Head assembly for implantable intracardiac device and corresponding intracardiac device

Abstract

The invention relates to a head assembly (0.1) for an implantable intracardiac device (0) which is automated assembly friendly wherein the head assembly comprises a cylindrical feedthrough arrangement (5.1, 15.1), an annular proximal cap (4, 14), an annular distal cap (1, 11), a base ring (2.1) having at least two tines (2.2) projecting distally from the base ring, and a pressing arrangement (1.7). The feed-through arrangement (5.1, 15.1) has a housing surface (5.2, 15.2). The proximal cap (4, 14) comprises an inner surface (4.1). The distal cap comprises (1, 11) an outer surface (1.1). The distal cap (1, 11) comprises a fixed portion (1.6) having an inner surface (1.2) which forms a locking connection with a housing surface (5.2, 15.2) of the feed-through arrangement (5.1, 15.1) to counteract a movement of the distal cap (1, 11) and the feed-through arrangement (5.1, 15.1) apart 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 an inner surface (4.1) of the proximal cap (4, 14) and an outer surface (1.1) of the distal cap (1) are coaxially arranged and face each other, and the base ring (2.1) is interposed between the inner surface (4.1) of the proximal cap (4, 14) and the outer surface (1.1) of the distal cap (1) so as to be coaxially rotatable relative to the distal cap (1). The pressing arrangement (1.7) is configured to exert an elastic force in a radial direction to press the base ring (2.1) against one of the inner surface (4.1) of the end cap (4) and the outer surface (1.1) of the distal cap (1). The invention also relates to a corresponding intracardiac device and to manufacturing methods for the head assembly and intracardiac device, respectively.

Description

Technical Field

[0001] The present invention relates to an implantable intracardiac device, such as an implantable intracardiac pacemaker, and a head assembly thereof, as well as a manufacturing method for such a head assembly and such an implantable intracardiac device. Background Art

[0002] Active or passive medical devices, such as implantable intracardiac devices, for example implantable intracardiac pacemakers (also known as leadless pacemakers), are well-known miniaturized medical devices that are completely implanted in a ventricle or atrium of the heart. Intracardiac pacemakers are used in patients suffering from bradycardia, i.e., if the heart beats too slowly to meet the patient's physiological needs. Intracardiac pacemakers apply electrical stimulation in the form of pulses to the heart in order to generate a physiologically appropriate heart rate and / or apply electrical stimulation in the form of electric shocks to the heart for cardioversion or defibrillation in order 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, sensing electrical or electromagnetic signals or other physiological parameters of the heart and / or its surrounding tissues.

[0003] Documents US2012 / 0172690A1 and US10,112,045B2 disclose a leadless pacemaker device, which includes a conductive shell and a fixing element assembly. The fixing element assembly includes a group of active fixing tines and an insulator, which is used to electrically insulate the group of active fixing tines from the conductive shell of the implantable medical device. The active fixing tines in the group can be deployed from a spring-loaded position to a hooked position, in which the distal ends of the active fixing tines point away from the implantable medical device, and in the hooked position, the active fixing tines are bent backward toward the implantable medical device. The active fixing tines are configured to fix the implantable medical device to the patient's tissue when deployed, while the distal ends of the active fixing tines are positioned adjacent to the patient's tissue.

[0004] However, known manufacturing methods for leadless pacemakers require complex alignment methods to secure the tine array to the medical implant housing. For example, microscopic components need to be precisely oriented to each other before assembly, or adhesive materials need to be complexly dispensed in microgram doses or fine bayonet features need to be aligned to combine the head with the housing. In addition, complex injection molded components with recesses are required to secure the tines. Such manufacturing steps are hardly suitable for automation, also because manual cleaning procedures of the silicone adhesive are required after assembly.

[0005] Additionally, known heads take space away from other critical components of implantable intracardiac devices, such as batteries or electronic modules. Therefore, smaller head sizes are desired.

[0006] Furthermore, when implanting an intracardiac device, it may be desirable to be able to reorient portions of the intracardiac device relative to its head assembly or, in particular, relative to the tines that are fixed in the cardiac tissue. Such a reorientation process may be required, for example, for establishing a desired communication orientation when using coil-induced electric field communication. However, during operation of the intracardiac device, i.e., after the implantation procedure has been completed, any unintended changes in the orientation of the intracardiac device should be prevented.

[0007] Therefore, there may be a need for an implantable intracardiac device and a corresponding head assembly and a method for manufacturing the implantable intracardiac device and the corresponding head assembly that address at least one of the above requirements. In particular, there may be a need for a head assembly that has a small size, provides a reliable mechanism for fixing the intracardiac device at the cardiac tissue, enables the orientation of the cardiac device to be set during implantation and maintained during subsequent device operation and / or enables low manufacturing effort and cost. Summary of the invention

[0008] This need is met by the subject matter of one of the independent claims. Advantageous embodiments are defined in the dependent claims, described in the present description and visualized in the associated drawings.

[0009] According to a first aspect of the present invention, a head assembly for an implantable intracardiac device is described. The head assembly includes a cylindrical feedthrough arrangement, an annular proximal cap, an annular distal cap, a base ring, and a pressing arrangement, the base ring having at least two tines protruding distally from the base ring. The feedthrough arrangement has a shell surface. The proximal cap includes an inner surface. The distal cap includes an outer surface. The distal cap includes a fixed portion having an inner surface. The inner surface forms a locking connection with the shell surface of the feedthrough arrangement for offsetting the movement of the distal cap and the feedthrough arrangement apart from each other in an axial direction. The proximal cap, the distal cap, and the base ring are configured so that the inner surface of the proximal cap and the outer surface of the distal cap are coaxially arranged and facing each other, and the base ring is interposed between the inner surface of the proximal cap and the outer surface of the distal cap so as to be coaxially rotatable relative to the distal cap. The pressing arrangement is configured so as to apply an elastic force in a radial direction so as to press the base ring against one of the inner surface of the proximal cap and the outer surface of the distal cap.

[0010] Merely as some introductory or overview notes and without limiting the scope of the invention, the basic ideas and associated possible advantages of embodiments of the invention can be roughly described as follows:

[0011] The head assembly presented herein is particularly configured for implementing a simple but reliable assembly process when mounting the head assembly to the housing of an implantable intracardiac device (hereinafter: "ID"). In particular, the annular proximal cap and the distal cap can be easily pressed in an axial direction onto a cylindrical feedthrough arrangement arranged at the distal end of the housing of the ID. Therein, the outer shell surface of the feedthrough arrangement and the inner surface of the fixed part of the distal cap are specifically configured so that when they are actually pressed together, a preferably irreversible (i.e., permanent) locking connection, such as a snap-fit ​​connection or a press-fit connection, is established between the two components. Due to this locking connection, the head assembly is reliably maintained at the housing of the ID.

[0012] In addition, the base ring with at least two tines is between the inner surface of the proximal cap and the outer surface of the distal cap, and is therefore also reliably maintained at the housing of the ID. Specifically, the base ring is arranged and configured to be coaxially rotatable relative to the distal cap. When the distal cap is fixed to the housing of the ID via a feed-through arrangement, the base ring is therefore rotatable relative to the housing. On the one hand, this rotational capability can be used during the implantation process to correctly orient the housing relative to the tines extending from the base ring, which are fixed to the cardiac tissue to correctly maintain the entire ID. However, on the other hand, it should be prevented from modifying this initial correct orientation during the normal operation of the ID (i.e., after completing the implantation procedure), for example, due to the rotational force acting on the ID during normal heartbeat and / or during the patient's movement. Therefore, on the one hand, as long as only a small rotational force acts on the housing, the base ring with tines should be prevented from rotating relative to the housing of the ID, and this small rotational force is lower than the rotational force usually applied to the housing during normal operation. On the other hand, it should be possible to rotate the base ring relative to the housing of the ID when a major rotational force acts on the housing, such as is applied during an implantation procedure for specifically orienting the ID housing.

