Implantable medical device and method of its operation

Abstract

The invention relates to an implantable medical device (IMD, 1) that can be operated in a very energy-efficient manner, comprising a functional unit (10, 11, 14) configured to monitor a bodily parameter of a patient (2) and / or to deliver a therapy signal to the patient (2), an internal communication unit (17) configured to wirelessly communicate data to an external device (3), namely to transmit data to an external communication unit (31) of the external device (3), and to receive data from said external communication unit (31), said internal communication unit (17) having an operational state for performing said communication and a switched-off state, a wake-up unit (12) for repeatedly transferring the internal communication unit (17) and a position analysis unit from the switched-off state to the operational state according to a first timing scheme and based on the signal of a clock unit, wherein a first time interval is realized between consecutive ones of such state transfers, a position sensor (19) configured to provided position data of the IMD (1) to the position analysis unit, wherein the position analysis unit (11) configured to receive the position data and to determine the position of the patient, whereby the position analysis unit (11) is further configured to provide a pre-defined control signal to the wake-up unit (12) if a pre-defined position of the patient is detected, wherein the wake-up unit (12) is further configured such that as soon as the wake-up unit (12) receives said pre-defined control signal from the position analysis unit (11), the wake-up unit (12) changes to a second timing scheme for said repeated state transfer of the internal communication unit (17) having a second time interval between consecutive state transfers that is different from the first time interval.

Description

[0001] Applicant: BIOTRONIK SE & Co. KG

[0002] Date: 26.01.2026

[0003] Our Reference: 23.032P-WO

[0004] IMPLANTABLE MEDICAL DEVICE AND METHOD OF ITS OPERATION

[0005] The invention is directed to an implantable medical device (IMD) configured to wirelessly communicate with an external device, to a system comprising such IMD and external device as well as to an operation method of such IMD.

[0006] Usually, a medical device, in particular an implantable medical device, is configured to monitor the health status of a patient and / or to deliver a therapy signal to the patient. Small active and passive implantable medical devices (IMDs, implants) are, for example, an implantable cardiac monitor (ICM), an Implantable Leadless Pacer (ILP), an Implantable Leadless Pressure Sensor (ILPS), an Implantable Cardiac Defibrillator (ICD), a Subcutaneously Implanted Cardiac Defibrillator (S-ICD), and a device that delivers spinal cord stimulation (SCS), deep brain stimulation (DBS) or neurostimulation. Such IMD may contain at least one sensor that collects physiological signals to monitor the health status of the patient and / or may deliver a therapy to the patient, for example electric stimulation. Such collected physiological signals or information regarding the applied therapy may be transmitted as data to an external device (e.g. smartphone, computer, remote server, wand or any transmitter device configured to communicate with the IMD) using an internal communication unit.

[0007] Usually, such IMD comprises a processor for processing of such sensor data and an internal communication unit configured to bi-directionally exchange signals with the external device. Accordingly, the communication unit of the external device is configured for bi-directional data exchange with the communication unit of the IMD, as well, wherein the communicated data may comprise the physiological data obtained by the sensor, data showing the patient’s health status, the IMD status or IMD operation (e.g., to configure the IMD for application of an appropriate therapy to the patient and / or to activate a pre-defined mode of the IMD).As IMD sizes continue to shrink at a rate that outpaces the ability for battery capacity densities to improve, the use of low-power circuitry plays a central role in supporting product service time needs. Unfortunately, developing and incorporating low-power circuitry often impedes instantaneous availability of information from the IMD or bodily parameter determination on the health care practitioner’s (HCP) request. Accordingly, it is desirable to provide an IMD, a system comprising an IMD and an external device as well as a respective operation method of the IMD that enhances the quality of user or external device interaction and that at the same time reduces energy consumption of the IMD components.

[0008] The above object is solved by an IMD with the features of claim 1, by a system comprising the IMD and an external device with the features of claim 13 as well as by an operation method of the IMD with the features of claim 16.

[0009] In particular, the object is solved by an implantable medical device (IMD) comprising a functional unit, for example comprising a position analysis unit, the functional unit being configured to monitor a bodily parameter of a patient and / or to deliver a therapy signal to the patient,

[0010] an internal communication unit configured to wirelessly send and / or receive requests and / or communicate data to an external device, namely to transmit data to an external communication unit of the external device, and to receive data from the external communication unit, said internal communication unit having an operational state for performing said communication and a switched-off state,

[0011] a wake-up unit for repeatedly transferring the internal communication unit and a position analysis unit from the switched-off state to the operational state according to a first timing scheme and based on the signal of a clock unit, wherein a first time interval is realized between consecutive ones of such state transfers, and / or for example repeatedly transferring the internal communication unit and a position analysis unit from the operational state to the switched-off state;

[0012] a position sensor configured to provided position data of the IMD to the position analysis unit, wherein the position analysis unit is configured to receive the position data and to determine the position of the patient, whereby the position analysis unit is further configured

[0013] 23.032P-WO | 26.01.2026to provide a pre-defined control signal to the wake-up unit if a pre-defined position of the patient is detected, wherein the wake-up unit is further configured such that as soon as the wake-up unit receives said pre-defined control signal from the position analysis unit, the wake-up unit changes to a second timing scheme for said repeated state transfer of the internal communication unit having a second time interval between consecutive state transfers that is different from the first time interval.

