WO2025011826A1

WO2025011826A1 - Implantable medical device and method for assembling an implantable medical device

Info

Publication number: WO2025011826A1
Application number: PCT/EP2024/065450
Authority: WO
Inventors: Martin Henschel; Marcel Starke; Jan Romberg; Kathy Hartmann-Bax
Original assignee: Biotronik SE and Co KG
Current assignee: Biotronik SE and Co KG
Priority date: 2023-07-07
Filing date: 2024-06-05
Publication date: 2025-01-16
Anticipated expiration: 2026-01-07

Abstract

An implantable medical device (20) is provided. The implantable medical device (20) comprises: an elongated housing (22) for accommodating one or more electronic components (28, 30) of the implantable medical device (20), wherein at least an outside of the housing (22) is completely made of a dielectric material; a first cap (24) coupled to a first longitudinal end of the housing (22) and being configured for closing the first longitudinal end of the housing (22), wherein at least an outside of the first cap (24) is at least partly configured as a first electrode of the implantable medical device (20) and wherein the first electrode is electrically coupled to one or more of the electronic components (28, 30); and a second cap (26) coupled to the housing (22) at a second longitudinal end of the housing (22) opposite to the first longitudinal end of the housing (22) and being configured for closing the second longitudinal end of the housing (22), wherein at least an outside of the second cap (26) is at least partly configured as a second electrode (27) and wherein the second electrode (27) is electrically coupled to one or more of the electronic components (28, 30).

Description

IMPLANTABLE MEDICAL DEVICE AND METHOD FOR ASSEMBLING AN IMPLANTABLE MEDICAL DEVICE

The present invention relates to an implantable medical device and to a method for assembling the implantable medical device.

Modern Implantable Medical Devices (IMDs), such e.g., as pacemakers, cardiac monitors, and/or implantable cardioverter defibrillators generally have conductive housings and insulating elements for carrying electrical signals. In their internal structure, electric circuits and/or electronic components, such as e.g., integrated circuits, memories, and batteries, are usually mounted side by side and positioned and held in relation to each other by a mounting frame. The corresponding electrical contacts are generally made by means of a material connection or, less frequently, by means of plug-in contacts.

An assembly of the internal structure and the preparation of the corresponding electrical connections are relatively complex and cannot be optimally automated. Further, the electrical connections are generally no longer detachable in the event of faults. In addition, material-locking connections in the internal structure of the IMDs require a proper accessibility, e.g., for laser welding operations (inert gas, laser light beam). For smaller IMDs, technical limits may be encountered and the choice of housing design may be severely restricted, e.g. by using a two-part implant housing that can only be closed after the welding operation.

Therefore, it is an objective of the present invention to provide an improved implantable medical device, which enables an assembly of the implantable medical device and/or a provision of electrical connections of the implantable medical device in a simple and/or automatic way, and/or which enables an electrical testing of the implantable medical device before the electrical connections are made inseparably, and/or which may have a low complexity and/or which may involve low costs only.

Further, it is an objective of the present invention to provide an improved method for assembling an implantable medical device, the method enabling the assembly of the implantable medical device and/or the provision of electrical connections of the implantable medical device in a simple and/or automatic way, and/or enabling an electrical testing of the implantable medical device before the electrical connections are made inseparably.

Such objectives may be met by the subject-matter of the independent claims. Advantageous embodiments are defined in the dependent claims as well as the corresponding specification and figures.

According to a first aspect of the present invention, an implantable medical device (IMD) is provided. The IMD comprises: an elongated housing for accommodating one or more electronic components of the IMD, wherein at least an outside of the housing is completely made of an electrically insulating or dielectric material; a first cap coupled to a first longitudinal end of the housing and being configured for closing the first longitudinal end of the housing, wherein at least an outside of the first cap is at least partly configured as a first electrode of the IMD and wherein the first electrode is electrically coupled to one or more of the electronic components; and a second cap coupled to the housing at a second longitudinal end of the housing opposite to the first longitudinal end of the housing and being configured for closing the second longitudinal end of the housing, wherein at least an outside of the second cap is at least partly configured as a second electrode and wherein the second electrode is electrically coupled to one or more of the electronic components.

According to a second aspect of the present invention, a method for assembling the IMD is provided. The method comprises: providing the elongated housing, wherein at least the outside of the housing is completely made of the electrically insulating or dielectric material; coupling the first cap for closing the first longitudinal end of the housing to the housing, wherein at least the outside of the first cap is at least partly configured as the first electrode of the IMD; arranging the one or more electronic components within the housing, wherein at least one of the electronic components is electrically coupled to the first electrode; and coupling the second cap to the housing, wherein the second cap is configured for closing the housing at the second longitudinal end of the housing opposite to the first longitudinal end of the housing, wherein at least the outside of the second cap is at least partly configured as the second electrode and wherein the second electrode is electrically coupled to the one or more of the electronic components.

Briefly summarised in a non-limiting manner, embodiments of the present invention relate to a new IMD-design, in particular to an IMD-flashlight-design. Most conventional flashlights have a design according to which an elongated flashlight-housing is provided. The flashlight-housing may be closed at one end in which some electronic components including a light source may be arranged. The flashlight-housing may be configured for accommodating one or more batteries within its flashlight-housing. The flashlight-housing may be closed at another end of the flashlight-housing, e.g. by screwing a flashlight-cap on the other end of the flashlight-housing. Electrical connections may at least in part be provided by one or more springs which may be formed and arranged such that they are biased when the flashlight-cap is fixedly coupled to the flashlight-housing. This design-concept is transferred in principle to the present IMD.

