Implantable medical device for substernal implantation externally to a patient's heart

Abstract

The present invention relates to an implantable medical device (1) for substernal implantation externally to a patient's heart (HP) comprising a housing (10), wherein the housing (10) comprises a first electrode pole (101), a second electrode pole (102), wherein the first electrode pole (101) and the second electrode pole (102) are arranged on a surface of the housing (10), a stimulation unit (103) configured to provide the first electrode pole (101) or the second electrode pole (102) with an electric pulse to stimulate a patient's heart (H), and a detection unit (104) configured to receive an electric signal of the same heart (HP) via the first electrode pole (101) or the second electrode pole (102). In addition, a cross-sectional area of the housing (10) lies in a range of 1.4 cm2 to 4.0 cm2.

Description

[0001] Applicant: BIOTRONIK SE & Co. KG

[0002] Date: 02.09.2025

[0003] Our Reference: 24.107P-WO

[0004] IMPLANTABLE MEDICAL DEVICE FOR SUBSTERNAL IMPLANTATION EXTERNALLY TO A PATIENT’S HEART

[0005] The present invention relates to an implantable medical device according to the preamble of claim 1.

[0006] Such implantable medical devices are usually implanted into the body of a patient and are in particular designed for emitting electrical shocks in case life-threatening arrhythmias of a patient’s heart are detected. By means of an electrical shock, a defibrillation shall be achieved in order to reset the cardiac rhythm back to a normal state.

[0007] Implantable medical devices known from prior art are typically implanted between the latissimus dorsi muscle and the serratus anterior muscle of a patient. The implantation at this location has multiple drawbacks. One drawback is that the implantable medical device, when implanted in a patient, is rather far apart from a patient's heart. Therefore, high amplitudes for example for emitting electrical shocks are necessary to allow proper functionality of the implantable medical device. However, these high amplitudes can cause discomfort and pain to a patient. Another drawback of this location is that the implantable medical device, when implanted in a patient, can cause distress or even pain when a patient tries to sleep on that side at which the implantable medical device has been implanted. Therefore, the implantable medical device implanted at this location can impact the sleep and the comfort of a patient. Moreover, an implantation of the implantable medical device at this location is cosmetically noticeable, which can also cause discomfort for a patient.

[0008] It is an object of the present invention to provide an implantable medical device that allows implantation at a different location and thereby circumvents the above-mentioned issues. This object is achieved with an implantable medical device having the features of claim 1.

[0009] Such an implantable medical device is designed for substemal implantation externally to a patient’s heart. The implantable medical device comprises a housing. The housing thereby comprises a first electrode pole and a second electrode pole, wherein the first electrode pole and the second electrode pole are arranged on the surface of the housing. Moreover, the housing comprises a stimulation unit configured to provide the first electrode pole and / or the second electrode pole with an electric pulse to stimulate a patient’s heart. The housing also comprises a detection unit configured to receive an electric signal of the same heart via the first electrode pole and / or the second electrode pole. Furthermore, a cross-sectional area of the housing lies in a range of 1.4 cm2to 4.0 cm2, in particular of 1.5 cm2to 3.4 cm2, in particular of 1.7 cm2to 3.0 cm2, in particular of 1.9 cm2to 2.7 cm2, in particular of 2.2 cm2to 2.5 cm2, or in arange of 1.7 cm2to 3.7 cm2, in particular of 1.8 cm2to 3.1 cm2, in particular of 2.0 cm2to 2.8 cm2, in particular of 2.3 cm2to 2.6 cm2, or in a range of 1.9 cm2to 3.6 cm2, in particular of 2.1 cm2to 3.1 cm2, orin a range of2.2 cm2to 3.2 cm2, in particular of 2.3 cm2to 2.7 cm2, in particular of 2.4 cm2to 2.7 cm2, or in a range of 1.4 cm2to 2.3 cm2, or in a range of 1.7 cm2to 2.7 cm2, or in a range of 1.9 cm2to 3.2 cm2, or in a range of 2.2 cm2to 3.6 cm2, or in a range of 2.3 cm2to 3.8 cm2, or in a range of 2.4 cm2to 4.0 cm2, or in a range of 1.4 cm2to 2.5 cm2, or in a range of 1.5 cm2to 2.7 cm2, or in a range of 1.9 cm2to 3.4 cm2, or in a range of 2.2 cm2to 3.9 cm2.