[0013] In order to establish this specific rotational capability, the base ring was tested to be clamped by a clamping action between the proximal cap and the distal cap, so that the base ring can rotate only when a rotational force is applied, so as to exceed the friction between the base ring on one side and the proximal cap and the distal cap on the other side, which is generated by the clamping action. However, it has been observed that in order to establish this clamping action, the distal cap will usually have to be mounted on the feed-through arrangement with its fixed portion in a configuration in which a considerable permanent mechanical stress is applied to the distal cap and its fixed portion. Although this distal cap is preferably made of a high-quality polymer material such as PEEK, it has been observed that this permanent mechanical stress may cause mechanical failure or damage to the material of the distal cap, an effect also known as environmental stress cracking (ESC). In particular, this ESC preferably occurs when the polymer components of the head assembly are loaded with a certain amount of mechanical stress (static or cyclic) and exposed to an oxidizing environment (such as contact with human blood). However, any ESC occurring at the fixed portion of the distal cap may cause the locking connection between this fixed portion and the housing surface of the feed-through arrangement to fail. In the event of such a failure, in the worst case, the distal cap may disengage from the feed-through arrangement, thereby releasing the entire fixation of the ID housing to the base ring and the tines fixed to the heart tissue. Of course, such a release action should be prevented.

[0014] In order to suppress this occurrence of ESC, the distal cap can be adapted so that its fixed part can be pushed onto the feed-through arrangement during the assembly process, and then a locking connection can be formed, wherein the fixed part will not be permanently mechanically stressed beyond the extent that ESC usually occurs. In addition, in order to ensure that sufficient rotational friction is established between the proximal cap and the distal cap and the base ring interposed between them, the head assembly also includes a specific pressing arrangement. This pressing arrangement is configured so that an elastic force is applied to the base ring, thereby pressing the base ring against the proximal cap or the distal cap, so as to eventually establish the required rotational friction. Therefore, by applying a rotational force exceeding the rotational friction caused by the pressing arrangement, it may be possible to correctly orient the ID shell during the implantation operation, while preventing the accidental misorientation of the ID shell during the later operation, because the rotational force exceeding the rotational friction is usually not caused during this normal operation of the ID. In addition, even in the case where excessive mechanical stress acts on the pressing arrangement and thus, for example, due to ESC, damage such as cracks eventually occur at the pressing arrangement, such damage or cracks will only affect the pressing arrangement without affecting the rest of the head assembly, in particular, without affecting the fixed part of the distal cap. Thus, even in the event of such damage or cracks, the integrity of the entire head assembly and in particular the fixation of the distal end to the feed-through arrangement is not compromised.

[0015] Subsequently, possible features of embodiments of the invention and associated possible advantages will be described in more detail.

[0016] An implantable intracardiac device may be, for example, an implantable intracardiac pacemaker (also known as a leadless pacemaker), which may apply electrical stimulation to the heart in the form of pulses to generate a physiologically appropriate heart rate and / or apply electrical stimulation to the heart in the form of electric shocks to restore a more normal heart rhythm. In the last case, the ID may alternatively be referred to as a defibrillator or cardioverter. Alternative or additional functions of the intracardiac device may include providing other electrical or electromagnetic signals to the heart or its surrounding tissues, sensing electrical or electromagnetic signals or other physiological parameters of the heart and / or its surrounding tissues. In the case where the ID focuses on sensing electrical or electromagnetic signals, it may alternatively be referred to as a (biological) monitor. The ID may include any combination of the above functions. Implantation of the ID may include any fixation of the cardiac tissue, including fixation within the atria and ventricles of the heart or fixation at the outer surface of the cardiac tissue using small pointed teeth.

[0017] The head assembly of the present invention is suitable for an ID that generally includes a cylindrical shell and a head assembly located at the distal end of the shell. In addition, a pin-shaped electrode protrudes from the distal end of the shell, wherein the head assembly is arranged at the distal end of the shell of the ID and attached to the distal end of the shell of the ID, so that the electrode protrudes through the head assembly, i.e., through the corresponding through or complete opening of the head assembly. The opening can be a central opening located at the longitudinal axis of the ID shell and the head assembly and positioned along the longitudinal axis of the ID shell and the head assembly. The longitudinal axis forms the axial direction of the ID and the head assembly. The proximal cap, the base ring and the distal cap also include a through opening, wherein the size of the opening of the proximal cap can make the electrode feedthrough located at the proximal end of the electrode at least partially arranged in the opening. The cylindrical shell includes an electronic module having a processor, an energy source (e.g., a battery or a coil (for wireless charging)) and (if applicable) a communication component such as an antenna. The processor can be suitable for processing signals / data determined from the patient's body or received from the surrounding environment and / or generating a signal for treating the patient's heart. Such signals may include electrical stimulation in the form of pulses to generate a physiologically appropriate heart rate, an electric shock for cardioversion or defibrillation to restore a more normal heart rhythm and / or other electrical signals or electromagnetic signals to the heart or its surrounding tissues. Such signals are converted and transmitted by an electronic module and may be applied to the heart or its surrounding tissues by a pin electrode. The pin electrode is electrically connected to the electronic module and the energy source. The hermetically sealed housing may include a conductive material, such as titanium or stainless steel, and may be used as another electrode. The head assembly includes an element (tine) for fixing the ID to a selected tissue of the patient (e.g., the ventricular wall of the patient's heart) according to a treatment plan of a health care provider (HCP). In addition, the head assembly provides electrical insulation of the pin electrode relative to the teeth and / or ID housing. The cylindrical feed-through provides a seat for the pin electrode and electrical insulation of the pin electrode relative to the housing. Electrical insulation is particularly caused by a distal cap and a proximal cap, wherein the distal cap and the proximal cap include an electrically insulating material, wherein the base ring is accommodated between the proximal cap and the distal cap in the axial direction. The base ring carries at least two tines, such as two tines, four tines or six tines, protruding in the distal direction from the base ring, which fix the ID at the desired treatment position in the patient's tissue after implantation. Thus, the tines are anchored in the tissue.

[0018] In order to accommodate the feedthrough and the electrode, the proximal cap, the base ring and the distal cap are all substantially and / or substantially annular and are accommodated in this continuous order from the proximal end to the distal direction along the axial direction, wherein the feedthrough and the pin-shaped electrode are located in the internal opening of the corresponding ring after manufacturing. This uniaxial stackable component configuration from all rotationally symmetrical parts is advantageous because these parts can be easily and at low cost to manufacture. In addition, they allow uniaxial assembly, which is automated production friendly. The head assembly configuration of the present invention as indicated above and below further avoids recesses in the isolation components (distal cap and proximal cap), which reduces the complexity of the head assembly components because they are symmetrical rotating components having a longitudinal axis that also represents the axial direction.

[0019] The cylindrical feed-through comprises a housing surface at least at its distal end. Furthermore, the cylindrical feed-through forms a distal end face. The distal end of the cylindrical feed-through forming the housing surface is considered to be a component of the head assembly.

[0020] After the ID is manufactured and the head assembly is fixed to its end face, the annular distal cap forms a permanent connection that counteracts the movement of the distal cap and the feed-through apart from each other in the distal direction. The connection is provided by a surface structure that is arranged at the inner surface of the through hole of the distal cap and / or the outer shell surface of the feed-through. According to the present invention, the inner surface of the distal cap forms a locking connection with the outer shell surface of the feed-through.

[0021] For example, according to an embodiment, the distal cap includes a structure at the inner surface of its fixed portion, which is configured to establish a snap-fit ​​locking connection with the housing surface of the feedthrough arrangement. In other words, the fixed portion of the distal cap and the feedthrough arrangement are adapted at their relative surfaces so that during the assembly of the two components by pushing the distal cap axially onto the feedthrough arrangement, at least one of the two components is temporarily deformed until a position is reached where a snap-fit ​​locking connection is established between the two components. In such a snap-fit ​​locking connection, the two components can be engaged at their relative surfaces in a form-fitting manner. Wherein the relative surfaces are in a form-fitting engagement without substantially permanently deforming one of the components, i.e., no significant force is applied to at least one of the fixed portion of the distal cap and the feedthrough arrangement in a radial direction.

