HEAD ASSEMBLY FOR IMPLANTABLE INTRACARDIAC DEVICE AND CORRESPONDING INTRACARDIAC DEVICE - Patent application

Abstract

The present invention refers to a header assembly (0.1) for an implantable intracardiac device (0) suitable for automated assembly, the header assembly comprising a cylindrical feedthrough arrangement (5.1, 15.1), a ring-shaped proximal cap (4, 14), a ring-shaped distal cap (1, 11), a base ring (2.1) having at least two tines (2.2) protruding distally therefrom, and a pressing arrangement (1.7). The feedthrough arrangement (5.1, 15.1) has an outer shell surface (5.2, 15.2). The proximal cap (4, 14) has an inner surface (4.1). The distal cap (1, 11) has an outer surface (1.1). The distal cap (1, 11) comprises a fixing portion (1.6) having an inner surface (1.2) that forms a locking connection with the outer shell surface (5.2, 15.2) of the feedthrough arrangement (5.1, 15.1) to counteract movement of the distal cap (1, 11) and the feedthrough arrangement (5.1, 15.1) away from each other in the axial direction (9). The proximal cap (4, 14), the distal cap (1, 11), and the base ring (2.1) are configured such that the inner surface (4.1) of the proximal cap (4, 14) and the outer surface (1.1) of the distal cap (1) are coaxially arranged and oriented toward each other, and the base ring (2.1) is positioned between the inner surface (4.1) of the proximal cap (4, 14) and the outer surface (1.1) of the distal cap (1) such that the inner surface (4.1) of the proximal cap (4, 14) and the outer surface (1.1) of the distal cap (1) are coaxially arranged and oriented toward each other, and the base ring (2.1) is coaxially rotatable relative to the distal cap (1). The pressing arrangement (1.7) is configured to exert a radial elastic force to press the base ring (2.1) against one of the inner surface (4.1) of the proximal cap (4) and the outer surface (1.1) of the distal cap (1). The present invention further refers to a corresponding intracardiac device and manufacturing methods for the header assembly and the intracardiac device, respectively.

Description

[Technical Field]

[0001] The present invention refers to an implantable intracardiac device, such as an implantable intracardiac pacemaker, and a header assembly therefor, as well as methods of manufacture for such a header assembly and such an implantable intracardiac device.

[0002] Implantable intracardiac devices, such as active or passive medical devices, e.g., implantable intracardiac pacemakers (also known as leadless pacemakers), are well-known miniature medical devices that are implanted entirely in the ventricles or atria of the heart. Intracardiac pacemakers are used in patients with bradycardia, i.e., when the heartbeat is too slow to meet the patient's physiological needs. Intracardiac pacemakers deliver electrical stimulation in the form of pulses to the heart to generate a physiologically appropriate heartbeat and / or in the form of shocks for cardioversion or defibrillation to restore a more normal heart rhythm. Alternative or additional functions of intracardiac devices include providing other electrical or electromagnetic signals to the heart or its surrounding tissues and sensing electrical or electromagnetic signals or other physiological parameters of the heart and / or its surrounding tissues.

[0003] US Patent Application Publication No. 2012 / 0172690 and US Patent No. 10,112,045 disclose a leadless pacemaker device comprising a conductive housing and a fixation element assembly. The fixation element assembly includes a set of active fixation tines and insulators for electrically isolating the set of active fixation tines from the conductive housing of an implantable medical device. The active fixation tines in the set are deployable from a spring-loaded position, in which the distal ends of the active fixation tines face outward from the implantable medical device, to a hook position, in which the active fixation tines bend backward toward the implantable medical device. The active fixation tines are configured to fixate the implantable medical device to patient tissue when deployed while the distal ends of the active fixation tines are positioned adjacent to patient tissue.

[0004] However, known manufacturing methods for leadless pacemakers require sophisticated alignment methods to secure the tine array to the medical implant housing. For example, precise orientation of miniature components relative to one another is required prior to assembly, or sophisticated dispensing of adhesive materials in microgram doses is required, or alignment of delicate bayonet features is required to mate a header with a housing. Furthermore, complex injection-molded parts with notches are required for tine fixation. Also, such manufacturing steps are poorly suited to automation, as a silicone adhesive manual cleaning procedure is required after assembly.

[0005] Furthermore, known headers take up space from other critical components of the implantable intracardiac device, such as the battery or electronics module. Therefore, smaller header sizes are desirable.

[0006] Furthermore, during implantation of the intracardiac device, it may be desirable to be able to reorient portions of the intracardiac device relative to its header assembly, or particularly relative to the tines that are anchored within the cardiac tissue. Such a reorientation process may be required, for example, to establish a desired communication orientation when using coil-induced electric field communication. However, unintentional changes in the orientation of the intracardiac device should be prevented during operation of the intracardiac device, i.e., after completing the implantation procedure.

[0007] Therefore, there may be a need for implantable intracardiac devices and corresponding header assemblies, and methods for manufacturing them, that address at least one of the above-mentioned requirements. In particular, there may be a need for header assemblies that have small dimensions that provide a reliable mechanism for anchoring the intracardiac device in cardiac tissue, allow for setting the orientation of the cardiac device during implantation and maintaining that orientation during subsequent device operation, and / or allow for low manufacturing labor and cost.

[0008] Such a need may be met by the subject matter of one of the independent claims. Advantageous embodiments are defined in the dependent claims which are described herein and visualized in the associated drawings.

[0009] According to a first aspect of the present invention, a header assembly for an implantable intracardiac device is described. The header assembly includes a cylindrical feedthrough arrangement, a ring-shaped proximal cap, a ring-shaped distal cap, a base ring having at least two tines protruding distally from the base ring, and a pressing arrangement. The feedthrough arrangement has an outer shell surface. The proximal cap has an inner surface. The distal cap has an outer surface. The distal cap includes a fixing portion having an inner surface. The inner surface forms a locking connection with the outer shell surface of the feedthrough arrangement to counteract axial movement of the distal cap and the feedthrough arrangement away from each other. The proximal cap, the distal cap, and the base ring are configured such that the inner surface of the proximal cap and the outer surface of the distal cap are coaxially arranged and oriented toward each other, and the base ring is positioned between the inner surface of the proximal cap and the outer surface of the distal cap such that the inner surface of the proximal cap and the outer surface of the distal cap are coaxially arranged and oriented toward each other, and the base ring is coaxially rotatable relative to the distal cap. The pressing arrangement is configured to exert a radially resilient force to press the base ring against one of the inner surface of the proximal cap and the outer surface of the distal cap.

[0010] As only some introductory or summary notes, and without limiting the scope of the present invention, the basic ideas underlying embodiments of the present invention and related possible advantages can be roughly described as follows.

[0011] The header assembly presented herein is particularly configured to enable a simple yet reliable assembly procedure when mounting the header assembly on the housing of an implantable intracardiac device (hereinafter "ID"). In particular, the ring-shaped proximal and distal caps can be easily pressed axially onto a cylindrical feedthrough feature provided at the distal end of the housing of the ID. The outer shell surface of the feedthrough feature and the inner surface of the fixed portion of the distal cap are particularly configured such that, when actually pressed together, a preferably irreversible, i.e., permanent, locking connection, such as a snap-fit ​​or press-fit connection, is established between both components. Such a locking connection securely holds the header assembly in the housing of the ID.

[0012] Furthermore, a base ring having at least two tines is positioned between the inner surface of the proximal cap and the outer surface of the distal cap, and is thus securely held in the housing of the ID. Specifically, the base ring is arranged and configured to be coaxially rotatable relative to the distal cap. Because the distal cap is secured to the housing of the ID via a feedthrough arrangement, the base ring is therefore rotatable relative to the housing. On the one hand, such rotational ability can be used during the implantation procedure to accurately orient the housing relative to the tines extending from the base ring, which are secured to the cardiac tissue to accurately hold the entire ID. However, on the other hand, such initially correct orientation should be prevented from being subsequently altered during normal operation of the ID (i.e., after the implantation procedure is completed) due to rotational forces acting on the ID, for example, during normal heartbeats and / or during patient movement. Therefore, on the one hand, the base ring with the tines should be prevented from rotating relative to the housing of the ID as long as only small rotational forces act on the housing, and such small rotational forces are lower than those typically applied to the housing during normal operation. On the other hand, rotation of the base ring relative to the ID housing should be possible when a large rotational force is applied to the housing, such as is applied during the implantation procedure to specifically orient the ID housing.

