System of an implantable medical device and an activation component

Abstract

The disclosure refers to a system comprising an implantable medical device (10, 110) and an activation component (14, 15, 30, 34, 35, 41, 42), wherein the medical device (10, 110) comprises a housing (112) and an antenna (13, 115), wherein an electrical circuit with a power supply is accommodated within the housing (112), wherein the antenna (13, 115) is electrically connected to the electrical circuit, wherein a first housing section (12, 112) forms medical device's ground or is electrically connected to medical device's ground. To eliminate possible sources of operating errors with regard to and to increase reliability of the activation process, the medical device is configured to adopt a first state and a second state such that in said first state a first signal is present at a predefined reference point (3) of the electrical circuit and that the first signal can be differentiated from a second signal by a sensor at said reference point (3) indicating said second state, wherein the medical device is further configured such that in the first state an electrical connection is provided between the antenna (13, 115) and the first housing section (12, 112) by the activation component (14, 15, 30, 34, 35, 41, 42) and such that the second state is adopted if said electrical connection between the antenna (13, 115) and the first housing section (12, 112) is disconnected thereby initializing the activation. The disclosure further refers to a respective activation method.

Description

[0001] Applicant: BIOTRONIK SE & Co. KG

[0002] Date: 25.09.2025

[0003] Our Reference: 23.123P-WO

[0004] SYSTEM OF AN IMPLANTABLE MEDICAL DEVICE AND AN ACTIVATION

[0005] COMPONENT

[0006] The disclosure relates to a system comprising an implantable medical device and an activation component as well as to an activation method for such system.

[0007] Miniature medical devices for implantation, e.g. sensors for temporary or permanent implantation in the cardiovascular system, e.g. for measuring local pressure, temperature, 02, flow measurement, etc., if applicable, with their own power supply and telemetry, have been of interest for some time for remote monitoring of critically ill patients. An implantable pressure sensor is, for example, described in document US 10,524,673 B2.

[0008] These implantable medical devices usually comprise a housing and an antenna for communication with a remote device. Further, an electrical circuit with a power supply and a processor is accommodated within the housing for measuring physiological parameters, controlling the device and providing therapy signals, if applicable. The antenna for telemetry is electrically connected to the electrical circuit.

[0009] Such medical devices are usually stored in a power saving state prior implantation in which the power consumption is extremely low - the so-called shelf mode. In connection with implantation, the medical device is activated in such a way that it is transferred to an implantation state in which it uses a higher energy demand and in which, for example, regular measurements and remote control can be provided. It is important, that the activation step works correctly to avoid difficulties during implantation and to ensure reliable operation of the medical device after activation within the patient’s body. At present, manual or automatic activation, for example, using a magnetic field or a timecontrol is used. The disadvantage of manually activating the implant by detecting a magnetic field of sufficient strength is that the activation and subsequent testing must mandatory be performed by medical personnel prior to implantation since the activation after implantation would require a very strong magnet due to the required working range therefor (approx. 15 cm). A high magnetic field for activation after implantation is not suitable for general use because of its potential danger for the patient involved. When the medical device is regularly manually activated prior implantation there is a risk that magnetic activation will be forgotten and that, therefore, the implanted device cannot be used and needs to be explanted. Furthermore, with this solution it is possible to accidentally activate the medical device long before the implantation process begins. Alternatively, for activation of the device a magnet in packaging of the medical device may be moved out of reach. The disadvantage of such automatic activation is that a permanent magnet would have to be integrated, for example in the packaging of the implant which increases the costs for this system. Such activation mechanism further requires having a sensor to detect the magnetic field within the medical device which shall not be used with most implantable sensors. The additional installation of such sensor would be costly and space consuming. If one uses time-controlled activation of the medical device by implantation planning it is usually required that the medical device is informed of the implantation time at least 24 hours before implantation. This can be realized using a radio frequency (RF) communication interface developed for this purpose. However, this method offers the lowest tolerance to operating error and flexibility in everyday clinical practice and is therefore not considered for practical implementation.

[0010] Accordingly, it is an object of the present invention to provide a more reliable solution for activation of the medical device. It is a further object to eliminate possible sources of operating errors with regard to and to increase reliability of the activation process. Furthermore, it is desired to initiate the activation process automatically during the implantation procedure.

[0011] The above object is solved by a system having the features of claim 1 and an activation method having the features of claim 13.

[0012] 23.123P-WO | 25.09.2025 In particular, the object is solved by a system comprising an implantable medical device and an activation component, wherein the medical device comprises a housing and an antenna, wherein an electrical circuit with a power supply is accommodated within the housing, wherein the antenna is electrically connected to the electrical circuit, wherein a first housing section forms medical device’s ground (i.e. the electric reference potential) or is electrically connected to medical device’s ground, wherein the medical device is configured to adopt a first state and a second state such that in said first state a first signal is present at a predefined reference point of the electrical circuit and that the first signal can be differentiated from a second signal by a respective sensor at said reference point indicating said second state, wherein the medical device is further configured such that in the first state an electrical connection is provided between the antenna and the first housing section by the activation component and such that the second state is adopted if said electrical connection between the antenna and the first housing section is disconnected.

[0013] In slightly other words, the object is solved by a system comprising an implantable medical device and an activation component, wherein the medical device comprises a housing and an antenna, wherein an electrical circuit with a power supply is accommodated within the housing, wherein the antenna is electrically connected to the electrical circuit, wherein a first housing section forms medical device’s ground (i.e. the electric reference potential) or is electrically connected to medical device’s ground, wherein the medical device is configured to adopt a first state and a second state such that in said first state a first signal is present at a predefined reference point of the electrical circuit and that the medical device is further configured by means of a respective sensor to differentiate the first signal from a second signal at said reference point indicating said second state, wherein the medical device is further configured to comprise in the first state an electrical connection between the antenna and the first housing section by the activation component and to not have an electrical connection in the second state if said electrical connection between the antenna and the first housing section is disconnected.

