Implantable medical device for sensing electrocardiogram signals and a method for operating an implantable medical device

Abstract

An implantable medical device (1) for sensing physiological signals comprises a sensing arrangement (14) configured to sense a physiological signal, a processing module (11), and at least one sensor device (15, 16) for sensing a sensor signal (S) indicative of a mechanical motion or an acoustic sound. The processing module (11) is configured to process said sensor signal (S) and to identify, based on said processing, a trigger event (E). The processing module (11) furthermore is configured to performing a specific function based on the trigger event (E).

Description

[0001] Applicant: BIOTRONIK SE & Co. KG

[0002] Our Reference: 22.134P-WO

[0003] Date: 21.08.2025

[0004] Implantable medical device for sensing electrocardiogram signals and a method for operating an implantable medical device

[0005] The present invention generally relates to an implantable medical device for sensing physiological signals, for example electrocardiogram signals (ECG signals), and to a method for operating such an implantable medical device.

[0006] An implantable medical device of the type concerned herein comprises a sensing arrangement, in particular an electrode pole arrangement, configured to sense ECG signals and a processing module.

[0007] An implantable medical device of this kind may for example be a pacemaker, an implantable cardioverter defibrillator, a sensor device such as a bio-sensor, or a monitoring device. The implantable medical device herein is configured to sense ECG signals.

[0008] For example, the implantable medical device may be a monitoring device which is configured to record ECG signals and to communicate recorded ECG signals or information derived from recorded ECG signals to an external device in the context of a home monitoring system.

[0009] An implantable medical device as for example described in EP 3 278 836 Bl may for example comprise a housing and an arrangement of electrode poles arranged on the housing. The electrode poles herein are arranged on the housing of the implantable medical device such that the electrode poles are aligned along a longitudinal axis along which the implantable medical device extends. The electrode poles may for example be formed by housing segments which are made from an electrically conductive material such as a metal material and are exposed to the outside such that they may be brought into electrical contact with surrounding tissue in order to establish an electrical coupling to the tissue in an implanted state of the implantable medical device.

[0010] An implantable medical device as e.g. used in a home monitoring system may for example allow for a reliable monitoring of a physiological state of a patient. In particular, using the implantable medical device it may be possible to detect an abnormal cardiac state based on recorded ECG signals. If an abnormality is detected in ECG signals, the implantable medical device may for example be enabled to communicate with for example an external device of a home monitoring system, e.g. in order to trigger a message to a service center to alert medical personnel of a potential need for attention.

[0011] An implantable medical device may be configured to allow for a recording of ECG signal data for example based on an intrinsic processing of the data. For example, the processing module of the implantable medical device may be configured to process sensed ECG signal data in order to identify an arrhythmia event based on the processing. A signal portion relating to the detected arrhythmia event may then be stored in memory and may be communicated to an external device such that such data may be examined by a physician.

[0012] Potentially, if a patient feels a particular symptom, such as a dizziness or an irregular heartbeat, it may be desirous that the patient himself is enabled to trigger a recording of ECG signals.

[0013] It has been envisioned to use an external device, for example a programming device, to cause the implantable medical device, by communication with the external device, to record and store ECG signal data. As a dedicated external device potentially is not easy to use for a patient and may not be at hand at all times, it potentially is not ensured that a patient may trigger a recording of ECG signal data in case the patient feels a particular need or desire for recording such data.

[0014] It is an object of the present invention to provide an implantable medical device for sensing physiological signals, for example ECG signals and a method for operating such an implantable medical device which in an easy, comfortable way allows a patient to trigger a

[0015] 22.134P-WO / 21.08.2025 recording of physiological data, for example ECG signal data. Physiological data may also be blood oxygen saturation (spO2), respiration, heart rate parameters, ECG parameters, temperature, activity, heart sounds, impedance and / or others. The following description for the example of ECG signals and ECG signal data shall also apply to other physiological signals and physiological data.

[0016] In one aspect, an implantable medical device for sensing ECG signals comprises a sensing arrangement, for example an electrode pole arrangement, configured to sense an ECG signal, a processing module, and at least one sensor device for sensing a sensor signal indicative of a mechanical motion or an acoustic sound. The processing module is configured to process said sensor signal and to identify, based on said processing, a trigger event. The processing module furthermore is configured to perform a specific function, for example to store at least a portion of the ECG signal, based on the trigger event.

