at least one groove or curved notch extending parallel to the longitudinal axis. The groove or curved notch may be configured to receive the second end of the anchoring member while the adapter piece is in its first position, such that the second end of the anchoring member extends along said groove or notch. The adapter piece may also have a plurality of such curved notches intermediate the proximal and distal end faces, thereby forming a cross section having a star shape. These grooves and notches may guide air and / or flush / rinse fluids and / or radiopaque fluids from the proximal end to the distal end of the delivery system or in the opposite direction.

[0029] In one embodiment, the positive locking member of the anchoring member has a trapezoidal, teardrop, or spherical shape. Regardless of the shape of the positive locking member, the positive locking member is configured to always abut the proximal end face of the adapter piece when the adapter piece is in the first position. The positive locking member may be integrally formed with the anchoring member or may form a separate element secured thereto. The shape of the positive locking member may be selected to best match the shape of the adapter piece and provide the best, most reliable form of locking connection in the first position of the adapter piece.

[0030] As indicated above, in one embodiment, the anchoring member forms a loop while the adapter piece is in its first position. This may be accomplished by threading the anchoring member, attached by its first end to the adapter piece, through an opening in the connecting member of the medical device, and then the anchoring member extends back toward the distal end of the adapter piece, and the second end of the anchoring member extends along the side of the adapter piece, thereby forming a loop. Thus, the medical device is positioned at one end of the loop and the adapter piece at the opposite end. By displacing the adapter piece from its first position to its second position, the connection between the second end of the anchoring member and the adapter piece is released, thereby opening the loop.

[0031] Additionally, the anchoring member may be formed by, for example, a cable, suture, or wire, and may be one-stranded or multi-stranded. The anchoring member may be generally flexible, or may be adapted to form a loop to connect the medical device to a delivery system. Additionally, the anchoring member may exhibit substantial stiffness (while allowing for sufficient bendability).

[0032] As described above, in one embodiment, the dimensions of the inner lumen of the delivery catheter, the adapter piece, and the positive locking member are selected such that the positive locking member prevents disengagement from the adapter piece in a first position, but allows disengagement from the adapter piece in a second position when the adapter piece is moved completely out of the inner lumen of the delivery catheter.

[0033] In one embodiment, the mandrel and / or the adapter piece and / or the anchoring member and / or the positive locking member comprise or consist of a biocompatible polymer or metallic material, such as stainless steel. Furthermore, the adapter piece may comprise a material that provides good trackability. Thus, a coating may be provided on the inner surface of the adapter piece and / or the anchoring member and / or the delivery catheter to reduce friction of the respective components. Furthermore, the anchoring member and / or the adapter piece may comprise a radiopaque material so that the anchoring member may be visualized, for example, during an x-ray examination.

[0034] Additionally, the delivery system may have a stopper disposed on the mandrel proximally relative to the adapter piece. The stopper may be made of the same material as the adapter piece and may be secured to the mandrel in the same manner as the adapter piece (welded, glued, pressed, or any other suitable manner). In this embodiment, the stopper ensures that the positive locking member and anchoring member are not inadvertently pushed back into the inner lumen of the delivery catheter when the mandrel is pushed distally.

[0035] The above problem is also solved by an assembly including a delivery system according to the previous description and a medical device including a connecting member, wherein the anchoring member is connected to the connecting member when the adapter piece is in a first position.

[0036] In one embodiment, the connecting member includes an opening through which the loop-shaped anchoring member extends while the adapter piece is in the first position. Thus, the medical device is fixedly connected to the delivery system when and while the adapter piece is in its first position. The connecting member of the medical device may be connected to a housing component of the medical device, and alternative shapes of the connecting member may be provided. However, the use of a rounded and / or curved profile, or at least a profile without edges, independent of the shape of the connecting member, may help ensure that the positive locking member does not get stuck when it is released from the adapter piece. Furthermore, the use of a profile without edges ensures that the anchoring member does not tear. Thus, when the positive locking member is released from the adapter piece, the anchoring member may be disengaged from the connecting member, in particular by threading the positive locking member through the opening formed by the connecting member, so that the medical device is released from the delivery system. Thus, in this embodiment, the opening of the connecting member is larger than the outer diameter of the positive locking member so that the positive locking member can pass through the opening.