[0014] The above system comprises the implantable medical device and an activation component wherein the activation component facilitates the transition from the first state (e.g. shelf mode) to the second state (e.g. active or implantation state) by a disconnection of an

[0015] 23.123P-WO | 25.09.2025 electrical connection provided by the activation component. The disconnection may be facilitated by removal of the activation component from the medical device if, for example, the activation component is separate from the medical device or by separating two mechanically connected elements in such a way that the electrical connection no longer exists if, for example, the mechanically connected elements are coupled to the medical device. The medical device is configured to detect the respective state by measuring, for example, a voltage signal at a predefined reference point of the electrical circuit accommodated within the housing using the sensor. The power supply provides the energy for the corresponding voltage signal at a predefined reference point of the electrical circuit. As soon as the second state of the medical device is detected within the electrical circuit of the medical device, the activation of the medical device may be triggered and a wake-up procedure may be conducted.

[0016] For example, in the first state the voltage signal may be approximately constant. In the second state, the voltage signal at the predefined reference point may be a time-varying voltage signal that may be detected by the electrical circuit or vice versa. E.g., the signal in the second state may contain rising or falling edges corresponding to temporal changes of the voltage triggered by, for example, a signal or pulse generator. Such an edge may be detected by the electrical circuit of the medical device which thereby recognizes that a transition from the first state to the second state has occurred (e.g. by means of a sensor or other suitable means). If the second state of the medical device is detected, a predefined wake-up procedure may be facilitated thereby transferring the medical device into a state in which it operates in its predefined operating mode requiring a higher energy consumption.

[0017] The implantable medical device may be an implantable (miniature) pressure sensor, implantable intracardiac pacemaker (sometimes also referred to as leadless pacemaker) or a cardiac monitor (sometimes also referred to as loop recorder). The implantable pressure sensor may be configured for implantation within the pulmonary artery.

[0018] The medical device housing may provide a hermetical closure relative to the environment. The housing may have a capsule shape, or a hollow cylinder shape or cuboid shape and may comprise at its outer surface a biocompatible material, for example Titanium or a Titanium

[0019] 23.123P-WO | 25.09.2025 alloy. The housing may comprise (may enclose) an electrical circuit, a processor, a data memory, a power supply and elements for transmitting and / or receiving data comprising or connected to an antenna which is, for example, a wire antenna. The processor, data memory, the power supply as well as elements for transmitting and / or receiving data may be electrically connected to the electrical circuit. The housing comprises a first housing section and may comprise a second housing section, as well. In one embodiment, the first housing section comprises the whole housing of the medical device. The first housing section is configured such that it forms the medical device’s ground or is electrically connected to the medical device’s ground.

[0020] The system uses (electrical connection to) the antenna to facilitate the transition from the first state to the second state prior and / or during implantation. The antenna may be a RF (radio frequency) antenna for communication within the RF range, in particular within the Medical Implant Communication System (MICS) range between 401-406 MHz. Alternatively, the antenna may be for Bluetooth Low Energy Communication using the range between 2402-2480 MHz for communication. In particular, in the first state the antenna is electrically connected to the first housing section, i.e. to the medical device’s ground, using the activation component. Accordingly, in the first state the electrical circuit is connected via the antenna to the medical device’s ground. In contrast, in the second state the electrical connection of the antenna to the medical device’s ground is disconnected thereby causing a change in the signal at the predefined reference point. The transition from the first state to the second state of the medical device is recognized by the sensor monitoring the signal at the predefined reference point (i.e. the sensor monitors whether the signal at the predefined reference point changes from the first signal to the second signal), e.g., if the sensor is a voltage sensor the sensor recognizes the change to the second signal by detection of a rising or falling edge in the voltage signal. For example, the voltage sensor may comprise a Schmitt-trigger, a flip-flop or a latch circuit to detect such rising or falling edge.

[0021] The activation component may be a removable or otherwise detachable single element or a component of a more complex device, e.g. a catheter or sleeve. For example, the activation component may be integrated within or attached to a catheter as explained below in more

[0022] 23.123P-WO | 25.09.2025 detail. Alternatively, the activation component may be coupled or attached to the medical device. The activation component may be a single piece or may comprise several pieces.

[0023] The above system provides the possibility to realize an automatic activation of the medical device. In one embodiment, the activation component is configured such that it mandatory needs to be removed prior usage of the whole system and / or prior implantation or is automatically removed during the implantation process. For example, the size and / or shape of the activation component is chosen such that the next step in the implantation process is impeded thereby forcing the user (e.g. the health care practitioner - HCP) to remove the activation component manually. For example, the system comprising the medical device and the activation component may be configured such that it cannot be introduced into an airlock if the activation component is not removed. Accordingly, the HCP is forced to remove the activation component. Hence in one embodiment, the activation component is configured to have a shape or size that cannot be introduced in a blood vessel of a human being. In another example, the implantation process comprises a step in which a predefined device is automatically removed prior normal operation of the medical device. This removal causes the automatic removal of the activation component integrated within or fixed to the predefined device and thereby a transition into the second state of the medical device.

[0024] The above system provides a more reliable activation of the medical device and eliminates possible sources of operation errors during activation. Accordingly, it increases reliability of the activation process. Additionally, the implantation process is simplified and may be conducted with less power consumption prior implantation. Additionally, it is possible to provide the implantation with the activation of the medical device in a more flexible way. Since there is no time dependent activation of the medical device, implantation delay or postponement does not have any influence on the activation process (i.e. hinder or disrupt the implantation process). Further, an accompanying technical support is not required for activation of the medical device.