[0017] The implantable medical device may for example be a cardiac simulation device, such as a cardiac pacemaker device or a cardiac defibrillator device, such as an IPG or an ICD, in particular ICD-D or ICD-P device. In other embodiments the implantable medical device may be a monitoring device configured to monitor cardiac signals and, in this context, to sense ECG signals.

[0018] The implantable medical device may comprise a generator device and one or multiple leads connected to the generator device, wherein electrode poles of the sensing arrangement, herein the electrode pole arrangement, may be placed on the generator device and / or on one or multiple leads connected to the generator device.

[0019] In other embodiments the implantable medical device may be a leadless device not comprising leads. An arrangement of electrode poles herein may be arranged on a housing of the implantable medical device. For example, different electrode poles of the electrode pole arrangement may be formed by different housing sections, which for this purpose may be made from an electrically conductive material and may be configured to contact tissue in order to establish a coupling in an implanted state of the implantable medical device.

[0020] 22.134P-WO / 21.08.2025 The implantable medical device, making use of the electrode pole arrangement, generally is configured to sense ECG signals. ECG signals herein may be sensed in one channel or in multiple channels, such that one ECG signal (relating to one channel) or multiple ECG signals (relating to multiple channels sensed by different pairs of electrode poles and hence across different signal vectors) may be recorded.

[0021] The implantable medical device may be configured to continuously sense ECG signals, wherein the ECG signals however for example are not continuously and permanently stored, but are for example cyclically overwritten, for example by a storing means similar to a loop recorder.

[0022] In other embodiments, the implantable medical device may be configured to sense ECG signals only upon a particular triggering of a sensing and hence non-continuously.

[0023] The processing module generally is configured to control operation of the implantable medical device.

[0024] The implantable medical device comprises at least one sensor device for sensing a sensor signal indicative of a mechanical motion or an acoustic sound.

[0025] In particular, the implantable medical device may comprise, in one embodiment, an accelerometer for detecting a sensor signal indicative of a mechanical motion. An accelerometer of this kind generally is enabled to detect acceleration signals indicative of a mechanical acceleration. Such accelerometer may be a one-axis accelerometer configured for sensing acceleration along one spatial axis. In other embodiments, an accelerometer of this kind may be a three-axes accelerometer configured for sensing an acceleration along three spatial axes and hence in a three-dimensional space.

[0026] In one embodiment, the implantable medical device comprises, alternatively or in addition to a sensor device for sensing a signal indicative of a mechanical motion, a sensor device configured to sense a sensor signal indicative of an acoustic sound. Such sensor device may for example be a microphone configured to detect sound signals, such as speech signals or

[0027] 22.134P-WO / 21.08.2025 the sounds resulting from mechanical disturbance from outside the device such as tapping on the skin over the device.

[0028] The processing module is configured to process a sensor signal sensed by means of the sensor device and to identify, based on the processing of the sensor signal, a trigger event. If a trigger event is identified by the processing module, the processing module is configured to store at least a portion of the ECG signal.

[0029] Generally, a motion at the location of the implantable medical device correlates with a motion of at least a body part of the patient. In that the sensor device, in one embodiment, is configured to sense a sensor signal indicative of a mechanical motion, the sensor device may pick up a specified motion signal which may be caused by the patient himself. In that the processing module is configured to process the sensor signal in order to identify a trigger event and to store a portion of the ECG signal based on the trigger event, a storing of the ECG signal may be caused by a patient-initiated triggering, without need for an additional external triggering device. Also, other possible action or specific function (that are triggered) may be performed and / or may change the mode of operation of the device, e.g. to increase sensitivity or specificity, or to turn on or off certain functions of the device.

[0030] Likewise, if the sensor device is configured to sense a sensor signal indicative of an acoustic sound, by detecting a sound, such as a specified voice command, the patient may trigger a storing of a portion of an ECG signal or another function.

[0031] The implantable medical device may for example be configured for continuously sensing ECG signals. Based on the trigger event as identified by processing the sensor signal, herein a particular portion of a sensed ECG signal may be stored and may for example be communicated to an external device, for example immediately or based on a predefined, for example regular reporting scheme in which information is communicated between the implantable medical device and an external device.