[0010] By limiting the cross-sectional area of the housing to a certain range, the implantable medical device ensures that only a small incision during the substemal implantation is necessary. This is due to the fact that an incision only needs to be capable to accommodate the cross- sectional area of the housing which is rather small when compared to implantable medical devices known from prior art.

[0011] The intended substemal implantation has also the advantage that the implantable medical device is closer to a patient’s heart than when being implanted between the latissimus dorsi muscle and the serratus anterior muscle so that the implantable medical device can use lower amplitudes for example for emitting electrical shocks to the patient’s heart, thereby increasing the comfort for a patient. The possible closer location of the implantable medical

[0012] 24.107P-WO | 02.09.2025 device to the patient’s heart also increases the accuracy of the detection unit by receiving the signal of the patient’s heart more accurately. Moreover, the substemal location does not impact a patient’s sleeping position, so that a patient can for example sleep on both sides without discomfort caused by the implantable medical device. Furthermore, the substemal implantation is not cosmetically noticeable.

[0013] In an embodiment, the cross-sectional area of the housing has a round or oval shape. A round or oval cross-sectional area of the housing leads to a shape that is appropriate to fit to a typical surface shape of a patient’s sternum. Therefore, an implantable medical device with a round or oval cross-sectional area of the housing uses the substemal space efficiently by allowing a tighter fit to a patient’s sternum.

[0014] In an embodiment, a volume of the housing lies in a range of 15 cm3to 35 cm3, in particular of 20 cm3to 32 cm3, in particular of 25 cm3to 30 cm3. The volume of the housing represents the amount of three-dimensional space the housing occupies. The volume of the housing also represents the quantity of space enclosed within the housing’s boundaries (only the volume of walls of the housing needs to be subtracted for calculating this quantity of space).

[0015] In an embodiment, the housing extends in a longitudinal extension direction. Furthermore, the housing has a length, a width, and a height. The length is the longest extension of the housing in the longitudinal extension direction. Moreover, the width and the height are perpendicular to the longitudinal extension direction, wherein the width is the bigger one of the height and the width. Additionally, a length-to- width ratio of the housing amounts to at least 4: 1, in particular at least 5: 1, in particular at least 6: 1, in particular at least 7: 1, in particular at least 8: 1, in particular at least 9: 1, in particular at least 10: 1, in particular at least 11 : 1, in particular at least 12: 1, in particular at least 13: 1, in particular at least 14: 1, in particular at least 15: 1. In an embodiment, the length-to-width ratio of the housing lies in a range of 4: 1 to 15: 1, in particular of 5: 1 to 14: 1, in particular of 6: 1 to 13 : 1, in particular of 7: 1 to 12: 1, in particular of 8: 1 to 11 : 1, in particular of 9: 1 to 10: 1. A length-to-width ratio of approximately (i.e., within ± 10 %, in particular ± 5 %) or exactly 4: 1, 5: 1, 6: 1, 7: 1, 8: 1, 9: 1, 10: 1, 11 : 1, 12: 1, 13: 1, 14: 1, or 15: 1 is particularly appropriate.

[0016] 24.107P-WO | 02.09.2025 For example, a housing with a round cross-sectional area, a length of 15 cm and a width of 1.65 cm has a length-to-width ratio of approximately 9: 1. The cross-sectional area of the housing lies then in a range of 2.1 cm2to 2.2 cm2and the volume lies in a range of 32 cm3to 33 cm3. Such a volume is comparable to volumes of implantable medical devices known from prior art. Therefore, all components of implantable medical devices known from prior art fit into the housing of this example. Thus, this example of the present invention is able to feature comparable functionalities like implantable medical devices known from prior art with all the benefits mentioned above and below of the present invention.

[0017] These length-to-width ratios utilize the substernal location and the fact that a conjunctive tissue of the substernal location has more capacity for an implantable medical device than other locations in patient’s body. Therefore, implantable medical devices with greater lengths than implantable medical devices known from prior art are achievable and even favorable.

[0018] In an embodiment, the implantable medical device comprises a fixture for fixing the implantable medical device to a body part or an anatomical structure of a patient carrying the implantable medical device in an implanted state. For example, the fixture can be a suture hole, wherein the implantable medical device is fixed to a body part or an anatomical structure of a patient by threading a thread though the suture hole and a body part or an anatomical structure of a patient. In one instance, the fixture is arranged on a surface of a terminus of the housing, wherein the housing comprises two termini, wherein the two termini are arranged on the housing in such a way that the distance between them is maximal.