[0025] In one embodiment, the antenna is electrically connected to the remaining electrical circuit via a decoupling capacitor and wherein the predefined reference point is arranged between the decoupling capacitor and the remaining electrical circuit. Preferably, the remaining

[0026] 23.123P-WO | 25.09.2025 electrical circuit and the decoupling capacitor are connected to the power supply. Using such circuitry, a cost-efficient and reliable possibility of activation using a voltage sensor of the medical device is provided which can be implemented for both antenna arrangements explained below.

[0027] In one embodiment, the antenna is formed by or integrated within a second housing section different from the first housing section or the antenna is formed by an elongated element electrically connected to the electrical circuit via a feedthrough. With regard to the first alternative in which the antenna is formed by or integrated within a second housing section the second housing section is electrically connected to the electrical circuit. If the antenna is formed by or integrated within the second housing section, the first housing section and the second housing section are electrically isolated from each other in the second state, for example by an electrically isolating component such as an electrically isolating ring accommodated between the first and the second housing section. This component, however, is fixed to the housing such that it hermetically seals the housing. In this embodiment, in the first state the activation component bypasses the electrical isolation and directly connects the first housing section and the second housing section. After removal of the activation component or disconnection of two parts of the activation component, the electrical isolation is reestablished. If the antenna is formed as an elongated element, e.g. a bar or wire loop, which is electrically connected to the electrical circuit of the medical device in a generally known way via a feedthrough, the antenna projects from the feedthrough extending through an opening within the housing to the outside. In this case, the antenna may be used to electrically connect the electrical circuit to the first housing section. For that, e.g., the antenna may be bent such that it directly contacts the first housing section thereby providing the electrical connection.

[0028] In one embodiment, the activation component is configured such that it provides a mechanical means for establishing a direct electrical connection of the antenna and the first housing section. For example, the activation component may be a sleeve configured to exert a force to an electrically conducting element, wherein the electrically conducting element is separate from the antenna or being the antenna such that said element forms an electrical connection to the first housing section in the first state. Alternatively, in one embodiment,

[0029] 23.123P-WO | 25.09.2025 the activation component is configured such that it forms the electrical connection between the antenna and the first housing section. In this case it bypasses the electrical isolation between the antenna (which may be realized as a second housing section or an elongated element) and the first housing section. For example, an activation component in the form of a sleeve or flap may comprise an electrically conducting platelet, rod or wire, wherein the rod or wire may have a circular or rectangular cross-section. The sleeve or flap may be arranged such with regard to the medical device that the electrically conducting platelet, rod or wire provide the electrical connection of the antenna and the first housing section in this position. Both possibilities provide a reliable and cost-efficient solution for providing an electrical connection between the antenna and the first housing section.

[0030] In one embodiment, said electrically conducting element projecting from the housing is a wire loop. For example, the medical device may comprise at least one wire loop which may be used to fix the medical device within a vessel (e.g. a blood vessel) of the patient. For example, the medical device may comprise two wire loops accommodated at opposite ends of the medical device housing in longitudinal direction. Such wire loop may be in a folded or compressed state prior implantation, e.g. by a sleeve of a catheter, and may transition into an expanded state during or after implantation, for example during release of the medical device from the catheter. In the expanded state, the wire loop is fixed within the respective vessel of the patient at the target location and has a distance to the second wire loop or the first housing section such that the electrical connection is disconnected. In one embodiment, in the compressed state such wire loop has a greater length than in the expanded state whereas the width of the wire loop in the expanded state is greater than in the compressed state thereby facilitating the disconnection. In one embodiment, the medical device may be introduced into the patient’s body and moved within the patient’s body by a catheter having a protecting sleeve at its distal end that compresses the at least one wire loop such that it provides an electrical connection between the antenna and a first housing section due to the loop’s greater length in the compressed state. Alternatively, the protecting sleeve comprises, for example, an electrically conducting wire forming an electric conduction between the antenna and the first housing section. With regard to both aforementioned alternatives, the antenna may be integrated within or formed by a second housing section or formed as a wire loop.

[0031] 23.123P-WO | 25.09.2025 In one embodiment and as explained above, the predefined reference point is arranged between the decoupling capacitor and the remaining electrical circuit, wherein the antenna is electrically connected to the remaining electrical circuit via a decoupling capacitor. Preferably, the remaining electrical circuit and the decoupling capacitor are connected to the power supply. Preferably within the remaining electrical circuit, the predefined reference point is electrically connected via a second capacitor having a capacitance Cl to a signal pulse generator, wherein in the first state the second capacitor is parallel to the decoupling capacitor having a capacitance C2, wherein, for example, Cl < C2. In one embodiment, Cl < C2 / 10. Preferably, the decoupling capacitor, the predefined reference point and the second capacitor are connected to the power supply. In one embodiment, the first connecting lead of the second capacitor is coupled to the decoupling capacitor. The second connecting lead of the second capacitor is electrically conducting coupled to a signal or pulse generator that introduces signals into the electrical circuit. In the first state, when the second capacitor is parallel to the decoupling capacitor having a capacitance C2, wherein, for example, Cl < C2, detection of signals introduced into the electrical circuit by the signal or pulse generator is prevented. For example, the signal or pulse generator provides a signal having a rectangular function, for example a 100 ps pulse every 1 s to 60 s. In the first state and for the connected capacitances Cl and C2, the signal variation caused by signal or pulse of the signal generator is so small that it cannot be distinguished from the signal produced in the second state. However, the rectangular signal and the above-mentioned capacitances Cl and disconnected C2 cause a rising or falling voltage edge in the second state that may be detected as indicated above to recognize the transition from the first state to the second state of the medical device. For example, a suitable range for C2 is, for example, 1 pF to 1 pF, e.g. C2 = 100 nF. In the latter case, for example, Cl= 100 pF. This circuitry allows an easy and cost-efficient detection of the first and second state of the medical device.