[0032] In one embodiment, the processing module is configured to process the sensor signal to detect a characteristic signal pattern in the sensor signal and to identify the trigger event

[0033] 22.134P-WO / 21.08.2025 based on the detection of the characteristic signal pattern. One or multiple characteristic signal patterns may be predefined. The processing module processes, during operation, the sensor signal as sensed by the sensor device in order to identify a characteristic signal pattern. If a characteristic signal pattern is identified, the processing module concludes a trigger event was received and correspondingly identifies the trigger event, upon which a storing of an ECG signal portion and / or another specific function is triggered. The ECG signal portion may be or comprise a record of parameters of the ECG signal.

[0034] In one embodiment, in particular relating to a sensor device configured to sense a sensor signal indicative of a mechanical motion, the characteristic signal pattern is correlated with a predefined motion of a body part of the patient. The predefined motion may for example be a predefined body position change performed by a body part, for example a predefined movement of an upper body of the patient (e.g. bending forward, bowing, turning to the left or right, leaning back).

[0035] In one embodiment, the characteristic signal pattern is correlated with a predefined tapping pattern caused by a body part, such as the patient's hand. For example, the patient may tap with one hand on his upper body, in a region close to the location at which the implantable medical device is implanted in the patient. For example, a predefined tapping pattern may be defined, such as a regular or irregular sequence of taps by which the patient shall tap on the upper body in proximity to the implantable medical device resting in the upper body. Such tapping causes a mechanical motion at the location of the implantable medical device, which may be picked up by the sensor device and may be identified by the processing module as a trigger event.

[0036] The characteristic signal pattern as sensed by the sensor device of the implantable medical device may for example be trained in an initial training phase in which the patient is asked to perform a predefined motion pattern, such as a tapping pattern. In the training phase the characteristic signal pattern as sensed by the sensor device is recorded and stored, such that during subsequent operation a sensor signal of the sensor device may be processed in order to identify a signal pattern which at least resembles the pre-stored characteristic signal pattern to a sufficient degree.

[0037] 22.134P-WO / 21.08.2025 For example, the processing module is configured to process the sensor signal to detect the characteristic signal pattern based on analyzing at least one of an occurrence of at least one signal peak of a signal waveform, a timing of at least one signal peak of a signal waveform, an amplitude value of at least one signal peak of a signal waveform or an area under at least a portion of a curve of a signal waveform. For example, if the characteristic signal pattern corresponds to a tapping pattern for which the patient taps on the upper body at a location close to the location of implantation of the implantable medical device, the tapping motion may cause a sequence of signal peaks in a waveform of the sensor signal as sensed by the sensor device. Such signal peaks may be analyzed with respect to their timing, for example a timing distance in between successive signal peaks, or with respect to the amplitudes of the signal peaks, or with respect to an area under a curve relating to a signal peak.

[0038] Different measures may be combined to analyze the sensor signal in order to identify a correlation with a characteristic signal pattern and to conclude, based on the identification, for a trigger event.

[0039] In one embodiment, in case the sensor device is configured to sense a sensor signal indicative of an acoustic sound, the characteristic signal pattern may correspond to a predefined acoustic sound command. For example, the predefined acoustic sound command may be a speech command. For example, it may be defined that, in case a user speaks a predefined phrase such as "Device, record ECG data", the processing module may identify such speech command and may conclude it is a trigger event, causing a specific function, for example a storing of ECG signal data, e.g. for communicating the ECG signal data to an external device.

[0040] More elaborate speech commands are conceivable, for example relating to particular instructions for recording and storing ECG signal data, for example commands such as "Device, record a 10 minute ECG portion" or "Device, start recording ECG now for 10 minutes".

[0041] 22.134P-WO / 21.08.2025 In one embodiment, the processing module is configured to store at least a portion of an ECG signal prior to the trigger event. For example, the implantable medical device may be configured to continuously sense, using the sensing arrangement (e.g. the electrode pole arrangement), ECG signals. Herein, the device may for example use a cyclic memory in which sensed ECG signal data is continuously (cyclically) overwritten. Based on the trigger event, a portion prior to the trigger event may be captured and may be stored such that it is not overwritten in the further operation of the implantable medical device.

[0042] In one embodiment, the processing module is configured to store at least a portion of an ECG signal starting at a time point between 1 hour to 5 seconds, in particular 15 minutes to 5 seconds, prior to the trigger event. For example, the processing module may capture a portion of an ECG signal starting 10 minutes, 9 minutes, 8 minutes, 7 minutes, 6 minutes, 5 minutes, 4 minutes, 3 minutes, 2 minutes, 1 minute or 30 seconds prior to the trigger event.