[0022] More specifically, according to an embodiment, the housing surface of the feed-through arrangement and the inner surface of the fixing part of the distal cap have a surface structure with protrusions and recesses that are at least partially complementary to each other so as to establish a snap-fit ​​locking connection between the housing surface and the inner surface. Thus, a protrusion at a surface of one of the inner surface of the fixing part of the distal cap and the housing surface of the feed-through arrangement can engage in a snap-fit ​​manner into a recess at an 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 locking connection with the housing surface of the feed-through arrangement. Similar to the above-mentioned establishment of the snap-fit ​​connection, the fixed portion of the distal cap and the feed-through arrangement can be pushed together in the axial direction and can slide onto each other while temporarily slightly deforming radially. When the final position is reached, the radial deformation can be partially released. However, the remainder of this elastic deformation may remain and may cause radial pressure to be applied between the inner surface of the fixed portion and the housing surface of the feed-through arrangement. Due to this radial pressure, some permanent deformation can be caused in at least one of these surfaces. Therefore, in this press-fit locking connection, considerable actual pressure can act between the connected components, and in addition, the preconfigured surface structures and / or the deformation caused at the relative surfaces of the components can be engaged in a form-fitting manner.

[0024] More specifically, according to an embodiment, the outer shell surface of the feed-through arrangement and the inner surface of the fixed part of the distal cap have surface structures that are at least partially non-complementary to each other so as to establish a press-fit locking connection between the outer shell surface and the inner surface. In other words, at least before engagement, the inner surface of the fixed part and the relative outer shell surface of the feed-through arrangement may both have protruding and / or recessed structures, which, however, are not complementary to each other. Therefore, during assembly, without locally causing radial forces at portions of the engagement surfaces that are not complementary to each other, those relative surfaces may not fully engage with each other. These radial forces and / or permanent deformations generated at the engagement surfaces are typical for press-fit locking connections.

[0025] Therefore, the inner surface of the distal cap and the outer shell surface of the feed-through may include a first surface structure, which is suitable for providing a shape-locked connection with the corresponding other surface when the distal cap is attached to the feed-through, wherein the shape-locked connection may also include force locking. The other surface is the inner surface of the distal cap or another shell surface of the feed-through. After assembly / fixing, the feed-through and the distal cap are permanently connected at their adjacent surfaces by a press-fit connection or a snap-fit ​​connection, so that they cannot move relative to each other. The first surface structure of the outer shell surface of the feed-through and / or the first surface structure of the inner surface of the distal cap or both interact with each other and engage and / or interlock to form a press-fit or snap-fit ​​connection. The first surface structure may include a protrusion, such as extending in a radial direction and forming an undercut, such as a sawtooth protrusion, a threaded structure, or may include a bayonet joint. The relative movement of the distal cap and the feed-through is impossible in a fixed state (i.e., fully assembled state), and therefore is not a movement separated from each other in an axial direction. Therefore, gluing is avoided. Furthermore, production can use simple movements and forces directed in the axial direction, thus avoiding more complex rotational assembly movements.

[0026] The annular proximal cap is adapted to be fitted in the corresponding circular recess of the distal end face of the ID housing and is assembled along the corresponding circular recess of the distal end face of the ID housing, so that easy, accurate and fast positioning is provided during production. For this reason, the proximal cap can form a cylindrical protruding edge at its proximal end surface.

[0027] In addition, another form of locking connection is provided for fixing the base ring between the distal cap and the proximal cap. This form-locking connection is further described below.

[0028] The distal cap may include a stop face at the distal section of its inner surface. The stop face may be formed by the proximal surface of a protrusion protruding from the inner surface of the distal cap in a radial direction, wherein the radial direction extends radially from the central longitudinal axis of the ID or its head assembly. The protrusion may be located at the distalmost section of the inner surface of the distal cap. The stop face interacts with the distal face of the distal section of the feed-through and forms a mechanical stop during the assembly of the head assembly and the ID. The stop face stops the press-fit or snap-fit ​​movement of the distal cap or ID housing in the correct position, thereby improving production quality. It further avoids mechanical damage to one of the press-fit or snap-fit ​​components because it avoids mechanical overload by limiting the moving distance of the component during the press-fit or snap-fit.

[0029] When the proximal cap is attached to the feed-through, the inner surface of the proximal cap formed by the through hole of the proximal cap can include a second surface structure and / or can form a shape-locked connection with the outer shell surface of the feed-through. In the same manner as the distal cap, the proximal cap can also form a permanent press fit or snap fit, forming a locked connection with the outer shell surface of the feed-through after completing the assembly. The force acting in this basically formed locked connection can also include force locking. The surface structure of the outer shell surface of the feed-through or the surface structure of the inner surface of the proximal cap or the surface structure of both can interact and engage and / or interlock in the same manner as the distal cap and the feed-through. Gluing is thus also avoided, and production efficiency is improved.

[0030] The first surface structure and / or the second surface structure may include at least two protrusions, wherein at least two protrusions are accommodated one above the other in the axial direction and / or adjacent to each other in the circumferential direction, and / or a thread profile. Preferably, the first surface structure and / or the second surface structure include a plurality of such protrusions accommodated one above the other or adjacent to each other as described above. All protrusions protrude at least partially in the radial direction from the surface forming the first surface structure or the 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 size of the protrusion in the radial direction (perpendicular to the axial direction) may be less than 200 μm, preferably less than 150 μm (for example, for the surface structure at the outer shell surface) so that the distal cap is reliably fixed to the feedthrough. It may be greater than 50 μm. By FEA calculation, these sizes of the protrusions widen the distal cap diameter so that the strain in the distal cap material (e.g., PEEK) reaches 50%-95% of its tensile strength (which is a maximum of about 100 MPa). The inner surface of the distal cap and / or the inner surface of the proximal cap may include a thread profile (female thread), and the outer shell surface may include a thread profile (male thread) that is engaged to secure the distal cap and / or the proximal cap to the feed-through. In one embodiment, the opposing thread profiles form a self-locking thread.

[0031] At least two projections can extend along at least a portion of the outer circumference of the shell surface of the feed-through, or extend along at least a portion of the inner circumference of the inner surface of the distal cap or the inner surface of the proximal cap. This means that at least two projections have a predefined length along the outer circumference or along the inner circumference. They can extend along 1 / 4 of the corresponding circumference, along 1 / 2 of the corresponding circumference, or along the entire circumference or even longer. At least two projections can extend obliquely relative to the axial direction or extend perpendicular to the direction. At least two projections can be distributed at the inner surface of the distal cap or the proximal cap or at the shell surface of the feed-through, or their lengths can be suitable for making the forces derived from the press fit or snap fit of the feed-through and the distal cap or the proximal cap, respectively, well distributed on these surfaces to avoid stress peaks.

[0032] In one embodiment, the corresponding other surface includes at least one indentation, and at least one indentation is used to receive at least two protrusions when the distal cap or the proximal cap is attached to the feed-through. For example, the outer surface of the feed-through includes at least two protrusions, and the inner surface of the distal cap includes at least one indentation, and at least one indentation can mirror at least two protrusions so that they are fully interlocked with each other after completing the assembly. This fixing can also be described as a snap-on 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-shaped protrusions extending from the shell surface of the feed-through and the L-shaped indentation on the inner surface of the distal cap form a bayonet connection. Having an indentation at another surface reduces the strain in the distal cap or the proximal cap material (e.g., polymer material), thereby alleviating the potential material fracture caused by high strain.