The above solution enables an assembly of the implantable medical device and/or a provision of electrical connections of the implantable medical device in a simple and/or automatic way. Several advantages result from the above construction: An electrical testing of the implantable medical device before the electrical connections are made inseparably may be enabled. An easy disassembly of the IMD without destroying its components may be enabled. This may lead to a further usability of good components of the IMD in case of conspicuities or poor performance of other components. A complexity of the IMD may be decreased. Costs which are involved in the manufacturing and/or assembly of the IMD may be relatively low only. The inherently electrically insulating housing material may eliminate the need to electrically insulate the outside of the housing to create a vector between electrical potentials for sensing and/or stimulating, wherein the corresponding potential difference may be created by the insulating housing between the electrodes of the IMD. The electrically insulating or dielectric material may for example comprise or be a ceramic, a glass, a glass alloy, or a biocompatible polymer, e.g. LCP (liquid crystal polymer), a PEEK (polyether ether ketone), or a polysulfone (e.g. PSU, CAS Nr. 25135-51-7). The first electrode may comprise or may be made of an electrically conductive material. The second electrode may comprise or may be made of an electrically conductive material. So, that at least an outside of the first and, respectively, second cap is at least partly configured as a first and, respectively, second electrode of the IMD may mean in this context that the outside of the first and, respectively, second cap at least partly comprises or is made of the electrically conductive material. The electrically conductive material of the first electrode may correspond to the electrically conductive material of the second electrode. The electrically conductive material may for example be niobium, aluminum, gold, or copper.

The one or more electronic components may comprise an electronics module 28 configured to execute and/or control the indented function of the medical device. For example, the electronics module may include for example a printed circuit board with one or more integrated circuits, e.g. Application-Specific-Integrated-Circuits (ASICs) configured to execute cardiac sensing and/ or pacing algorithms. Particularly, the electronics module may be configured for receiving correspondingly one or more physiological body signals from a body in which the IMD is implanted (via the first and/or second electrode) or to provide therapeutic pulse to the body. The one or more electronic components may further comprise at least one energy source for providing energy to the electronic components. The sensors may comprise a motion sensor, a temperature sensor, a current sensor, and/or a voltage sensor. The energy source may comprise one or more batteries. The electronic components may be arranged within the housing before or after the first cap is arranged for closing the first longitudinal end of the housing.

In the following, characteristics of embodiments of the present invention will be described in more detail.

According to an embodiment, the elongated housing is made of the electrically insulating or dielectric material. In other words, the housing is completely made or consists of the electrically insulating or dielectric material. This contributes to a very good electric insulation of an interior of the housing in which the electronic components are arranged. Alternatively, only an outer layer of the elongated housing may be made of the electrically insulating or dielectric material, wherein an inner layer of the elongated housing may be made of a material different form the electrically insulating or dielectric material. This may contribute to that a material of a main body of the housing may be chosen relatively freely. In an embodiment, the outer layer of the housing may be manufactured by a forming process such as molding, particularly injection molding, or milling or machining, and the inner layer may be manufactured onto the outer layer by an additive process, e.g. 3D-printing. Alternatively in an embodiment, both the outer and inner layer are manufactured by an additive process, e.g. 3D-printing, in either sequence (outer layer first or inner layer first).

According to an embodiment, the IMD comprises one or more electrically conductive layers and/or lines on an inner wall of the housing. The electrically conductive layers may be configured as Electromagnetic Shielding (EMS). In this context, the electrically conductive layers may extend over a large part of an inner wall of the housing, e.g. one electrically conductive layer may extend over the complete inner wall of the housing. Further, the electrically conductive layers on the inside surface of the insulating housing may also act as a diffusion barrier for body fluids from outside of the IMD. This may particularly be of importance in case of a polymer housing for a long-term implant.

In another embodiment, the IMD comprises one or more electrically conductive layers and/or lines on an outer wall of the housing, wherein particularly the one or more electrically conducting layer or lines may connected to the one or more electronic components by one or vias extending through the housing. In one embodiment, IMD comprises one electrical layer or line designed in form of circumferential layer or line around the housing and may be configured as an additional return electrode for the first or second electrode.

In still another embodiment, the IMD comprises one or more electrically conductive layers and/or lines embedded in the housing, wherein particularly the housing may be formed at least two layer of insulating material, and the one or more electrically conducting layers and/or lines may be arranged between the two layers of insulating material, wherein particularly the one or more electrically conducting layer or lines may connected to the one or more electronic components by one or vias extending through on of the two layer of insulating material.

Alternatively or additionally, the electrically conductive layers may be configured as the one or more electrically conductive lines for guiding a current, e.g. from one of the longitudinal ends to one or more of the electronic components. In this context, the electrically conductive layer(s) may be separated in the one or more of the electrically conductive lines. The electrically conductive lines may establish an electrically conductive connection from one of the electronic components to the corresponding return electrode potential without contact resistance losses via the battery and a corresponding electrically conductive spring, which is explained below. Further, the electrically conductive lines may act as an antenna for a wireless communication of the IMD, e.g. for Home Monitoring.

According to an embodiment, the first and/or second cap are made of the electrically conductive material. For example, the whole first and/or, respectively, second cap are completely made from the electrically conductive material. In this context, the first and/or, respectively, second cap may constitute the first and/or, respectively, second electrode. In other words, the first electrode may be formed by the first cap and/or the second electrode may be formed by the second cap. Alternatively, only the outside of the first and/or, respectively, second cap may constitute the first and/or, respectively, second electrode and may comprise the corresponding electrically conductive material. For example, the first and/or, respectively, second cap each may comprise an outer layer covering the complete outside of the corresponding cap, wherein this outer layer comprises the electrically conductive material for forming the corresponding electrode. Alternatively, the first and/or second cap are made of a dielectric material and the electrically conductive material of the first and/or, respectively, second electrode are arranged on or embedded within the corresponding first or second cap, e.g. in the form of electrically conductive pads which are exposed to the outside of the IMD.

According to another embodiment, the first cap and/or the second cap comprises a first portion made on an electrically insulating material and a second portion made of an electrically conducting material. Particularly, the second portion is configured as the first electrode or the second electrode, respectively. Particularly, the first portion may be formed by a glass, e.g., designed in form of a glass wafer, wherein the first portion, i.e. the glass wafer comprises one or more throughgoing openings (vias), and the second portion formed by an electrically conductive material, particularly a biocompatible metal, e.g. gold, is arranged in and extends through the one or more openings of the first portion. The second portion may additionally comprise an electrically conductive layer made from the electrically conductive material, wherein the electrically conductive layer may be arranged on a surface of the first portion that faces the interior of the medical device. Particularly, the electrically conductive layer may be configured to be at least partly solderable, For example, the electrically conductive layer may be made form gold and comprise an additionally layer of coating made from a solderable material, e.g. nickel, copper or tin.