[0019] In an embodiment, the housing is rigid. A rigid housing prevents a change of a relative arrangement between singular sections of the housing due to external influences impacting the housing. The rigid housing eases an implantation as the rigid housing can withstand forces that might be applied during the implantation without compromising the structure of the housing.

[0020] However, a rigid housing is not always appropriate. Therefore, in an alternative embodiment, the housing comprises at least one flexible section between two rigid sections. The flexible

[0021] 24.107P-WO | 02.09.2025 section allows a relative arrangement of the two rigid sections. A relative arrangement can lead to a tighter fit of the implantable medical device in an implanted state by allowing a fit that adapts to the anatomical characteristics or anatomical structures of a patient carrying the implantable medical device in an implanted state.

[0022] In an embodiment, the implantable medical device further comprises an electrode lead comprising a third electrode pole. The third electrode pole is arranged and designed for delivering stimulation pulses to a patient in need thereof and for sensing electrocardiogram signals of the same patient. The third electrode pole functions for example as a counter electrode pole to the first electrode pole and / or the second electrode pole.

[0023] In one instance, the third electrode pole is designed as a shock coil. Such a shock coil is particularly appropriate for delivering defibrillation shocks as stimulation pulses. In addition, a shock coil is likewise appropriate for delivering a post-shock stimulation and for sensing electrocardiogram signals of the patient.

[0024] In an embodiment, the electrode lead is an epicardial electrode.

[0025] In an embodiment, the electrode lead is connected to a terminus of the housing, wherein the housing comprises two termini, wherein the two termini are arranged on the housing in such a way that the distance between them is maximal.

[0026] In an embodiment, the housing further comprises a capacitor arrangement comprising at least one capacitor (in particular two or three capacitors) and at least one energy source connected to the capacitor arrangement.

[0027] In an embodiment, the cross-sectional area of the housing is round and the at least one energy source and the capacitor arrangement within the housing have a round cross-sectional area as well. The round cross-sectional area of the housing, the at least one energy source and the at least two capacitors lead to an optimal arrangement which reduces the volume of the housing. This volume reduction is due to an efficient usage of the allocated space of the

[0028] 24.107P-WO | 02.09.2025 housing through a tight fit of the at least one energy source and the at least two capacitors within the housing.

[0029] In an embodiment, the at least one capacitor of the capacitor arrangement has a round cross- sectional area.

[0030] In an embodiment, an electronic module comprising the sensing unit and the detection unit, the capacitor arrangement, and the at least one energy source are arranged in an arrangement axis, wherein the arrangement axis is a straight line, in particular extending along the longitudinal extension direction of the housing, i.e., along the length of the housing. Such an arrangement in the arrangement axis leads to a simplistic structure. Due to the simplistic structure, the manufacturing of the implantable medical device is facilitated compared to prior art devices as the sensing unit, the detection unit, the capacitor arrangement and the at least one energy source can be mounted one after another.

[0031] Furthermore, in an embodiment, the implantable medical device comprises a first contact and a second contact. The first contact forms thereby an electrical connection between an electronic module comprising the stimulation unit and the detection unit and the capacitor arrangement. Moreover, the second contact forms an electrical connection between the capacitor arrangement and the energy source. Additionally, the first contact is arranged in a contact direction, wherein the second contact is arranged in the same contact direction. By arranging the first contact and the second contact in the same contact direction, the construction of the implantable medical device is simplified with respect to the construction of prior art devices.

[0032] In an embodiment, the housing comprises a first section and a second section.

[0033] The first section extends thereby in a first longitudinal extension direction. The first section has a first length being the longest extension of the first section in the first longitudinal extension direction, a first width and a first height, wherein the first width and the first height are perpendicular to the first longitudinal extension direction. Furthermore, the first width is the bigger one of the first height and the first width.

[0034] 24.107P-WO | 02.09.2025 The second section extends in a second longitudinal extension direction. The second section has a second length being the longest extension of the second section in the longitudinal extension direction, a second width and a second height, wherein the second width and the second height are perpendicular to the second longitudinal extension direction. Furthermore, the second width is the bigger one of the second height and the second width.