[0033] In one embodiment, at least a portion of at least two protrusions has a sawtooth shape, for example, at least two protrusions form at least two sawtooth circular edges, at least two sawtooth circular edges are accommodated one above the other in the axial direction and extend along the entire circumference or along a portion of the circumference, wherein the inclined surface of the sawtooth shape has an angle, for example a small angle, for example, with respect to the radial direction, having a value greater than or equal to 45°, preferably greater than or equal to 60° but less than 90°. With its angled shape, the sawtooth protrusion makes assembly easy by the slide-in chamfer. On the contrary, the sawtooth edge has a second angle between 110° and 70°, preferably between 100° and 80°, relative to the axial direction surrounded by the surface of each protrusion protruding from the shell surface of the feed-through, "biting" into the inner surface of the distal cap and preventing the distal cap from becoming loose. Permanent fixation is thus established. Alternatively or additionally, at least two protrusions can form barbs at their most outwardly protruding ends to further enhance their retention properties.

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

[0035] In the following, some possible features and advantages of a pressing arrangement of embodiments of the head assembly are described.

[0036] According to an embodiment, the pressing arrangement has a higher deformability in radial direction and against the radial direction than the fixed part 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 pressing arrangement. Since the pressing arrangement has a higher deformability than the fixed part of the distal cap, as a result of such radial forces, smaller deformations are caused in the fixed part compared to the pressing arrangement. Therefore, any risk of environmental stress cracking is reduced in the fixed part of the distal cap. As a result, the reliability of the distal cap being fixed to the feed-through arrangement can be increased.

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

[0038] For example, according to an embodiment, the distal cap includes at least one lip portion protruding from the outer surface of the distal cap. The lip portion can be a protrusion extending away from the main part of the distal cap, and this main part especially includes the fixed part of the distal cap. The lip portion can be a cantilever geometry. The lip portion can be annular. In particular, the lip portion can extend coaxially or at an angle relative to the main part of the distal cap. The lip portion can have a much smaller thickness than the main part of the distal cap. Due to its geometry and / or small thickness, the lip portion has significantly greater deformability compared to the main part and in particular compared to the fixed part of the distal cap. Therefore, when the base portion applies force to the lip portion, the lip portion can easily deflect or bend.

[0039] According to a specific embodiment, the distal cap includes an undercut recess extending adjacent to the outer surface in a direction parallel to the axial center axis of the distal cap, and the undercut recess separates the lip portion from the inner portion of the distal cap. Such a recess can separate the integral part of the distal cap used as the lip portion from the rest of the distal cap including the fixed portion. The width of the recess can be wider than the thickness of the lip portion. Since the recess extends in a direction parallel to the axial center axis of the distal cap, the lip portion can then be easily deformed or deflected in a direction intersecting with the axial center axis (i.e., in a direction toward the fixed portion of the distal cap). When elastically deflected in such a direction, the lip portion can apply force to the base ring, thereby pressing the base ring against the inner surface of the proximal cap. In this embodiment, the main axis of the lip portion will point to the proximal direction. Pointing to the proximal direction should be understood as 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 center axis of the distal cap, and the undercut recess separates the lip portion from the upper portion of the distal cap. Similarly, this recess can separate the integral part of the distal cap that acts as the lip portion from the rest of the distal cap. The width of the recess can be wider than the thickness of the lip portion. Since the recess extends in a direction intersecting with the axial center axis of the distal cap, the lip portion can then be easily deformed or deflected in a direction parallel to the axial center axis (i.e., for example, in a direction away from the inner surface of the proximal cap). When elastically deflected in such a direction, the lip portion can apply force to 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 can be a cantilever geometry pointing to the distal direction. Pointing to the distal direction should be understood as away from the radial direction towards the distal end. The lip portion can be annular. In particular, the lip portion can extend at an angle relative to the main part of the distal cap. The lip portion can have a much smaller thickness than the main part of the distal cap. Due to its geometry and / or small thickness, the lip portion has significantly greater deformability compared to the main part and in particular compared to the fixed part of the distal cap. Therefore, when a force is applied to the lip portion by at least two tines, the lip portion can be easily deflected or bent. Then, the lip portion can be easily deformed or deflected in a direction intersecting with the axial center axis (for example, in a direction toward the axial center axis). When elastically deflected in such a direction, the lip portion can apply a force to at least two tines, thereby applying to the base ring, thereby pressing the base ring against the inner surface of the proximal cap. This will be particularly advantageous in cases when at least two tines are bent in the distal direction, for example when the implant is loaded into an implantation catheter.

[0042] The above disclosed embodiments describing the lip may be implemented individually or in combination with each other, in particular, the distal cap may include a lip pointing in the proximal direction and / or a lip pointing in the distal direction.

[0043] According to another alternative embodiment, the pressing arrangement includes a pressing ring inserted between the distal cap and the proximal cap so as to be pressed onto the base ring. In such an embodiment, the pressing arrangement is not implemented by an integral part of the distal cap button through a separate pressing ring. Such a pressing ring can be prepared and provided as a separate component and can be included in the head assembly during assembly. The pressing ring can be accommodated in a recessed feature in the head assembly, such as an annular recess in the distal cap at or near the inner surface. The pressing ring can be made of another material different from the distal cap, in particular made of a material with higher elastic flexibility.

[0044] According to another embodiment, the base ring is configured to be non-circular in its non-deformed state. Such a non-circular base ring may, for example, have an elliptical shape, a polygonal shape, etc. In particular, such a base ring may have a portion having a smaller diameter than the outer surface of the distal cap and / or a portion having a larger diameter than the inner surface of the proximal cap in its non-deformed state. Therefore, when inserted between the distal cap and the proximal cap, such a non-circular base ring may be elastically deformed so as to conform to the circular outer surface of the distal cap and / or the circular inner surface of the proximal cap. Due to such deformation, the base ring will apply forces to at least one of the distal cap and the proximal cap, which forces result in the expected friction between the base ring and the corresponding cap.

[0045] In the following, some other possible features and advantages of the head assembly are described.

[0046] In one embodiment, the inner surface of the distal cap is inclined or tapered, wherein the inner diameter of the proximal section is greater than the inner diameter of the section from the proximal section to the distal side. Alternatively, the inner diameter of the proximal section is less than the inner diameter of the section from the proximal section to the distal side. If there is a protrusion at the inner surface of the distal cap or at the shell surface of the feed-through, their inner diameter or outer diameter can be increased or decreased in the axial direction accordingly. If the inner diameter of the surface or protrusion increases in the proximal direction along the axial direction, the retention force of the connection of the distal cap and the feed-through increases. However, the 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 additionally comprise an elastic material. The distal cap and / or the proximal cap may comprise or may be entirely composed of polyetheretherketone (PEEK), liquid crystal polymer (LCP), polysulfone (PSU), or other polymer materials having similar properties. The elasticity of the above materials is advantageous for the manufacturing process because it facilitates the establishment of a press-fit connection.

[0048] In one embodiment, the head assembly may include an annular steroid reservoir, which is accommodated between the distal end face of the distal cap and the feed-through in the axial direction. The steroid reservoir contains at least one medical substance, such as an anticoagulant and / or an antibacterial substance. The medical substance can be gradually released into the blood near the fixed position of the ID in the patient's tissue to heal the damaged tissue near the fixed position. The steroid reservoir can be clamped between the stopper face of the distal cap and the distal end face of the feed-through so that it is permanently fixed to the head assembly and the ID. In addition, the inner edge protruding in the distal direction can be located near the corresponding stopper face of the needle electrode located at the proximal end of the needle head. Therefore, the electrode holds the steroid reservoir in place.