[0032] In one embodiment, the decoupling capacitor and the second capacitor are each connected to the power supply via a current limiting resistor R2. This current limiting resistor is for example, large enough to limit the current that flows if the second capacitor Cl is periodically connected to ground. The electrical circuit may further comprise a second current limiting resistor Rl. In one embodiment, the second capacitor Cl is located between

[0033] 23.123P-WO | 25.09.2025 the current limiting resistor R1 and R2. In one embodiment, R2 is smaller than R1. A suitable range for the current limiting resistor R1 is, 100 kQ to 10 GO. In one embodiment, the decoupling capacitor and the second capacitor are each connected to the power supply via the current limiting resistors R1 and R2.

[0034] The signal or pulse generator may be configured as main clock or main timer of the implantable medical device. Further, the signal or pulse generator may also be connected to the power supply.

[0035] In one particularly preferred embodiment, the present invention is directed at a system comprising an implantable medical device and an activation component, wherein the medical device comprises a housing and an antenna, wherein an electrical circuit with a power supply is accommodated within the housing, wherein the antenna is electrically connected to the electrical circuit, wherein a first housing section forms medical device’s ground (i.e. the electric reference potential) or is electrically connected to medical device’s ground, wherein the medical device is configured to adopt a first state and a second state such that in said first state a first signal is present at a predefined reference point of the electrical circuit and that the medical device is further configured by means of a respective sensor to differentiate the first signal from a second signal at said reference point indicating said second state, wherein the medical device is further configured to comprise in the first state an electrical connection between the antenna and the first housing section by the activation component and to not have an electrical connection in the second state if said electrical connection between the antenna and the first housing section is disconnected, wherein the antenna (13, 115) is electrically connected to the remaining electrical circuit via a decoupling capacitor (C2) and wherein the predefined reference point (3) is arranged between the decoupling capacitor (C2) and the remaining electrical circuit, wherein the remaining electrical circuit and the decoupling capacitor are connected to the power supply, and wherein the predefined reference point (3) is electrically connected via a second capacitor having a capacitance Cl to a signal or pulse generator capable of introducing signals into the electrical circuit, wherein in the first state the second capacitor Cl is parallel to the decoupling capacitor having a capacitance C2, wherein Cl < C2 preventing detection

[0036] 23.123P-WO | 25.09.2025 of signals from the signal or pulse generator, wherein in the second state the second capacitor is disconnected to ground facilitating detection of signals from the signal or pulse generator.

[0037] In one embodiment, the system further comprises a catheter having an elongated shaft, wherein the activation component is fixed to the outer surface of the catheter shaft and / or to a distal end of the catheter shaft. This embodiment provides a very reliable and cost-efficient possibility to activate the medical device since the activation component is integrated into the catheter device. In one embodiment, the catheter shaft comprises a sleeve at its distal end for covering the medical device during implantation. This sleeve may be configured such that it exerts a force to an electrically conducting element projecting from the housing such that this conducting element provides an electrical connection of the antenna and the first housing section. Alternatively, this sleeve may comprise an electrically conducting element such as a wire or a rod that may be attached to an inner surface of sleeve providing the electrical connection between the antenna (e.g. integrated into or forming a second housing section) and the first housing section.

[0038] The above object is further solved by an activation method of the system of any one of the previous claims comprising the following steps:

[0039] • Providing the implantable medical device and the activation component such that the medical device is in the first state,

[0040] • Disconnecting the electrical connection provided by the activation component from the system such that the medical device is transferred into the second state, for example, by removing the activation component or by separating the activation component.

[0041] For example, the method can be carried out in that the implant is further configured such that in the first state an electrical connection is provided between the antenna and the first housing section by the activation component and such that the second state is adopted if said electrical connection between the antenna and the first housing section is disconnected.

[0042] The activation method for the above defined system may further be carried by removal of the activation component from the medical device if, for example, the activation component

[0043] 23.123P-WO | 25.09.2025 is separate from the medical device or by separating two mechanically connected elements in such a way that the electrical connection no longer exists if, for example, the mechanically connected elements are coupled to the medical device. The method therefore may also comprise the step of by measuring, for example, a voltage signal at a predefined reference point of the electrical circuit accommodated within the housing using the sensor in order to detect the respective state. As soon as the second state of the medical device is detected within the electrical circuit of the medical device, the method further comprises the activation of the medical device by conducting a wake-up procedure. The method described above and herein can well be conducted without any further intended use of the implant. The method is considered to be in one embodiment reversable by re-connecting the electrical connection provided by the activation component from the system such that the medical device is transferred back into the first state, for example, by re-placing the activation component in the original position or by re-connecting the activation component.

[0044] For example, the said electrical connection is disconnected prior implantation or during implantation. It may be automatically disconnected (e.g. be removing a respective flap being the activation component or by removing a catheter shaft) or it may be manually removed prior implantation or prior introduction into the patient’s body because otherwise the implantable medical device cannot be introduced into an airlock or catheter shaft. The activation causes transition of the medical device into an implantation state with a higher energy consumption.

[0045] In one embodiment, as explained above, the activation component is coupled to a catheter, and, in particular, to the catheter shaft. The activation component may be coupled, e.g., to the outer surface of the catheter shaft or to an inner surface of the catheter shaft. The disconnection of the electrical connection between the antenna and the first housing section may be provided by release of the medical device from the catheter or catheter shaft.