[0037] The above problems are further solved by a method for releasing a medical device from a delivery system, the method comprising: providing a delivery system with a medical device coupled to the delivery system, the delivery system comprising: a delivery catheter having an internal lumen; a mandrel received within the internal lumen of the delivery catheter and movable relative to the delivery catheter; an anchoring member including a first end, a second end, and a positive locking member secured to the second end; and an adapter piece having a longitudinal axis and including a proximal end face and a side face, the adapter piece forming a fixed connection between a distal end of the mandrel and the first end of the anchoring member, the adapter piece being positioned at a first position within the internal lumen of the delivery catheter by moving the mandrel relative to the delivery catheter, wherein in the first position of the adapter piece, the second end of the anchoring member extends beyond the proximal end face of the adapter piece along a side of the adapter piece parallel to the longitudinal axis such that the positive locking member is adjacent the proximal end face of the adapter piece, thereby achieving a locked connection with the adapter piece, and forming a loop for connection with the medical device; The method further comprises: displacing the adapter piece from a first position to a second position where the adapter piece is positioned outside the inner lumen of the delivery catheter by moving the mandrel, thereby also allowing the medical device to be disconnected from the anchoring member;

[0038] The above methods and systems can be used for medical devices such as an implantable leadless pacemaker (ILP) or any other type of implantable sensor device suitable for implantation in a chamber of the heart. Such sensors can measure pressure, potassium concentration, and / or oxygen saturation.

[0039] Prior to disengagement of the positive locking member from the adapter piece, the medical device is moved and positioned on the tissue of the patient's body, e.g., myocardial tissue, at the implantation target location by partially releasing the medical device from the delivery system. The medical device may have an anchoring member, which may have the form of a tine, wire, sheet, or tube extending from the medical device, and is used to fix the medical device to the tissue at this location. A tensile test and / or an electrical test may be performed following fixation of the medical device. If the test is passed, the HCP may release the medical device by displacing the adapter piece from its first position to a second position. However, if the test is unsuccessful, the HCP may reposition the medical device using the delivery system. In this case, if necessary, the medical device remains connected to the delivery system until it reaches the appropriate implantation location and passes the test.

[0040] The invention will now be described in more detail with reference to the accompanying schematic drawings. [Brief description of the drawings]

[0041] [Figure 1] FIG. 1 is a cross-sectional view of a human heart including an implanted medical device and delivery system. [Diagram 2] FIG. 1 is a side view of a medical device to be implanted in a patient's heart. [Diagram 3] FIG. 1 is a side view of a first embodiment of a delivery system for implanting a medical device coupled to a medical device. [Figure 4] 4 is a close-up side view of the medical device according to FIG. 3, in which a loop-shaped anchoring member includes a connecting member extending therethrough. [Figure 5A] FIG. 4 is a side view of a first embodiment of an adapter piece that can be used in the delivery system according to FIG. [Figure 5B] FIG. 5B is a front view of the proximal end face of the adapter piece of FIG. 5A. [Figure 5C]5A is a schematic diagram of a partially cut-away depiction of the delivery catheter of the delivery system of FIG. 3 including the adapter piece and the positive locking member in a first position. [Figure 6A] FIG. 4 is a side view of a second embodiment of an adapter piece that can be used in the delivery system according to FIG. [Figure 6B] FIG. 6B is a front view of the proximal end face of the adapter piece of FIG. [Figure 6C] 6A is a schematic diagram of a partially cut-away depiction of a delivery catheter of the delivery system of FIG. 3 including an adapter piece according to FIG. 6A and a positive locking member in a first position. [Figure 7A] FIG. 4 is a side view of a third embodiment of an adapter piece that can be used in the delivery system according to FIG. [Figure 7B] FIG. 7B shows a cross-section of the adapter piece of FIG. 7A taken along axis CC. [Figure 7C] FIG. 7B is a front view of the distal end face of the adapter piece of FIG. [Figure 7D] FIG. 7C shows a longitudinal cross-section of the adapter piece of FIG. 7A along axis DD. [Figure 7E] FIG. 7C shows a longitudinal cross-section of the adapter piece of FIG. 7A along axis AA. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0042] FIG. 1 depicts a human heart including a right atrium RA, a right ventricle RV, a left atrium LA, and a left ventricle LV, and a medical device 1 implanted in the right ventricle RV, e.g., a leadless pacemaker device for providing pacing of cardiac activity in the right ventricle RV.