[0049] In one embodiment, the shape locking fixation of the tines between the base ring and the proximal cap and the distal cap is provided by the surfaces formed by the cones at the proximal cap and the distal cap and the conical form of the base ring. The conical shape of the base ring means that the inner and outer surfaces of the ring have a tapered inclined shape, wherein the two surfaces extend substantially in parallel. In particular, the conical shape of the base ring means that the inner and outer diameters of the base ring are greater than the corresponding diameters at its proximal end at its distal end. If the two sides of the base ring extend in parallel, the wall thickness of the base ring is constant along its entire axial length. In another embodiment, its wall thickness can change along its length (i.e., become thinner or thicker along the axial direction and into the distal direction). The base ring with at least one tines 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 (distal face) of the proximal cap adjacent to the base ring and the side (proximal face) of the distal cap adjacent to the base ring have the same inclination or slope as the corresponding side surfaces of the base ring. This optimizes space and results in fewer head components, resulting in fewer handling and assembly steps at less cost during the manufacture of the ID. The axial length and volume of the head are minimized. This improvement allows more space for other more critical features of the device, such as batteries, which will increase device life. The base ring is conical to allow the axial height to be reduced while maintaining the band height. In other words, space can be allocated to the electronic module to incorporate more therapeutic features. Conversely, for the same battery and electronic module size, a reduction in head length will allow a reduction in the overall device length. This enables 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 comprises an adjacent section and a flexure zone, the adjacent section extending directly from the base ring and forming a connection with the base ring, wherein the adjacent section of the corresponding tine continues the conical shape of the base ring. Each of the plurality of tines terminates in the base ring tangentially to the arc of the tine just below the surface of the distal cap, and the base ring is completely contained by the distal cap at its distal side and by the proximal cap at its proximal side. The middle section of each of the plurality of tines has a curved form (e.g., a circular curve), and the end section farthest from the base ring comprises a straight section. Other forms of each tine are also possible. In one embodiment, the base ring and at least one tine are formed integrally. The base ring and / or at least two tines may be partially or completely composed of a biocompatible material, such as a shape memory material, such as Nitinol.

[0051] According to a second aspect of the invention, an implantable intracardiac device is described, which has a cylindrical shell and a head assembly implemented as described above, wherein a feed-through is accommodated at the distal end of the shell, wherein the feed-through is formed integrally with the shell or is formed by a separate element, which is fixed and hermetically sealed at the distal face of the shell, for example by welding.

[0052] According to a third aspect of the present invention, a method for manufacturing a header assembly as described above is described, wherein the manufacturing method comprises the following steps:

[0053] providing the feed-through, the proximal cap, the distal cap and the base ring with at least two tines,

[0054] The proximal cap, base ring and distal cap are arranged one above the other in the axial direction (ie,

[0055] in this sequential order) such that the base ring is arranged between the proximal cap and the distal cap,

[0056] The proximal cap, the base ring and the distal cap are fixed to the feedthrough by applying an axial force to the distal surface of the distal cap and / or the proximal section of the feedthrough, so that the base ring is fixed between the distal cap and the proximal cap in the axial direction and can rotate relative to the distal cap around the axial direction, the feedthrough is accommodated in the through hole of the distal cap, and the surface structure of at least one of the inner surface of the distal cap and the outer shell surface of the feedthrough provides one of a snap-fit ​​locking connection and a press-fit locking connection with the corresponding other surface in a fixed state, wherein, in the fixed state, the surface structure forming the locking connection resists the movement of the distal cap and the feedthrough apart from each other in the axial direction.

[0057] The axial force can be provided by a pressing tool, which applies an axial force to the distal face of the distal cap in the distal direction and / or applies an axial force to the proximal section of the feed-through in the proximal direction. The friction between the inner surface of the distal cap and the outer shell surface of the feed-through is overcome by the applied axial force, so that the above-mentioned snap-fit ​​or press-fit connection between the distal cap and the feed-through is established, thereby offsetting the movement of the distal cap and the feed-through apart from each other in the axial direction. During this snap-fit ​​or press-fit process, the housing / feed-through is supported / fixed. The same applies to the connection between the proximal cap and the feed-through if a snap-fit ​​or press-fit connection is also established between these components.

[0058] According to a fourth aspect of the present invention, a method for manufacturing an implantable intracardiac device as described above is described, wherein the method comprises the following steps:

[0059] providing a cylindrical housing with electrical or electromagnetic components within the housing, a cylindrical feedthrough formed integrally with the housing at the distal end of the housing or as a separate element secured and hermetically sealed at the distal face of the housing, and a needle electrode protruding from the distal end of the feedthrough and secured within a recess of the feedthrough,

[0060] providing a proximal cap, a distal cap and a base ring having at least two tines,

[0061] arranging the proximal cap, the base ring and the distal cap one above the other in the axial direction such that the base ring is arranged between the proximal cap and the distal cap,

[0062] The proximal cap, the base ring and the distal cap are fixed to the feedthrough by applying an axial force to the distal surface of the distal cap and / or the proximal section of the feedthrough, so that the base ring is fixed between the distal cap and the proximal cap in the axial direction and can rotate relative to the distal cap around the axial direction, the feedthrough is accommodated in the through hole of the distal cap, and the surface structure of at least one of the inner surface of the distal cap and the outer shell surface of the feedthrough provides one of a snap-fit ​​locking connection and a press-fit locking connection with the corresponding other surface in a fixed state, wherein, in the fixed state, the surface structure forming the locking connection resists the movement of the distal cap and the feedthrough apart from each other in the axial direction.

[0063] In one embodiment, the annular steroid reservoir is arranged in the axial direction proximal to the distal cap before fixation, wherein the annular steroid reservoir is fixed between the distal cap and the distal end face of the feedthrough in the fixed / assembled state.

[0064] In one embodiment, the proximal cap is fixed in a recess on the distal surface of the housing, wherein the recess is circumferentially surrounded by an outer edge extending from the distal face of the housing. The distal cap is an element arranged at the distal end of the head assembly, but it can extend through the through hole of the proximal cap, and therefore can also form a part of the proximal face of the head assembly. In this case, the proximal cap and the distal cap form the end face of the distal face of the adjacent housing of the head assembly accommodated. Alternatively, only the proximal cap forms the proximal face of the head assembly. In this another case, only the proximal cap is accommodated near the distal face of the housing.

[0065] In a further step, the pin-shaped electrode can be fixed in the through hole of the feedthrough, wherein the proximal end face of the electrode tip abuts the steroid reservoir in the fixed state. The electrode is brazed into the ceramic of the feedthrough by means of a gold brazing material, which holds the pin and hermetically seals it in the feedthrough ceramic. As an alternative, the electrode is fixed in the feedthrough by means of a glass-to-metal connection. The electrode can also be a two-piece component consisting of a needle and an electrode tip. The two components are welded together, for example, by laser welding.

[0066] As described herein, fixation of the base head component is provided by a method that does not use adhesive bonding forces but rather uses the elasticity and plastic material properties of a polymer (e.g., thermoplastic) distal cap to achieve a reliable, long-term, stable connection to the ID housing. Stretching the diameter of the distal cap to a certain extent so that it does not break from bonding to a surface structure (e.g., at the feedthrough housing surface) demonstrates that this snap-fit ​​or press-fit connection is a permanent attachment.

[0067] It will be apparent to those skilled in the art that, in accordance with the above teachings, many modifications and variations of the described examples and embodiments are possible. The disclosed examples and embodiments are presented for illustrative purposes only. Other alternative embodiments may include some or all of the features disclosed herein. Therefore, the present invention is intended to cover all of these modifications and alternative embodiments that may fall within the true scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] The present invention will now be described in further detail with reference to the accompanying schematic drawings, in which:

[0069] Figure 1 A first embodiment of an implantable ID according to the invention with a head assembly according to the invention is shown in longitudinal section, exploded and perspective views,

[0070] Figure 2 The longitudinal section and perspective view show Figure 1 An embodiment of

[0071] Figure 3 The longitudinal cross-section shows Figure 1 An embodiment of

[0072] Figure 4 Describes the Figure 1 An enlarged portion of the feedthrough and the housing of the electrode of an embodiment,

[0073] Figure 5 The longitudinal section diagram outlines Figure 1 The manufacturing steps of the embodiment,

[0074] Figure 6 A second embodiment of the intracardiac device of the invention is shown in longitudinal section during manufacture with a head assembly of the invention,

[0075] Figure 7 The longitudinal cross-section shows the Figure 6 An embodiment of the invention, and

[0076] Figure 8 A third embodiment of the implantable ID device of the invention is shown in longitudinal section with a head assembly of the invention.