[0046] The above activation method and activation components provide a very simple, reliable and fast activation of the medical device in connection with the implantation. In one embodiment, the activation component is removed prior introduction into the patient’s body.

[0047] 23.123P-WO | 25.09.2025 The present invention will now be described in further detail with reference to the accompanying schematic drawing, wherein

[0048] Fig. 1 shows an embodiment of the medical device in an expanded state in a perspective side view,

[0049] Fig. 2 depicts a part of the electrical circuitry of the medical device including the activation component,

[0050] Fig. 3 illustrates the first state of a first embodiment of the system with the medical device and the activation component,

[0051] Fig. 4 illustrates the second state of the embodiment of Fig. 3,

[0052] Fig. 5, 6 depict the electrical circuitry part of Fig. 2 in the first state,

[0053] Fig. 7 shows the electrical circuitry part of Fig. 2 in the second state,

[0054] Fig. 8 illustrates a first specific example of the embodiment depicted in Fig. 3 comprising the medical device in the first state and the activation component with a distal end of a catheter shaft and further shows an airlock for introduction into the patient’s body, all elements in a perspective side view,

[0055] Fig. 9 depicts the elements of Fig. 8 with the medical device in the second state all elements in a perspective side view,

[0056] Fig. 10 shows a second specific example of the embodiment depicted in Fig. 3 comprising the medical device in the first state and the activation component attached to a distal end of a catheter shaft and further shows an airlock for introduction into the patient’s body, all elements in a perspective side view,

[0057] Fig. 11 illustrates a third specific example of the embodiment depicted in Fig. 3

[0058] 23.123P-WO | 25.09.2025 comprising the medical device in the first state and attached to a distal end of a catheter shaft and the activation component and further shows an airlock for introduction into the patient’s body, all elements in a perspective side view,

[0059] Fig. 12 depicts the specific example of Fig. 11 in a perspective side view, wherein the medical device is in the second state,

[0060] Fig. 13 illustrates a fourth specific example of the embodiment depicted in Fig. 3 comprising the medical device in the first state and attached to a distal end of a catheter shaft and the activation component, all elements in a perspective side view,

[0061] Fig. 14 shows a fifth specific example of the embodiment depicted in Fig. 3 comprising the medical device in the first state and the activation component, all elements in a perspective side view and the activation component partially transparent,

[0062] Fig. 15 shows a sixth specific example of the embodiment depicted in Fig. 3 comprising the medical device in the first state and the activation component, all elements in a perspective side view and the activation component partially transparent,

[0063] Fig. 16 illustrates the first state of a second embodiment of the system with the medical device and the activation component, and

[0064] Fig. 17 depicts the embodiment of Fig. 16 in the second state.

[0065] Fig. 1 shows an exemplary medical device 10 in the form of a pressure sensor which may be implanted into a patient’s vasculature using a catheter. The medical device 10 comprises a housing with a first housing section 12 and a second housing section 13 and wire loops 14, 15 projecting from the distal end and from the proximal end of the housing, respectively. The first housing section 12 and the second housing section 13 are electrically isolated from one another by an isolating ring-shaped housing section 17 located between the first housing section 12 and the second housing section 13. The housing is hermetically closed by its first

[0066] 23.123P-WO | 25.09.2025 section 12, second section 13 and ring-shaped central section 17. The medical device housing has the overall shape of an elongated cuboid. The housing contains, for example, the electronic circuit including a processor for pressure measurement, for transmitting and receiving signals, and a battery for power supply. The second housing section 13 is configured such that it forms or integrates the antenna for sending and / or receiving signals to / from a remote device. Accordingly, it is electrically connected to the electrical circuit as explained below in more detail. The first housing section 12 forms the ground (i.e. the reference potential) of the medical device 10 and is in this function electrically connected to the electrical circuit. The pressure measurement is carried out by means of two sensitive membranes (not shown), each of which is located at one larger lateral surface of the housing. The membranes are provided, for example, at lateral surfaces of the housing. The distal and proximal wire loops 14, 15 are attached to the opposite end faces of the housing, respectively. Each wire loop 14, 15 is shaped, for example, as closed three-dimensional curve providing fixation of the medical device 10 within the patient’s vessel. The fixation function is provided in a state in which the two unfolded / expanded wire loops 14 and 15 appear, for example, as an opposing pair of hooks to fix the medical device axially in the vessel. For example, the radial fixation of the medical device is based on the property of the wire loops 14, 15 to form congruent circles pressing the medical device radially with one side against the vessel wall. The wire loops 14, 15 may be made of self-expandable material such as Nitinol. For example, the fixation is provided such that the two membranes at the lateral surface are in direct blood contact thereby receiving the blood pressure. In the following, the invention is described with reference to this implantable medical device (blood pressure sensor) but is not limited thereto. It can be realized similarly for other implantable devices such as Implantable intracardiac pacemakers or implantable cardiac monitors as well.

[0067] In one specific example of an embodiment of the system comprising the medical device and the activation component is shown in Fig. 11 and 12, in which the medical device 10 is attached to the outer surface of a catheter shaft 27 by a holder 21. Further, in this embodiment, the wire loop 14 is electrically connected to the second housing section 13 and the wire loop 15 is electrically connected to the first housing section 12. In the first state prior implantation of the medical device 10 (i.e. the shelf state, shown in Fig. 11) the wire loop 14 electrically contacts the wire loop 15 since they are folded / compressed in the way

[0068] 23.123P-WO | 25.09.2025 that they are in mechanical and electrical contact. In this mechanical state the medical device 10 attached to the catheter 27 may be introduced into the patient’s body through the airlock 23. In the first state, there is an electrical connection of the first housing section 12 and the second housing section 17 via the wire loops 14, 15. This means that in this example, the wire loops 14, 15 form the activation component. The first state of the medical device of this embodiment and specific example is simplified depicted in Fig. 3, wherein the dashed line 21 shows the electrical connection (via the wire loops 14, 15) between the first housing section 12 forming ground and the second housing section 13 forming the antenna. Additionally, the electrical isolation of the first housing section 12 and the second housing section 13 (in this example the isolating ring 17) is represented by the distance between these two housing sections. The first state of the medical device is further demonstrated by means of the electrical circuit part shown in Fig. 5 and 6. The operation of this circuit is explained below.