Independent from the detailed embodiment of the first and/or second cap, the first and/or second electrode may comprise a fractal coating for increasing a contact surface of the corresponding cap. This may contribute to a proper electric coupling of the corresponding electrode to a tissue of the body in which the IMD is implanted.

According to an embodiment, the implantable medical device comprises: a first coupling body for mechanically coupling the first cap to the housing; and/or a second coupling body for mechanically coupling the second cap to the housing. The first and/or second coupling body may comprise or may be made of a joinable biocompatible, particularly a biocompatible metal that may be soldered, brazed or welded, e.g. of, gold, stainless steel, platin niobium or titanium or a titanium alloy. A first coupling layer configured for coupling the first coupling body to the housing may be formed between the housing and the first coupling body. A second coupling layer configured for coupling the second coupling body to the housing may be formed between the housing and the second coupling body. The coupling layers may comprise or may be made of gold, a gold alloy, a copper alloy or a silver alloy, platinum, graphite, conductive composites, or an amorphous metal or alloy, e.g. a metallic glass such as, for example, an amorphous zirconium alloy

According to an embodiment, the first cap and/or the second cap may be coupled to the housing by a press-fit connection, snap fit connection, wherein optionally a sealing member is arranged between the first cap and/or second cap and the housing. In an embodiment, the first cap and/or the second cap may be coupled by a screw connection, wherein particularly the first cap and/or the second cap and the housing comprise matching screw threads, and wherein optionally a sealing member is arranged between the first cap and/or second cap and the housing. Particularly, the sealing member may be designed in form of a sealing ring or a sealing compound.

The coupling bodies and/or the corresponding coupling layers may enable to couple the electrically insulating or dielectric material of the housing to the first and/or, respectively, second coupling body first, e.g. at a very high first temperature, e.g. of more than 1.000° C, e.g. by brazing, and to couple the housing via the coupling bodies to the corresponding caps afterwards, e.g. at a second temperature lower than the first temperature. This may contribute to protect the electronic components during the manufacturing of the IMD, because the electronic components may be inserted in the housing with the coupling bodies after they have been coupled to each other at the first temperature, and because afterwards only the lower second temperature is needed for closing the housing by the caps, wherein the second temperature may be chosen such that the electronic components may not be damaged by the second temperature.

In case of only one of the coupling bodies being provided for coupling one of the caps to the housing, the other cap may be fixed to the housing directly, in particular at the high first temperature. Before or after that step, the coupling body for the other cap may also be fixed to the housing, e.g. at the high temperature also. Then, the electronic components may be arranged in the housing. Afterwards, the other longitudinal end of the housing may be closed with the other cap via the corresponding coupling body.

According to an embodiment, the above implantable medical device comprises: a first spring for coupling the first cap to at least one of the electronic components, wherein the first spring is formed and arranged such that it is biased or strained when the first cap is fixedly arranged at the housing; and/or a second spring for coupling the second cap to at least one of the electronic components, wherein the second spring is formed and arranged such that it is biased when the second cap is fixedly arranged at the housing. The first and/or second spring may contribute to that the electronic components are fixed within the housing by the press fit provided by the first and/or second spring. The first spring may be configured for mechanically coupling the first cap to the corresponding electronic component. The second spring may be configured for mechanically coupling the second cap to the corresponding electronic component.

According to an embodiment, the first spring is electrically conductive and is electrically coupled to the first electrode and to the corresponding electronic component, and/or the second spring is electrically conductive and is electrically coupled to the second electrode and the corresponding electronic component. In this context, the first spring may be configured for electrically coupling the first electrode to the corresponding electronic component, and the second spring may be configured for electrically coupling the second electrode to the corresponding electronic component. So, the first and/or second spring may not only be arranged for providing the mechanical connection but also the electrical connection between the corresponding caps and electronic components.

According to an embodiment, one of the electronic components is formed and arranged such that a longitudinal end of the corresponding electronic component is formed as the first or second cap. So, the corresponding cap is formed by the corresponding electronic component. This may contribute to that less parts are needed for the IMD, decreasing the complexity of the IMD. The corresponding electronic component may be the battery of the IMD. In this context, the battery may comprise a widening at one of its longitudinal ends such that the widening may act as the corresponding cap and that the rest of the battery may be accompanied within the housing.

According to an embodiment, one of the electronic components is formed and arranged such that a housing of the corresponding electronic component forms at least a part of the housing of the implantable medical device. So, the corresponding section of the housing is formed by the corresponding electronic component. This may contribute to that less parts are needed for the IMD, decreasing the complexity of the IMD. For example, the corresponding electronic component may be the battery of the IMD. In this context, the battery may be formed such that a diameter of the battery corresponds or at least approximately corresponds to a diameter of the housing and that at least an outer layer of the battery is electrically insulated for forming the electrically insulated outside of the housing.

According to an embodiment, the IMD comprises: one or more connectors being arranged between the first and/or second caps and the corresponding electronic components and/or between different ones of the electronic components, wherein the connectors are configured for electrically and/or mechanically coupling the corresponding first and/or second caps to the corresponding electronic components and/or, respectively, for electrically and/or mechanically coupling the corresponding electronic components to each other. The connectors each may comprise a printed circuit board (PCB). The PCB may comprise one or more contact pads For electrically contacting the corresponding springs and/or neighboured ones of the electronic components. Further, the PCB may comprise one or more through-vias for guiding a current from one side of the connector to another side of the connector.

According to an embodiment, the IMD may be configured as implantable monitor. The implantable monitor may for example be an Implantable Cardiac Monitor.

According to an embodiment, the IMD may be configured as intracardiac pacemaker.

According to an embodiment, the method comprises coupling the first coupling body to the housing before coupling the first cap to the housing, and coupling the first cap to the housing via the first coupling body afterwards; and/or coupling the second coupling body to the housing before coupling the second cap to the housing, and coupling the second cap to the housing via the second coupling body afterwards. This enables to couple the corresponding coupling body to the housing at the high temperature, optionally to close one of the longitudinal ends of the housing with the corresponding cap, to insert the electronic components afterwards, and to finally close the housing completely by arranging the other cap or both caps at the housing using the lower temperature.