[0077] Fig. 9 A fourth embodiment of the implantable ID device of the invention is shown in longitudinal section with a head assembly of the invention.

[0078] Fig.10 Depicted are cross-sectional views of a feedthrough and internal components thereof of a fifth embodiment of a head assembly or intracardiac device of the present invention, respectively.

[0079] Fig.11A sixth embodiment of the implantable ID of the present invention having a head assembly of the present invention is shown in cross-section.

[0080] FIG. 12 shows in cross-sectional view a seventh embodiment of an implantable ID of the present invention having a head assembly of the present invention, wherein the tines are shown in an unrestrained configuration (A) and in a configuration as loaded into an implant catheter (B) DETAILED DESCRIPTION

[0081] Figures 1 to 5 An exploded view of the components of a first embodiment of an implantable ID (0) (e.g., a leadless pacemaker) having a head assembly (0.1) is shown. The components are an annular distal cap 1, a base ring assembly 2 comprising a base ring 2.1 and four tines 2.2, a washer-shaped steroid reservoir 3, an annular proximal cap 4, and an ID housing 5, the ID housing 5 comprising a cylindrical distal section forming a feedthrough 5.1. In addition, a needle electrode 6 extends from it in the distal direction. The base ring 2.1 is formed conically in such a way that the distal end of the base ring 2.1 has a larger inner diameter and outer diameter than these diameters at its proximal end.

[0082] The distal cap 1, the base ring 2.1, the steroid reservoir 3 and the proximal cap 4, each of these components comprises a central through opening for accommodating the electrode 6. The components mentioned in the previous sentence are axially symmetrical with respect to the longitudinal axial center axis 9 defining the axial direction. The diameter of the central opening of the distal cap 1, the base ring 2.1 and the proximal cap 4 is such that the electrode feedthrough 5.1 is located in the opening in the fixed / assembled state. The diameter of the electrode feedthrough 5.1 is greater than the diameter of the electrode 6.

[0083] The annular distal cap 1 comprises a through opening forming an inner surface 1.2 at a fixing portion 1.6. At the distal end of the opening, an edge-shaped protrusion 1.3 is provided, which extends from the inner surface 1.2 in radial direction and forms a circular stopper surface 1.4. Furthermore, the distal cap 1 comprises an outer (proximal) conical inclined surface 1.1, to which an inclined base ring 2.1 abuts in the assembled state. The distal cap 1 consists of an electrically insulating and elastic material, for example PEEK.

[0084] Four tines 2.2 extend from a conical base ring 2.1, wherein each tine 2.2 has an adjacent section (flexure zone) transitioning to the base ring 2.1, a curved middle section, and a straight end section (farthest from the base ring 2.1). The tine 2.2 provides mechanical fixation of the ID within the patient's heart after deployment and penetration of the heart tissue, so that the central electrode 6 is in mechanical and electrical contact with the internal tissue of the patient's heart within one ventricle or atrium. The proximal cap 4 ensures electrical insulation of the tine 2.2 from the housing 5. The base ring assembly 2 is composed of, for example, Nitinol.

[0085] The head assembly 0.1 comprises a pressing arrangement 1.7. Figures 1 to 7 In the first and second embodiments shown, the pressing arrangement 1.7 is provided by a lip portion 1.8 protruding at the outer surface 1.10 of the distal cap 1. The lip portion 1.8 is an integral part of the distal cap 1. Compared with the fixing portion 1.6 of the distal cap 1, the pressing arrangement 1.8 has a higher deformability in a radial direction perpendicular to the axial center axis 9 and against the radial direction. Specifically, the distal cap 1 includes an undercut recess 1.9, which extends adjacent to the outer surface 1.10 in a direction parallel to the axial center axis 9 of the distal cap 1 (i.e. vertically). The undercut recess 1.9 separates the lip portion 1.8 from an inner portion 1.11 of the distal cap 1, the inner portion 1.11 including the fixing portion 1.6.

[0086] With this particular configuration, the pressing arrangement 1.7 is configured to apply a resilient force in a radial direction (i.e. orthogonal to the axial center 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 inserted between the proximal cap 4 and the distal cap 1. Therefore, in such an assembly configuration, the pressing arrangement 1.7 causes a friction force acting on the base ring 2.1 when the base ring 2.1 is rotated relative to the caps 4, 1 about the axial direction 9. Due to its high local deformability, the pressing arrangement 1.7 can be deflected when assembling the head assembly, and due to this resilient deflection, the pressing arrangement 1.7 can then reliably press the base ring 2.1 against the inner surface 4.1 of the proximal cap 4 without the inner part 1.11 of the distal cap 1 being significantly deformed.

[0087] Therefore, even in the assembled state where the base ring 2.1 is compressed between the distal cap 1 and the proximal cap 4, no significant permanent mechanical stress is applied to the inner part 1.11 of the distal cap 1, in particular the fixing part 1.6. Therefore, the risk of any environmental stress cracking (ESC) occurring at the inner part 1.11 of the distal cap 1 can be minimized. Therefore, the locking connection formed between the outer shell surface 5.2 of the feedthrough arrangement 5.1 and the inner surface 1.2 of the distal cap 1 as further described below will not be compromised due to ESC. On the contrary, permanent mechanical stress is only applied at the pressing arrangement 1.7. However, even in the case where such stress leads to ESC at the pressing arrangement 1.7, the mechanical connection between the head assembly 0.1 and the housing 5 of the intracardiac device 0 is still reliably maintained.

[0088] There is a gasket-like steroid reservoir 3 comprising a through hole 3.1. The steroid reservoir 3 is made of a mixture of silicone and dexamethasone acetate. The inner part of the steroid reservoir 3 is slightly arched upwards in the distal direction, forming a distally protruding edge 3.2, against which the stopper face 6.3 of the electrode head 6.2 abuts (see Figure 2 and Figure 3).

[0089] The head assembly and ID also include a proximal cap 4 having an inclined surface 4.1 formed on its distal side. If the proximal cap 4 is viewed from the proximal direction, the proximal cap includes a rim 5.5 for abutting against the distal end face of the housing 5 (see Figure 4 ) of the proximal cap 4. The circular stop surface 4.2 of the proximal cap 5. The circular edge 5.5 together with the circular recess 5.3 around the feed-through 5.1 causes the centering of the proximal cap 4 and the distal cap 5. The proximal cap consists of an electrically insulating and elastic material, such as PEEK.

[0090] As described above, the ID housing 5 forms a feedthrough 5.1 at its distal end. In the depicted embodiment, the feedthrough 5.1 is formed integrally with the housing 5, but may alternatively be formed as a separate element hermetically attached to the housing 5. The feedthrough 5.1 forms a housing surface 5.2 having a surface structure 5.2.0 having a plurality of sawtooth-shaped protrusions 5.2.1 which are arranged at a distal end of the housing 5. Figure 4 . Each protrusion forms a circular edge extending completely around the shell surface 5.2 and forming a first inclined surface and a second inclined surface. The first angle 5.2.2 is defined by the first inclined surface and the radial direction (the radial direction extends perpendicular to the longitudinal axis 9), and the second angle 5.2.3 is defined by the second inclined surface and the axial direction. In addition, the height of the protrusion in the radial direction is depicted with reference numeral 5.2.4. The first angle 5.2.2 may be greater than or equal to 45°, for example 70°. The second angle 5.2.3 may be equal to 110° or less, preferably greater than or equal to 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. Thereby, the distal cap 1 whose inner surface 1.2 interacts with the protrusion 5.2.1 during the press-fit movement during manufacturing can easily slide along the shell surface 5.2 in the proximal direction, but cannot be removed in the opposite distal direction because the protrusion 5.2.1 "bites" into the inner surface 1.2 of the distal cap 1.

[0091] The housing 5 of the intracardiac device contains a battery and an electronic module including a processor in its internal volume 5.4 and ensures a hermetic seal 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. In addition, the housing may contain components for communication, such as an antenna. The housing may be made of titanium alloy or stainless steel.