[0014] The IMD may be an ICM, an ILP, an ILPS, an ICD, an S-ICD, or a device that delivers SCS, DBS or neurostimulation. In a preferred embodiment, the IMD is an implantable leadless pressure sensor (iLPS). The IMD comprises the functional unit that may determine or monitor a bodily parameter of the patient and may comprise at least one suitable sensor for measuring the respective local parameter of the patient’s body such as electrical signals (e.g. electrical voltage), magnetic signals, impedance, temperature, bodily activity, sound (e.g. heart sound), blood pressure and / or flow, respiration data, wherein such data may be processed to ECG, EEG, and other derived or combined data. For data processing, the functional unit may contain and / or may be connected to a processor located within a housing of the IMD. The IMD further may provide a time information with regard to each measured data referring to the time point of the respective measurement. Further, the functional unit may additionally or alternatively deliver a therapy signal to the patient. In this case, the functional unit comprises a therapy signal generator that is configured to generate the respective pre-defined therapy signal, for example, an electrical signal, a magnetic signal, a light signal, or a pressure signal, and apply the signal to the pre-defined bodily target position or area. In both cases the HCP may receive such data via a suitable external device from the internal communication unit of the IMD. With regard to the monitoring of the bodily parameter, the HCP may receive measured values of such parameter or data derived therefrom and with regard to the delivery of a therapy signal, the HCP may receive information about the provided actual therapy signal. Such data may be transmitted from the functional unit to the internal communication unit and from there to the external communication unit of the external device as described below. Additionally, the internal communication unit may receive and transmit other data referring to the status of the IMD in general such as battery status data to the external communication device. Generally, the internal communication unit may receive patient and IMD specific data from other

[0015] 23.032P-WO | 26.01.2026components of the IMD and transmit this information to the external communication unit of the external device. Additionally, the IMD may request and / or receive from the external device data and information regarding the operation of the IMD such as changed parameters for the therapy signal to be applied, parameters for the timing scheme of the wake-up unit or requests for transmission of specified data, for performing of measurements or application of therapy. Further, such data may be current data or data collected within a pre-defined past time period.

[0016] In the latter case, the IMD may comprise a storage unit storing such data. The IMD is at least partly implantable within the patient's body. In one embodiment, the IMD is configured for being completely implantable in a human blood vessel. After implantation the IMD is configured to provide and or request communication with the external device in the manner described herein using the internal communication unit.

[0017] In particular, the IMD may be an ILPS configured for implantation into the pulmonary artery for blood pressure monitoring / measurement. Moreover, in this embodiment all electrical parts described herein for the implantable medical device are incorporated therein.

[0018] As indicated above, the IMD comprises an internal communication unit configured to wirelessly communicate data to an external device, namely to request and / or send and / or transmit data to an external communication unit of the external device, and to receive data from the external communication unit using a pre-defined communication means. Accordingly, the internal communication unit provides bi-directional communication in the operational state. Preferably, communication with the external device is initiated and requested from the IMD, and not from the external device. In that, communication between the IMD and the external device shall only take place when the external device is close to the IMD. In doing so communication between the IMD and the external device can benefit that the external device comprises a larger antenna and can also detect weak signals. Thereby, the IMD does not need to communicate with strong and thereby energy consuming signals and can save energy. In the switched-off state the communication with the external communication unit is suspended, i.e. the internal communication unit does not request or send or receive any communication signals to / from the external communication unit as long

[0019] 23.032P-WO | 26.01.2026as it is in the switched-off state, until the wake-up unit provides a pre-defined control signal to the internal communication unit thereby transferring the internal communication unit from the switched-off state to the operational state. For recognizing the pre-defined control signal, the position analysis unit reads the actual position data of the device from the position sensor. This happens mandatorily after the device, in particular at least the position analysis unit and the communication unit, was transferred from the switched-off state to the operational state according to a first timing scheme with a first time interval. The position analysis unit then determines whether the patient is in a pre-defined position, e.g. horizontal or any other position requested. The activated internal communication unit verifies whether an external device is present. Both exchange data in this case. The wakeup-unit may transfer the device to the switched-off state if no external device is present irrespective whether the patient is in the pre-defined position or not.

[0020] A wakeup-event may additionally be scheduled according to a second timing scheme with a second time interval. This may for example happen on demand of an HCP. If no external device is present and the patient is not in a horizontal position or any other position, the wakeup-unit transfers the device back to the switched-off state. Additionally, a wakeupevent remains scheduled according to a first timing scheme with a first time interval.

[0021] In an embodiment, the position analysis unit may be integrated in the functional unit, in particular integrated in the processor. The processor may be perfectly equipped to analyse the position data and thereby the position analysis unit may be integrated or may be part of the processor. In such an embodiment a very basic and cheap position sensor may be used. The position sensor may just provide position data or signals which may be analysed by the processor. Consequently, the wake-up unit may repeatedly transfer at least parts of the functional unit, in particular the processor, from the switched-off state to the operational state according to a first timing scheme and based on the signal of a clock unit.

[0022] In an alternative embodiment, the position analysis unit may integrated in the position sensor. In this embodiment the position sensor itself may be configured to analyse the position data or signals and determine the position of the implant and thereby the patient,

[0023] 23.032P-WO | 26.01.2026e.g. the position analysis unit may be integrated into or part of the position sensor. In this embodiment the number of parts needed to wake-up may be reduced.

[0024] The communication in the operational state of the IMD’S internal communication unit and the external communication unit of the external device is a wireless communication and comprises communication over the air (without wire) using electromagnetic waves, for example, MedRadio / MICS / MEDS, EDGE, EV-DO, Flash-OFDM, GPRS, HSPA, LoRaWAN, RTT, UMTS, Narrowband loT, Bluetooth, WLAN (WiFi), ZigBee, NFC, LTE, Wireless USB, Wibree (BLE), Ethernet or WiMAX in the radio frequency region, or IrDA or free-space optical communication (FSO) in the infrared or optical frequency region or inductive coil communication. Accordingly, the respective communication protocols, often with the same name (i.e. a system of rules that allows two or more entities of a communications system to transmit information via a kind of variation of a physical quantity, defining rules, syntax, semantics and synchronization of communication and possible error recovery methods and being implemented by hardware, software or a combination of both) or cooperating protocols (protocol suites) may be used, for example TCP / IP protocol suite (e g. IPv6, TCP, UDP, SMTP, HTTP / 2) also with TLS or SSL, IPX / SPX, X.25, AX.25, ebXML, Apple Talk, Bluetooth protocols (e.g. BR / EDR), Bluetooth 4.0 (BLE), ZigBee protocol, NFC protocol, IEEE 802.11 and 802.16 protocols, etc.. The internal communication unit of the IMD and the external communication unit of the external device are configured for bi-directional communication with each other and therefore each communication unit may comprise a transceiver for signals of the pre-defined communication path, for example, an antenna. Alternatively, the bi-directional communication between the internal communication unit of the IMD and the external communication unit of the external device may be provided by ultrasonic waves or by electromagnetic induction. The internal communication module of the IMD and the external communication unit of the external device may comprise the respective hardware and software adapted to the used communication techniques / communication protocols.