[0013] To establish such specific rotational capabilities, tests were conducted to clamp the base ring between the proximal and distal caps so that it could only be rotated when a rotational force exceeding the frictional force between the base ring on one side and the proximal and distal caps on the other side was applied, the frictional force resulting from the clamping action. However, it was observed that to establish such a clamping action, the distal cap must generally be mounted with its fixed portion on the feedthrough arrangement in a configuration that subjects the distal cap and its fixed portion to substantial permanent mechanical stress. While such distal caps are preferably made from high-quality polymeric materials such as PEEK, it has been observed that such permanent mechanical stress can result in mechanical failure or damage to the distal cap material, an effect also known as environmental stress cracking (ESC). In particular, such ESC preferably occurs when the polymeric components of the header assembly are loaded under a specific amount of mechanical stress (static or cyclic) and exposed to an oxidizing environment, such as contact with human blood. However, any ESC occurring in the fixation portion of the distal cap may result in failure of the locking connection between such fixation portion and the outer shell surface of the feed-through arrangement. In the worst case scenario, such failure could result in the distal cap becoming dislodged from the feed-through arrangement, thereby releasing the entire fixation of the ID housing to the base ring and the tines secured to the cardiac tissue. Of course, such a release action is intended to be prevented.

[0014] To prevent such occurrence of ESC, the distal cap may be adapted so that its fixed portion can be pressed into the feedthrough configuration during the assembly procedure, then forming a locked connection in which the fixed portion is not permanently mechanically stressed beyond the extent to which ESC normally occurs. Furthermore, to ensure that sufficient rotational friction is established between the proximal and distal caps and the base ring disposed therebetween, the header assembly further includes a specific pressing configuration. Such a pressing configuration is configured so that a resilient force is exerted on the base ring, thereby pressing the base ring against the proximal or distal cap so as to ultimately establish the required rotational friction. Thus, while accurate orientation of the ID housing during the implantation procedure may be possible by applying a rotational force that exceeds the rotational friction induced by the pressing configuration, unintentional misorientation of the ID housing during subsequent operation is generally prevented because rotational forces exceeding the rotational friction are not induced during such normal operation of the ID. Furthermore, even if excessive mechanical stress is applied to the pressing feature and thus damage, such as cracks, eventually occurs in the pressing feature, for example, due to the ESC, such damage or cracks only affect the pressing feature and not the rest of the header assembly, particularly the fixed portion of the distal cap. Thus, even in the event of such damage or cracks, the integrity of the entire header assembly, and particularly the fixation of the distal cap to the feedthrough feature, is not jeopardized.

[0015] Subsequently, possible features and related possible advantages of embodiments of the present invention are described in more detail.

[0016] An implantable intracardiac device may be, for example, an implantable intracardiac pacemaker (also known as a leadless pacemaker) that can apply electrical stimulation in the form of a pulse to the heart to generate a physiologically appropriate heartbeat and / or in the form of a shock for cardioversion or defibrillation to restore a more normal heart rhythm. In the latter case, the ID may instead be called a defibrillator or cardioverter. Alternative or additional functions of an intracardiac device may include providing other electrical or electromagnetic signals to the heart or its surrounding tissue and sensing electrical or electromagnetic signals or other physiological parameters of the heart and / or its surrounding tissue. In some cases, the ID focuses on sensing electrical or electromagnetic signals, which may alternatively be called a (bio)monitor. The ID may include any combination of the above functions. Implantation of the ID may include any fixation to the heart tissue, including fixation within the atria and ventricles of the heart or on the outer surface of the heart tissue using small tines.

[0017] The header assembly of the present invention is suitable for an ID, which typically includes a cylindrical housing and a header assembly located at the distal end of the housing. Furthermore, pin-shaped electrodes protrude from the distal end of the housing, and the header assembly is disposed at and attached to the distal end of the housing of the ID so that the electrodes protrude through the header assembly, i.e., through corresponding through or full openings in the header assembly. The openings may be central openings located at or along the longitudinal axis of the ID housing and header assembly. The longitudinal axis forms the axial direction of the ID and header assembly. The proximal cap, base ring, and distal cap also include through openings, and the opening in the proximal cap may be sized so that an electrode feedthrough located at the proximal end of the electrode can be at least partially disposed within this opening. The cylindrical housing includes an electronics module having a processor, an energy source (e.g., a battery or coil (for wireless charging)), and, if applicable, communication components such as an antenna. The processor may be adapted to process signals / data determined from the patient's body or received from the surrounding environment and / or generate signals for treatment of the patient's heart. Such signals may include electrical stimulation in the form of pulses to generate a physiologically appropriate heartbeat, shocks for cardioversion or defibrillation to restore a more normal heart rhythm, and / or other electrical or electromagnetic signals to the heart or its surrounding tissue. Such signals may be converted and transmitted by the electronics module and applied to the heart or its surrounding tissue by pin electrodes. The pin electrodes are electrically connected to the electronics module and an energy source. The sealed housing may comprise a conductive material, such as titanium or stainless steel, and may function as another electrode. The header assembly includes elements (tines) for securing the ID to selected tissue of the patient, such as the ventricular wall of the patient's heart, in accordance with a healthcare provider's (HCP's) treatment plan. Additionally, the header assembly provides electrical insulation of the pin electrodes relative to the tines and / or ID housing. The cylindrical feedthrough provides a seat for the pin electrodes and electrical insulation of the pin electrodes relative to the housing.The electrical insulation is provided particularly by the distal cap and the proximal cap, which comprise an electrically insulating material, and the base ring is axially housed between the proximal and distal caps. The base ring supports at least two tines, e.g., two tines, four tines, or six tines, protruding distally from the base ring, which provide fixation of the ID in the patient's tissue at the desired treatment site after implantation. Thus, the tines are anchored in the tissue.

[0018] To accommodate the feedthroughs and electrodes, the proximal cap, base ring, and distal cap are all basically and / or essentially ring-shaped and are housed in this sequential order from proximal to distal along the axial direction, with the feedthroughs and pin-shaped electrodes positioned within the inner openings of the corresponding rings after completion of fabrication. Such a uniaxial, stackable assembly configuration from all rotationally symmetric components is advantageous because these components can be manufactured easily and at low cost. Furthermore, they enable uniaxial assembly suitable for automated production. The header assembly construction of the present invention, as shown above and below, further avoids notches in the insulating components (the distal cap and the proximal cap), which reduces the complexity of the header assembly components because they are symmetric, rotated components with a longitudinal axis that also represents the axial direction.

[0019] The cylindrical feedthrough has an outer shell surface at least at its distal end. Further, the cylindrical feedthrough defines a distal end face. The distal end of the cylindrical feedthrough that defines the outer shell surface is considered a component of the header assembly.

[0020] After completion of ID production and fastening of the header assembly to its end face, the ring-shaped distal cap forms a permanent connection that counteracts distal movement of the distal cap and the feedthrough away from each other. The connection is provided by surface structures on the inner surface of the distal cap's through-hole and / or the outer shell surface of the feedthrough. According to the present invention, the inner surface of the distal cap forms a locking connection with the outer shell surface of the feedthrough.

[0021] For example, according to one embodiment, the distal cap includes, at an inner surface of its fixed portion, a structure configured to establish a snap-fit ​​locking connection with the outer shell surface of the feed-through arrangement. In other words, the fixed portion of the distal cap and the feed-through arrangement are adapted at their opposing surfaces such that, during assembly of both components by axially pressing the distal cap onto the feed-through arrangement, at least one of both components temporarily deforms until a position is reached at which the snap-fit ​​locking connection is established between both components. In such a snap-fit ​​locking connection, both components may engage in a form-fit manner at their opposing surfaces, where the opposing surfaces are form-fit engaged without substantially permanently deforming one of the components, i.e., without significant radial force being exerted on at least one of the fixed portion of the distal cap and the feed-through arrangement.

[0022] More specifically, according to one embodiment, the outer shell surface of the feed-through arrangement and the inner surface of the fixed portion of the distal cap have surface structures with protrusions and recesses that are at least partially complementary to one another to establish a snap-fit ​​locking connection between the outer shell surface and the inner surface, such that a protrusion on one of the inner surface of the fixed portion of the distal cap and the outer shell surface of the feed-through arrangement can engage in a snap-fit ​​manner with a recess on the opposing surface of the other component.