[0092] like Figure 5As shown, during manufacture, first the proximal cap 4 is accommodated at the distal end of the housing 5 so that its stopper face 4.2 is adjacent to the distal edge 5.5. Furthermore, the base ring 2.1 is arranged so that its outer conical surface is adjacent to the inclined distal surface 4.1 of the proximal cap 4. The base ring 2.1 is accommodated at the distal side of the proximal cap 4. In addition, the electrode 6 is arranged with its proximal shaft 6.1 in the through hole of the feed-through, wherein the electrode 6 is electrically insulated from the housing 5 by a hollow cylindrical separator 7, but is electrically connected to the electrical components located in the housing 5. The steroid reservoir 3 is clamped between the distal face of the feed-through 5.1 and the proximal stopper face 6.3 at the head 6.2 of the electrode 6, wherein the distal edge 3.2 of the steroid reservoir 3 is adjacent to the stopper face 6.3.

[0093] like Figure 5 As shown, the last manufacturing step is a press-fit step provided by distal movement of the distal cap 1 and applying an axial force at the distal surface 1.5 of the distal cap, for example by using a die (depicted by arrow 10), so that the inner surface 1.2 of the distal cap 1 slides along the housing surface 5.2 of the feed-through 5.1 until the stopper face 1.4 abuts the distal surface of the steroid reservoir 3. The interaction method is a press-fit connection using the elasticity of the PEEK material of the distal cap 1 and the plastic material behavior to produce a permanent fixation between the feed-through flange (feed-through housing surface 5.2) and the distal cap 1. The press-fit connection is achieved by overcoming the friction between the inner surface 1.2 of the distal cap 1 and the serrated protrusion 5.2.1. The housing 5 / feed-through housing surface 5.2 is supported / fixed during this press-fit process. As described above, the protrusion 5.2.1 "bites" 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, counteracting the movement of the distal cap 1 and the feedthrough 5.1 away from each other in the axial direction. Thus, the base ring assembly 2 and the proximal cap 4 and the steroid reservoir 3 are also permanently fixed.

[0094] 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 can 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 4. To this end, the inner diameter of the proximal cap 4 is smaller than Figures 1 to 5 The inner diameter of the embodiment shown.

[0095] Figures 1 to 5 A first embodiment of the invention comprises a distal cap 1 which does not have any indentations at its inner surface 1 .2 . Figure 6 and Figure 7 The second embodiment shown in FIG. 1 differs from the first embodiment in this respect. The reference numerals of the elements of the second embodiment correspond to the reference numerals of the respective elements of the first embodiment plus the number ten.

[0096] The inner surface 11.2 of the distal cap 11 includes a circular groove 11.3 forming an indentation that interlocks with the distal serrations 15.2.1 at the outer shell surface 15.2 of the feed-through 15.1 during and after assembly. This can reduce strain in the polymer material of the distal cap 11, thereby alleviating potential material fractures caused by high strains.

[0097] In the first and second embodiments, the inner surface 1.2 at the fixing part 1.6 of the distal cap 1 is configured to form a locking connection with the shell surface 5.2 of the feed-through arrangement 5.1 to counteract the movement of the distal cap 1 and the feed-through arrangement 5.1 away from each other in the axial direction. In this embodiment, the inner surface 1.2 and the relative shell surface 5.2 having the surface structure 5.2.0 are configured to form a locking connection as a press-fit connection. Wherein, the surface structure 5.2.0 at the shell surface 5.2 of the feed-through arrangement 5.1 and the inner surface 1.2 of the fixing part 1.6 are at least partially non-complementary to each other, so that when the distal end 1 is pushed onto the feed-through arrangement 5.1, a press-fit locking connection is established between the two relative surfaces.

[0098] However, in Figure 8 and Fig. 9 In the alternative embodiment shown, the inner surface 1.2 and the housing surface 5.2 may also comprise a surface structure 5.2.0, wherein the protrusions and recesses at least partially or preferably completely complement each other so as to establish a snap-fit ​​locking connection between the housing surface 5.2 and the inner surface 1.2. Therein, during the assembly process, the distal cap 1 is pushed onto the feed-through arrangement 5.1, but is only temporarily deformed (i.e. widened) in the radial direction when the protrusions and recesses slide along each other. However, when the final configuration is reached, the protrusions engage with the recesses in a complementary manner so that no significant permanent stress or deformation is induced between the distal cap 1 and the feed-through arrangement 5.1.

[0099] exist Figure 8 In the third embodiment shown, the pressing arrangement 1.7 comprises a lip portion 1.8 extending in a radial direction (i.e. horizontally). The lip portion 1.8 is formed by an undercut recess 1.9 extending adjacent to the outer surface 1.10 in a direction intersecting the axial center axis 9 of the distal cap 1 (i.e. horizontally or diagonally). Thus, the undercut recess 1.9 separates the lip portion 18 from the upper portion 1.12 of the distal cap 1.

[0100] When the head assembly is assembled with the base ring 2.1 between the proximal cap 4 and the distal cap 1, the lip portion 1.8 is slightly elastically deflected, thereby pressing on the base ring 2.1 and causing friction when the base ring 2.1 is rotated around the axial direction 9. However, no substantial permanent mechanical stress is applied to the inner portion 1.11 and the fixing portion 1.6 of the distal cap 1, thereby preventing any local environmental stress cracking and thus preventing damage to the reliable connection of the head assembly with the rest of the ID.

[0101] exist Fig. 9 In the fourth embodiment shown, the pressing arrangement 1.7 includes a separate pressing ring 18, such as a silicon O-ring. The pressing ring 18 is a separate component and is inserted between the distal cap 1 and the proximal cap 4. In particular, the pressing ring 18 can be accommodated and retained in an annular recess 19 included at 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. Therefore, when the head assembly is assembled with the base ring 2.1 and the pressing ring 18 is between the proximal cap 4 and the distal cap 1, the pressing ring 18 is elastically compressed and thereby pressed onto the base ring 2.1. Therefore, due to any significant deformation, no significant permanent mechanical stress will occur locally in the distal cap 1, thereby preventing ESC and ultimately preventing damage to the reliable connection of the head assembly to the rest of the ID.

[0102] Fig.10 A third embodiment relates to a header assembly / ID. Figure 8 The embodiment of the present invention differs from the first embodiment in the cross section of the sawtooth-shaped protrusion 5.2. The first embodiment of the head assembly 1D of the present invention comprises a protrusion 25.2 of circular cross section. Figure 8 The embodiment shown in has a protrusion which does not have a circular cross section but has a rounded polygonal, for example trilobal, form. This form is Fig.10 Shown in.

[0103] Notice, Fig.10 The sketch does not show the components of the head assembly within the feed-through 25.1 in detail.

[0104] In another embodiment (not shown), the diameters of the protrusions at the housing surface of the feedthrough can be different from each other. They can have all the same protrusion type, but implement an overall angled shape, including an outer diameter that increases or decreases from one protrusion to the next (e.g., a sawtooth protrusion). Increasing the diameter starting from the distal end to the proximal end will increase the retention force, but also increase the stress of the polymer material of the distal cap.

[0105] Another embodiment of the head assembly 0.1 is Fig.11Shown in. Among them, the pressing arrangement 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 perpendicular to the first direction. The first diameter and the second diameter are different from each other, for example, b < a. Therefore, when such a non-circular base ring 2.1 is inserted between the conical outer surface 1.1 of the distal cap 1 and the conical inner surface 4.1 of the opposite proximal cap 4, its non-circular geometry is slightly elastically deformed and thus becomes approximately circular. Thereby, an elastic pressing force is applied between the base ring 2.1 and the opposite caps 1, 4. These pressing forces result in a frictional force when the base ring 2.1 rotates relative to the caps 1, 4. However, the distal cap 1 does not cause significant deformation, so that the locking connection of the distal cap 1 with the feedthrough arrangement is not damaged by the occurrence of any stress-induced cracking.