[0025] The communication in the operational state of the IMD’S internal communication unit and the external communication unit of the external device is configured to take place in a manner such that the external device preferably selects the least interfered channel (LIC) of

[0026] 23.032P-WO | 26.01.2026the used communication band. The LIC may be detected, for example, by performing a channel scan over a specific range of frequencies, and then selected. The communication in this manner is initiated by the IMD by requesting communication to the external device. In the embodiment, where the IMD is an ILPS this way of communication via the LIC is advantageous since the ILPS is miniaturized for being suitable of working within a blood vessel and antenna sizes and capabilities are small. The communication by demand hence benefits from the bigger antenna capabilities of the external device to facilitate proper communication.

[0027] The external device is always located at least partially extracorporeally. The external device may be a computer, a smartphone, a server or similar computing device comprising a communication unit (so-called external communication unit) and a processor. The external communication unit may be located within (i.e. inside the housing of the external device) or at the external device (fixedly attached to the external device). The external device may be a so-called patient remote device (PR) or wand which may serve as a transceiver to route communication between the IMD and a remote monitoring server (further referred to as Home Monitoring Service Center - HMSC). The external device may give the user (e.g. a health care practitioner (HCP), patient, technician) or the HMSC the ability to change the active therapy program of the IMD, control its therapy signal amplitude, turn therapy signal on / off and / or view battery status. Accordingly, it may also serve as an external programmer for the IMD. The described functionality of the external device may be realized by using a corresponding app. and / or by activating a respective button at the external device.

[0028] Additionally, the external device may be freely movable with regard to the patient's body, for example, by a user or by a moving module. To establish the communication connection the internal communication unit of the IMD sends pre-defined signal(s) with a pre-defined signal strength (amplitude), signal length and / or frequency (e.g. a pre-defined signal package) - the so-called connection set-up request. As soon as the external communication unit of the external device receives such connection set-up request, the external communication unit sends a respective pre-defined confirmation signal(s) (e.g. signal package) to the internal communication unit of the IMD. In one embodiment, patient and / or device specific data may be sent with the signal package provided by the internal

[0029] 23.032P-WO | 26.01.2026communication unit for establishment of the communication connection and / or at least one data request may be sent with the confirmation signal package provided by the external communication unit. As soon as the internal communication unit of the IMD receives such confirmation signal(s) the communication connection between the IMD and the external device is established. The communication connection may then be used and maintained for data transmission between the external device and the IMD until it is actively terminated by the IMD or the external device or until the communication connection is lost.

[0030] For data / signal processing the IMD and the external device, each comprises a dedicated processor which is - with regard to the IMD - generally regarded as belonging to the functional unit of the IMD. The processor interprets and executes instructions comprising an instruction control unit and an arithmetic and logic unit. In the IMD and, if applicable, in the external device, the processor is electrically connected to the respective communication unit. Each processor may comprise a microprocessor, a controller, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), discrete logic circuitry or any combination thereof. Alternatively or additionally, the processor may be realized using integrated dedicated hardware logic circuits, in particular in the case of an IMD due to the small size and extreme power limitation. The processor may comprise a plurality of processing subunits.

[0031] The wake-up unit is a module of the IMD having a clock unit configured to provide a clock signal. The clock unit may be realized by an RC oscillator and / or a quartz oscillator. In one embodiment, the quartz oscillator may be used to repeatedly calibrate the RC oscillator in order to enhance accuracy of the RC oscillator. Based on the clock signal of the clock unit, the wake-up unit repeatedly effects a transfer of the state of the internal communication unit from the switched-off state to the operational state along a first timing scheme, e.g. by providing a pre-defined control signal to the internal communication unit. The control signal provided by the wake-up unit is received by the internal communication unit and effects the transfer from the switched-off state of the internal communication unit to the operational state. If, at that time, the internal communication unit is already in the operational state, it remains in the operational state. As explained above, in the operational state, the internal communication unit sends the connection set-up request to the external device at least once

[0032] 23.032P-WO | 26.01.2026or, in an embodiment, a pre-defined number of times. Further, in the operational state, the internal communication unit further waits to receive the pre-defined confirmation signal(s) from the external unit, in an embodiment over a pre-defined third time interval (from the transition into the operational state) and may, in this embodiment, revert to the switched-off state after expiry of the third time interval if no communication connection was established between the internal communication unit of the IMD and the external communication unit of the external device.

[0033] The first timing scheme may comprise producing the pre-defined control signal by the wakeup device and for the communication unit, for example, three times a day, two times a day, once a day, every two days or every three days (for example at night, 1-5 times per night, in particular 3 times per night 1 min to 50 minutes apart, in particular 30 minutes apart). Accordingly, the time interval of consecutive state transfers may be between several hours and some days. The timing scheme may comprise periodically repeated time intervals or irregular time intervals. For many cases, the provision of actual data referring to the health status of the patient is preferably done at night when the patient is at rest. Such setting better allows to compare determined values and to observe its development over time. Accordingly, the transfer to the operational status may be provided at night.