[0023] According to an alternative exemplary embodiment, the fixed portion of the distal cap is configured to establish a press-fit lock connection with the outer shell surface of the feed-through arrangement. Similar to the above-described establishment of a snap-fit ​​connection, the fixed portion of the distal cap and the feed-through arrangement may be pressed together axially and slide against each other while undergoing a slight temporary radial deformation. Upon reaching the final position, the radial deformation may be partially released. However, residual elastic deformation may remain, resulting in radial pressure between the inner surface of the fixed portion and the outer shell surface of the feed-through arrangement. Such radial pressure may induce some permanent deformation in at least one of these surfaces. Thus, in such a press-fit lock connection, substantial actual pressure may act between the connected components, and further, pre-configured surface structures and / or induced deformations in the opposing surfaces of the components may engage in a form-fit manner.

[0024] More specifically, according to one embodiment, the outer shell surface of the feedthrough arrangement and the inner surface of the fixed portion of the distal cap have surface structures that are at least partially non-complementary to one another to establish a press-fit locking connection between the outer shell surface and the inner surface. In other words, at least prior to engagement, the inner surface of the fixed portion and the opposing outer shell surface of the feedthrough arrangement may both have protruding and / or recessed structures that are not complementary to one another. Thus, when assembled, the opposing surfaces may not fully engage with one another without locally induced radial forces at the non-complementary portions of the engaged surfaces. These radial forces, and / or resulting permanent deformations at the engaged surfaces, are typical of a press-fit locking connection.

[0025] Thus, the inner surface of the distal cap and the outer shell surface of the feedthrough may have first surface structures adapted to provide a form-locking connection with the other surface when the distal cap is attached to the feedthrough, and the form-locking connection may also include force-locking. The other surface is the inner surface of the distal cap or the other shell surface of the feedthrough. After assembly / fixing, the feedthrough and the distal cap are permanently connected by a press-fit or snap-fit ​​connection at their adjacent surfaces so that they cannot move relative to each other. The first surface structures of the outer shell surface of the feedthrough and / or the inner surface of the distal cap, or both, interact, engage, and / or interlock with each other to form the press-fit or snap-fit ​​connection. The first surface structures may, for example, include radially extending protrusions forming undercuts, such as serrated protrusions, threaded structures, or bayonet joints. Relative movement of the distal cap and the feedthrough is not possible in the fixed state (i.e., fully assembled state), and therefore, movement away from each other in the axial direction is also not possible. Thus, adhesion is avoided. Furthermore, production can use simple movements and axially directed forces, thereby avoiding more complex rotational assembly movements.

[0026] The ring-shaped proximal cap is adapted to fit into and along a corresponding circular recess in the distal end face of the ID housing to provide easy, accurate, and fast positioning during production. To that end, the proximal cap may form a cylindrical protruding rim at its proximal surface.

[0027] Additionally, another form of locking connection is provided for securing the base ring between the distal cap and the proximal cap, which is further described below.

[0028] The distal cap may include a stop surface at a distal section of its inner surface. The stop surface may be formed by a proximal surface of a protrusion that protrudes radially from the inner surface of the distal cap, the radial direction extending radially from the central longitudinal axis of the ID or its header assembly. The protrusion may be located at the distal-most section of the inner surface of the distal cap. The stop surface interacts with a distal end face of the distal section of the feedthrough to form a mechanical stop during assembly of the header assembly and the ID. The stop surface stops the press-fit or snap-fit ​​movement of the distal cap or ID housing at the correct position, thereby improving production quality. The stop surface further avoids mechanical overload by limiting the travel distance of the components during press-fit or snap-fit, thereby avoiding mechanical damage to one of the press-fit or snap-fit ​​components.

[0029] The inner surface of the proximal cap, formed by the through-holes in the proximal cap, may include a second surface structure and / or may form a form-locking connection with the outer shell surface of the feedthrough when the proximal cap is attached to the feedthrough. Like the distal cap, the proximal cap may also form a permanent press-fit or snap-fit, form-locking connection with the outer shell surface of the feedthrough after assembly is complete. The forces acting in this essentially form-locking connection may also include force locking. The surface structures of the outer shell surface of the feedthrough, or the inner surface of the proximal cap, or both, may interact, engage, and / or interlock in the same manner as the distal cap and the feedthrough, thereby again avoiding adhesion and improving production efficiency.

[0030] The first surface structure and / or the second surface structure may include at least two protrusions and / or thread profiles, where the at least two protrusions are housed axially one above the other and / or circumferentially adjacent to one another. Preferably, the first surface structure and / or the second surface structure include a plurality of such protrusions housed one above the other or adjacent to one another as described above. All protrusions protrude at least partially radially from the surfaces forming the first or second surface structure, i.e., from the inner surface of the distal cap, from the inner surface of the proximal cap, and / or from the outer shell surface of the feedthrough. The radial dimension of the protrusions (perpendicular to the axial direction) may be less than 200 μm, preferably less than 150 μm (e.g., for surface structures on the outer shell surface), to ensure a secure fixation of the distal cap to the feedthrough. The dimension of the protrusions may be greater than 50 μm. These dimensions of the protrusion were calculated by FEA to widen the distal cap diameter such that the strain of the distal cap material (e.g., PEEK) reaches 50% to 95% of its tensile strength (up to approximately 100 MPa). The inner surface of the distal cap and / or the inner surface of the proximal cap may include a thread profile (female threads), and the outer shell surface may include a thread profile (male threads) that engages to secure the distal cap and / or the proximal cap to the feedthrough. In one embodiment, the opposing thread profiles form a self-locking thread.

[0031] The at least two protrusions may extend along at least a portion of the outer periphery of the outer shell surface of the feedthrough, or along at least a portion of the inner periphery of the inner surface of the distal cap or the inner surface of the proximal cap. This means that the at least two protrusions have a predetermined length along the outer periphery or along the inner periphery. The protrusions may extend along one-quarter of the respective circumference, along one-half of the respective circumference, along the entire circumference, or even longer. The at least two protrusions may extend at an angle to the axial direction or perpendicular to this direction. The at least two protrusions may be distributed on the inner surface of the distal cap or the proximal cap or on the outer shell surface of the feedthrough, or their lengths may be adapted to ensure a good distribution of forces resulting from the press-fit or snap-fit ​​of the feedthrough and the distal cap or the proximal cap, respectively, across these surfaces to avoid stress peaks.

[0032] In one embodiment, each other surface includes at least one recess for receiving at least two protrusions when the distal cap or proximal cap is attached to the feedthrough. For example, the outer surface of the feedthrough includes at least two protrusions, and the inner surface of the distal cap includes at least one recess that can overlap with the at least two protrusions, so that they fully interlock with each other after assembly is complete. The fastening can also be described as a snap-type step. For example, the inner surface of the distal cap can include a circular groove extending around the entire circumference of the inner surface. In another embodiment, at least two pin-like protrusions extending from the outer shell surface of the feedthrough and an L-shaped recess on the inner surface of the distal cap form a bayonet connection. Having recesses on the other surface reduces strain in the distal cap or proximal cap material, such as a polymer material, thereby mitigating potential material failure caused by high strain.

[0033] In one embodiment, at least a portion of the at least two protrusions has a sawtooth shape. For example, the at least two protrusions form at least two serrated circular rims axially nested one above the other, extending along the entire circumference or along a portion of the circumference, with the inclined surfaces of the sawtooth shapes having an angle, e.g., a small angle with respect to the radial direction of 45° or more, preferably 60° or more but less than 90°. Due to their angled shape, the sawtooth protrusions facilitate assembly through this slide-in chamfer. Conversely, a sawtooth rim with a second angle of between 110° and 70°, preferably between 100° and 80°, with respect to the axial direction, bounded by the surface of each protrusion protruding from the outer shell surface of the feedthrough, "bites" into the inner surface of the distal cap, preventing the distal cap from loosening. A permanent fixation is thereby established. Alternatively or additionally, the at least two protrusions may form barbs at their outermost protruding ends to further enhance retention characteristics.