[0106] Figure 12 relates to a seventh embodiment of the head assembly / ID, where the cusp teeth are shown in a non-restricted configuration (A) and in a configuration (B) when loaded into an implant catheter. In addition to Figure 1-7 the lip portion 1.8 of the first and second embodiments shown in, the head assembly according to this embodiment further includes a second lip portion 1.13. The second lip portion 1.13 has a cantilever geometry and points in the distal direction. If the cusp teeth 2 are bent distally (B) due to loading an implant into an implant catheter (not shown), the cusp tooth array is also held attached to the device by the second lip at the distal cap 1, thereby creating a hanging surface such that the cusp ring cannot disengage from the head assembly. In addition, the cusp teeth 2 contact the second lip portion 1.13, and the second lip portion 1.13 elastically supports the cusp teeth beyond the original height of the head, thereby providing a gradual transition of the catheter stiffness.

[0107] The above embodiments have the following advantages:

[0108] Gluing is not required during manufacturing because it alternatively achieves a press-fit permanent connection.

[0109] · The manufacturing process is friendly to automated assembly (uniaxial assembly).

[0110] · The structure of the head assembly of the present invention reduces the head height.

[0111] · Regarding the isolation components, namely the distal cap and the proximal cap, no notches are required, thereby reducing the complexity of the head components (all symmetric and rotatable components).

[0112] · The upper distal cap is fixed with low permanent stress, thus reducing environmental stress cracking in the polymer.

[0113] · Prevents the tines from rotating by friction, with a safety clutch mechanism in the same case when excessive strain is applied to the tines.

Claims

1. A head assembly (0.1) for an implantable intracardiac device (0), wherein the head assembly comprises: Cylindrical feedthrough arrangement (5.1, 15.1), annular proximal cap (4, 14), annular distal cap (1, 11), a base ring (2.1) having at least two pointed teeth (2.2) protruding distally from the base ring, and Press Arrangement (1.7), wherein the feedthrough arrangement (5.1, 15.1) has a housing surface (5.2, 15.2), wherein the proximal cap (4, 14) comprises an inner surface (4.1), wherein the distal cap (1, 11) comprises an outer surface (1.1), wherein the distal cap (1, 11) comprises a fixing portion (1.6) having an inner surface (1.2), the inner surface (1.2) forming a locking connection with an 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 an axial direction (9), wherein 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 face each other, and the base ring (2.1) is interposed between the inner surface (4.1) of the proximal cap (4, 14) and the outer surface (1.1) of the distal cap (1) so as to coaxially rotate relative to the distal cap (1), The pressing arrangement (1.7) is configured to apply a spring force in a radial direction to press the base ring (2.1) against one of an inner surface (4.1) of the proximal cap (4) and an outer surface (1.1) of the distal cap (1).

2. The head assembly according to claim 1, The distal cap (1) comprises a structure (5.2.0) at the inner surface (1.2) of its fixing portion (1.6), the structure (5.2.0) being configured to establish a snap-fit ​​locking connection with a housing surface (5.2, 15.2) of the feed-through arrangement (5.1, 15.1).

3. A head assembly according to any one of the preceding claims, The outer shell surface (5.2, 15.2) of the feed-through 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), the surface structure (5.2.0) having protrusions and recesses that 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).

4. The head assembly according to claim 1, The fixing portion (1.6) of the distal cap (1) is configured to establish a press-fit locking connection with a housing surface (5.2, 15.2) of the feed-through arrangement (5.1, 15.1).

5. The head assembly according to claim 1 or 4, The outer shell surface (5.2) of the feed-through arrangement (5.1, 15.1) and the inner surface (1.2) of the fixing part (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 locking connection between the outer shell surface (5.2, 15.2) and the inner surface (1.2).

6. A head assembly according to any one of the preceding claims, The pressing arrangement (1.7) has a higher deformability in the radial direction and opposite to the radial direction than the fixing part (1.6) of the distal cap (1).

7. A head assembly according to any one of the preceding claims, Wherein the pressing arrangement (1.7) is an integral part of the distal cap (1).

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

9. The head assembly according to claim 8, 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 center axis (9) of the distal cap (1), the undercut recess (1.9) separating the lip portion (1.8) from the inner portion (1.11) of the distal cap (1).

10. The head assembly according to claim 8, The distal cap (1) includes an undercut recess (1.9) extending adjacent to the outer surface (1.10) in a direction intersecting the axial center axis (9) of the distal cap (1), and the undercut recess (1.9) separates the lip portion (1.8) from the upper portion (1.12) of the distal cap (1).

11. Head assembly according to any one of claims 8 to 10, wherein the distal cap comprises a lip portion (1.13) having a cantilever geometry pointing in a distal direction.

12. The head assembly according to any one of claims 1 to 6, The pressing arrangement (1.7) comprises a pressing ring (18) which is inserted between the distal cap (1) and the proximal cap (4) so ​​as to be pressed onto the base ring (2.1).

13. A head assembly according to any one of claims 1 to 6, in, The base ring (2.1) is configured to be non-circular in its non-deformed state.

14. An implantable intracardiac device (0) having a cylindrical shell (5) and a head assembly (0.1) according to any of the preceding claims, wherein the feedthrough arrangement (5.1, 15.1) is arranged at the distal end of the shell (5), wherein the feedthrough arrangement (5.1, 15.1) is formed integrally with the shell (5) or is formed by a separate element fixed and hermetically sealed at the distal face (5.3, 5.5) of the shell (5).

15. A method for manufacturing a head assembly (0.1) according to any one of claims 1 to 13, comprising the following steps: providing the feed-through arrangement (5.1, 15.1), the proximal cap (4), the distal cap (1) and the base ring (2.1) with the 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) such that the base ring (2.1) is arranged between the proximal cap (4) and the distal cap (1), The proximal cap (4), the base ring (2.1) and the distal cap (1) are fixed to the feedthrough arrangement (5.1, 15.1) by applying an axial force to the distal surface of the distal cap and / or the proximal section of the feedthrough, so that the base ring is fixed between the distal cap and the proximal cap in the axial direction and can rotate relative to the distal cap around the axial direction, the feedthrough arrangement (5.1, 15.1) is accommodated in the through hole of the distal cap, and the surface structure of at least one of the inner surface of the distal cap and the outer shell surface of the feedthrough provides one of a snap-fit ​​locking connection and a press-fit locking connection with the corresponding other surface in the fixed state, wherein in the fixed state, the surface structure forming the locking connection resists the movement of the distal cap and the feedthrough apart from each other in the axial direction.

16. A method for manufacturing an implantable intracardiac device (10) according to claim 14, comprising the following steps: providing the cylindrical housing (5) with electrical or electromagnetic components within the housing, the cylindrical feedthrough arrangement (5.1, 15.1) being at the distal end of the housing, being integrally formed with the housing, or being fixed as a separate element at the distal end face of the housing and being hermetically sealed at the distal end face of the housing, and a needle electrode (6) protruding from the distal end of the feedthrough arrangement (5.1, 15.1) and being fixed in a recess of the feedthrough arrangement (5.1, 15.1), providing the proximal cap (4), the distal cap (1) and the base ring (2.1) with the at least two tines (2.2), arranging the proximal cap, the base ring and the distal cap one above the other in the axial direction such that the base ring is arranged between the proximal cap and the distal cap, The proximal cap, the base ring and the distal cap are fixed to the feedthrough arrangement by applying an axial force to the distal face of the distal cap and / or the proximal section of the feedthrough, so that the base ring is fixed between the distal cap and the proximal cap in the axial direction and can rotate relative to the distal cap around the axial direction, the feedthrough is accommodated in the through hole of the distal cap, and the surface structure of at least one of the inner surface of the distal cap and the outer shell surface of the feedthrough provides one of a snap-fit ​​locking connection and a press-fit locking connection with the corresponding other surface in the fixed state, wherein in the fixed state, the surface structure forming the locking connection resists the movement of the distal cap and the feedthrough away from each other in the axial direction.

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