[0069] The medical device 10 may be activated during implantation, e.g. when the medical device 10 is released from the catheter shaft 27. In the same moment, the wire loops 14, 15 may expand caused, for example, by the shape memory effect, such that they then form fixation elements for fixing the medical device within the patient’s blood vessel, in particular within the pulmonary artery. The release and expansion is depicted in Fig. 12. Accordingly, after expansion the wire loops 14, 15 do not have any electrical contact anymore so that the first housing section 12 forming ground is electrically isolated from the second housing section 13 forming the antenna and the medical device 10 is transitioned into the second state. This is explained by means of a part of the electrical circuit of the medical device 10 and with reference to Fig. 2 and 5 to 7 in the following.

[0070] A part of the electrical circuit located within the housing of the medical device 10 is presented in Fig. 2, wherein the numbers 1, 2 and 3 drawn in circles represent different levels of electrical potential within this circuit. The second housing section 13 forming the antenna at an electrical potential level 2 is connected via a decoupling capacitance C2 to a predefined reference point 3. This reference point 3 is coupled via a current limiting resistance R2 parallel to a diode DI to the power source voltage level Vcc. The reference point 3 is connected via a second capacitance Cl to a signal or pulse generator represented by switch

[0071] 23.123P-WO | 25.09.2025 S2 that may be closed / opened according to the rectangular signal depicted in diagram A (in short: signal A) at the right hand side of the electrical circuit of Fig. 2. The signal generator represented by switch S2 has the electrical potential level 1. For example, the signal generated by the signal generator may have negative pulse of Ton = 100 ps represented by a closed switch S2 and a duration Toff of about 1 to 60 s between two rectangular pulses represented by an open switch S2. The signal generator S2 is further connected to the voltage level Vcc via another current limiting resistor Rl. In one embodiment R1 = 10 MO, R2 = 1 MO, Cl = 100 pF and C2 = 100 nF.

[0072] The electrical circuit works as follows in the first and second state of the medical device, wherein both states are distinguished by monitoring the voltage at reference point 3.

[0073] In the first state, prior implantation and as shown in detail in Fig. 5 and 6, the antenna of the second housing section 13 is electrically connected via the wire loop 14 to ground realized by the first housing section 12 as indicated by dashed line 21 in Fig. 3 and closed switch SI in the circuit. This state corresponds to the folded wire loops 14, 15 in electrical contact as depicted in Fig. 11. The measured voltage drop versus time t at reference point 3 during repetitive switching of S2 with Ton / Toff is depicted by diagram C (via arrow B) in Fig. 2. The state of the electrical circuit during Toff is drawn in Fig. 5. During Toff and in the first state, the decoupling capacitor C2 is charged with an electrical charge Q2 = C2 x Vcc. The second capacitor Cl has a charge QI = 0. During the time period Toff the voltage at the reference point 3 is approximately at that level Vcc (see diagram C). During the short time Ton of the rectangular pulse - represented by a closed switch S2 (shown in Fig. 6) - current flows from C2 to Cl. This current is much greater than the current that is limited by R2. Accordingly, compared to the time period Toff there is virtually no voltage drop at reference point 3 that can be detected since C2 » Cl. Hence, the first state of the medical device 10 is characterized in that the signal provided by the signal generator (represented by S2) does not cause any measurable signal change at reference point 3 and the measured signal at reference point 3 corresponds approximately to the signal depicted in diagram C over many periods of the signal A provided by the signal generator.

[0074] 23.123P-WO | 25.09.2025 This is changing as soon as the electrical contact between the antenna (second housing section 13) and ground (the first housing section 12) is disconnected. This second state of the medical device 10 is shown schematically in Fig. 4 by removal of the dashed line 21 compared with Fig. 3. Regarding the electrical circuit this second state is depicted in Fig. 7, wherein the electrical connection between the antenna (second housing section 13) at potential level 2 and ground is opened at S 1. Fig. 7 shows the situation in the electrical circuit during the time period Toff of signal A represented by an open switch at S2. When the system transitions from the first state into the second state, the charge on C2 is trapped and any current flow from C2 in the direction of the reference point 3 and Cl is inhibited. Accordingly, during the time period Toff of signal A the voltage level at reference point 3 is approximately Vcc. If then, the signal generator provides the rectangular signal during the time period Ton the second capacitance Cl is connected to ground (S2 is closed). Immediately, the voltage at reference point 3 is drawn to zero and will then rise to U = Vcc, wherein the rise time depends on T = R2 x Cl. The signal measured at reference point 3 is therefore the signal shown in diagram E (see arrow D). Accordingly, at reference point 3 a voltage drop can be detected at the voltage drop edge of this signal and may be used for automatic activation of the medical device. For example, a wake-up procedure may be automatically initiated as soon as a voltage drop greater than a pre-defined voltage limit is detected (thereby distinguishing this signal from smaller deviations of the signal, e.g. in the first state of the medical device 10).