[0034] In one embodiment, the outer rim of the protrusion can have a circular cross-section. In another embodiment, the cross-section of the outer rim of the protrusion can have a rounded polygonal shape, such as a trilobular shape. This provides the polymer distal cap space for inward deformation, reducing stress on the distal cap and preventing it from breaking. Furthermore, this solution is less prone to manufacturing tolerances as a wider range of cap inner diameters can fit without breaking and / or may have self-locking behavior.

[0035] Below, some possible characteristics and advantages of the compression configuration of embodiments of the header assembly are described.

[0036] According to one embodiment, the press-fit configuration has a higher radial deformability than the fixed portion of the distal cap. Therefore, when radial forces are applied between the base ring on one side and the distal cap on the other side, these forces also act on the press-fit configuration. Because the press-fit configuration has a higher deformability than the fixed portion of the distal cap, the deformation induced in the fixed portion as a result of such radial forces is smaller compared to the press-fit configuration. Therefore, the risk of environmental stress cracking in the fixed portion of the distal cap is reduced. As a result, the reliability of the fixation of the distal cap to the feed-through configuration can be increased.

[0037] According to one embodiment, the pressing arrangement is an integrated part of the distal cap. In other words, the pressing arrangement does not have to be provided as a separate component, but can be an integrated part of the distal cap. Therefore, no additional components need to be manufactured and / or handled during the assembly procedure.

[0038] For example, according to one embodiment, the distal cap includes at least one lip portion protruding from an outer surface of the distal cap. The lip portion may be a protrusion extending away from a main portion of the distal cap, including, among other things, the fixed portion of the distal cap. The lip portion may be cantilever-shaped. The lip portion may be ring-shaped. In particular, the lip portion may extend coaxially or at an angle relative to the main portion of the distal cap. The lip portion may have a thickness substantially smaller than the main portion of the distal cap. Due to its geometric shape and / or smaller thickness, the lip portion has a substantially greater deformability compared to the main portion, particularly compared to the fixed portion of the distal cap. Thus, when a force is applied to the lip portion by the base portion, the lip portion may easily flex or bend.

[0039] According to certain embodiments, the distal cap includes an undercut recess extending adjacent to the outer surface in a direction parallel to the distal cap's central axial axis, separating the lip portion from the distal cap's inner portion. Such a recess may separate the integral portion of the distal cap that functions as the lip portion from the remainder of the distal cap, including the fixed portion. The width of the recess may be greater than the thickness of the lip portion. The recess extending in a direction parallel to the distal cap's central axial axis allows the lip portion to easily deform or flex in a direction transverse to the axial axis, i.e., toward the fixed portion of the distal cap. When elastically flexed in such a direction, the lip portion may exert a force on the base ring, thereby pressing the base ring against the inner surface of the proximal cap. In this embodiment, the major axis of the lip portion faces proximally. Facing proximally should be understood as facing away from the radial direction toward the proximal end.

[0040] According to an alternative specific embodiment, the distal cap includes an undercut recess extending adjacent to the outer surface in a direction intersecting, or particularly perpendicular to, the axial central axis of the distal cap, separating the lip portion from the upper portion of the distal cap. Again, such a recess may separate the integral portion of the distal cap that functions as the lip portion from the remainder of the distal cap. The width of the recess may be greater than the thickness of the lip portion. The recess extending in a direction intersecting the axial central axis of the distal cap allows the lip portion to easily deform or flex in a direction parallel to the axial central axis, i.e., away from the inner surface of the proximal cap. When elastically flexing in such a direction, the lip portion may exert a force on the base ring, thereby pressing the base ring against the inner surface of the proximal cap.

[0041] According to another specific embodiment, the lip portion may have a cantilevered shape facing distally. Facing distally should be understood as facing away from the radial direction toward the distal end. The lip portion may be ring-shaped. In particular, the lip portion may extend at an angle relative to the main portion of the distal cap. The lip portion may have a thickness substantially smaller than that of the main portion of the distal cap. Due to its geometric shape and / or smaller thickness, the lip portion has a substantially greater deformability compared to the main portion, particularly compared to the fixed portion of the distal cap. Thus, when a force is applied to the lip portion by the at least two tines, the lip portion may easily flex or bend. The lip portion may then easily deform or flex in a direction intersecting the axial central axis, for example, toward the axial central axis. When elastically flexing in such a direction, the lip portion may apply a force to the at least two tines, thereby applying a force to the base ring, thereby pressing the base ring against the inner surface of the proximal cap. This is particularly advantageous in situations where at least two tines are bent distally, for example when the implant is loaded into an implantation catheter.

[0042] The above disclosed embodiments describing lips may be implemented alone or in combination with one another, in particular, the distal cap may include a proximally facing lip and / or a distally facing lip.

[0043] According to a further alternative embodiment, the pressing arrangement includes a pressing ring disposed between the distal cap and the proximal cap to press against the base ring. In such an embodiment, the pressing arrangement is not implemented by an integral part of the distal cap button but by a separate pressing ring. Such a pressing ring may be prepared and provided as a separate component and included in the header assembly during the assembly procedure. The pressing ring may be housed within the header assembly in a recessed feature, such as a ring-shaped recess provided in the distal cap on or near its inner surface. The pressing ring may be made of a material other than the distal cap, particularly a material with higher resilience and flexibility.

[0044] According to another embodiment, the base ring is configured to be non-circular in its undeformed state. Such a non-circular base ring may have, for example, an elliptical shape, a polygonal shape, or the like. In particular, such a base ring may have, in its undeformed state, a portion having a diameter smaller than the outer surface of the distal cap and / or a portion having a diameter larger than the inner surface of the proximal cap. Thus, when placed between the distal cap and the proximal cap, such a non-circular base ring may elastically deform to conform to the circular outer surface of the distal cap and / or the circular inner surface of the proximal cap. Such deformation causes the base ring to exert a force on at least one of the distal cap and the proximal cap, resulting in the intended frictional force between the base ring and the corresponding cap.

[0045] Below, some further possible features and advantages of the header assembly are described.

[0046] In one embodiment, the inner surface of the distal cap is sloped or tapered, with the inner diameter of the proximal-most section being larger than the inner diameter of the section distal to the proximal-most section. Alternatively, the inner diameter of the proximal-most section is smaller than the inner diameter of the section distal to the proximal-most section. If there are protrusions on the inner surface of the distal cap or the outer shell surface of the feedthrough, their inner or outer diameters may increase or decrease accordingly along the axial direction. If the inner diameter of the surface or protrusion increases in the proximal direction along the axial direction, the retention force of the connection between the distal cap and the feedthrough increases. However, stress on the material of the distal cap also increases.

[0047] In one embodiment, the distal cap and the proximal cap comprise an electrically insulating material, and the distal cap and / or the proximal cap may further comprise an elastic material. The distal cap and / or the proximal cap may comprise or be entirely composed of polyetheretherketone (PEEK), liquid crystal polymer (LCP), polysulfone (PSU), or other polymeric materials with similar properties. The elasticity of the materials is advantageous in the manufacturing process because it helps establish a press-fit connection.

[0048] In one embodiment, the header assembly may include a ring-shaped steroid depot axially housed between the distal cap and the distal end face of the feedthrough. The steroid depot includes at least one medical substance, such as an anticoagulant and / or an antibacterial substance. The medical substance may be gradually released into the bloodstream near the anchoring point of the ID within the patient's tissue to heal damaged tissue near the anchoring point. The steroid depot may be clamped between the stopper surface of the distal cap and the distal end face of the feedthrough so as to be permanently secured in the header assembly and the ID. Additionally, a distally protruding inner rim may be positioned adjacent to a corresponding stop surface of a pin-shaped electrode located at the proximal end of the pin head. The electrode thereby holds the steroid depot in place.