[0043] For implantation, the medical device 1 is positioned by the delivery system 2 at an implantation location, for example, within the right ventricle RV as shown in FIG. 1, so that the medical device 1 comes to rest on the myocardial tissue M and is secured thereto using its anchor members 12.

[0044] FIG. 2 shows an example of a medical device 1, which is a leadless pacemaker device having a housing 10 with a number of anchoring members 12 in the form of tines extending from the housing 10 for anchoring the medical device to the myocardial tissue M of a patient. Furthermore, the medical device 1 has an electrode 11 at its distal end, which serves for pacing and cardiac stimulation. A second electrode may be formed by the proximal end of the housing. To guide the medical device 1 to a target location, the medical device 1 is connected to a delivery system 2 by an anchoring member 21, which is released after the medical device 1 is mechanically anchored to the patient's tissue. However, before the medical device is released, tests such as a pull test and / or an electrical test are usually performed on the medical device 1 to ensure that it is mechanically anchored and functions properly. The medical device 1 has a connecting member 13, which is used to releasably connect the medical device 1 to the delivery system 2 via the anchoring member 21. An embodiment of the connecting member 13 is shown in more detail in FIG.

[0045] The delivery system shown in FIG. 3 comprises a delivery catheter 20 having an inner lumen 201 and a pushing catheter formed by a mandrel 23, an adapter piece 22, and an anchoring member 21 including a positive locking member 213.

[0046] As shown in Figure 3, the anchoring member 21 of the delivery system 2 comprises a first end 211 fixedly connected to the adapter piece 22, for example by welding, and a second end 212 having a positive locking member 213. The positive locking member 213 shown in Figure 3 has a spherical shape. Regardless of the shape, the positive locking member 213 should always be configured to achieve positive locking with the adapter piece 22 while the adapter piece 22 is in the first position. This is accomplished, among other things, by the adapter piece 22 being disposed within the inner lumen 201 of the delivery catheter 20, with the second end 212 of the anchoring member 21 extending along a side surface 220 of the adapter piece 22 and the positive locking member 213 adjacent to a proximal end surface 221 of the adapter piece 22, such that the positive locking member 213, and therefore the second end 212 of the anchoring member 21, cannot be moved in the distal direction D without the adapter piece 22 moving, however, the adapter piece 22 is connected, for example by welding, to the mandrel 23. The first position of the adapter piece 22 is shown in FIG.

[0047] Although the adapter piece 22 shown in FIG. 3 is depicted in its second position, the second end 212 of the anchoring member 21 still extends beyond the proximal end face 221 of the adapter piece 22 along a side 220 of the adapter piece 22 parallel to the longitudinal axis L (see FIG. 5A ), and the positive locking member 213 is adjacent to the proximal end face 221 of the adapter piece 22. However, the anchoring member 21 shown in FIG. 3 does not provide a locked connection with the adapter piece 22 when the adapter piece 22 is in its second position, and therefore can be released at any time. An embodiment of the adapter piece 22 will be described in more detail with respect to FIGS. 5A-7E. It is easily seen in FIG. 3 that the release of the positive locking member 213 from the side of the adapter piece 22 is not hindered by the delivery catheter 20. Thus, in the second position, the medical device 1 can be disconnected from the delivery system, as described in more detail below.

[0048] 3 further shows two arrows D and P pointing in distal and proximal directions D and P of the delivery system. The proximal end face 221 of the adapter piece 22 faces in the proximal direction P. The distal end face is located at the distal end of the adapter piece 22 (opposite the proximal end face 221).

[0049] The delivery system 2 further includes a proximally disposed delivery catheter 20 including an end cap 200 and an inner lumen 201. A mandrel 23 extends through the inner lumen 201 of the delivery catheter 20 and is connected by its distal end 230 to the adapter piece 22. The mandrel 23 includes a biocompatible polymeric or metallic material. Typically, the mandrel 23 has a diameter greater than or at least equal to the anchoring member 21. The anchoring member 21 may be formed by a cable, a suture, or a wire made of a biocompatible polymeric or metallic material.