[0043] In one embodiment, the processing module is configured to store at least a portion of an ECG signal subsequent to the trigger event. For example, the processing module may be configured to store at least a portion of an ECG signal ending at a time point between 5 seconds to 1 hour, in particular 5 seconds to 15 minutes, subsequent to the trigger event. For example, a portion of an ECG signal is stored by the processing module upon the occurrence of the trigger event which may end 30 seconds, 1 minute, 2 minutes, 3 minutes, 4 minutes, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes or 10 minutes subsequent to the trigger event.

[0044] For example, a portion of an ECG signal is stored by the processing module which starts prior to the trigger event and ends subsequent to the trigger event.

[0045] In one embodiment, the implantable medical device is configured to communicate information relating to a stored portion of an ECG signal to an external device. By storing, upon the occurrence of the trigger event, a portion of an ECG signal such portion is captured within the implantable medical device and is prevented from overwriting during further operation of the implantable medical device. Information relating to the stored portion may

[0046] 22.134P-WO / 21.08.2025 be immediately reported to the external device, or following a predefined reporting scheme, such as a regular reporting scheme or an event-driven reporting scheme.

[0047] As the patient - by causing a corresponding, predefined command by performing a predefined motion or by outputting a specified sound command, in particular a speech command - may cause a storing and reporting of a portion of an ECG signal, no external triggering device for triggering the storing of the ECG signal is required. In case a patient feels a particular need or desire for recording a portion of an ECG signal, for example in case of a sudden dizziness or in case the patient feels an irregular heartbeat, the patient for example may perform a predefined motion and / or body position change, such as tapping on his upper body, or may output a sound command in order to cause the implantable medical device to record and store ECG signal data relating to the particular moment in which the triggering has occurred, for example a portion surrounding the trigger event.

[0048] In another aspect, a method for operating an implantable medical device for sensing physiological signals, for example ECG signals, comprises: sensing a physiological signal using a sensing arrangement, for example an electrode pole arrangement, of the implantable medical device; sensing a sensor signal indicative of a mechanical motion or an acoustic sound using at least one sensor device of the implantable medical device; processing, using a processing module of the implantable medical device, said sensor signal and to identify, based on said processing, a trigger event; and performing a specific function, for example storing at least a portion of the physiological signal, based on the trigger event.

[0049] The advantages and advantageous embodiments described above for the implantable medical device equally apply also to the method, such that it shall be referred to the above in this respect.

[0050] The various features and advantages of the present invention may be more readily understood with reference to the following detailed description and the embodiments shown in the drawings. Herein,

[0051] 22.134P-WO / 21.08.2025 Fig. 1 shows a schematic drawing of an implantable medical device implanted in a patient;

[0052] Fig. 2 shows a schematic drawing of an implantable medical device in communication with an external device;

[0053] Fig. 3 shows a schematic drawing of an implantable medical device in an implanted state in a patient, illustrating a motion performed by the patient;

[0054] Fig. 4 shows a schematic graph of a signal pattern corresponding to a motion pattern performed by a patient; and

[0055] Fig. 5 shows a schematic illustration of a processing of a signal pattern in order to identify a trigger event causing a storing of a portion of an electrocardiogram signal.

[0056] 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.

[0057] It is to be noted that the embodiments are not limiting for the invention, but merely represent illustrative examples.

[0058] Referring to Fig. 1, in one embodiment an implantable medical device 1 implanted (for example subcutaneously) into a patient for serving a therapeutic and / or diagnostic function. The implantable medical device 1 may for example be implanted subcutaneously into a patient P for monitoring cardiac activity of the patient’s heart H. The implantable medical device 1, for this, comprises a sensing arrangement, for example an arrangement of electrode poles, which are used to couple to surrounding tissue and to sense physiological signals, for example ECG signals originating from the heart H.

[0059] An external device 2 is operated external to the patient P and is in communication connection with the implantable medical device 1.

[0060] 22.134P-WO / 21.08.2025 Referring now to Fig. 2, in one embodiment an implantable medical device 1 comprises a housing 10, a processing module 11 including a memory 110, an energy storage 12, a communication circuitry 13 and an electrode pole arrangement 14.