[0049] In one embodiment, the shape-locking fixation of the base ring with tines between the proximal cap and the distal cap is provided by the conically shaped surfaces of the proximal cap and the distal cap and the conical shape of the base ring. The conical shape of the base ring means that the inner and outer surfaces of the ring have a conical, tapered shape, and both surfaces extend essentially parallel. In particular, the conical shape of the base ring means that the inner and outer diameters of the base ring are larger at its distal end than at its proximal end. When both sides of the base ring extend parallel, the wall thickness of the base ring is constant along its entire axial length. In another embodiment, the wall thickness can vary along its length (i.e., it can be thinner or thicker in the axial direction distally). The base ring with at least one tine is clamped and fixed between the proximal cap (on its proximal side) and the distal cap (on its distal side). To this end, the side of the proximal cap adjacent to the base ring (the distal face) and the side of the distal cap adjacent to the base ring (the proximal face) have the same slope or inclination as the corresponding outer surface of the base ring. This optimizes space, resulting in fewer header components, which results in fewer processing and assembly steps at lower cost during the manufacture of the ID. The axial length and volume of the header are minimized. This improvement allows more space for other, more critical features of the device, such as the battery, which extends the device's lifespan. The base ring is conically shaped to allow for a reduced axial height while maintaining the height of the band. In other words, space can be allocated to the electronics module to incorporate more therapeutic features. Conversely, for the same battery and electronics module size, reducing the length of the header allows for a reduction in the overall length of the device. This allows for application to smaller patients or alternative placement within the heart, such as the right atrium.

[0050] In one embodiment, each of the at least two tines includes an abutment section extending directly from the base ring and forming a connection with the base ring, and a flexible zone, with the abutment section of each tine continuing the conical shape of the base ring. Each of the multiple tines terminates in the base ring tangent to the arc of the tine just below the surface of the distal cap, and the base ring is completely contained on its distal side by the distal cap and on its proximal side by the proximal cap. The midsection of each of the multiple tines has a curved shape (e.g., a circular curve), and the end furthest from the base ring includes a straight section. Other shapes for each tine are also possible. In one embodiment, the base ring and at least one tine are integrally formed. The base ring and / or the at least two tines may be partially or completely made of a biocompatible material, such as a shape-memory material, such as Nitinol.

[0051] According to a second aspect of the present invention, an implantable intracardiac device is described having a cylindrical housing and a header assembly realized as described above, with a feedthrough accommodated at the distal end of the housing, the feedthrough being either integrally formed with the housing or formed by a separate element fixed and sealed at the distal end face of the housing, for example by welding.

[0052] According to a third aspect of the present invention, a manufacturing method for the header assembly described above is described, the manufacturing method comprising: Providing a feedthrough, a proximal cap, a distal cap, and a base ring having at least two tines; axially arranging the proximal cap, the base ring, and the distal cap one above the other (i.e., in this sequential order) such that the base ring is disposed between the proximal cap and the distal cap; securing the proximal cap, base ring, and distal cap to the feedthrough by application of an axial force to a distal surface of the distal cap and / or a proximal section of the feedthrough, such that the base ring is axially fixed between the distal cap and the proximal cap and rotatable about the axial direction relative to the distal cap, the feedthrough is received within the throughbore of the distal cap, and a surface structure of at least one of an inner surface of the distal cap and an outer shell surface of the feedthrough provides one of a snap-fit ​​locking connection and a press-fit locking connection with the other surface in the secured state, wherein in the secured state the surface structure forming the locking connection counteracts movement of the distal cap and the feedthrough away from each other in the axial direction; Includes.

[0053] The axial force may be provided by a pressing tool that applies an axial force distally to the distal end face of the distal cap and / or proximally to the proximal section of the feedthrough. The applied axial force overcomes the frictional force between the inner surface of the distal cap and the outer shell surface of the feedthrough, thereby establishing the above-described snap-fit ​​or press-fit connection between the distal cap and the feedthrough, thereby counteracting axial movement of the distal cap and the feedthrough away from each other. The housing / feedthrough is supported / secured during this snap-fit ​​or press-fit process. The same applies to the connection between the proximal cap and the feedthrough if a snap-fit ​​or press-fit connection is also established between these components.

[0054] According to a fourth aspect of the present invention, a manufacturing method for the implantable intracardiac device described above is described, the manufacturing method comprising: Providing a cylindrical housing having electrical or electromagnetic components therein, a cylindrical feedthrough at a distal end of the housing either integrally formed with the housing or as a separate element secured and sealed at a distal end face of the housing, and a pin-shaped electrode protruding from the distal end of the feedthrough and secured within a recess in the feedthrough; Providing a proximal cap, a distal cap, and a base ring having at least two tines; Axially arranging the proximal cap, the base ring, and the distal cap one above the other such that the base ring is disposed between the proximal cap and the distal cap; securing the proximal cap, base ring, and distal cap to the feedthrough by application of an axial force to a distal surface of the distal cap and / or a proximal section of the feedthrough, such that the base ring is axially fixed between the distal cap and the proximal cap and rotatable about the axial direction relative to the distal cap, the feedthrough is received within the throughbore of the distal cap, and a surface structure of at least one of an inner surface of the distal cap and an outer shell surface of the feedthrough provides one of a snap-fit ​​locking connection and a press-fit locking connection with the other surface in the secured state, wherein in the secured state the surface structure forming the locking connection counteracts movement of the distal cap and the feedthrough away from each other in the axial direction; Includes.

[0055] In one embodiment, the ring-shaped steroid depot is positioned axially proximally from the distal cap prior to fixation, and the ring-shaped steroid depot is secured between the distal cap and the distal end face of the feedthrough in the secured / assembled state.

[0056] In one embodiment, the proximal cap is secured within a recess in the distal surface of the housing, the recess being circumferentially surrounded by an outer rim extending from the distal end face of the housing. Although the distal cap is an element disposed at the distal end of the header assembly, the distal cap may extend through the throughbore of the proximal cap, thereby also forming a section of the proximal end face of the header assembly. In this case, the proximal and distal caps form the end face of the header assembly that is received adjacent to the distal end face of the housing. Alternatively, only the proximal cap forms the proximal end face of the header assembly. In other cases, only the proximal cap is received adjacent to the distal end face of the housing.

[0057] In another step, a pin-shaped electrode can be fixed into the through-hole of the feedthrough, with the proximal end face of the electrode head abutting the steroid depot in a fixed state. The electrode is brazed to the ceramic of the feedthrough by gold brazing, which holds and seals the pin in the feedthrough ceramic. Alternatively, the electrode is fixed in the feedthrough by a glass-to-metal connection. The electrode can also be a two-piece component consisting of a pin and an electrode tip. The two components are welded together, for example, by laser welding.

[0058] As described herein, securing of the essential header components is provided by a method that uses the elastic-plastic material properties of the polymer (e.g., thermoplastic) distal cap to achieve a reliable, long-term stable connection to the ID housing without the use of adhesive bonding forces. Stretching the diameter of the distal cap to an extent that it does not break in combination with the surface structure (e.g., at the feedthrough outer shell surface) certifies this snap-fit ​​or press-fit connection as a permanent attachment.

[0059] Many modifications and variations of the described examples and embodiments will be apparent to those skilled in the art in light of the above teachings. The disclosed examples and embodiments are presented for illustrative purposes only. Other alternative embodiments may incorporate 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.

[0060] The invention will now be described in more detail with reference to the accompanying schematic drawings. [Brief explanation of the drawings]

[0061] [Figure 1] 1 is an exploded perspective longitudinal cross-sectional view of a first embodiment of an implantable ID of the present invention having a header assembly of the present invention. [Figure 2] FIG. 2 is a longitudinal cross-sectional perspective view of the embodiment of FIG. 1. [Figure 3] FIG. 2 is a longitudinal cross-sectional view of the embodiment of FIG. 1. [Figure 4] 2 is an enlarged cross-sectional view of the housing with the feedthrough and electrodes of the embodiment of FIG. 1. [Figure 5] 2A to 2C are longitudinal cross-sectional views illustrating the outline of the manufacturing steps of the embodiment of FIG. 1. [Figure 6] 1 is a longitudinal cross-sectional view of a second embodiment of an intracardiac device of the present invention having a header assembly of the present invention during manufacture. [Figure 7] 7 is a longitudinal cross-sectional view of the embodiment of FIG. 6 after fabrication steps have been completed. [Figure 8] FIG. 10 is a longitudinal cross-sectional view of a third embodiment of an implantable ID of the present invention having a header assembly of the present invention. [Figure 9] FIG. 10 is a longitudinal cross-sectional view of a fourth embodiment of an implantable ID of the present invention having a header assembly of the present invention. [Figure 10] FIG. 10 is a cross-sectional view of a feedthrough and its internal components of a fifth embodiment of a header assembly or intracardiac device, respectively, of the present invention. [Figure 11] FIG. 10 is a cross-sectional view of a sixth embodiment of an implantable ID of the present invention having a header assembly of the present invention. [Figure 12A] FIG. 10 is a cross-sectional view of a seventh embodiment of an implantable ID of the present invention with a header assembly of the present invention, with the tines shown in a free configuration. [Figure 12B] FIG. 10 is a cross-sectional view of a seventh embodiment of an implantable ID of the present invention having a header assembly of the present invention shown in a configuration such as when the tines are loaded onto an implanted catheter.