[0034] Further, the IMD comprises a position sensor (e.g. at least one accelerometer) electrically connected to the processor. The accelerometer may detect an acceleration (i.e. the rate of change of velocity) related to a two-dimensional or three-dimensional movement of the IMD with regard to the gravitational force from which a corresponding position of the IMD or the patient can be calculated. In connection with the position sensor, the term “position” means the orientation of the sensor / IMD / patient within 3 -dimensional space. Examples of an accelerometer are piezoelectric accelerometer, laser accelerometer, pendulous integrating gyroscopic accelerometer, accelerometer using magnetic induction, optical accelerometer, strain gauge, accelerometer using surface acoustic waves and / or any combination of above principles. The at least one accelerometer may comprise a micromachined microelectromechanical systems (MEMS) accelerometer to detect changes in the position of the IMD.

[0035] 23.032P-WO | 26.01.2026The at least one accelerometer may detect both the magnitude and the direction of the acceleration, as a vector quantity, and is used to sense orientation (because the direction of weight changes) and coordinate acceleration and may be used to sense vibration. Accordingly, in one embodiment, the accelerometer may detect whether the patient is in a horizontal position (i.e. sleeps or is at a doctor’s appointment), i.e. the detectable pre-defined position corresponds to the horizontal position of the patient.

[0036] Such detection of the horizontal position of the patient may be provided in one embodiment by comparison of the patient’s actual position P (P = [x,y,z] in a pre-defined coordinate system) with a reference position Pref= \xref,yrefZref\ for the horizontal position. The reference position may be determined during implantation of the IMD or as a mean value (e.g. arithmetic mean) from a pre-defined number of measurements. If for the value Diff the relation Diff < T, wherein

[0037]

[0038] (equation 1),

[0039] and Zis a pre-defined threshold value, it is assumed that the patient is in a horizontal position. For other positions, the above calculation can be used with a reference position that corresponds to this other position.

[0040] As soon as the position sensor detects the pre-defined position (e.g. the horizontal position, the recumbent or semi -recumbent position of the patient), a pre-defined control signal is provided to the wake-up unit that is electrically connected to the position sensor and the functional unit. After receipt of this pre-defined control signal, the wake-up unit changes from the first timing scheme to a second timing scheme. According to one embodiment, in the second timing scheme, the second time interval between two consecutive control signals provided to the internal communication unit and thereby between two consecutive state transfers is reduced or prolonged compared with the first time interval. Accordingly, in one embodiment of the IMD, the second time interval is smaller than the first time interval. In this case, the internal communication unit is more often transferred to the operational state so that this communication unit tries more often to establish a communication connection with the external device than according to the first timing scheme. Hence, by the invention,

[0041] 23.032P-WO | 26.01.2026the waiting times between connection attempts (connection intervals) are dynamically varied by the IMD based on the signal provided by the position sensor of the IMD. This, on the one hand, allows energy-efficient operation of the internal communication unit during most of the time, i.e. when the first timing scheme applies. However, if it is necessary, for example, when a doctor’s consultation is scheduled, a delay-free examination may be possible due to the reduction of the time interval between consecutive transfers to the operational state. The inventors have recognized, that in cases where specific data from the IMD are needed, for example in such consultation, the patient is often asked to take a pre-defined position, for example, to lay down. Then, the second timing scheme that is initiated at this pre-defined position comprises a changed timing of provision of the pre-defined control signal by the wake-up device for state transfer of the internal communication unit to the operational state, for example, a more frequent provision of the pre-defined control signal, e.g. every 1 second to every 30 seconds. Accordingly, the timing of data communication can be dynamically adapted to the HCP’s needs. Accordingly, the reaction time of the implant is adapted and battery life of the IMD is increased by dynamically adjusting the timing scheme of the wakeup device. The internal communication unit is in the operational state with higher energy consumption only if it is necessary.

[0042] In one embodiment of the IMD, as indicated above, the internal communication unit is configured such that it transmits at least one connection set-up request to the external communication unit in the operational state and remains in the operational state to receive a confirmation signal confirming receipt of said connection set-up request over a pre-defined third time interval (the third time interval commences on the start of the operational state after the transfer from the switched-off state) and reverts to the switched-off state after expiry of the third time interval.

[0043] In one embodiment of the IMD, the internal communication unit is configured to transmit data provided from the functional unit with the connection set-up request. Such data may be most actual data or a pre-defined summary of most relevant data of the patient and / or the IMD (e.g. the battery status) and / or the provided therapy, wherein the patient’s data may be at least one of the above mentioned patient’s bodily parameter determined by the functional

[0044] 23.032P-WO | 26.01.2026unit. This gives a fast overview of the patient’s health status, therapy status and / or the IMD status to the HCP.

[0045] In one embodiment of the IMD, if the confirmation signal comprises data requesting further information from the functional unit, e.g. measured values of at least one of patient’s bodily parameters, the internal communication unit is configured to transmit said data request to the functional unit and said functional unit is configured to provide, i.e. transmit, the corresponding information / data according to the data request to the internal communication unit for transmittal to the external communication unit. Accordingly, it is possible to provide additional information, for example, on the patient’s health status fast.