According to an embodiment, the method comprises arranging the first spring between the first cap and the corresponding electronic component, wherein the first spring is formed and arranged such that it is biased or strained when the first cap is fixedly arranged at the housing; and/or arranging the second spring between the second cap and the corresponding electronic component, wherein the second spring is formed and arranged such that it is biased when the second cap is fixedly arranged at the housing. The springs may be fixed to the corresponding cap before arranging the corresponding cap at the housing. In this case, the springs may be arranged when arranging the corresponding caps. This may contribute to the easy assembly of the IMD.

According to an embodiment, the method comprises coupling a first electronic component, particularly an electronics module, to a second electronic component, particularly an energy storage to an electronic component assembly and arranging the electronic component assembly in the housing.

According to an embodiment, the housing is provided at least in parts by an additive process, e.g. 3D-printing.

It shall be noted that possible features and advantages of embodiments of the invention are described herein with respect to various embodiments of the IMD, on the one hand, and with respect to various embodiments of the method for assembling the IMD, on the other hand. One skilled in the art will recognize that the features may be suitably transferred from one embodiment to another and features may be modified, adapted, combined and/or replaced, etc. in order to come to further embodiments of the invention.

In the following, advantageous embodiments of the invention will be described with reference to the enclosed drawings. However, neither the drawings nor the description shall be interpreted as limiting the invention.

Figs. 1 - 7 each show a cross section of various exemplary embodiments of an implantable medical device.

Fig. 8 shows a flowchart of an exemplary embodiment of a method for assembling the implantable medical device. The figures are only schematic and not to scale. Same reference signs refer to same or similar features.

All embodiments described in the following relate to a new design of an implantable medical device (IMD), in particular to an IMD-flashlight-design.

Fig. 1 shows a cross section of an exemplary embodiment of an IMD 20. The IMD 20 may be configured as implantable cardiac monitor (ICM). Alternatively, the IMD 20 may be configured as intracardiac pacemaker.

The IMD 20 comprises an elongated housing 22 for accommodating one or more electronic components 28, 30 of the IMD 30. The housing 22 may have a tubular shape. A cross section of the housing 22 perpendicular to the longitudinal extension of the housing 22 may be round, oval, or rectangular. At least an outside of the housing 22 is completely made of a dielectric or electrically insulating material. In the embodiment of figure 1, the elongated housing 22 is made of the dielectric or electrically insulating material. In other words, in figure 1, the housing 22 is completely made of the dielectric or electrically insulating material. Alternatively, only an outer layer of the elongated housing 22 may be made of the dielectric or electrically insulating material. The dielectric or electrically insulating material may for example comprise or be a ceramic, a glass or a glass alloy (see fig. 6), or a biocompatible polymer, e.g. a LCP (liquid crystal polymer), PEEK (polyether ether ketone), or a polysulfone, e.g. PSU (CAS Nr. 25135-51-7).

A first cap 24 is coupled to a first longitudinal end of the housing 22. The first cap 24 is configured for closing that first longitudinal end of the housing 22. At least an outside of the first cap 24 is at least partly configured as a first electrode of the IMD 20. A second cap 26 is coupled to the housing 22 at a second longitudinal end of the housing 22 opposite to the first longitudinal end of the housing 22. The second cap 26 is configured for closing the second longitudinal end of the housing 22. At least an outside of the second cap 26 is at least partly configured as a second electrode. The first and/or second cap 24, 26 may be made of the electrically conductive material. For example, the whole first and/or, respectively, second cap 24, 26 may be made completely from the electrically conductive material. In this context, the first and/or, respectively, second cap 24, 26 may constitute the first and/or, respectively, second electrode. In other words, the first electrode may be formed by the first cap 24, and/or the second electrode may be formed by the second cap 26. Alternatively, only an outside of the first and/or, respectively, second cap 24, 26 may constitute the first and/or, respectively, second electrode and may comprise the corresponding electrically conductive material. For example, the first and/or, respectively, second cap 24, 26 each may comprise an outer layer (not shown) covering the complete outside of the corresponding cap 24, 26, wherein this outer layer comprises the electrically conductive material. Alternatively, the first and/or second cap 24, 26 are made of a dielectric or electrically insulating material and the electrically conductive material of the first and/or, respectively, second electrode, 26 may be arranged on or embedded within the corresponding first or second cap 24, 26, e.g. in the form of electrically conductive pads or throughgoing vias filled with electrically conductive material (Figures 9 and 10).

The first electrode is electrically coupled to one or more of the electronic components 28. The second electrode is electrically coupled to one or more of the electronic components 30. The first electrode may comprise or may be made of an electrically conductive material. The second electrode may comprise or may be made of an electrically conductive material. The electrically conductive material of the first electrode may correspond to the electrically conductive material of the second electrode. The electrically conductive material may for example be titanium, platinum, niobium, or biocompatible coated aluminum, or biocompatible coated copper.

Independent from the detailed embodiment of the first and/or second cap 24, 26, the first and/or second electrode may comprise a fractal coating 25 for increasing a contact surface of the corresponding cap 24, 26 and/or electrode. This may contribute to a proper electric coupling of the corresponding electrode to a tissue of the body (not shown) in which the IMD 20 is implanted. In the embodiment shown in figure 1, a first coupling body 32 is configured for mechanically coupling the first cap 24 to the housing 22, and a second coupling body 3 is configured for mechanically coupling the second cap 26 to the housing 22. The first and/or second coupling bodies 32, 34 may comprise or may be made of a joinable, electrically conductive material, particularly a metal, e.g. , gold, stainless steel, platinum, niobium, titanium or a titanium alloy. Cross-sections of the coupling bodies 32, 34 perpendicular to the longitudinal extension of the housing 22 may correspond to the of the cross section of the housing 22. For example, in case of the housing 22 having the tubular shape, the coupling bodies 32, 34 may have a ring shape.