[0075] By means of Fig. 8 to 15 different examples which provide an automatic or manual removal of the electrical connection between the antenna and ground for activation of the medical device 10 are depicted. Please note that in Fig. 8 to 10 and 15 the wire loops 14, 15 are omitted for better clarity. In these examples the wire loops 14, 15 are not electrically connected, not even in the first state of the medical device 10.

[0076] The embodiment illustrated in Fig. 8 and 9 has an activation component in the form of a flap 30 comprising an electrically conducting platelet 31 at its upper surface. The flap 30 further comprises a handle section 32 that the extents from the section supporting the platelet 31. Further, the medical device 10 is attached to the electrical the conducting platelet 31 which electrically connects the first housing section 12 and the second housing section 13. The

[0077] 23.123P-WO | 25.09.2025 assembly formed by the medical device 10 and the flap 30 is attached to a distal end of a catheter shaft 22 such that the flap 30 may be removed without separating the medical device 10 from the catheter shaft 22. Further, Fig. 8 and 9 show an airlock 23 for introduction of the medical device 10 into the patient’s body using the catheter. As the flap 30 extents from the catheter shaft 22 and medical device 10 such far to the side, i.e. its width is greater than the diameter of the opening 24 of the airlock 23, the assembly cannot be introduced into the airlock 23 opening 24 when the flap 30 is in its initial position. Accordingly, the HCP must remove the flap 30 just prior the implantation into the patient’s vasculature (see arrow H in Fig. 9). By removal of flap 30 the electrical connection between the first housing section 12 and the second housing section 13 of the medical device 10 is disconnected thereby activating the medical device 10 (i.e. transferring the medical device 10 from the first state to the second state) as explained above. Then, the activated medical device 10 may be introduced into the opening 24 of the airlock 23 (see arrow G) by catheter having catheter shaft 22 for implantation into the predefined patient’s vessel.

[0078] Fig. 10 shows another embodiment of the system comprising the medical device 10 and a catheter shaft 25 comprising an electrically conducting rod 27 at its outer surface forming a holder for the medical device 10. The electrically conducting rod 27 electrically connects the first housing section 12 and the second housing section 13 so that the medical device 10 is in its first state. In the first state, the medical device 10 may be introduced into the patient’s body. When the medical device 10 is at its target position, the medical device 10 is released from the catheter shaft 25 and thereby also from the electrically conducting rod 27. Thereby, the electrical connection between the first housing section 12 and the second housing section 13 is disconnected so that the medical device 10 transitions into its second state thereby activating the medical device 10 as explained in detail above.

[0079] In another embodiment the electrical connection between the first housing section 12 and the second housing section 13 is provided by an activation component formed by an electrically conducting wire 35 which, at the same time, fixes the medical device 10 to the catheter shaft 28. The electrical conducting wire 35 extends within an inner lumen of the catheter shaft 28 and is led out of the catheter shaft 28 at the distal end of the catheter shaft 28. There, it extends along the surface of the medical device 10 along the first housing

[0080] 23.123P-WO | 25.09.2025 section 12 and second housing section 13 thereby providing the electrical connection between both sections as shown in Fig. 13. The medical device 10 adopts its first state (shelf state) until it is at its target position with the patient’s vessel. Then, the electrical and mechanical connection of the medical device 10 to the catheter shaft 28 is removed by pulling the conducting wire 28 thereby releasing the medical device 10. Accordingly, due to the disconnection of the first housing section 12 and the second housing section 13, the medical device 10 transitions into the second state and is thereby automatically activated.

[0081] The same can be realized using a cylindrical sleeve 41 as an activation component fixed with one end at a distal end of a catheter shaft 40 and having an opening at the opposite (distal) end. Such sleeve 41 is shown in Fig. 14. The sleeve 41 accommodates / houses the medical device 10 within its inner lumen during implantation such that it is protected. Further, the sleeve 41 provides a radial outer force to the wire loops 14, 15 thereby effecting that the wire loops 14, 15 come into and stay in electrical contact thereby electrically connecting the first housing section 12 and the second housing section 13. This is accomplished by the inner diameter of the sleeve 41 which is dimensioned such that the radial force caused by the inner surface of the sleeve 41 is sufficient to bring and keep the wire loops 14, 15 in electrical contact in the area indicated by arrow K. Accommodated within the sleeve 41, the medical device 10 is moved to its target position in the patient’s body during implantation. Then, it is released from this sleeve 41 there. During this setting free, the wire loops 14, 15 expand as explained above in connection with the example shown in Fig. 11 and 12. Thereby, as indicated above, the electrical connection of the wire loops 14, 15 and thereby of the first housing section 12 and the second housing section 13 is lost and the medical device 10 is automatically activated as outlined above.

[0082] Analogously, a similar cylindrical sleeve 42 may be used as an activation component which shown in Fig. 15. This sleeve 42 is attached to the distal end of the catheter shaft 40 and comprises an opening at the opposite end. The sleeve 42 comprises an inner lumen for accommodation of the medical device 10 and an exposed, electrically conducting bar 45 at its inner surface overlapping the first and second housing section 12, 13. The inner diameter of the inner lumen of the sleeve 42 and the exposed conducting surface of the conducting bar are dimensioned such that a reliable electrical contact between the first housing section

[0083] 23.123P-WO | 25.09.2025 12 and the bar 45 and, at the same time between the second housing section 13 and the bar 45 is ensured prior and during implantation. Thereby an electrical connection between the first housing section 12 and the second housing section 13 so that the medical device 10 is in its first state. When the medical device 10 is released from the sleeve, the electrical connection is lost, the medical device 10 transitions into its second state thereby causing an automatic activation of the medical device 10 as explained above.