[0035] Additionally, each of the first section and the second section comprises an outer surface extending along the respective width and length. Said outer surfaces of the first section and the second section are each flat. Moreover, a first alignment plane aligned with the outer surface of the first section is arranged at an angle to a second alignment plane aligned with the outer surface of the second section. Furthermore, the angle is larger than 0° and smaller than 90°. In an embodiment, the angle lies in a range of 5° to 85°, in particular of 10° to 80°, in particular of 15° to 75°, in particular of 20° to 70°, in particular of 25° to 65°, in particular of 30° to 60°, in particular of 35° to 55°, in particular of 40° to 50°, in particular of 45° to 60°.

[0036] In an instance, the angle between the two alignment planes leads to a housing with a slight bend or curvature. This bend or curvature leads to a housing that fits even better to an anatomical structure or anatomical characteristic of a sternum of a patient carrying the implantable medical device in an implanted state than a straight housing, as human or animal sternums typically contain a slight bend.

[0037] Moreover, the bend or curvature allows the implantable medical device to be arranged in such a way that it can adapt better to an anatomical structure or anatomical characteristic of a heart of a patient carrying the implantable medical device in an implanted state than an implantable medical device having a straight housing. For example, the housing is, in its implanted state, arranged in such a way that the bend or curvature is further away to the heart than two termini of the housing, wherein the two termini are arranged on the housing in such a way that the distance along the housing between them is maximal. Thereby, the two termini of the housing are closer to a patient’s heart than two termini of a housing without having such bend or curvature. If the first electrode pole and the second electrode pole are each

[0038] 24.107P-WO | 02.09.2025 arranged close to one of the two termini, the closer proximity of the two termini to a patient’s heart results in the first electrode pole and the second electrode pole being closer to a patient's heart than in case of a housing without a bend or curvature.

[0039] In an embodiment, the implantable medical device is a non-transvenous implantable cardioverter-defibrillator.

[0040] The term “non-transvenous” in this respect in particular shall express that the electrode lead of the non-transvenous implantable cardioverter defibrillator device is designed to not extend transvenously into a heart, but in an implanted state fully rests outside of a patient’s heart.

[0041] A non-transvenous implantable cardioverter defibrillator device generally is configured to emit a shock pulse for achieving a defibrillation. The non-transvenous implantable cardioverter defibrillator device may serve for monitoring and treating potentially lifethreatening arrhythmias of a patient's heart. The non-transvenous implantable cardioverter defibrillator is configured for non-transvenous implantation, that is an implantation such that no electrode leads transvenously are implanted within the heart of a patient. The non- transvenous implantable cardioverter defibrillator hence is to be implanted in a patient such that a housing and an electrode lead of the non-transvenous implantable cardioverter defibrillator are implanted extracardially and do not reach into a heart of a patient, that is into the right or left ventricle or the right or left atrium.

[0042] Generally, a non-transvenous implantable cardioverter defibrillator device does not comprise any portions which extend transvenously into a patient’s heart, but the defibrillator device is configured to achieve a sensing and emission of signals outside of a patient’s heart.

[0043] In an embodiment, the implantable medical device is an implantable pulse generator (IPG), a device for cardiac resynchronization therapy (CRT), or an implantable cardiac monitor. An appropriate cardiac monitor is a loop recorder.

[0044] In an embodiment, the implantable medical device comprises a communication unit by which the implantable medical device can be connected with a home monitoring system in

[0045] 24.107P-WO | 02.09.2025 a wireless manner. Then, it is possible to monitor the functioning of implantable medical device from a remote entity and optionally to perform setting adjustments of the implantable medical device from this remote entity. All standard data transmission protocols or specifications are appropriate for such a wireless data communication. Examples of standard data transmission protocols or specifications are the Medical Device Radiocommunications Service (MICS), the Bluetooth Low Energy (BLE) protocol, the Zigbee specification, the long range wide area network (LoRaWAN) protocol, the wireless personal area network (WPAN) specification, the low-power wide-area network (LPWAN) specification, the wireless local area network (WLAN) specification, the Global System for Mobile Communications (GSM) specification, the Long-Term Evolution (LTE) standard, and the fifth-generation technology standard for broadband cellular networks (5G).