[0050] The mandrel 23 is sufficiently flexible so that it can deform with the delivery catheter 20 as it is guided through the patient's body part, yet is stiff and kink resistant so that it can move relative to the delivery catheter 20. Additionally, the mandrel 23 is used to displace the adapter piece 22 by applying a pushing and / or pulling force to the mandrel 23. The first position of the adapter piece 22, in which the positive locking member 213 provides a positive form of locking connection with the adapter piece 22 (see FIG. 5C), differs from the second position shown in FIG. 3 in that in the first position, the adapter piece 22 is at least partially disposed within the inner lumen 201 of the delivery catheter 20.

[0051] Furthermore, Fig. 3 depicts the medical device 1 of Fig. 2 shown at one end of the delivery system 2 in the distal direction D. However, the medical device 1 is not part of the delivery system 2, but is part of an assembly including the medical device 1 and the delivery system 2. The anchoring member 21 is guided through the opening 130 (see Fig. 4) of the connecting member 13 and returns to the adapter piece 22, thereby forming a loop. This loop is disconnected from the connecting member 13 to release the medical device after implantation. Therefore, the size and shape of the opening 130 of the connecting member 13 needs to be larger than the size and shape of the positive locking member 213 to allow safe release of the medical device 1.

[0052] The adapter piece 22 is in its first position while guiding the assembly through the patient's body to a target location for implantation. The mandrel 3 is retracted such that the adapter piece 22 is positioned completely inside the inner lumen 201 of the delivery catheter 20. The adapter piece 22 is further aligned such that the medical device 1 is securely drawn towards the end cap 200 and thus fixedly connected to the delivery catheter 20. Thus, a secure connection between the medical device 1 and the delivery catheter 20 is established. In this state, the medical device 1 can be guided towards the target location by the delivery system 2. The delivery system 2 further has a stopper 40 disposed on the mandrel 23 proximal to the adapter piece 22.

[0053] After the medical device 1 has reached the target location and all necessary steps have been performed, i.e., for example, the medical device has been secured to the patient's tissue M by the anchoring member 12, the mandrel 23 is operated (i.e., pushed) to displace the adapter piece 22, such that the medical device 1 is released from the end cap 200, with the adapter piece 22 still remaining inside the inner lumen 201 of the delivery catheter 20. Thereby, the medical device 1 is spatially removed from the end cap 200 of the delivery catheter 20, while the connection via the anchoring member 21 still remains in force.

[0054] In this so-called intermediate position, a pull test as well as an electrical test can be performed, thus ensuring proper fixation of the medical device 1 in the tissue M by the anchoring members 12 by pulling the medical device 1 away from the tissue M via the anchoring members 21 of the delivery system 2, as well as proper functioning of the stimulation by the electrodes 11. The pull test can be performed, for example, by pulling the mandrel 23 together with the adapter piece 22 in the proximal direction P.

[0055] If during the test step the medical device 1 is found not to be reliably fixed to the tissue M but releases when a predefined force is applied during the pull test, or if the medical device 1 is found not to be correctly aligned to perform its electrical function (e.g. the contact resistance is higher than a predefined value), the medical device 1 may have to be realigned. For this, the adapter piece 22 can be retracted again into the delivery catheter 20 by pulling the mandrel 23 and the adapter piece 22 together with the mandrel 23 in the proximal direction P, so that the medical device 1 can again engage with the end cap 200. The medical device 1 can then be aligned in another location and the test can be repeated until it is confirmed that the medical device 1 is properly aligned and functional.

[0056] After the medical device 1 is found to be properly implanted and secured in the tissue M and to function properly, the medical device 1 will be released from the anchoring member 21. To this end, by pushing the mandrel 23 in the distal direction D, the adapter piece 22 is moved completely out of the inner lumen 201 of the delivery catheter 20, as shown in FIG. 3. In the second position of the adapter piece 22, the positive locking member 213 adjacent the proximal end face 221 of the adapter piece 22 is no longer locked, so that the positive locking member 213 is released from the adapter piece 22 and the loop formed by the anchoring member 21 is opened. The stopper 40 ensures that the distal pushing of the mandrel 23 does not inadvertently push the positive locking member 213 back into the delivery catheter.

[0057] Release of the anchoring member 21, and thus of the medical device 1, is then performed, for example, by pulling the anchoring member 21 in its proximal direction P, causing the positive locking member 213 to slide through the opening 130 of the connecting member 13. When the positive locking member 213 is released from the adapter piece 22, the anchoring member 21 and the positive locking member 213 of the second end 212, respectively, are pulled through the opening 130.