A first coupling layer 36 configured for coupling the first coupling body 32 to the housing 22 may be formed between the first coupling body 32 and the housing 22. A second coupling layer 38 configured for coupling the second coupling body 34 to the housing 22 may be formed between the second coupling body 34 and the housing 22. The coupling layers 36, 38 may comprise or may be made of a suitable soldering or brazing material such as gold, a gold alloy, a copper alloy, a silver alloy, platinum, graphite, conductive composites, or an amorphous metal or alloy, e.g. a metallic glass such as, for example, an amorphous zirconium alloy.

A first spring 40 may be configured for coupling the first cap 26 to at least one of the electronic components 28, 30. The first spring 40 may be configured for mechanically coupling the first cap 24 to the corresponding electronic component 28. The first spring 40 may be formed and arranged such that it is biased or strained when the first cap 24 is fixedly arranged at the housing 22. A second spring 42 may be configured for coupling the second cap 26 to at least one of the electronic components 28, 30. The second spring 42 may be configured for mechanically coupling the second cap 26 to the corresponding electronic component 30. The second spring 42 may be formed and arranged such that it is biased or strained when the second cap 26 is fixedly arranged at the housing 22. The first and/or second springs 40, 42 may contribute to that the electronic components 28, 30 are fixed within the housing 22 by a press fit provided by the first and/or second spring 40, 42. The first spring 40 may be electrically conductive. For example, the first spring 40 may be made of an electrically conductive material, e.g. of spring steel, Beryllium Copper, Phosphor Bronze, Stainless Steel, TiCu, an amorphous metal or alloy, e.g. a metallic glass such as, for example, an amorphous zirconium alloy. In this context, the first spring 40 may be electrically coupled to the first electrode and to the corresponding electronic component 28. So, the first spring may be configured for electrically coupling the first electrode to the corresponding electronic component. Alternatively or additionally, the second spring 26 may electrically conductive. For example, the second spring 42 may be made of an electrically conductive material, e.g. of spring steel. In this context, the second spring 42 may be electrically coupled to the second electrode and the corresponding electronic component 30. So, the second spring 42 may be configured for electrically coupling the second electrode to the corresponding electronic component 30. So, the first and/or second spring 40, 42 may not only be arranged for providing the mechanical connection but also the electrical connection between the corresponding caps 24, 26 and electronic components 28, 30.

Optionally, one or more intermediate springs 44 may be arranged, e.g. between two of the electronic components 38, 40. The intermediate springs 44 may be configured for pressing the corresponding electronic components 38, 40 away from each other. The intermediate springs 44 may be formed and arranged such that the intermediate springs 44 may be biased or strained when the housing 22 is closed by the caps 24, 26.

The one or more electronic components 28, 30 may comprise an electronics module 28 configured to execute and/or control the indented function of the medical device. For example, the electronics module may include for example a printed circuit board with one or more integrated circuits, e.g. Application-Specific-Integrated-Circuits (ASICs) configured to execute cardiac sensing and/ or pacing algorithms. Particularly, the electronics module may be configured to receiving correspondingly one or more physiological body signals from a body in which the IMD is implanted (via the first and/or second electrode) or to provide therapeutic pulse to the body. The one or more electronic components 28, 30 may further comprise at least one energy source 30, e.g. one or more batteries and/or one or more capacitors) for providing energy to the other electronic components 28, 30, e.g. the electronics module 28. The electronics module 28 may further comprise one or more sensors, for example a motion sensor, a temperature sensor, a current sensor, and/or a voltage sensor. The energy source may comprise one or more batteries. In the following, it is assumed that a first electronic component 28 of the electronic components 28, 30 is an electronics module as described above, and a second electronic component 30 of the electronic components 28, 30 comprises the battery.

Fig. 2 shows a cross section of an exemplary embodiment of an IMD 20. The IMD 20 according to figure 2 may widely correspond to the IMD 20 of figure 1,. wherein only those features of the IMD 20 according to figure 2 are explained in the following, in which the IMD 20 of figure 2 differs from the IMD 20 of figure 1.

In the embodiment of figure 2, only one of the coupling bodies 32, 34 is provided for coupling one of the caps 24, 26 to the housing 22. In particular, only the second coupling body 34 is provided for coupling the second cap 26 to the housing 22 and for closing the corresponding longitudinal end of the housing 22. The other one of the caps 24, 26, in this case the first cap 24, may be fixed to the housing 22 directly, i.e. without the first coupling body 32, in particular at the high first temperature. Before or after that high-temperature- coupling-step, the second coupling body 34 for the second cap 26 may be fixed to the housing 22, e.g. at the high temperature also. Then, the electronic components 28, 30 may be arranged in the housing 22. Afterwards, the other longitudinal end of the housing 22 may be closed with the second cap via the second coupling body 34.

In an alternative embodiment, only the first coupling body 32 may be provided for coupling the first cap 24 to the housing 22 and the second cap 26 may be fixed to the housing 22 directly.

Fig. 3 shows a cross section of an exemplary embodiment of an IMD 20. The IMD 20 according to figure 3 may widely correspond to one of the above IMDs 20, wherein only those features of the IMD 20 according to figure 3 are explained in the following, in which the IMD 20 of figure 3 differs from the above IMDs 20. One of the electronic components 28, 30, in this embodiment the second electronic component 30, may be formed and arranged such that a longitudinal end of the second electronic component 30 is formed as the second cap 26. So, in this embodiment, the second cap 26 may be formed by the second electronic component 30. This may contribute to that less parts are needed for the IMD 20, because no separate second cap 26 is necessary.

As mentioned above, the second electronic component 30 may be embodied as the battery of the IMD 20. In this context, the battery may comprise a widened longitudinal end, in other words a widening 46 at the corresponding longitudinal end, such that the widening 46 at this longitudinal end may act as the second cap 26 and that the rest of the battery may be accompanied within the housing 22.

Fig. 4 shows a cross section of an exemplary embodiment of an IMD 20. The IMD 20 according to figure 4 may widely correspond to one of the above IMDs 20, wherein only those features of the IMD 20 according to figure 4 are explained in the following, in which the IMD 20 of figure 4 differs from the above IMDs 20.