[0046] In an embodiment, the housing is hermetically sealed. Such a sealing protects all components within the housing and therefore ensures the proper functionality of the implantable medical device.

[0047] In an embodiment, the implantable medical device contains a maximal energy of 40 J, in particular of 35 J, in particular of 30 J, in particular of 25 J, in particular of 20 J.

[0048] In another aspect, the present invention relates to a method for implanting an implantable medical device, according to the preceding explanations, in a patient. In this context, the method comprises the steps explained in the following.

[0049] In a first step, an incision below or at the height of the patient’s sternum is made. For example, an incision is made subxiphoidally.

[0050] In a further method step, a housing of the implantable medical device is pushed through the incision into a body of the patient to a substemal area such that a terminus of the housing enters the body of the patient first, wherein the housing comprises two termini, wherein the two termini are arranged on the housing in such a way that the distance along the housing between them is maximal.

[0051] 24.107P-WO | 02.09.2025 In an even further method step, the housing is rotated around an axis, wherein the axis is parallel to a vector intersecting the two termini.

[0052] In an embodiment, the method comprises an additional step, in which an electrode lead of the implantable medical device is pushed through the incision. By using the same incision for the housing and the electrode lead the impact on the patient’s body is reduced as only one cut is necessary. The electrode lead is preferable pushed in an area left of a patient’s heart in order to create an optimal field for defibrillation.

[0053] In another embodiment, the terminus which enters a body first, is blunt or radiused. The blunt or radiused terminus is pushed non-traumatically without additional tools into a body. Being blunt or radiused makes a non-traumatic insertion possible.

[0054] All embodiments of the implantable medical device can be combined in any desired way and can be transferred either individually or in any arbitrary combination to the described method. Likewise, all embodiments of the described method can be combined in any desired way and can be transferred either individually or in any arbitrary combination to the implantable medical device.

[0055] The idea of the invention shall subsequently be described in more detail with reference to the embodiments as shown in the drawings. Herein:

[0056] Fig. 1 shows a schematic drawing of the upper body of a patient with his heart, his sternum and an implanted embodiment of an implantable medical device;

[0057] Fig. 2A shows a schematic lateral view illustrating the surface of the housing of the implantable medical device of Figure 1;

[0058] Fig. 2B shows a schematic lateral view illustrating the inside of the housing of the implantable medical device of Figure 1;

[0059] 24.107P-WO | 02.09.2025 Fig. 3 shows a schematic lateral view illustrating the termini of a housing of the implantable medical device of Figure 1;

[0060] Fig. 4 shows a schematic perspective view illustrating the length, the height and the width of the housing of the implantable medical device of Figure 1;

[0061] Fig. 5 shows a schematic lateral view illustrating a housing of an implantable medical device comprising a fixture;

[0062] Fig. 6 shows a schematic lateral view illustrating the housing and the electrode lead of the implantable medical device of Figure 1;

[0063] Fig. 7 shows a schematic lateral view illustrating the components arranged within the housing of the implantable medical device of Figure 1; and

[0064] Fig. 8 shows a schematic lateral view illustrating a first section and a second section of a housing of another embodiment of an implantable medical device.

[0065] Subsequently, embodiments of the invention shall be described in detail with reference to the drawings. In the drawings, like reference numerals designate like structural elements.

[0066] It is to be noted that the embodiments are not limiting for the invention, but merely represent illustrative examples.

[0067] Fig. 1 shows a schematic drawing of a patient’s upper body, wherein a sternum S and a heart HP of the patient is shown. Fig. 1 also shows that an implantable medical device 1 is implanted substernally. Furthermore, the implantable medical device 1 is shown as being non-transvenously implanted, that is an implantation external to a patient’s heart HP. In particular, an electrode lead 2 of the implantable medical device 1 shall rest outside of a patient’s heart HP and shall not extend transvenously into a patient’s heart HP.

[0068] 24.107P-WO | 02.09.2025 On a surface of the housing 10 a first electrode pole 101 and a second electrode pole 102 are arranged (cf. Fig. 2A for more details). The electrode lead 2 comprises a third electrode pole 20 (cf. Fig. 6 for more details).

[0069] Fig. 2A and Fig. 2B show a schematic drawing of the housing 10. Fig. 2A shows a surface of the housing 10, wherein the housing 10 comprises a first electrode pole 101 and a second electrode pole 102. The first electrode pole 101 and the second electrode pole 102 are arranged on the surface of the housing.