[0062] 1-5 show exploded views of the components of a first embodiment of an implantable ID (0), e.g., a leadless pacemaker, having a header assembly (0.1). The components are a ring-shaped distal cap 1, a base ring assembly 2 comprising a base ring 2.1 and four tines 2.2, a washer-shaped steroid depot 3, a ring-shaped proximal cap 4, and an ID housing 5 comprising a cylindrical distal section forming a feedthrough 5.1. Extending distally therefrom are pin-shaped electrodes 6. The base ring 2.1 is conically shaped so that its distal end has larger inner and outer diameters compared to those at its proximal end.

[0063] Each of these components, the distal cap 1, the base ring 2.1, the steroid depot 3, and the proximal cap 4, has a central through-opening for accommodating the electrode 6. The components mentioned in the previous sentence are axially symmetrical about a longitudinal central axis 9, which defines the axial direction. The diameters of the central openings of the distal cap 1, the base ring 2.1, and the proximal cap 4 are such that the electrode feedthrough 5.1 is located within this opening in the fixed / assembled state. The diameter of the electrode feedthrough 5.1 is larger than the diameter of the electrode 6.

[0064] The ring-shaped distal cap 1 has a through opening forming an inner surface 1.2 at the fixing portion 1.6. At the distal end of this opening, a rim-like protrusion 1.3 is provided, extending radially from the inner surface 1.2 and forming a circular stop surface 1.4. Furthermore, the distal cap 1 has an outer (proximal) conical beveled surface 1.1 against which the beveled base ring 2.1 abuts in the assembled state. The distal cap 1 is made of an electrically insulating and elastic material, such as PEEK.

[0065] Four tines 2.2 extend from the conical base ring 2.1, each having an abutment section (flexibility zone) that transitions to the base ring 2.1, a curved mid-section, and a straight end section (farthest from the base ring 2.1). The tines 2.2 provide mechanical fixation of the ID within the patient's heart after deployment and penetration of the cardiac tissue, so that the central electrode 6 makes mechanical and electrical contact with the internal tissue of the patient's heart in one of the ventricles or atria. The proximal cap 4 ensures electrical insulation of the tines 2.2 from the housing 5. The base ring assembly 2 is made of, for example, Nitinol.

[0066] The header assembly 0.1 includes a pressing feature 1.7. In the first and second embodiments shown in FIGS. 1-7, the pressing feature 1.7 is provided by a lip portion 1.8 protruding from the outer surface 1.10 of the distal cap 1. The lip portion 1.8 is an integral part of the distal cap 1. The pressing feature 1.7 has a higher deformability in a radial direction perpendicular to the axial central axis 9 and in a radial direction than the fixed portion 1.6 of the distal cap 1. Specifically, the distal cap 1 includes an undercut recess 1.9 extending adjacent to the outer surface 1.10 in a direction parallel to (i.e., perpendicular to) the axial central axis 9 of the distal cap 1. The undercut recess 1.9 separates the lip portion 1.8 from an inner portion 1.11 of the distal cap 1, which includes the fixed portion 1.6.

[0067] With such a particular configuration, the pressing arrangement 1.7 is configured to exert an elastic force in a radial direction, i.e., perpendicular to the axial central axis 9, so as to press the base ring 2.1 against the inner surface 4.1 of the proximal cap 4 when the base ring 2.1 is placed between the proximal cap 4 and the distal cap 1. Thus, in such an assembled configuration, the pressing arrangement 1.7 induces a frictional force that acts on the base ring 2.1 when the base ring 2.1 rotates about the axial direction 9 relative to the caps 4, 1. Due to its high local deformability, the pressing arrangement 1.7 can deflect when the header assembly is assembled, and as a result of such elastic deflection, the pressing arrangement 1.7 can reliably press the base ring 2.1 against the inner surface 4.1 of the proximal cap 4, without significantly deforming the inner portion 1.11 of the distal cap 1.

[0068] Thus, even when the base ring 2.1 is compressed between the distal cap 1 and the proximal cap 4 in the assembled state, significant permanent mechanical stress is not exerted on the inner portion 1.11 of the distal cap 1, particularly the anchoring portion 1.6. Therefore, the risk of environmental stress cracking (ESC) occurring in the inner portion 1.11 of the distal cap 1 can be minimized. Therefore, as explained further below, the locking connection formed between the outer shell surface 5.2 of the feedthrough configuration 5.1 and the inner surface 1.2 of the distal cap 1 is not compromised by ESC. Instead, permanent mechanical stress is applied only in the pressed configuration 1.7. However, even if such stress results in ESC in the pressed configuration 1.7, the mechanical connection between the header assembly 0.1 and the housing 5 of the intracardiac device 0 is still reliably maintained.

[0069] There is a washer-shaped steroid depot 3 with a through hole 3.1. The steroid depot 3 is made of a mixture of silicone and dexamethasone acetate. The inner section of the steroid depot 3 is slightly arched upward in the distal direction to form a distally projecting rim 3.2 against which the stop surface 6.3 of the electrode head 6.2 abuts (see Figures 2 and 3).

[0070] The header assembly and ID further comprise a proximal cap 4 which defines a beveled surface 4.1 on its distal side. When viewed proximally, the proximal cap 4 comprises a circular stop surface 4.2 for abutting against a rim 5.5 (see FIG. 4) on the distal end face of the housing 5. The circular rim 5.5, together with a circular recess 5.3 surrounding the feedthrough 5.1, causes centering of the proximal cap 4 and the distal cap 1. The proximal cap is made of an electrically insulating and elastic material, such as PEEK.

[0071] As described above, the ID housing 5 forms a feedthrough 5.1 at its distal end. In the illustrated embodiment, the feedthrough 5.1 is integrally formed with the housing 5, but may alternatively be formed as a separate element that is hermetically attached to the housing 5. The feedthrough 5.1 forms an outer shell surface 5.2 with a surface structure 5.2.0 having a plurality of sawtooth protrusions 5.2.1, shown in more detail in FIG. 4. Each protrusion forms a circular rim that extends completely around the outer shell surface 5.2 and forms a first angle 5.2.2 and a radial direction (the radial direction extending perpendicular to the longitudinal axis 9), and a second angle 5.2.3 and a second angle 5.2.3 are defined by the second angled surface and an axial direction. Furthermore, the height of the protrusion in the radial direction is indicated by reference numeral 5.2.4. The first angle 5.2.2 may be 45° or greater, for example, 70°. The second angle 5.2.3 may be less than 110°, preferably greater than 70°, for example 90°. The height may be selected to be less than 200 μm, preferably between 50 μm and 150 μm. The protrusions 5.2.1 are formed so that their outer diameter is smaller at their distal end and larger at their proximal end. This allows the distal cap 1, whose inner surface 1.2 interacts with the protrusions 5.2.1 during the press-fit movement during manufacturing, to easily slide proximally along the outer shell surface 5.2 but cannot be removed in the opposite distal direction because the protrusions 5.2.1 "bite" into the inner surface 1.2 of the distal cap 1.

[0072] The housing 5 of the intracardiac device contains within its internal volume 5.4 a battery and an electronic module with a processor, ensuring the sealing of these components. These components are electrically connected to the electrodes 6 and provide electrical stimulation of the heart or processing of electrical signals determined from the heart. Additionally, the housing may contain components for communication, such as an antenna. The housing may be made of titanium alloy or stainless steel.

[0073] As shown in FIG. 5 , during initial manufacturing, the proximal cap 4 is received at the distal end of the housing 5 with its stop surface 4.2 adjacent to the distal rim 5.5. Furthermore, the base ring 2.1 is provided with its outer conical surface abutting the sloped distal surface 4.1 of the proximal cap 4. The base ring 2.1 is received distally from the proximal cap 4. Furthermore, the electrode 6 includes its proximal shaft 6.1 within the feedthrough throughbore, which is electrically insulated from the housing 5 by a hollow cylindrical isolator 7 but electrically connected to electrical components located within the housing 5. The steroid depot 3 is clamped between the distal end face of the feedthrough 5.1 and the proximal stop surface 6.3 on the head 6.2 of the electrode 6, with the distal rim 3.2 of the steroid depot 3 abutting the stop surface 6.3.