The IMD 20 may comprise one or more connectors 48. The connectors 48 may be arranged between the first and/or second caps 24, 26 and the corresponding electronic components 28, 30. In this case, the connectors 48 may be configured for electrically and/or mechanically coupling the corresponding first and/or second caps 24, 26 to the corresponding electronic components 28, 30. Alternatively or additionally, one or more of the connectors 48 may be arranged between different ones of the electronic components 28, 30, e.g. between the first and second electronic component 28, 30. In this case, the connectors 48 may be configured for electrically and/or mechanically coupling the corresponding electronic components 28, 30 to each other.

The connectors 48 each may comprise a printed circuit board (PCB). The PCB may comprise one or more contact pads (not shown) for electrically contacting the corresponding springs 40, 42, 44 and/or neighboured ones of the electronic components 28, 30. Further, the PCB may comprise one or more through-vias (not shown) for guiding a current from one side of the corresponding connector 48 to another side of the corresponding connector 48. Fig. 5 shows a cross section of an exemplary embodiment of an IMD 20. The IMD 20 according to figure 5 may widely correspond to one of the above IMDs 20, wherein only those features of the IMD 20 according to figure 5 are explained in the following, in which the IMD 20 of figure 5 differs from the above IMDs 20.

The IMD 20 may comprise one or more electrically conductive layers 52 and/or lines on an inner wall of the housing 22. The electrically conductive layer(s) 52 may be configured as Electromagnetic Shielding (EMS). In this context, the electrically conductive layer(s) 52 may extend over a large part of the inner wall of the housing 22. For example, one electrically conductive layer 52 may extend over the complete inner wall of the housing 22.

Alternatively or additionally, the electrically conductive layer(s) 52 may be configured as the one or more electrically conductive lines for guiding a current, e.g. from one of the longitudinal ends of the housing 22 to one or more of the electronic components 28, 30. In this context, the electrically conductive layer(s) 52 may be separated in the one or more of the electrically conductive lines. Further, the electrically conductive lines may be used as an antenna for a wireless communication of the IMD 20, e.g. for Home Monitoring.

Further, the IMD 20 may comprise an insulator 50 instead of one of the first or second springs 40, 42. For example, the IMD 20 may comprise the insulator 50 instead of second spring 42. The insulator 50 may be configured for electrically insulating the second cap 26 against the second electronic component 30. In this context, the electrically conductive layer 52 may be used to electrically contact the second electronic component 30.

Fig. 6 shows a cross section of an exemplary embodiment of an IMD 20. The IMD 20 according to figure 6 may widely correspond to one of the above IMDs 20, wherein only those features of the IMD 20 according to figure 6 are explained in the following, in which the IMD 20 of figure 6 differs from the above IMDs 20.

The housing 22 of the IMD 20 may be made of glass, a glass alloy, or a biocompatible polymer, e.g. an LCP, PEEK or a polysulfone. In this case, the caps 24, 26 and/or the coupling bodies 32, 34 may be coupled to the housing 22 directly, i.e. without the corresponding coupling layers 36, 38. For example, the first cap 24 may be coupled to the housing 22 directly, i.e. without the first coupling body 32 and without the first coupling layer 38. In contrast, the second cap 26 may be coupled to the housing 22 via the second coupling body 34, but without the second coupling layer 38. The first cap 24 may be coupled to the housing 22 by a Glass-To-Metal(GTM)-seal 54 in case of the housing is made of glass or a glass alloy . The second coupling body 34 may be coupled to the housing 22 by a corresponding other Glass-To-Metal(GTM)-seal 54. Alternatively, in case of a polymer housing 22, the connections to the first cap 24 and/or to the second coupling body 34 may be realized by thermal staking, ultrasonic staking, or laser welding.

Fig. 9 in combination with Fig. 10 shows a cross section of an exemplary embodiment of an IMD 20, which close relates to the embodiment shown in Fig. 6. The IMD 20 according to figure 9 may widely correspond to one of the above IMDs 20, wherein only those features of the IMD 20 according to figure 9 are explained in the following, in which the IMD 20 of figure 9 differs from the above IMDs 20.

Like the embodiment shown in Fig. 6., IMD 20 of Fig. 9 comprises a housing 22 made of glass, a glass alloy, or a biocompatible polymer, e.g. an LCP, PEEK or a polysulfone. In contrast to the above described embodiments, one or both caps 24, 24 comprises an insulating body 24b, 26 made from, e.g. glass, a glass alloy or a biocompatible polymer, wherein the insulating body 24b, 26b comprises one or more throughgoing holes and a conductor structure comprising electrically conductive material 24a, 26b filled in the one or more throughgoing holes (vias) and an electrically conductive layer being arranged on the insulating body on a surface facing one of the electronic components 28, 30 and being in electrical contact with the electrically conductive material. Alternatively, the insulating body is made from a ceramic, a ceramic-glass composite or fibre-reinforce polymer. Preferably, the electrically conductive layer is electrically connected to one of the electronic components 28, 30 by a soldering joint. Alternatively, the conductor structure may be electrically connected to the electronic components 28, 30 by a spring. Furthermore, such insulating body may be formed by glass wafer. Moreover, the electrically conductive material 24a, 26b and/or the electrically conductive layer 24c, 26c preferably comprise or essentially consists of an biocompatible metal, e.g. gold, wherein in case of the biocompatible material is not solderable, the electrically conductive layer 24c, 26c additionally comprises an additional layer made of a solderable metal, e.g. tin, nickel, copper, etc.

Also shown in Fig. 9 is an alternative for the spring 44 connecting both electronic components 28, 30, Here, both components are connected by means of a plug-in connection, wherein one electric component, e.g. component 30 designed in form of abatterie, comprises a pin, and the other electric component, e.g. component 28 designed as an electrics module, comprises a pin receptacle configured to receive and electrically contact the pin.

Fig. 7 shows a cross section of an exemplary embodiment of an IMD 20. The IMD 20 according to figure 7 may widely correspond to one of the above IMDs 20, wherein only those features of the IMD 20 according to figure 7 are explained in the following, in which the IMD 20 of figure 7 differs from the above IMDs 20.