[0070] Fig. 2B shows an inside of the housing 10, wherein the housing 10 comprises an electronic module 107 comprising a stimulation unit 103 and a detection unit 104. The stimulation unit 103 is configured to provide the first electrode pole 101 and / or the second electrode pole 102 with an electric pulse to stimulate a patient’s heart HP. The detection unit 104 is configured to receive an electric signal of the same heart HP via the first electrode pole 101 and / or the second electrode pole 102.

[0071] Fig. 3 shows two termini 16, 17 of the housing 10, wherein the two termini 16, 17 are arranged on the housing 10 in such a way that the distance between them is maximal. Furthermore, an axis X intersects the two termini 16, 17 of the housing 10.

[0072] Fig. 4 shows that the housing 10 extends in a longitudinal extension direction D. Moreover, it shows that the housing 10 has a length L, a height H and a width W, wherein the length L is the longest extension of the longitudinal extension direction D. The height H and the width W are perpendicular to the longitudinal extension direction. Typically, the width W is the bigger one of the height H and the width W. However, Fig. 4 shows the housing as a cylinder with a round cross-sectional area 100, therefore the height H and the width W amount to the same value.

[0073] Due to the round cross-sectional area 100 the housing 10 fits well into the slightly bend shape of the sternum S and therefore uses the substernal space efficiently by allowing a tight fit to the sternum S. Moreover, the housing 10 is shown to have an elongated shape.

[0074] 24.107P-WO | 02.09.2025 The cross-sectional area 100 lies in a range of 1.4 cm2to 4.0 cm2. Due to this small cross- sectional area 100, an incision, which is necessary to implant the implantable medical device 1, can be rather small compared to an incision needed for implanting an implantable medical device known from prior art. The incision only needs to be big enough to accommodate the cross-sectional area 100 of the housing 10. The implantable medical device 1 is implanted within a body of a patient by pushing the implantable medical device 1 through the incision into the patient’s body such that a terminus 16 of the housing 10 (cf. Fig. 3 for more details) enters the body of the patient P first.

[0075] Furthermore, during an implantation, after the housing 10 has been pushed into a patient’s body, the housing 10 may be rotated about the axis X (cf. Fig. 3 for more details) to allow an optimized positioning of the first electrode pole 101 and the second electrode pole 102 (cf. Fig. 2A for more details).

[0076] Fig. 5 shows another embodiment of an implantable medical device 1 comprising a suture hole 13 as a fixture. A thread can be threaded through the suture hole for fixing the implantable medical device 1 to a body part or an anatomical structure of a patient carrying the implantable medical device 1 in an implanted state. The implantable medical device 1 of Fig. 5 is essentially the same as the implantable medical device 1 of Fig. 2A and Fig. 3. The features of both embodiments can well be combined. The fixture 13 is arranged on one terminus 17 (cf. Fig. 3 for more details). However, it could likewise be arranged on the other terminus 16.

[0077] Fig. 6 shows an embodiment of the implantable medical device 1, wherein the medical device 1 comprises an electrode lead 2 having a third electrode pole 20. The electrode lead 2 is connected with the housing 2 via one terminus 16 (cf. Fig. 3 for more details). However, it could likewise be connected via the other terminus 17. The third electrode pole 20 is arranged at a distal position close to a tip of the electrode lead 2. It can also encompass the tip of the electrode lead 2.

[0078] Fig. 7 shows an embodiment of the implantable medical device 1, wherein the housing 10 comprises a capacitor arrangement 105 and at least one energy source 106 connected to the

[0079] 24.107P-WO | 02.09.2025 capacitor arrangement 105. The capacitor arrangement 105 comprises at least one capacitor. The electronic module 107, comprising the stimulation unit 103 and the detection unit 104, is shown as well (cf. Fig. 2B for more details).

[0080] A first contact 14 establishes an electric connection between the electronic module 107 and the capacitor arrangement 105. A second contact 15 establishes an electric connection between the capacitor arrangement 105 and the energy source 106. The first contact 14 and the second contact 15 are arranged in the same contact direction CD. In the embodiment shown in Fig. 7, the electric connection is realized as a plug connection.