[0058] Alternative shapes and sizes of connecting member 13 may be used in assembly with differently shaped positive locking members 213. However, the use of a rounded and / or curved profile, or at least a profile without edges, regardless of the shape of the connecting member, helps ensure that the positive locking member 213 does not get caught when it is released from the adapter piece 22 and pulled through the opening 130 of the connecting member 13 of the medical device 1.

[0059] 5A to 7E, three exemplary embodiments of an adapter piece that may be used within delivery system 2 are shown, with adapter piece 22 shown in FIGS. 5A to 5C being hereinafter referred to as the first adapter piece 22, adapter piece 32 shown in FIGS. 6A to 6C being hereinafter referred to as the second adapter piece 32, and adapter piece 42 shown in FIGS. 7A and 7E being hereinafter referred to as the third adapter piece 42.

[0060] All three adapter pieces 22, 32, 42 have side surfaces 220, 320, 420, i.e., circumferential surfaces, a proximal end surface 221, 321, 421 that is used adjacent to the positive locking member 212 when the adapter piece 22, 32, 42 is in the first position, a distal end surface 222, 322, 422, and through holes 223, 323, 423 for receiving and securing the anchoring member 21 and the mandrel 23. Additionally, all adapter pieces 22, 32, 42 of Figures 5A to 7E have chamfered edges 224, 324, 424. Additionally, each adapter piece 22, 32, 42 has a longitudinal axis L (located at the center) and a radial distance D1 that is the distance between the respective side surface 220, 320, 420 and the longitudinal axis L. Thus, depending on the design of the adapter pieces 22, 32, 42, the distance D1 may vary with respect to the circumferential direction of the adapter pieces 32, 42. Each of the three adapter pieces 22, 32, 42 is rotationally symmetrical with respect to the respective longitudinal axis L. Furthermore, the respective through holes 223, 323, 423 of the three adapter pieces 22, 32, 42 extend along the longitudinal axis L, whereby the connection of the anchoring member 21 and the mandrel 23 with the respective adapter piece 22, 32, 42 inside the respective through holes 223, 323, 423 provides a central connection, whereby tilting of the respective adapter piece 22, 32, 42 is prevented.

[0061] The first adapter piece 22 shown in Figs. 5A to 5C has a cylindrical shape, and when the first adapter piece 22 is in its first position, the second end 212 of the anchoring member 21 extends along the lateral shell surface 220 of the cylinder. After the first adapter piece 22 is received inside the inner lumen 201 of the delivery catheter 20, the inner surface of the inner lumen 201 and the lateral surface 220 of the first adapter piece 22 form one contact surface. The distance D1 of the first adapter piece 22 is formed by the radius of the cylinder and does not vary with respect to the circumferential direction of the first adapter piece 22. The cylindrical form of the first adapter piece 22 results in a cost-effective manufacture of the adapter piece, for example by turning. Moreover, the assembly is very simple and thereby very cost-effective, since the second end 212 of the anchoring member 21 may be located at any position of the periphery of the lateral surface 220. Furthermore, the proximal end face 221 of the adapter piece 22 is substantially flat and extends perpendicular to the longitudinal axis L.

[0062] 6A to 6C show the second adapter piece 32 including a rotationally symmetrical star-shaped design with six (star) tips (when viewed in cross section in FIG. 6B) or ribs (when viewed three-dimensionally) 325 and a curved notch 326 in the middle of two consecutive ribs 325. Thus, the second adapter piece 32 having a star shape (in its cross section) has a variable distance D1 along its circumferential direction. When the second adapter piece 32 is in its first position, i.e., when it is received inside the inner lumen 201 of the delivery catheter 20, only the longitudinally extending ribs 325 contact the inner surface of the inner lumen 201 forming six contact lines, thereby increasing the trackability compared to the larger contact surface of the first adapter piece 22. Furthermore, the curved notch 326 extending parallel to the longitudinal direction L is used to guide the second end 212 of the anchoring member 21, as shown in FIG. 6C. The proximal end face 321 of the adapter piece 32 is slightly curved. This helps the positive locking member 213 to slide off the second adapter piece 32 more easily when the adapter piece 32 reaches its second position. The dimensions of the positive locking member 213 are selected such that the adapter piece 22, 32 cannot pass between the inner surface of the inner lumen 201 of the delivery catheter 20 and the side surface 220, 320 of the adapter piece 22, 32 in the distal direction D while the adapter piece 22, 32 is in the first position shown in Figures 5C and 6C relative to the delivery catheter 20.