One of the electronic components 28, 30, in this embodiment the second electronic component 30, e.g. the battery, may be formed and arranged such that a housing of the second electronic component 30 forms at least a part of the housing 22 of the IMD 20. So, the corresponding section of the housing 22 is formed by the second electronic component 30. In this context, the battery may be formed such that a diameter of the battery corresponds or at least approximately corresponds to a diameter of the housing 22 and that at least an outer layer of the battery is electrically insulated for forming the electrically insulated outside of the housing 22. For example, an electrically insulating layer 56 may be provided as the outer layer of the battery. The electrically insulating layer 56 may extend over the rest of the housing 22 and may form a part of the outside of the housing 22, which is generally electrically insulated against its environment. The electrically insulating, biocompatible and biostable layer 56 may be formed by a coating or a shrinking tube. Non-limiting examples for suitable coating materials include silicon carbide, a parylene, a silicone, or a glass. Coating may be conducted by dipping, vacuum coating or printing. Fig. 8 shows a flowchart of an exemplary embodiment of a method for assembling the IMD 20, in particular one of the above IMDs 20. The method is configured for coupling one or both coupling bodies 32, 34 to the housing 22 at the high temperature, optionally to close one of the longitudinal ends of the housing 22 with the corresponding cap 24, 26, to insert the electronic components 28, 30 afterwards, and to finally close the housing 22 completely by arranging the other cap 24, 26 or both caps 24, 26 at the housing 22 using the lower temperature.

In a step S2, the elongated housing 22 is provided. At least the outside of the housing 22, e.g. the complete housing 22, is completely made of the dielectric material, as explained above. Further, in step S2, the first and/or the second coupling layers 36, 38 may be formed. In particular, the elongated housing 22 may be metallized on its end faces by the coupling layers 36, 38.

In an optional step S4, the first coupling body 32 may be attached to the housing 22. For example, the first coupling body 32 may be hermetically brazed to the corresponding end face of the housing 22, e.g. via the first coupling layer 36. At least the outside of the first cap 24 may at least partly be configured as the first electrode of the IMD 20, as explained above. The first coupling body 32 may be arranged for coupling the first cap 24 to the housing 22.

In a step S6, the second coupling body 34 may be attached to the housing 22. For example, the second coupling body 34 may be hermetically brazed to the corresponding end face of the housing 22, e.g. via the second coupling layer 38. At least the outside of the second cap 26 may at least partly be configured as the second electrode of the IMD 20, as explained above. The second coupling body 34 may be arranged for coupling the second cap 26 to the housing 22. In case the optional step S4 is carried out, the order of steps S4 and S6 may be altered such that the second coupling body 34 may be attached to the housing 22 before the first coupling body 36 is attached to the housing 22.

In a step S8, the first cap 24 may be coupled to the housing 22, e.g. by laser seam welding. If the optional step S4 has been carried out, the first cap 24 may be coupled to the housing 22 via the first coupling body 32. When assembling the IMD 20, the order of steps S6 and step S8 may be changed such that the second coupling body 34 may be attached to the housing 22 after coupling the first coupling body 24 to the housing 22 or, respectively, to the first coupling body 32.

In a step S10, the one or more electronic components 28, 30 may be arranged within the housing 20, wherein at least one of the electronic components 28, 30, e.g. the first electronic component 28, may be electrically coupled to the first electrode. The first electronic component 28 may be electrically coupled to the first electrode by the first spring 40 which may be arranged between the first cap 24 and the first electronic component 28, wherein the first spring 40 may be formed and arranged such that it is biased or strained when the first cap 24 is fixedly arranged at the housing 22 and/or when the housing 22 is closed. The first spring 40 may be fixed to the first cap 24 before arranging the first cap 24 at the housing 22. The electronic components 28, 30 may be arranged within the housing 22 before or after the first cap 24 is arranged for closing the first longitudinal end of the housing 22, i.e. before or after step S8.

In a step SI 2, the second cap 26 may be coupled to the housing 22, e.g. by laser seam welding. The second cap 26 is configured for closing the housing 22 at the second longitudinal end of the housing 22 opposite to the first longitudinal end of the housing 22. At least the outside of the second cap 26 is at least partly configured as the second electrode. The second electrode is electrically coupled to the second electronic component 30. The second electrode may be electrically coupled to the second electronic component 30 by the second spring 42 between the second cap 26 and the second electronic component 30. The second spring 52 may be formed and arranged such that it is biased when the second cap 26 is fixedly arranged at the housing 22. The second spring 26 may be fixed to the second cap 26 before arranging the second cap 26 at the housing 22.

Now, the IMD 20 may be finally assembled and ready to use.

In this embodiment of the method, the first cap 24 may be attached to the housing 22 without the first coupling body 32 and the second cap 26 may be attached to the housing 22 via the second coupling body 34. In an alternative embodiment, the second cap 26 may be attached to the housing 22 without the second coupling body 34 and the first cap 24 may attached to the housing 22 via the first coupling body 32.

The coupling bodies 32, 34 and/or the corresponding coupling layers 36, 38 may enable to couple the dielectric material of the housing 22 to the first and/or, respectively, second coupling body 32, 34 first, e.g. at the high first temperature, e.g. of more than 1.000° C, e.g. by brazing, and to couple the housing 22 via one or more of the coupling bodies 32, 34 to the corresponding caps 24, 26 afterwards, e.g. at the second temperature lower than the first temperature. Then, the electronic components 28, 30 may be inserted in the housing 22 with the one or more coupling bodies 32, 34 after they have been coupled to the housing 22 at the first temperature, and afterwards only the lower second temperature may be needed for closing the housing by one or both caps 24, 26, wherein the second temperature may be chosen such that the electronic components 28, 30 may not be damaged by the second temperature.

The invention is not restricted to the above embodiments. For example, the above embodiments may be combined. For example, each of the above embodiments may comprise or may not comprise the first and/or second coupling body 32, 34. Alternatively or additionally, each of the above embodiments may comprise or may not comprise one or more of the connectors 48. Further, each of the above embodiments may comprise or may not comprise the battery with the widening which may be used as one of the caps 24, 26. Further, each of the above embodiments may comprise or may not comprise the insulator 50, and/or the electrically conductive layer 52, and/or the electrically insulating layer 52. Further, each of the above embodiments may comprise or may not comprise the housing 22 being made of glass or the glass alloy.