[0081] The electronic module 107, the capacitor arrangement 105 and the energy source 104 are arranged in an arrangement axis that runs along the contact direction CD. An arrangement in the arrangement axis makes a construction of the implantable medical device 1 easy as each of the electronic module 107, the capacitor arrangement 105 and the energy source 106 can simply be stacked on top of any other of these components.

[0082] Fig. 8 shows a lateral view illustrating an embodiment of the housing 10 having a bend or curvature facing to the top in the illustration of Fig. 8. The housing 10 comprises a first section 11 and a second section 12. The bend or curvature faces towards a sternum. The first electrode pole 101 and the second electrode pole 102 are arranged on that side of the housing

[0083] 10 facing away from a sternum and thereby facing towards a patient’s heart.

[0084] The first section 11 extends in a first longitudinal extension direction DI. The first section

[0085] 11 has a first length LI, a first height Hl and a first width Wl, wherein the first length LI is the longest extension of the first section 11 in the first longitudinal extension direction DI. The first height Hl and the first width Wl are perpendicular to the first longitudinal extension direction. The first width Wl is the bigger one of the first height Hl and the first width W 1.

[0086] The second section 12 extends in a second longitudinal extension direction D2. The second section 22 has a second length L2, a second height H2 and a second width W2, wherein the second length L2 is the longest extension of the second section 12 in the second longitudinal

[0087] 24.107P-WO | 02.09.2025 extension direction D2. The second height H2 and the second width W2 are perpendicular to the second longitudinal extension direction. The second width W2 is the bigger one of the second height H2 and the second width W2. Each of the first section 11 and the second section 12 comprises an outer surface extending along the respective width Wl, W2 and length LI, L2, and said outer surfaces of the first section 11 and the second section 12 are each flat.

[0088] In the illustration of Fig. 8, a first alignment plane Pl is aligned with the outer surface of the first section 11 and a second alignment plane P2 is aligned with the outer surface of the second section 12. The first alignment plane Pl is arranged at an angle A to the second alignment plane P2, wherein the angle A is larger than 0° and smaller than 90°.

[0089] 24.107P-WO | 02.09.2025 List of reference numerals

[0090] 1 Implantable medical device

[0091] 10 Housing

[0092] 100 Cross-sectional area

[0093] 101 First electrode pole

[0094] 102 Second electrode pole

[0095] 103 Simulation unit

[0096] 104 Detection unit

[0097] 105 Capacitors

[0098] 106 Energy source

[0099] 107 Electronic Module

[0100] 11 First section

[0101] 12 Second section

[0102] 13 Fixture

[0103] 14 First contact

[0104] 15 Second contact

[0105] 16,17 Termini

[0106] 2 Electrode lead

[0107] 20 Third electrode pole

[0108] A Angle

[0109] CD Contact direction

[0110] D Longitudinal extension direction

[0111] DI First longitudinal extension direction

[0112] D2 Second longitudinal extension direction

[0113] H Height

[0114] Hl First Height

[0115] H2 Second Height

[0116] HP Heart

[0117] L Length

[0118] LI First length

[0119] L2 Second length

[0120] 24.107P-WO | 02.09.2025 Pl First alignment plane

[0121] P2 Second alignment plane

[0122] S Sternum

[0123] W Width W1 First width

[0124] W2 Second width

[0125] X Axis

[0126] 24.107P-WO | 02.09.2025

Claims

1. Claims1. An implantable medical device (1) for substemal implantation externally to a patient’ s heart (HP) comprising a housing (10), wherein the housing (10) comprises a first electrode pole (101), a second electrode pole (102), wherein the first electrode pole (101) and the second electrode pole (102) are arranged on a surface of the housing (10), a stimulation unit (103) configured to provide the first electrode pole (101) and / or the second electrode pole (102) with an electric pulse to stimulate a patient’s heart (HP), and a detection unit (104) configured to receive an electric signal of the same heart (HP) via the first electrode pole (101) and / or the second electrode pole (102), characterized in that a cross-sectional area (100) of the housing (10) lies in a range of 1.4 cm2to 4.0 cm2.

2. Implantable medical device (1) according to claim 1, characterized in that the cross- sectional area of the housing (10) is round or oval.

3. Implantable medical device (1) according to claim 1 or 2, characterized in that a volume of the housing (10) lies in a range of 15 cm3to 35 cm3.