[0084] In Fig. 16 and 17 another embodiment of the system is schematically depicted. In this embodiment, the medical device 110 comprises a housing 112 or housing section forming the ground (i.e. the reference potential) of the medical device 110. Further, the medical device 110 comprises an antenna 115 which is electrically isolated from the housing 112 and connected to the electrical circuit within the housing 112 by a feedthrough 116. In the first state, shown in Fig. 16, the antenna 115 is electrically connected to the housing 112 which is represented by a dashed line 121. This electrical connection may be provided by a sleeve forming the activation component comprising an electrically conducting bar located at the inner surface of this sleeve or by other examples explained above with regard to first embodiment depicted in Fig. 3, 4. In one embodiment, the antenna 115 may be directly electrically connected to the housing 112 in the first state and removed from the housing 112 to provide the transition into the second state. The electrical circuit part of such medical device 110 is basically similar and operates similarly to the above embodiment shown in Fig. 2 and 5 to 7 in which a housing section is formed as an antenna. Just the reference number 13 is replaced by the antenna 115 and the first housing section 12 by the housing or housing section 112. The automatic activation is provided by removal of the electrical connection (see dashed line 121) between the antenna 115 and the ground (housing 112). The second state of this embodiment is depicted in Fig. 17.

[0085] The above explanation of the system comprising a medical device and an activation component shows that the activation can be provided automatically so that incorrect operation is eliminated. Further, the activation can be flexibly used because the activation may be provided just prior or during implantation of the medical device. Accordingly, a maximum lifetime of the medical device can provided since it transitions into the activated

[0086] 23.123P-WO | 25.09.2025 state having higher energy consumption just when it is necessary for correct operation of the medical device.

[0087] 23.123P-WO | 25.09.2025

Claims

- 23 -Claims1. A system comprising an implantable medical device (10, 110) and an activation component (14, 15, 30, 34, 35, 41, 42), wherein the medical device (10, 110) comprises a housing (112) and an antenna (13, 115), wherein an electrical circuit with a power supply is accommodated within the housing (112), wherein the antenna (13, 115) is electrically connected to the electrical circuit, wherein a first housing section (12, 112) forms medical device’s ground oris electrically connected to medical device’s ground, wherein the medical device is configured to adopt a first state and a second state such that in said first state a first signal is present at a predefined reference point (3) of the electrical circuit and that the first signal can be differentiated from a second signal by a sensor at said reference point (3) indicating said second state, wherein the medical device is further configured such that in the first state an electrical connection is provided between the antenna (13, 115) and the first housing section (12, 112) by the activation component (14, 15, 30, 34, 35, 41, 42) and such that the second state is adopted if said electrical connection between the antenna (13, 115) and the first housing section (12, 112) is disconnected.

2. The system of claim 1, wherein the antenna (13, 115) is electrically connected to the remaining electrical circuit via a decoupling capacitor (C2) and wherein the predefined reference point (3) is arranged between the decoupling capacitor (C2) and the remaining electrical circuit.

3. The system of any one of the previous claims, wherein the antenna is formed by or integrated within a second housing section (13) different from the first housing section (12) or the antenna (115) is formed by an elongated element electrically connected to the electrical circuit via a feedthrough (116).

4. The system of any one of the previous claims, wherein the activation component (30, 34, 35, 41, 42) is a component separate from the medical device (10) such that for disconnection of the electrical connection between the antenna (13) and the first housing section (12) the activation component is removed.23.123P-WO | 25.09.20255. The system of any one of the previous claims, wherein the activation component (14, 15, 30, 34, 35, 41, 42) is configured such that it provides mechanical means for establishing a direct electrical connection of the antenna (13, 115) and the first housing (12, 112) section or such that it forms the electrical connection between the antenna and the first housing section.

6. The system of any one of the previous claims, wherein the activation component comprises an electrically conducting platelet (31), rod (34, 45) or wire (35).

7. The system of any one of the previous claims, wherein the activation component is a sleeve (41, 42) configured to exert a force to an electrically conducting element, wherein the electrically conducting element (14, 15, 45) is separate from the antenna or is the antenna (115) and wherein said element forms an electrical connection to the first housing section (12, 112) in the first state.

8. The system of claim 7, wherein said electrically conducting element is a wire loop (14, 15).

9. The system of any one of the previous claims, wherein the predefined reference point (3) is electrically connected via a second capacitor having a capacitance Cl to a signal or pulse generator, wherein in the first state the second capacitor is parallel to the decoupling capacitor having a capacitance C2, wherein, for example, Cl < C2.

10. The system of any one of the previous claims, wherein the decoupling capacitor and the second capacitor are each connected to the power supply via a current limiting resistor (Rl, R2).

11. The system of any one of the previous claims further comprising a catheter having an elongated shaft (20, 22, 25, 27, 28, 40), wherein the activation component (30, 34, 35, 41, 42) is fixed to the outer surface of the catheter shaft and / or to a distal end of the catheter shaft.23.123P-WO | 25.09.202512. The system of any one of the previous claims, wherein the medical device is an implantable pressure sensor.

13. An activation method of the system of any one of the previous claims comprising the following steps:• Providing the implantable medical device (10, 110) and the activation component (14, 15, 30, 34, 35, 41, 42) such that the medical device is in the first state,• Disconnecting the electrical connection provided by the activation component from the system such that the medical device is transferred into the second state.

14. The activation method of claim 13, wherein the electrical connection provided by the activation component in the first state of the medical device (10, 110) is disconnected prior introduction into the patient’s body.

15. The activation method of claim 13, wherein the activation component (30, 34, 35, 41, 42) is coupled to the catheter shaft (20, 22, 25, 27, 28, 40) providing the implantation of the medical device, wherein the electrical connection is disconnected during release of the medical device from the catheter.23.123P-WO | 25.09.2025

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