[0063] 7A to 7E, a third embodiment of the adapter piece 42 is shown. The third adapter piece 42 comprises a generally cylindrical tubular section 427 located at the distal end of the third adapter piece 42 and a star-shaped proximal section 428 (with respect to its cross section) located at the proximal end of the third adapter piece 42, which includes five longitudinally extending ribs 425 (i.e., five possible contact lines with the surface of the inner lumen 201 of the delivery catheter 20). As can be derived from FIGS. 7A, D and E, the outer diameter of the tubular section 427 (e.g., between 0.2 mm and 0.4 mm) is smaller than the radial distance D1 of the third adapter piece 42, which can vary between 0.5 mm and 0.8 mm. The length of the tubular section 427 can be intermediate between 1.5 mm and 1.7 mm. The shape and use of the proximal section 428 of the third adapter piece 42 is similar to that of the second adapter piece.

[0064] The overall length of each of the three adapter pieces 22, 32, 42 may be, for example, between 3 mm and 3.4 mm.

[0065] The third adapter piece 42 further has a through hole 423 having a smaller diameter along the tubular section 427 than in the proximal section 228, thereby forming an intermediate vertically extending abutment surface 429 (see FIGS. 7B, 7D and 7E). The abutment surface 429 is used to limit slippage of the mandrel 23 during manufacture of the delivery system prior to welding. The mandrel 23 is secured to the adapter piece 42 by welding or adhesive within the through hole 423.

[0066] To attach the anchoring member 21 to the adapter piece 42, the first end 211 of the anchoring member 21 is received within the through hole 423 in the tubular section 427 of the adapter piece 42. The tubular section 427 is then crimped to form a permanent connection between the first end 211 of the anchoring member 21 and the third adapter piece 42.

[0067] Materials used for the elements of the delivery system 2 are, for example, stainless steel, PEEK, ceramic.

[0068] Thus, the delivery system disclosed in the present invention, particularly through the improved construction of the adapter piece, not only makes manufacturing more cost-effective but also facilitates handling during implantation of the medical device. [Explanation of symbols]

[0069] 1 Medical devices (leadless pacemakers) 10. Housing 11 electrodes 12 Anchor member 13 Connection parts 130 Aperture 2. Delivery System 20 Delivery Catheter 200 End Cap 201 Internal Lumen 21 Mooring members 211 First end 212 Second End 213 Positive locking components 22, 32, 42 Adapter Piece 220, 320, 420 Side 221, 321, 421 Proximal end face 222, 322, 422 Distal end face 223, 323, 423 through hole 224, 324, 424 chamfered edge 325, 425 Ribs 326, 426 Curved notch 427 Tubular Section 428 Proximal Section 429 Contact surface 23 Mandrel 230 Distal end D Distal direction L Longitudinal axis LA Left atrium LV left ventricle M tissue (myocardium) P Proximal direction RA right atrium RV right ventricle

[0070] It will be apparent to those skilled in the art that many modifications and variations of the described examples and embodiments are possible in light of the above teachings. The disclosed examples and embodiments are presented for illustrative purposes only. Other alternative embodiments may include some or all of the features disclosed herein. It is therefore intended to cover all such modifications and alternative embodiments that may fall within the true scope of the present invention.