4. Implantable medical device (1) according to any of the preceding claims, characterized in that the housing (10) extends in a longitudinal extension direction (D), has a length (L) being the longest extension of the housing (10) in the longitudinal extension direction (D), a width (W), and a height (H), wherein the width (W) and the height (H) are perpendicular to the longitudinal extension direction (D), wherein the width (W) is the bigger one of the height (H) and the width (W), wherein a length-to- width ratio of the housing is at least 4: 1.

5. Implantable medical device (1) according to any of the preceding claims, characterized in that the implantable medical device (1) comprises a fixture (13) for24.107P-WO | 02.09.2025fixing the implantable medical device (1) to a body part of a patient carrying the implantable medical device (1) in an implanted state.

6. Implantable medical device (1) according to any of the preceding claims, characterized in that the housing (10) is rigid.

7. Implantable medical device (1) according to any claim 1 to 5, characterized in that the housing (10) comprises at least one flexible section between two rigid sections.

8. Implantable medical device (1) according to any of the preceding claims, characterized in that the implantable medical device (1) further comprises an electrode lead (2) comprising a third electrode pole (20).

9. Implantable medical device (1) according to claim 8, characterized in that the electrode lead (2) is an epicardial electrode.

10. Implantable medical device (1) according to any of the preceding claims, characterized in that the housing (10) further comprises a capacitor arrangement(105) comprising at least one capacitor and at least one energy source (106) connected to the capacitor arrangement (105).

11. Implantable medical device (1) according to claim 10, characterized in that the cross- sectional area of the housing (10) is round and in that the at least one energy source(106) and the capacitor arrangement (105) have a round cross-sectional area.

12. Implantable medical device (1) according to claim 10 or 11, characterized in that the implantable medical device (1) comprises a first contact (14) and a second contact (15), wherein the first contact (14) forms an electrical connection between the capacitor arrangement (105) and an electronic module comprising the stimulation unit (103) and the detection unit (104), and wherein the second contact (15) forms an electrical connection between the capacitor arrangement (105) and the energy source24.107P-WO | 02.09.2025(106), wherein the first contact (14) is arranged in a contact direction (CD), wherein the second contact (15) is arranged in the same contact direction (CD).

13. Implantable medical device (1) according to any of the preceding claims, characterized in that the housing (10) comprises a first section (11) and a second section (12), wherein the first section (11) extends in a first longitudinal extension direction (DI), has a first length (LI) being the longest extension of the first section in the first longitudinal extension direction (DI), a first width (Wl) and a first height (Hl), wherein the first width (Wl) and the first height (Hl) are perpendicular to the first longitudinal extension direction (DI), wherein the first width (Wl) is the bigger one of the first height (Hl) and the first width (Wl), and wherein the second section (12) extends in a second longitudinal extension direction (D2), has a second length (L2) being the longest extension of second section in the longitudinal extension direction (D2), a second width (W2) and a second height (H2), wherein the second width (W2) and the second height (H2) are perpendicular to the second longitudinal extension direction (D2), wherein the second width (W2) is the bigger one of the second height (H2) and the second width (W2), wherein each of the first section (11) and the second section (12) comprises an outer surface extending along the respective width (Wl, W2) and length (LI, L2) and said outer surfaces of the first section (11) and the second section (12) are each flat, wherein a first alignment plane (Pl) aligned with the outer surface of the first section (11) is arranged at an angle (A) to a second alignment plane (P2) aligned with the outer surface of the second section (12), wherein the angle (A) is larger than 0° and smaller than 90°.

14. Implantable medical device (1) according to any of the preceding claims, characterized in that the implantable medical device (1) is a non-transvenous implantable cardioverter-defibrillator.

15. Method for implanting the implantable medical device (1) according to any of the preceding claims in a patient (P), the method comprising the following steps:24.107P-WO | 02.09.2025a) making a subxiphoidal incision, b) pushing a housing (10) of the implantable medical device (1) through the incision into a body of the patient to a substernal area such that a terminus (16) of the housing (10) enters the body of the patient (P) first, wherein the housing (10) comprises two termini (16, 17), wherein the two termini (16, 17) are arranged on the housing (10) in such a way that the distance between them is maximal, c) rotating the housing (10) around an axis (X), wherein the axis (X) is parallel to a vector intersecting the two termini (16, 17).24.107P-WO | 02.09.2025

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