[0046] In one embodiment of the IMD, the wake-up unit is further configured to change from the first timing scheme to a third timing scheme for said repeated state transfer of the internal communication unit having a fourth time interval between consecutive state transfers that is different from the first time interval and the second time interval. Accordingly, instead of the first timing scheme, the wake-up unit is operated according to the third timing scheme, wherein, for example, the fourth time interval is smaller than the first time interval. In one embodiment, the information regarding the change from the first timing scheme to the third timing scheme is provided as respective timing scheme data received by the internal communication unit during communication with the external device (e.g. the start time point of the third timing scheme and its duration), wherein preferably the first time interval is greater than the fourth time interval and the fourth time interval is greater than the second time interval. The change to the third timing scheme may be initiated at a pre-defined start time point, for example at a specified time during the following day - e.g. when the doctor’s appointment is scheduled. Further, the wake-up unit may remain in the third timing scheme over a pre-defined duration, e.g. the expected duration of the doctor’s appointment. The state, in which the wake-up device is operated according to the third timing scheme is also referred to as On-Demand-Mode. For example, the fourth time interval between initiating consecutive state transfers from the switched-off state to the operational state of the internal communication unit is smaller than the first time interval, which means that the internal communication unit tries to establish a communication connection more often than usual (i.e. according to the first time scheme). In one embodiment, the operation of the wake-up

[0047] 23.032P-WO | 26.01.2026unit according to the second timing scheme as described above initiated by the detection of a pre-defined position of the IMD may be realized independently from the condition whether the wake-up device actually operates according to the first timing scheme or according to the third timing scheme. For example, the third timing scheme may comprise producing the pre-defined control signal by the wake-up device and for the communication unit, for example, every 1 minute to every 10 minutes. Accordingly, the fourth time interval of consecutive state transfers may be between 1 minute and 10 minutes. The third timing scheme may comprise periodically repeated time intervals or irregular time intervals and allows a communication more often.

[0048] Further, in one embodiment, a change of the timing scheme of the wake-up device to the second timing scheme may be restricted. For example, the change to the second timing scheme of the wake-up unit is only permitted if the wake-up unit is operated according to the third timing scheme and / or if the absolute time is within a pre-defined time period and / or in a predefined time period different from the first timing scheme. In this embodiment, the energy consuming operation according to the second time scheme is further restricted to predefined time period, for example a time period, in which a doctor’ s consultation is scheduled. After the end of the pre-defined time period, the wake-up unit may automatically revert to the first timing scheme or the third timing scheme. This embodiment further reduces energy consumption since only adoption of a pre-defined position by the patient on purpose will change the timing scheme to the one that is the most energy consuming (the second timing scheme). If the patient adopts the pre-defined position outside the pre-defined time period of the third timing scheme, the second timing scheme is not initiated. Alternatively or additionally, only during the pre-defined time period defined by the time period data (i.e. if the absolute time is within the pre-defined time period) the wake-up unit is allowed to change from any timing scheme (e.g. the first timing scheme or the third timing scheme) to the second timing scheme. The term “absolute time” means the local time of the time zone in which the patient wearing the IMD actually stays. Such time period may be the day time, e.g. between 8 am and 6 pm. This time period may be the usual doctor’s working time for consultation. Accordingly, in this embodiment the detection of a pre-defined position (e.g. the horizontal position) at a time point outside the pre-defined time period would not change the operation mode of the wake-up device to the second timing scheme. In one embodiment

[0049] 23.032P-WO | 26.01.2026time period data (having, for example a starting time and a duration value) regarding a predefined time period may be transmitted via the communication connection between the internal communication unit and the external communication unit or may be pre-defined and stored within the memory.

[0050] In a specific embodiment, the invention is directed to an iLPS, comprising

[0051] a functional unit (10, 11, 14) configured to monitor blood pressure of a patient (2), an internal communication unit (17) configured to wirelessly request communication to an external device (3), namely to transmit data to an external communication unit (31) of the external device (3), and to receive data from said external communication unit (31), said internal communication unit (17) having an operational state for performing said communication and a switched-off state,

[0052] a wake-up unit (12) for repeatedly transferring the internal communication unit (17) and a position analysis unit from the switched-off state to the operational state according to a first timing scheme and based on the signal of a clock unit, wherein a first time interval is realized between consecutive ones of such state transfers,

[0053] a position sensor (19) configured to provided position data of the IMD (1) to the position analysis unit, wherein the position analysis unit (11) configured to receive the position data and to determine the position of the patient, whereby the position analysis unit (11) is further configured to provide a pre-defined control signal to the wake-up unit (12) if a pre-defined position of the patient is detected, wherein the wake-up unit (12) is further configured such that as soon as the wake-up unit (12) receives said pre-defined control signal from the position analysis unit (11), the wake-up unit (12) changes to a second timing scheme for said repeated state transfer of the internal communication unit (17) having a second time interval between consecutive state transfers that is different from the first time interval; and wherein the change to the second timing scheme of the wake-up unit is only permitted if the wakeup unit is operated according to the third timing scheme and / or if the absolute time is within a pre-defined time period and / or in a predefined time period different from the first timing scheme.

[0054] For all above timing schemes, the third time interval referring to the time span in which the internal communication stays in the operational mode if no communication connection to

[0055] 23.032P-WO | 26.01.2026the external communication unit can be established, may be, for example, between 100 ms and 500 ms. In one embodiment, if a communication connection is established within the third time interval, the operational mode is maintained as long as the communication connection is not terminated.

[0056] In one embodiment of the IMD, the wake-up unit is further configured to activate the functional unit for determination of a bodily parameter of the patient and / or for delivery of a therapy signal to the patient simultaneously with the transfer of the internal communication unit from the switched-off state to the operational state. If the functional unit is activated with the state transfer of the internal communication unit to the operational state, providing of actual measurement data is fast realized. Accordingly, very actual measurement data of the patient’s health status can be provided without delay.

[0057] The above problem is further solved by a system comprising the IMD as described above and an external device comprising an external communication unit configured to wirelessly communicate data to the IMD, namely to transmit data to the internal communication unit of the IMD and to receive data from the internal communication unit of the IMD. Such system has the advantages and embodiments that were already discussed with regard to the IMD above. It is therefore referred to above explanation.

[0058] In one embodiment of the system, the external communication unit is configured to transmit a confirmation signal confirming the connections set-up request to the internal communication unit of the IMD in order to establish the communication connection with the internal communication unit.

[0059] In one embodiment of the system, the external communication unit is configured to transmit a signal comprising a data request for data to be provided from the functional unit of the IMD and / or comprising a control signal for initiation and / or change of the third timing scheme.