Claims

Claim 1 A delivery system (2) for implanting a medical device (1), comprising: a delivery catheter (20) having an internal lumen (201); a mandrel (23) received within the internal lumen of the delivery catheter and movable relative to the delivery catheter; a tethering member (21) including a first end (211), a second end (212), and a positive locking member (213) fixed to the second end (212); an adapter piece (22, 32, 42) having a longitudinal axis (L) and including a proximal end face (221, 321, 421) and side faces (220, 320, 420), the adapter piece (22, 32, 42) forming a fixed connection between the distal end (231) of the mandrel and the first end of the tethering member; the adapter piece is displaceable between a first position inside the internal lumen of the delivery catheter and a second position where the adapter piece is disposed outside the internal lumen of the delivery catheter by moving the mandrel relative to the delivery catheter; in the first position of the adapter piece, the second end of the tethering member extends beyond the proximal end face of the adapter piece along the side face of the adapter piece substantially parallel to the longitudinal axis such that the positive locking member is in proximity to the proximal end face of the adapter piece, thereby achieving a locking connection with the adapter piece. A delivery system (2) Claim 2 The delivery system according to claim 1, wherein the adapter piece (22, 32, 42) is rotationally symmetric about its longitudinal axis (L). Claim 3 The delivery system according to claim 1 or 2, wherein the radial distance (D1) between the longitudinal axis (L) and the side faces (220, 320, 420) of the adapter piece (22, 32, 42) varies along its outer peripheral direction. Claim 4 The delivery system according to claim 1 or 2, wherein the inner surface of the delivery catheter (20) and the adapter piece (22, 32, 42) have from one to six contact lines or contact surfaces. Claim 5 The adapter piece is configured to receive the distal end (231) of the mandrel (23) and / or the first end (211) of the tethering member (21), and has a through-hole (223, 323, 423) extending along or parallel to its longitudinal axis (L), the delivery system according to claim 1 or 2.

6. The through-hole (223, 323, 423) has a contact surface (429) extending perpendicular to the longitudinal axis (L), the delivery system according to claim 5.

7. The adapter piece (42) has a tubular section (427) at its distal end, the tubular section is configured to receive the first end (212) of the tethering member (21), and the tubular section (427) has an outer diameter smaller than that of the proximal section (428) of the adapter piece (42), the delivery system according to claim 1 or 2.

8. The side surfaces (220, 320, 420) of the adapter piece (22, 32, 42) have at least one groove or curved notch (326, 426) extending parallel to the longitudinal axis (L), the delivery system according to claim 1 or 2.

9. The positive locking member (213) of the tethering member (21) has a trapezoidal shape, a drip shape, or a spherical shape, the delivery system according to claim 1 or 2.

10. The tethering member (21) forms a loop while the adapter piece (22, 32, 42) is in the first position, the delivery system according to claim 1 or 2.

11. The dimensions of the internal lumen (201) of the delivery catheter (20), the adapter piece (22, 32, 42), and the positive locking member (213) are selected such that the positive locking member prevents disengagement from the adapter piece in the first position, but allows disengagement from the adapter piece in the second position, the delivery system according to claim 1 or 2.

12. The mandrel (23) and / or the adapter piece (22, 32, 42) and / or the tethering member (21) includes a biocompatible polymer or a metallic material, the delivery system according to claim 1 or 2.

13. The delivery system according to claim 1 or 2, wherein a stopper (40) is disposed proximally to the adapter piece (22, 32, 42) on the mandrel (23).

14. An assembly comprising a delivery system (2) according to claim 1 or 2 and a medical device (1) including a connecting member (13), wherein the mooring member (21) is coupled to the connecting member while the adapter piece is in the first position.

15. The assembly according to claim 14, wherein the connecting member (13) includes an opening (130) through which the loop-shaped mooring member (21) extends while the adapter piece (22, 32, 42) is in the first position.

16. A method for releasing a medical device (1) from a delivery system (2), comprising providing the delivery system with the medical device coupled thereto, the delivery system comprising a delivery catheter (20) having an internal lumen (201), a mandrel (23) received within the internal lumen of the delivery catheter and movable relative to the delivery catheter, a mooring member (21) including a first end (211), a second end (212), and a positive locking member (213) fixed to the second end, and an adapter piece (22, 32, 42) having a longitudinal axis (L) and including a proximal end face (221, 321, 421) and a side face (220, 320, 420), the adapter piece forming a fixed connection between the distal end of the mandrel and the first end of the mooring member, the adapter piece being disposed in a first position within the internal lumen of the delivery catheter by moving the mandrel relative to the delivery catheter, at the first position of the adapter piece, the second end of the mooring member is such that the positive locking member is in proximity to the proximal end face of the adapter piece, whereby a locking connection with the adapter piece is achieved and a loop for connection with the medical device is formed, extending beyond the proximal end face of the adapter piece along the side face of the adapter piece substantially parallel to the longitudinal axis. The method further comprises A method, including enabling the positive locking member to be disengaged from the adapter piece by displacing the adapter piece from the first position to the second position, wherein at the second position, the adapter piece is disposed outside the inner lumen of the delivery catheter by moving the mandrel.

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