[0074] As shown in Figure 5, the final manufacturing step is a press-fit step, which is achieved by distally moving the distal cap 1 and applying an axial force at the distal surface 1.5 of the distal cap, for example, by using a stamp (indicated by arrow 10), causing the inner surface 1.2 of the distal cap 1 to slide along the outer shell surface 5.2 of the feedthrough 5.1 until the stopper surface 1.4 abuts the distal surface of the steroid depot 3. The interaction method is a press-fit connection that uses the elastic-plastic material behavior of the PEEK material of the distal cap 1 to create a permanent fixation between the feedthrough flange (feedthrough outer shell surface 5.2) and the distal cap 1. The press-fit connection is achieved by overcoming the frictional forces between the inner surface 1.2 of the distal cap 1 and the serrated protrusions 5.2.1. The housing 5 / feedthrough outer shell surface 5.2 is supported / fixed during this press-fit process. As described above, the protrusions 5.2.1 "bite" into the inner surface 1.2 of the distal cap 1, thereby forming a permanent mechanical connection between the distal cap 1 and the feedthrough 5.1, which counteracts axial movement of the distal cap 1 and the feedthrough 5.1 away from each other, thereby permanently securing the base ring assembly 2 and proximal cap 4, as well as the steroid depot 3.

[0075] In this embodiment, the proximal cap 4 does not interact with the outer shell surface 5.2 of the feedthrough 5.1. In an alternative embodiment, the inner surface of the distal cap 1 may be shorter, and the inner surface of the proximal cap 4 interacts with the outer shell surface 5.2 of the feedthrough 5.1 in the same manner as the distal cap 1. To that end, the inner diameter of the proximal cap 4 is smaller than in the embodiment shown in Figures 1-5.

[0076] The first embodiment of Figures 1 to 5 comprises a distal cap 1 that does not have a recess on its inner surface 1.2. The second embodiment shown in Figures 6 and 7 differs from the first embodiment in this respect. The reference numbers of the elements of the second embodiment correspond to the reference numbers of the corresponding elements of the first embodiment plus the number 10.

[0077] The inner surface 11.2 of the distal cap 11 includes a circular groove 11.3 that forms a recess that mates with the distal serrations 15.2.1 on the outer shell surface 15.2 of the feedthrough 15.1 during and after assembly. This may reduce strain on the distal cap 11 polymer material and mitigate potential material failure caused by high strain.

[0078] In the first and second embodiments, the inner surface 1.2 of the fixing portion 1.6 of the distal cap 1 is configured to form a locking connection with the outer shell surface 5.2 of the feedthrough arrangement 5.1 to counteract axial movement of the distal cap 1 and the feedthrough arrangement 5.1 away from each other. In this embodiment, the inner surface 1.2 and the opposing outer shell surface 5.2 having the surface structure 5.2.0 are configured to form the locking connection as a press-fit connection, where the shell surface 5.2 of the feedthrough arrangement 5.1 and the surface structure 5.2.0 of the inner surface 1.2 of the fixing portion 1.6 are at least partially non-complementary to each other such that a press-fit locking connection is established between both opposing surfaces when the distal cap 1 is pressed onto the feedthrough arrangement 5.1.

[0079] However, in an alternative embodiment shown in Figures 8 and 9, the inner surface 1.2 and the outer shell surface 5.2 may also include a surface structure 5.2.0 in which protrusions and recesses are at least partially, or preferably completely, complementary to one another to establish a snap-fit ​​locking connection between the outer shell surface 5.2 and the inner surface 1.2. During the assembly procedure, the distal cap 1 is pressed against the feedthrough arrangement 5.1, but only temporarily deforms radially (i.e., expands in width) as the protrusions and recesses slide along one another. However, once the final configuration is reached, the protrusions engage the recesses in a complementary manner such that no substantial permanent stress or deformation is induced between the distal cap 1 and the feedthrough arrangement 5.1.

[0080] In a third embodiment shown in Figure 8, the pressing arrangement 1.7 comprises a radially (i.e., horizontally) extending lip portion 1.8. The lip portion 1.8 is formed by an undercut recess 1.9 extending adjacent to the outer surface 1.10 in a direction transverse to the axial central axis 9 of the distal cap 1 (i.e., horizontally or obliquely). The undercut recess 1.9 therefore separates the lip portion 1.8 from the upper portion 1.12 of the distal cap 1.

[0081] When the header assembly is assembled with the base ring 2.1 placed between the proximal cap 4 and the distal cap 1, the lip portion 1.8 elastically flexes slightly, thereby pressing against the base ring 2.1 and inducing friction as the base ring 2.1 rotates about the axial direction 9. However, no substantial permanent mechanical stress is applied to the inner portion 1.11 and the fixed portion 1.6 of the distal cap 1, thereby preventing localized environmental stress cracking and therefore compromising the reliable connection of the header assembly to the rest of the ID.

[0082] In a fourth embodiment shown in FIG. 9 , the pressing arrangement 1.7 includes a separate pressing ring 18, such as a silicone O-ring. The pressing ring 18 is a separate component and is placed between the distal cap 1 and the proximal cap 4. In particular, the pressing ring 18 can be received and held within a ring-shaped recess 19 provided in the outer surface of the distal cap 1. The pressing ring 18 is made of a material having a higher deformability than the material of the distal cap 1. Thus, when the header assembly is assembled with the base ring 2.1 and the pressing ring 18 placed between the proximal cap 4 and the distal cap 1, the pressing ring 18 is elastically compressed, thereby pressing against the base ring 2.1. Therefore, substantial deformation does not generate substantial permanent mechanical stress locally in the distal cap 1, thereby preventing ESC and ultimately compromising a reliable connection between the header assembly and the rest of the ID.

[0083] FIG. 10 refers to a third embodiment of a header assembly / ID. The embodiment of FIG. 8 differs from the first embodiment in the cross section of the serrated protrusions 25.2. The first embodiment of the header assembly and ID of the present invention includes a circular cross section of the protrusions 25.2. The embodiment shown in FIG. 8 does not have a circular cross section, but has protrusions with a rounded polygonal shape, for example for a trilobular shape. Such a shape is shown in FIG. 10.

[0084] It should be noted that the sketch of Figure 10 does not show in detail the components of the header assembly within feedthrough 25.1.

[0085] In another embodiment (not shown), the diameters of the protrusions on the outer shell surface of the feedthrough may differ from one another. They may all have the same protrusion type, but achieve an overall angled shape (e.g., sawtooth protrusions) with an outer diameter that increases or decreases from one protrusion to the next. As the diameter increases starting from the distal end toward the proximal end, retention force increases, but so does stress on the polymer material of the distal cap.

[0086] Another embodiment of the header assembly 0.1 is shown in FIG. 11. In that embodiment, the pressing configuration 1.7 is achieved by using a base ring 2.1 that is non-circular in its non-deformed state. In other words, in its non-deformed state, the base ring 2.1 has a first diameter "a" in a first direction and a second diameter "b" in a second direction that is perpendicular to the first direction. The first diameter and the second diameter are different from each other, for example, b < a. Thus, when such a non-circular base ring 2.1 is placed between the circular conical outer surface 1.1 of the distal cap 1 and the opposing circular conical inner surface 4.1 of the proximal cap 4, its non-circular shape elastically deforms slightly so as to become approximately circular. Thereby, an elastic pressing force is applied between the base ring 2.1 and the opposing caps 1, 4. These pressing forces result in frictional forces when the base ring 2.1 rotates relative to the caps 1, 4. However, no substantial deformation is induced in the distal cap 1, whereby the lock connection to the feed-through configuration is not impaired by the occurrence of stress-induced cracks.

[0087] FIG. 12 refers to a seventh embodiment of the header assembly / ID and shows the configuration with the tines free (A) and the configuration when the tines are loaded into an implantable catheter (B). The header assembly according to this embodiment includes a second lip portion 1.13 in addition to the lip portion 1.8 of the first and second embodiments shown in FIGS. 1-7. The second lip portion 1.13 has a cantilever beam shape and faces in the distal direction. When the tines 2.2 bend distally (B) due to loading of the implant into an implantable catheter (not shown), the tine array also remains attached to the device by the second lip in the distal cap 1, creating an overhang surface so that the tine ring cannot separate from the header assembly. Further, the tines 2.2 contact a second lip 1.13 that elastically supports the tines above the original height of the header, thereby providing a gradual transition in the stiffness of the catheter.