[0061] The electrode pole arrangement 14 is formed by a multiplicity of electrode poles, for example one or multiple pairs of electrode poles. The electrode poles may for example be arranged on one or multiple leads connected to the housing 10 of the implantable medical device 1. One or multiple leads herein may be implanted such that they reach into the patient's heart H, for example into the right ventricle, the right atrium or the left ventricle. In other embodiments, a lead may be implanted to rest outside of the patient's heart H.

[0062] In other embodiments, electrode poles of the electrode pole arrangement 14 may be placed on the housing 10 or a rigid portion connected to the housing 10, such as a header portion, the implantable medical device 1 in these embodiments not comprising any leads.

[0063] The implantable medical device 1 may for example be a cardiac stimulation device, such as a cardiac pacemaker device or a cardioverter defibrillator device, such as an IPG, ICD, in particular ICD-D or ICD-P device. In other embodiments, the implantable medical device 1 may be a monitoring device configured for monitoring a cardiac function, without however performing a therapeutic action.

[0064] The implantable medical device 1 is generally configured to sense ECG signals during its operation and for example process such ECG signals, for example in the context of operation of a pacemaker device in order to trigger a cardiac stimulation. The implantable medical device 1 herein may be configured to continuously sense ECG signals and to record ECG signals in a cyclic memory, wherein the cyclic memory has a memory comparatively of limited size and is continuously overwritten in a cyclic fashion. For example, such cyclic memory may have the capacity to record ECG signals of a maximum time range between 5 minutes and 20 minutes.

[0065] 22.134P-WO / 21.08.2025 The implantable medical device 1, in the shown embodiment, in addition may comprise a sensor device 15 configured to sense a sensor signal indicative of a mechanical motion. The sensor device 15 may for example be an accelerometer device configured to sense an acceleration signal relating to an acceleration at the location of the implantable medical device 1. The accelerometer may for example be a one-axis accelerometer configured to sense an acceleration along one spatial axis. In other embodiments, the accelerometer may be a three-axes accelerometer configured to sense an acceleration along three spatial directions and hence in a three-dimensional space.

[0066] Alternatively or in addition to the sensor device 15, the implantable medical device 1 comprises a sensor device 16 configured to sense a sensor signal indicative of an acoustic sound, such as a speech signal. The sensor device 16 may for example be a microphone configured to sense sound signals in the vicinity of the implantable medical device 1.

[0067] It is desirous that a patient P is enabled to trigger a recording and performing a specific function, e.g. storing of an ECG signal portion and / or a record of parameters of the ECG signal like heart rate, heart interval, QT interval, PR interval, ST segment and others. It herein is desirous that such triggering may be effected by the patient P in a comfortable way without the need for an additional device, such as an additional external triggering device.

[0068] For this, the processing module 11 is configured to process a sensor signal as sensed by a sensor device 15, 16 and to identify a trigger event based on a processing of the sensor signal.

[0069] For example, referring now to Fig. 3, the patient P may perform, using a body part B such as the patient's hand, a predefined motion and / or body position change G on the upper body where the implantable medical device 1 is implanted. For example, a motion pattern may be defined, such as a tapping pattern, by which the patient P may tap on the upper body in which the implantable medical device 1 rests in an implanted state. Such tapping causes a mechanical motion at the location of the implantable medical device 1, which is sensed by the sensor device 15.

[0070] 22.134P-WO / 21.08.2025 Referring now to Fig. 4, for example a tapping sequence of a particular kind may be predefined. For example, in order to trigger a recording of an ECG signal portion and / or a record of parameters of the ECG signal, the patient P may be required to tap on the upper body at a location close to the implantable medical device 1 making use of a particular tapping pattern. The tapping causes a signal pattern SP in the sensor signal S as sensed by the sensor device 15, as illustrated in Fig. 4.

[0071] The sensor signal S may be analyzed by the processing module 11, and a signal pattern SP may be identified to (sufficiently) correlate with a predefined characteristic signal pattern.

[0072] Referring now to Fig. 5, based on the identification of the characteristic signal pattern SP, a trigger event E is identified by the processing module 11. Upon the occurrence of the trigger event E, the processing module 11 causes a storing of a portion RP of an ECG signal in a particular recording period.