Finally, it should be noted that the term “comprising” does not exclude other elements or steps and the “a” or “an” does not exclude a plurality. Also elements described in association with different embodiments may be combined. It should also be noted that reference signs in the claims should not be construed as limiting the scope of the claims. List of Reference Numerals

20 implantable medical device

22 housing

24 first cap

25 fractal coating

26 second cap

28 first electronic component

30 second electronic component

32 first coupling body

34 second coupling body

36 first coupling layer

38 second coupling layer

40 first spring

42 second spring

44 intermediate spring

46 widening

48 connector

50 insulator

52 electrically conductive layer

54 GTM-seal

56 electrically insulating layer

Claims

1. An implantable medical device (20), comprising: an elongated housing (22) for accommodating one or more electronic components (28, 30) of the implantable medical device (20), wherein at least an outside of the housing (22) is completely made of an electrically insulating or dielectric material; a first cap (24) coupled to a first longitudinal end of the housing (22) and being configured for closing the first longitudinal end of the housing (22), wherein at least an outside of the first cap (24) is at least partly configured as a first electrode of the implantable medical device (20) and wherein the first electrode is electrically coupled to one or more of the electronic components (28, 30); and a second cap (26) coupled to the housing (22) at a second longitudinal end of the housing (22) opposite to the first longitudinal end of the housing (22) and being configured for closing the second longitudinal end of the housing (22), wherein at least an outside of the second cap (26) is at least partly configured as a second electrode (27) and wherein the second electrode (27) is electrically coupled to one or more of the electronic components (28, 30).

2. The implantable medical device (20) of claim 1, wherein the elongated housing (22) is essentially made of the electrically insulating or dielectric material, or comprises an outer layer made essentially made of the electrically insulating or dielectric material and an inner layer essentially made from a material different form the electrically insulating or dielectric material.

3. The implantable medical device (20) of one of the preceding claims, comprising: one or more electrically conductive layers (52) and/or lines on an inner wall of the housing (22), on an outer wall of the housing (22) or embedded in the housing (22).

4. The implantable medical device (20) of one of the preceding claims, wherein the first cap (24) and/or the second cap (26) are made of an electrically conductive material.

5. The implantable medical device (20) of one of claims 1 to 3, wherein the first cap (24) and/or the second cap (26) comprises a first portion made of an electrically insulating material and second portion made of an electrically conducting material, wherein the second portion is at least partly configured as the first electrode or the second electrode.

6. The implantable medical device (20) of claim 1, comprising: a first coupling body (32) for mechanically coupling the first cap (24) to the housing (22); and/or a second coupling body (34) for mechanically coupling the second cap (26) to the housing (22).

7. The implantable medical device (20) of any one of the preceding claims, comprising: a first spring (40) for coupling the first cap (24) to at least one of the electronic components (28, 30), wherein the first spring (40) is formed and arranged such that it is biased when the first cap (24) is fixedly arranged at the housing (22); and/or a second spring (42) for coupling the second cap (26) to at least one of the electronic components (28, 30), wherein the second spring (42) is formed and arranged such that it is biased when the second cap (26) is fixedly arranged at the housing (22).

8. The implantable medical device (20) of claim 6, wherein the first spring (40) is electrically conductive and is electrically coupled to the first electrode and to the corresponding electronic component (28, 30), and/or the second spring (42) is electrically conductive and is electrically coupled to the second electrode (27) and the corresponding electronic component (28, 30).

9. The implantable medical device (20) of any one of the preceding claims, wherein one of the electronic components (28, 30) is formed and arranged such that a longitudinal end of the corresponding electronic component (28, 30) is formed as the first or second cap (26).

10. The implantable medical device (20) of any one of the preceding claims, wherein one of the electronic components (28, 30) is formed and arranged such that a housing (22) of the corresponding electronic component (28, 30) forms at least a part of the housing (22) of the implantable medical device (20).

11. The implantable medical device (20) of any one of the preceding claims, comprising: one or more connectors (48) being arranged between the first and/or second caps (24, 26) and the corresponding electronic components (28, 30) and/or between different ones of the electronic components (28, 30), wherein the connectors (48) are configured for electrically and/or mechanically coupling the corresponding first and/or second caps (24, 26) to the corresponding electronic components (28, 30) and/or, respectively, for electrically and/or mechanically coupling the corresponding electronic components (28, 30) to each other.

12. The implantable medical device (20) of any one of the preceding claims, being configured as an implantable monitor, or an intracardiac pacemaker

13. A method for assembling an implantable medical device (20), the method comprising: providing an elongated housing (22), wherein at least an outside of the housing (22) is completely made of an electrically insulating or dielectric material; coupling a first cap (24) for closing a first longitudinal end of the housing (22) to the housing (22), wherein at least an outside of the first cap (24) is at least partly configured as a first electrode of the implantable medical device (20); arranging one or more electronic components (28, 30) within the housing (22), wherein at least one of the electronic components (28, 30) is electrically coupled to the first electrode; and coupling a second cap (26) to the housing (22), wherein the second cap (26) is configured for closing the housing (22) at a second longitudinal end of the housing (22) opposite to the first longitudinal end of the housing (22), wherein at least an outside of the second cap (26) is at least partly configured as a second electrode (27) and wherein the second electrode (27) is electrically coupled to one or more of the electronic components (28, 30).

14. The method of claim 13, comprising coupling a first coupling body (32) to the housing (22) before coupling the first cap (24) to the housing (22), and coupling the first cap (24) to the housing (22) via the first coupling body (32) afterwards; and/or coupling a second coupling body (34) to the housing (22) before coupling the second cap (26) to the housing (22), and coupling the second cap (26) to the housing (22) via the second coupling body (34) afterwards.

15. The method of any one of claims 13 or 14, comprising arranging a first spring (40) between the first cap (24) and the corresponding electronic component (28, 30), wherein the first spring (40) is formed and arranged such that it is biased when the first cap (24) is fixedly arranged at the housing (22); and/or arranging a second spring (42) between the second cap (26) and the corresponding electronic component (28, 30), wherein the second spring (42) is formed and arranged such that it is biased when the second cap (26) is fixedly arranged at the housing (22).