[0088] The above embodiments have the following advantages. Instead, a permanent press-fit connection is achieved, so no adhesive is required during manufacturing. The manufacturing process is suitable for automated assembly (single-axis assembly). The construction of the header assembly of the present invention reduces the height of the header. No notches are required for the insulating parts, i.e., distal and proximal caps, thereby reducing the complexity of the header components (all symmetrical, rotatable components). · Low permanent stress securing the upper distal cap reduces environmental stress cracking in the polymer. -Has a safety clutch mechanism to prevent tine rotation due to friction and in the same case when excessive strain should be applied to the tines.

Claims

1. A header assembly (0.1) for an implantable intracardiac device (0), said header assembly comprising: a cylindrical feedthrough arrangement (5.1, 15.1); a ring-shaped proximal cap (4, 14); a ring-shaped distal cap (1, 11); a base ring (2.1) having at least two tines (2.2) protruding distally therefrom; Pressing configuration (1.7) and the feedthrough arrangement (5.1, 15.1) having an outer shell surface (5.2, 15.2), the proximal cap (4, 14) has an inner surface (4.1); The distal cap (1, 11) has an outer surface (1.1), the distal cap (1, 11) comprises a fixing portion (1.6) having an inner surface (1.2) that forms a locking connection with the outer shell surface (5.2, 15.2) of the feed-through arrangement (5.1, 15.1) to counteract movement of the distal cap (1, 11) and the feed-through arrangement (5.1, 15.1) away from each other in the axial direction (9); the proximal cap (4, 14), the distal cap (1, 11) and the base ring (2.1) are configured such that the inner surface (4.1) of the proximal cap (4, 14) and the outer surface (1.1) of the distal cap (1) are coaxially arranged and directed towards each other, and the base ring (2.1) is placed between the inner surface (4.1) of the proximal cap (4, 14) and the outer surface (1.1) of the distal cap (1) such that the inner surface (4.1) of the proximal cap (4, 14) and the outer surface (1.1) of the distal cap (1) are coaxially arranged and directed towards each other, and the base ring (2.1) is coaxially rotatable relative to the distal cap (1); The header assembly (0.1), wherein the pressing arrangement (1.7) is configured to exert a radial elastic force to press the base ring (2.1) against one of the inner surface (4.1) of the proximal cap (4) and the outer surface (1.1) of the distal cap (1).

2. the distal cap (1) comprises, at the inner surface (1.2) of its fixing portion (1.6), a structure (5.2.0) configured to establish a snap-fit ​​locking connection with the outer shell surface (5.2, 15.2) of the feedthrough arrangement (5.1, 15.1); The header assembly of claim 1 .

3. the outer shell surface (5.2, 15.2) of the feedthrough arrangement (5.1, 15.1) and the inner surface (1.2) of the fixing part (1.6) of the distal cap (1) have a surface structure (5.2.0) in which protrusions and recesses are at least partially complementary to each other so as to establish a snap-fit ​​locking connection between the outer shell surface (5.2, 15.2) and the inner surface (1.2), 3. The header assembly of claim 1.

4. the fixing portion (1.6) of the distal cap (1) is configured to establish a press-fit lock connection with the outer shell surface (5.2, 15.2) of the feed-through arrangement (5.1, 15.1); The header assembly of claim 1 .

5. the outer shell surface (5.2) of the feedthrough arrangement (5.1, 15.1) and the inner surface (1.2) of the fixing portion (1.6) of the distal cap (1) have surface structures (5.2.0) that are at least partially non-complementary to each other so as to establish a press-fit lock connection between the outer shell surface (5.2, 15.2) and the inner surface (1.2), The header assembly of claim 1 .

6. the pressing arrangement (1.7) has a higher deformability in and towards the radial direction than the fixing part (1.6) of the distal cap (1), The header assembly of claim 1 .

7. said pressing arrangement (1.7) being an integral part of said distal cap (1); The header assembly of claim 1 .

8. The distal cap (1) comprises at least one lip portion (1.8, 1.13) protruding from the outer surface (1.10) of the distal cap (1), The header assembly of claim 7 .

9. the distal cap (1) comprises an undercut recess (1.9) extending adjacent to the outer surface (1.10) in a direction parallel to the axial central axis (9) of the distal cap (1), the undercut recess (1.9) separating the lip portion (1.8) from an inner portion (1.11) of the distal cap (1); The header assembly of claim 8 .

10. the distal cap (1) comprises an undercut recess (1.9) extending adjacent to the outer surface (1.10) in a direction transverse to the axial central axis (9) of the distal cap (1), the undercut recess (1.9) separating the lip portion (1.8) from an upper portion (1.12) of the distal cap (1); The header assembly of claim 8 .

11. Header assembly according to any one of claims 8 to 10, wherein the distal cap comprises a lip portion (1.13) having a cantilevered shape facing distally.

12. The pressing arrangement (1.7) comprises a pressing ring (18) placed between the distal cap (1) and the proximal cap (4) so ​​as to press against the base ring (2.1), The header assembly of claim 1 .

13. the base ring (2.1) is configured to be non-circular in its undeformed state; The header assembly of claim 1 .

14. 14. An implantable intracardiac device (0) comprising a cylindrical housing (5) according to any one of claims 1 to 13 and a header assembly (0.1), wherein a feedthrough arrangement (5.1, 15.1) is arranged at the distal end of the housing (5), the feedthrough arrangement (5.1, 15.1) being integrally formed with the housing (5) or being formed by a separate element fixed and sealed at the distal end face (5.3, 5.5) of the housing (5).

15. A manufacturing method for a header assembly (0.1) according to any one of claims 1 to 13, comprising: Providing a feedthrough arrangement (5.1, 15.1), a proximal cap (4), a distal cap (1) and a base ring (2.1) having at least two tines (2.2); - arranging the proximal cap (4), the base ring (2.1) and the distal cap (1) one above the other in the axial direction (9) so that the base ring (2.1) is located between the proximal cap (4) and the distal cap (1); - fixing the proximal cap (4), the base ring (2.1) and the distal cap (1) to the feedthrough arrangement (5.1, 15.1) by application of an axial force to a distal face of the distal cap and / or a proximal section of the feedthrough such that the base ring is axially fixed between the distal cap and the proximal cap and rotatable about the axial direction relative to the distal cap, the feedthrough arrangement (5.1, 15.1) is received in a through hole of the distal cap, and a surface structure of at least one of an inner surface of the distal cap and an outer shell surface of the feedthrough provides one of a snap-fit ​​locking connection and a press-fit locking connection with the respective other surface in a fixed state, wherein the surface structure forming the locking connection counteracts movement of the distal cap and the feedthrough away from each other in the axial direction; A manufacturing method comprising:

16. 15. A manufacturing method for an implantable intracardiac device (0) according to claim 14, comprising: Providing a cylindrical housing (5) with electrical or electromagnetic components therein, a cylindrical feedthrough arrangement (5.1, 15.1) at the distal end of said housing, either integrally formed with said housing or as a separate element fixed and sealed at the distal end face of said housing, and a pin-shaped electrode (6) protruding from the distal end of said feedthrough arrangement (5.1, 15.1) and fixed in a recess of said feedthrough arrangement (5.1, 15.1); Providing a proximal cap (4), a distal cap (1) and a base ring (2.1) having at least two tines (2.2); - axially positioning the proximal cap, the base ring, and the distal cap one above the other such that the base ring is disposed between the proximal cap and the distal cap; securing the proximal cap, the base ring, and the distal cap in the feedthrough configuration by application of an axial force to a distal face of the distal cap and / or a proximal section of the feedthrough, such that the base ring is axially fixed between the distal cap and the proximal cap and rotatable about the axial direction relative to the distal cap, the feedthrough is received within a throughbore of the distal cap, and a surface structure of at least one of an inner surface of the distal cap and an outer shell surface of the feedthrough provides one of a snap-fit ​​locking connection and a press-fit locking connection with the other surface in a secured state, wherein the surface structure forming the locking connection counteracts movement of the distal cap and the feedthrough away from each other in an axial direction; A manufacturing method comprising:

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