[0060] The above object is further solved by an operation method of an implantable medical device (IMD) comprising

[0061] 23.032P-WO | 26.01.2026a functional unit configured to monitor a bodily parameter of a patient and / or to deliver a therapy signal to the patient, an internal communication unit configured to wirelessly communicate data to an external device, e.g. to send a communication request to the external device and to transmit data to an external communication unit of the external device and to receive data from the external communication unit, said internal communication unit having an operational state for performing said communication and a switched-off state, a wake-up unit comprising a clock unit for repeatedly transferring the internal communication unit from the switched-off state to the operational state according to a first timing scheme and based on the signal of the clock unit, wherein a first time interval is realized between consecutive ones of such state transfers, and a position sensor, wherein the method comprises the following steps:

[0062] - Measuring the position of the IMD by the position sensor,

[0063] - Providing a pre-defined control signal to the wake-up unit if a pre-defined position of the IMD is detected,

[0064] Changing the wake-up unit to a second timing scheme for said repeated state transfer of the internal communication unit having a second time interval between consecutive state transfers that is different from the first time interval as soon as the wake-up unit receives said control signal from the position sensor, wherein preferably the second time interval is smaller than the first time interval.

[0065] The above method and below embodiments of the method have the advantages and embodiments that were already discussed with regard to the IMD above. It is therefore referred to above explanation.

[0066] The above method may be realized as a computer implemented method as it is executed by the processing unit(s) of the IMD, in particular by the processor of the functional unit, the processing element of the internal communication unit, of the wake-up unit, the position sensor.

[0067] In one embodiment of the method, the internal communication unit transmits at least one connection set-up request to the external communication unit in the operational state and remains in the operational state to receive a confirmation signal confirming receipt of said

[0068] 23.032P-WO | 26.01.2026connection set-up request over a pre-defined third time interval and reverts to the switched-off state after expiry of the third time interval.

[0069] In one embodiment of the method, the wake-up unit changes from the first timing scheme to a third timing scheme for said repeated state transfer of the internal communication unit having a fourth time interval between consecutive state transfers that is different from the first time interval and the second time interval, wherein the change from the first timing scheme to the third timing scheme is initiated by a control signal received by the internal communication unit, wherein preferably the first time interval is greater than the fourth time interval and the fourth time interval is greater than the second time interval.

[0070] In one embodiment, the wake-up device may be configured such that the first timing scheme is the standard timing scheme and the wake-up device reverts to the first timing scheme from the second timing scheme or the third timing scheme after a pre-defined time period that may be different for both timing schemes. The implementation of further timing schemes with different parameters but similar to the first, second or third for further enhancement of the dynamic behavior is possible.

[0071] The present invention will now be described in further detail with reference to the accompanying schematic drawing, wherein

[0072] Fig. 1 shows an embodiment of an IMD implanted in a patient along with an external device, and

[0073] Fig. 2 depicts the IMD of Fig. 1 in a side view showing its internally located components.

[0074] In the following, the invention is explained with regard to an IMD being an implantable leadless pressure sensor (ILPS) 1 measuring the blood pressure of the patient 2. It may be realized in the same manner in connection with other IMDs. Accordingly, the following discussion of the embodiment shall apply to other IMDs, as well, and is not limited to ILPSs.

[0075] 23.032P-WO | 26.01.2026In Fig. 1 the ILPS 1 is shown implanted in a patient’s vessel, e.g. an artery. The ILPS 1 is used to perform blood pressure measurements in a patient over a prolonged period of time. For example, the ILPS 1 shall remain in the patient’s body for multiple years to record blood pressure data during the lifetime of the ILPS 1 and to communicate with an external device 3, e.g. a laptop computer, so that the measurement data may be used to diagnose or monitor the health status of the patient 2.

[0076] The ILPS 1 is small in size. As shown in Fig. 2, the ILPS 1, for example, comprises a hermetically sealed housing 15, which, in one embodiment, may comprise an essentially cylindrical housing shape or long cuboid shape with rounded edges, with a length between 10 mm and 40 mm.

[0077] The ILPS 1 further comprises a functional unit 10 which contains a processor 11 and serves to perform a predetermined function - in this case the blood pressure measurement. For that, the functional unit 10 further comprises a sensor unit 20 comprising a membrane 14, wherein the membrane 14 forms a section of the housing and transmits the blood pressure into the housing 15 when implanted. The housing 15 and the membrane 14 may consist of a Titanium alloy. Within the housing 15 the ILPS 1 further comprises an electrical circuitry electrically connecting the components located within the housing 15, for example, the processor 11, a wake-up unit 12, a battery 13, a data memory 16, an internal communication unit 17 and a position sensor 19. These components are electrically connected to each other. The battery 13 provides the power supply of all components of the ILPS 1. The ILPS may further comprise a fixation loop (not shown) or similar fixation element extending from the housing 15 which provides a mechanical fixation of the implant at a pre-defined measuring location within the patient’s vasculature. The fixation loop may consist of Nitinol.

[0078] In one embodiment, the housing 15 comprises the membrane 14 which deforms according to the pressure acting on the implant. The sensor unit 20 connected to membrane 14 thereby receives a signal corresponding to the pressure acting on the membrane 14. The sensor unit 20 may comprise a piezoresitive element or any suitable sensor element to translate the displacement of the membrane caused by the pressure into an electrical signal. The signal

[0079] 23.032P-WO | 26.01.2026may be amplified, digitized or otherwise processed by the senor unit 20 and / or the processor 10 to obtain the blood pressure data as physiological data.