[0073] Referring now again to Fig. 4, the processing module 11 in particular may be configured to process the signal S to identify a correlation of a signal pattern SP with a predefined, characteristic signal pattern indicative of a trigger event E by determining characteristic measures, such as a time Tl, T2, T3 of signal peaks, amplitude values Al, A2, A3 of signal peaks, or area values of curves relating to particular signal peaks.

[0074] Other characteristic measures may be analyzed and are not limited to the particular measures shown in Fig. 4. For example, properties of signals that may be used to discriminate a characteristic signal pattern from other artifacts may include at least one of: the number of motion peaks or impulses, an absolute peak value e.g. of an acceleration signal, the sign of the signal, the duration of an impulse, the area under the curve of an impulse, the consistency of the properties from each impulse, statistics relating to each peak, and other similar measures of one or multiple peaks.

[0075] Relating again to Fig. 5, upon the identification of a trigger event E by the processing module I l a storing of a signal portion RP in a time range of an ECG signal is caused in the memory 110, such that the signal portion is captured and is no longer cyclically overwritten for

[0076] 22.134P-WO / 21.08.2025 example in a cyclic memory. Information relating to the signal portion may hence be communicated to an external device 2, for example immediately or making use of a predefined reporting scheme, such as a regular or event-driven reporting scheme.

[0077] Herein, the signal portion which is stored upon the occurrence of a trigger event E may be predefined, for example by programming settings of the implantable medical device 1. For example, a stored portion may start at a time point XI prior to a time TE of the trigger event E and may end at a time point X2 subsequent to the time TE of the trigger event E. The time point XI may for example lie in a time range between 1 hour to 5 seconds, in particular 15 minutes to 5 seconds, prior to the time TE of the trigger event E. The time point X2 may lie for example in a range between 5 seconds to 1 hour, in particular 5 seconds to 15 minutes, subsequent to the time TE of the trigger event E.

[0078] Multiple different motion patterns may be defined which enable a patient P to trigger a storing of ECG signal data. For example, different tapping sequences may be defined in order to cause a storing of a short portion of ECG signal data or a long portion. For example, a long tapping sequence, e.g. including 5 tabs of a particular timing, may cause a storing of a comparatively long ECG signal portion, whereas a short tapping sequence, including for example three taps of a particular timing, may cause a recording of a short portion of an ECG signal (ECG signal).

[0079] Alternatively or in addition to using the sensor device 15 to sense a sensor signal indicative of a mechanical motion, the sensor device 16 may be used to sense a sensor signal indicative of an acoustic sound, such as a speech command. For example, a speech command may be defined such as "Device, store an ECG measurement", which may be processed by the processing module 11 and may be identified as a trigger event E, upon which a portion of a sensed ECG signal is stored and hence captured.

[0080] Different speech commands may cause a storing of different portions. For example, speech commands such as "Store the next 10 seconds", or "Store the previous 5 minutes" may precisely define what signal portion shall be stored by the device 1 and may correspondingly be captured by the processing module 11.

[0081] 22.134P-WO / 21.08.2025 In addition, the patient P may enter additional information using speech signals which may be recorded and stored by the implantable medical device 1. For example, the patient P may provide information using speech such as "I felt a sudden dizziness" together with a specific speech command causing a triggering of a storing of an ECG signal portion. Such information may be stored by the processing module 11 together with the ECG signal data.

[0082] The implantable medical device 1 may be configured to provide a feedback to the patient P upon the identification of a trigger event E. For example, the implantable medical device 1 may include a vibration device, such as a mechanical vibration motor, for outputting a vibration signal, which may be recognized by the patient P and may indicate to the patient P a successful identification of a trigger event E.

[0083] In addition, information relating to a trigger event E may be included in a report which is output by the implantable medical device 1 to an external device 2.

[0084] Additional information, such as a temperature reading, information relating to a blood oxygen saturation or a tissue impedance may be recorded and stored together with ECG signal information in the implantable device 1 and may be included in a report to the external device 2.