[0080] The wake-up unit 12 comprises a clock unit so that the wake-up unit 12 can be operated based on a pre-defined timing scheme, usually on a pre-defined first timing scheme as explained above, wherein the first time interval is, for example 1 day and the pre-defined control signal is transmitted from the wake-up unit 12 to the internal communication unit 17 during night to transfer it from the switched-off state to the operational state. In the operational state, the internal communication unit 17 may transmit a connection set-up request to an external communication unit 31 of the external device 3. As soon as the external communication unit 31 receives the connection set-up request, the external communication unit 31 examines this signal with regard to whether the signal is the expected one. If this is confirmed, the external communication unit 31 sends a confirmation signal confirming receipt of said connection set-up request to the internal communication unit 17. For communication, for example, the MICS band may be used. The fixation loop of the ILPS 1 may be used as an antenna for sending the data to the external communication unit 31 or receiving signals from there. As soon as the confirmation signal is received by the internal communication unit 17, the communication connection is established and data may be transmitted bi-directionally, for example blood pressure measurement data, data requests from the external device to the ILPS, e.g. a data request for blood pressure measurement data measured within a specific time period, data regarding the status of the ILPS 1 (e.g. the status of the battery 13) and / or parameter regarding the communication with the external device 31. If the internal communication unit 17 does not receive any confirmation signal from the external communication unit 31 the internal communication unit 17 reverts to the switched-off state after, for example, 200 milliseconds.

[0081] The position sensor 19, e.g. a piezoelectric accelerometer, determines in pre-defined time intervals, e.g. every 1 second, the position of the ILPS 1 and, accordingly, the position of the patient. For that, the ILPS position was calibrated during implantation and the above-mentioned reference position Pref, for example, for the horizontal position of the patient 2 was determined. If, for the actual position P of the ILPS 1 determined by the position sensor 19 the above defined value / L / / '( see above equation 1) is smaller than a pre-defined threshold

[0082] 23.032P-WO | 26.01.2026value Z, it is detected that the patient 2 is in a pre-defined position, e.g. in a horizontal position. If the this position is detected, the wake-up unit 12 is transferred to the second timing scheme, wherein the second time interval between two consecutive control signals transferring the internal communication unit 17 to the operational state is, for example every second. This means, that e.g. every second, the internal communication unit 17 triggered by the wake-up unit 12 is transferred to the operational state and sends at least one connection set-up request to the external communication unit 31 of the external device 3. Then, either a communication connection with the external device 3 may be established or not, wherein the internal communication unit 17 reverts to the switched-off state after, for example, 200 ms, if no communication connection could be established. The second timing scheme may be ended after, for example, 30 minutes. Then, the wake-up unit 12 operates again with the first timing scheme but may revert to the second timing scheme if the pre-defined position is detected again. As indicated above, this dynamic communication control effects a considerable energy consumption reduction by the communication unit 17, as it is only fully energized during its operational state.

[0083] In another embodiment, the energy consumption may further be reduced by using a third timing scheme within a pre-defined time period. The timing parameter of the third timing scheme may be transmitted, for example, at least one night before this third timing scheme shall be used, for example during the once-a-day-communication effected based on the first timing scheme. For example, the ILPS 1 receives the information, that the third timing scheme shall be used on the following day between 1 pm and 3 pm because a doctor’s appointment is scheduled for this time period.

[0084] If - based on the clock unit of the wake-up unit 12 - the specified time point (1 pm on the next day) is reached, the wake-up unit switches to operation according to the third timing scheme, wherein a pre-defined control signal for transferring the internal communication unit 17 to the operational state is provided, for example, every minute. Accordingly, the ILPS 1 can react faster to requests of the external unit 3. Further, in this embodiment, the operation of the wake-up unit 12 according to the second timing scheme (when the patient 1 is in a pre-defined position) is allowed during the time period in which the wake-up unit

[0085] 23.032P-WO | 26.01.2026operates in the third timing scheme. This further reduces the energy consuming time periods where communication attempts are often provided.

[0086] The information with regard to the time period of the third timing scheme may be transmitted to the external device 3, for example, by the HCP via usual communication way, e.g. wireless via Bluetooth or a LAN internet connection. The data may be transmitted, for example, from the HMSC.

[0087] In another embodiment, the timing scheme change of the wake-up unit 12 to the second timing scheme after detection of a pre-defined position of the ILPS 1 by the position sensor 19, may only be permitted within a pre-defined time period, e.g. between 8 am and 6 pm absolute time. The data defining this time period may either be pre-defined and stored within the data memory or may be transmitted according to the HCP’s request via the established communication connection of the external communication unit 31 and the internal communication unit 17. If the absolute time is not within the specified time period, the timing scheme change of the wake-up unit 12 is not executed even if the pre-defined position of the ILP is detected by the position sensor 19.

[0088] With the confirmation signal or by a later request from the external communication unit 31 of the external device 3 the functional unit with the pressure sensor of the ILPS 1 may be activated to conduct a blood pressure measurement as indicated above. Accordingly, such actual data or previously measured and stored blood pressure measurement data may be transmitted to the external device 3 by the internal communication unit 17.

[0089] 23.032P-WO | 26.01.2026

Claims

Claims1. An implantable medical device (IMD, 1) comprisinga functional unit (10, 11, 14) configured to monitor a bodily parameter of a patient (2) and / or to deliver a therapy signal to the patient (2),an internal communication unit (17) configured to wirelessly communicate data to an external device (3), namely to transmit data to an external communication unit (31) of the external device (3), and to receive data from said external communication unit (31), said internal communication unit (17) having an operational state for performing said communication and a switched-off state,a wake-up unit (12) for repeatedly transferring the internal communication unit (17) and a position analysis unit from the switched-off state to the operational state according to a first timing scheme and based on the signal of a clock unit, wherein a first time interval is realized between consecutive ones of such state transfers, a position sensor (19) configured to provided position data of the IMD (1) to the position analysis unit, wherein the position analysis unit (11) configured to receive the position data and to determine the position of the patient, whereby the position analysis unit (11) is further configured to provide a pre-defined control signal to the wake-up unit (12) if a pre-defined position of the patient is detected, wherein the wake-up unit (12) is further configured such that as soon as the wake-up unit (12) receives said predefined control signal from the position analysis unit (11), the wake-up unit (12) changes to a second timing scheme for said repeated state transfer of the internal communication unit (17) having a second time interval between consecutive state transfers that is different from the first time interval.