[0085] 22.134P-WO / 21.08.2025 List of reference numerals

[0086] 1 Implantable medical device

[0087] 10 Housing

[0088] 11 Processing module

[0089] 110 Data memory

[0090] 12 Energy storage

[0091] 13 Communication circuitry

[0092] 14 Electrode pole arrangement

[0093] 15 Sensor device (motion sensor)

[0094] 16 Sensor device (microphone)

[0095] 2 External device

[0096] Al, A2, A3 Amplitude value

[0097] B Body part

[0098] E Trigger event

[0099] ECG El ectrocardi ogram

[0100] G Motion / Body position change

[0101] H Heart

[0102] P Patient

[0103] RP portion (of ECG signal)

[0104] S Sensor signal

[0105] SP Signal pattern

[0106] Tl, T2, T3 Time

[0107] TE Time of trigger event

[0108] XI, X2 Time point

[0109] 22.134P-WO / 21.08.2025

Claims

Claims1. An implantable medical device (1) for sensing physiological signals, comprising: a sensing arrangement (14) configured to sense a physiological signal; a processing module (11); and at least one sensor device (15, 16) for sensing a sensor signal (S) indicative of a mechanical motion or an acoustic sound; wherein the processing module (11) is configured to process said sensor signal (S) and to identify, based on said processing, a trigger event (E); wherein the processing module (11) furthermore is configured to perform a specific function based on the trigger event (E).

2. The implantable medical device (1) according to claim 1, wherein the at least one sensor device (15, 16) includes at least one of an accelerometer for detecting a sensor signal (S) indicative of a mechanical motion or a microphone for detecting a sensor signal (S) indicative of an acoustic sound.

3. The implantable medical device (1) according to claim 1 or 2, wherein the at least one sensor device (15, 16) includes at least a three-axis accelerometer.

4. The implantable medical device (1) according to one of claims 1 to 3, wherein the processing module (11) is configured to process said sensor signal (S) to detect a characteristic signal pattern (SP), in particular a predefined acoustic sound command, in said sensor signal (S) and to identify said trigger event (E) based on the detection of the characteristic signal pattern (SP).

5. The implantable medical device (1) according to claim 4, wherein the characteristic signal pattern (SP) is correlated with a predefined motion of a body part (B) of the patient (P).22.134P-WO / 21.08.20256. The implantable medical device (1) according to claim 4 or 5, wherein the characteristic signal pattern (SP) is correlated with a predefined motion and / or body position change (G) performed by a body part (B) of the patient (P).

7. The implantable medical device (1) according to one of claims 4 to 6, wherein the characteristic signal pattern (SP) is correlated with a predefined tapping pattern caused by a body part (B) of the patient (P).

8. The implantable medical device (1) according to one claims 4 to 7, wherein the processing module (11) is configured to process said sensor signal (S) to detect said characteristic signal pattern (SP) based on analyzing at least one of an occurrence of at least one signal peak of a signal waveform, a timing (T1-T3) of at least one signal peak of a signal waveform, an amplitude value (Al -A3) of at least one signal peak of a signal waveform or an area under at least a portion of a curve of a signal waveform.

9. The implantable medical device (1) according to one of the preceding claims, wherein the sensing arrangement is an electrode pole arrangement.

10. The implantable medical device (1) according to one of the preceding claims, wherein the processing module (11) is configured to store at least a portion (RP) of a physiological signal prior to the trigger event (E).

11. The implantable medical device (1) according to one of the preceding claims, wherein the processing module (11) is configured to store at least a portion (RP) of a physiological signal starting at a time point (XI) between 1 hour to 5 seconds prior to the trigger event (E).

12. The implantable medical device (1) according to one of the preceding claims, wherein the processing module (11) is configured to store at least a portion (RP) of a physiological signal subsequent to the trigger event (E).22.134P-WO / 21.08.2025- 19 -13. The implantable medical device (1) according to one of the preceding claims, wherein the processing module (11) is configured to store at least a portion (RP) of a physiological signal ending at a time point (X2) between 5 seconds to 1 hour subsequent to the trigger event (E).

14. The implantable medical device (1) according to one of the preceding claims, wherein the implantable medical device (1) is configured to communicate information relating to a stored portion (RP) of an physiological signal to an external device (2).

15. A method for operating an implantable medical device (1) for sensing physiological signals, the method comprising: sensing a physiological signal using a sensing arrangement (14) of the implantable medical device (1); sensing a sensor signal (S) indicative of a mechanical motion or an acoustic sound using at least one sensor device (15, 16) of the implantable medical device (1); processing, using a processing module (11) of the implantable medical device (1), said sensor signal (S) and to identify, based on said processing, a trigger event (E); and performing a specific function based on the trigger event (E).22.134P-WO / 21.08.2025

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