2. The IMD according to claim 1, wherein the second time interval is smaller than the first time interval.

3. The IMD according to any one of the previous claims, wherein the pre-defined position of the IMD (1) corresponds to a horizontal position of the patient (2).23.032P-WO | 26.01.20264. The IMD according to any one of the previous claims, wherein the position analysis unit (9, 11) is integrated in the functional unit (10), in particular integrated in the processor (11).

5. The IMD according to any one of the previous claims, wherein the wake-up unit (12) repeatedly transfers at least parts of the functional unit, in particular the processor (11), from the switched-off state to the operational state according to a first timing scheme and based on the signal of a clock unit.

6. The IMD according to any of the claims 1 to 3, wherein the position analysis unit is integrated in the position sensor (9).

7. The IMD according to any one of the previous claims, wherein the internal communication unit (17) is configured such that it transmits at least one connection set-up request to the external communication unit (31) in the operational state and remains in the operational state to receive a confirmation signal confirming receipt of said connection set-up request over a pre-defined third time interval and reverts to the switched-off state after expiry of the third time interval.

8. The IMD according to claim 7, wherein the internal communication unit (17) is configured to transmit data provided from the functional unit (10, 11, 14) with the connection set-up request.

9. The IMD according to any one of claims 7 to 8, wherein if the confirmation signal comprises data requesting further information from the functional unit (10, 11, 14), the internal communication unit (17) is configured to transmit said data request to the functional unit (10, 11, 14) and said functional unit (10, 11, 14) is configured to provide said data request corresponding information to the internal communication unit (17) for transmittal to the external communication unit (31).

10. The IMD according to any one of the previous claims, wherein the wake-up unit (12) is further configured to change from the first timing scheme to a third timing scheme23.032P-WO | 26.01.2026for said repeated state transfer of the internal communication unit (17) having a fourth time interval between consecutive state transfers that is different from the first time interval and the second time interval, wherein the information regarding the change from the first timing scheme to the third timing scheme is provided as timing scheme data received by the internal communication unit (17) during communication, wherein preferably the first time interval is greater than the fourth time interval and the fourth time interval is greater than the second time interval.

11. The IMD according to any one of the previous claims, wherein the change to the second timing scheme of the wake-up unit (12) is only permitted if the wake-up unit (12) is operated according to the third timing scheme and / or if the absolute time is within a pre-defined time period.

12. The IMD according to any one of the previous claims, wherein the wake-up unit (12) is further configured to activate the functional unit (10, 11, 14) for determination of a bodily parameter of the patient (2) and / or for delivery of a therapy signal to the patient (2) simultaneously with the transfer of the internal communication unit (17) from the switched-off state to the operational state.

13. A system comprising the IMD (1) according to any one of the previous claims and an external device (3) comprising an external communication unit (31) configured to wirelessly communicate data to the IMD (1), namely to transmit data to the internal communication unit (17) of the IMD (1) and to receive data from the internal communication unit (17) of the IMD (1).

14. The system of claim 10, wherein the external communication unit (31) is configured to transmit a confirmation signal confirming the connections set-up request to the internal communication unit (17) of the IMD (1).

15. The system of any one of the claims 10 to 11, wherein the external communication unit (31) is configured to transmit a signal comprising a data request for data to be23.032P-WO | 26.01.2026provided from the functional unit (10, 11, 14) of the IMD (1) and / or comprising a control signal for initiation and / or change of the third timing scheme.

16. An operation method of an implantable medical device (IMD, 1) comprisinga functional unit (10, 11, 14) configured to monitor a bodily parameter of a patient (2) and / or to deliver a therapy signal to the patient (2), an internal communication unit (17) configured to wirelessly communicate data to an external device (3), namely to transmit data to an external communication unit (31) of the external device (3) and to receive data from the external communication unit (31), said internal communication unit (17) having an operational state for performing said communication and a switched-off state, a wake-up unit (12) comprising a clock unit for repeatedly transferring the internal communication unit (17) from the switched-off state to the operational state according to a first timing scheme and based on the signal of the clock unit, wherein a first time interval is realized between consecutive ones of such state transfers, and a position sensor (19), wherein the method comprises the following steps:- Measuring the position of the IMD (1) by the position sensor (19),- Providing a pre-defined control signal to the wake-up unit (12) if a pre-defined position of the IMD (1) is detected,Changing the wake-up unit (12) to a second timing scheme for said repeated state transfer of the internal communication unit (17) having a second time interval between consecutive state transfers that is different from the first time interval as soon as the wake-up unit (12) receives said pre-defined control signal from the position sensor (19), wherein preferably the second time interval is smaller than the first time interval.

17. The method of claim 16, wherein the internal communication unit (17) transmits at least one connection set-up request to the external communication unit (31) in the operational state and remains in the operational state to receive a confirmation signal confirming receipt of said connection set-up request over a pre-defined third time interval and reverts to the switched-off state after expiry of the third time interval.23.032P-WO | 26.01.202618. The method of any one of the claims 16 and 17, wherein the wake-up unit (12) changes from the first timing scheme to a third timing scheme for said repeated state transfer of the internal communication unit (17) having a fourth time interval between consecutive state transfers that is different from the first time interval and the second time interval, wherein the change from the first timing scheme to the third timing scheme is initiated by a control signal received by the internal communication unit (17), wherein preferably the first time interval is greater than the fourth time interval and the fourth time interval is greater than the second time interval.23.032P-WO | 26.01.2026

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