Method and system for communicating between multiple implantable medical devices

Abstract

This invention relates to a wireless communication method and a multi-device system configured to implement the method for adjusting a communication window and adapting the communication window to the electrophysiological rhythm of a patient. Each device in the system is configured to determine a time stamp (P) associated with the detection of a PQRST complex wave. ref1n P ref2n ), and rearrange the communication window according to the time stamp determined for each cardiac cycle.

Description

[0001] The present invention relates to methods and systems for communication between multiple implantable medical devices.

[0002] The heart contracts to ensure blood circulation. These contractions are generated by electrical impulses called stimuli. In a healthy heart, the stimuli originate in the sinoatrial node, located in the wall of the right atrium. The stimuli travel from the sinoatrial node to the atrium, where the atrium contracts to force blood out of the atrium and into the resting ventricles to fill them.

[0003] Subsequently, following a delay known as the atrioventricular delay, the ventricles are stimulated and contract. This atrioventricular delay is necessary for optimal cardiac function.

[0004] In patients with cardiac conditions, the source of stimulation and / or its pathway through the heart may be interrupted due to dysfunction in the stimulation conduction system. This causes changes in heart rhythm, known as arrhythmias.

[0005] When the heart's rhythm is too weak to meet the body's oxygenation needs, it is called bradycardia.

[0006] To treat bradycardia when medication is insufficient, artificial pacing of the heart using implantable devices such as pacemakers is known. Specifically, pacing systems known to use a biventricular pacemaker consist of a device implanted subcutaneously and connected to two leads for delivering artificial stimulation. The leads are implanted in a vein to connect the right atrium and right ventricle. When the leads are connected to the same implantable medical device (such as a conventional pacemaker), synchronization between the leads can be achieved directly through the electronic circuitry of the implantable medical device. However, there are risks associated with using intravenous leads. Lead breakage is one of the most common causes of pacemaker malfunction. Removal of the implanted intravenous lead (or pacemaker) is a procedure with a high morbidity and mortality rate, and is therefore usually performed only in cases of severe systemic infections that cannot be treated with antibiotics. In most cases, the broken lead will disconnect from the device and remain in the heart. A new lead is then implanted next to the old lead and connected to an automated implantable defibrillator. However, this solution is only possible if there is still sufficient space in the vein, as the presence of another lead can lead to venous obstruction. Therefore, the use of intracardiac leads is not ideal for young patients who may require multiple leads throughout their lives. One solution to the problems associated with intracardiac leads listed above is to replace them with subcutaneous leads and / or an autopiatric pacemaker.

[0007] One of the main advantages of autonomous pacemakers is the absence of a casing and the reduction of foreign objects such as leads, which lowers the risk of infection.

[0008] However, spontaneous pacemakers can only be used for single-room therapy, which limits the number of patients that can be treated.

[0009] This invention particularly relates to a pacemaker system comprising at least one autonomous leadless pacemaker. The leadless pacemaker consists of a power source (such as a battery cell), sensors, a current generator, and a telemetry module. Specifically, it is envisioned to be implanted inside the right ventricle and can be used as an alternative to an implantable monoventricular pacemaker.

[0010] To increase the percentage of the population that can benefit from autonomous pacemakers, one solution is a system with multiple implantable medical devices, requiring wireless communication between the devices to send and receive physiological information, such as the detection of PQRST complex waves. Specifically, this information is needed to provide synchronized therapy. Therefore, a synchronization signal indicating the detection of PQRST complex waves can be sent by a device implanted in one chamber to synchronize therapy with another device implanted in another chamber.

[0011] However, wireless communication methods for implantable medical devices (such as radio frequency, in-body communication (IBC), and inductive coupling) are energy-intensive and reduce battery life.

[0012] This problem is even more critical for devices configured to receive synchronization signals, as it requires the device's receiver to remain active while waiting to receive a signal, thereby further reducing battery capacity.

[0013] Therefore, the objective of this invention is to improve the wireless communication of such implantable device systems in order to reduce their power consumption and thereby extend their lifespan.

[0014] The object of the present invention is achieved by a communication method in a system comprising a plurality of implantable medical devices, wherein a first device includes at least one means for detecting a signal representing atrial activity, a transmitter means, and a controller configured to analyze the signal representing atrial activity; and a second device, independent of the first implantable medical device, includes at least one receiver means and a controller. The method includes: A) a step of synchronizing the first device with the second device in time by transmitting a synchronization signal from the transmitter means of the first device to the second device, the synchronization signal being transmitted after the controller of the first device identifies a predefined wave of a PQRS complex representing atrial activity; B) a step of determining the duration of a cardiac cycle. Following steps A and B is: C) a step of determining a synchronization interval, the duration of which is determined to be shorter than the duration of the cardiac cycle, and the start of the synchronization interval is determined based on the synchronization signal; D) a step of activating the receiver means of the second device during the synchronization interval, wherein the receiver means of the second device is deactivated by the controller of the second device outside the synchronization interval.

[0015] The communication method is improved because the receiving device of the second device is not continuously activated, but only for a time interval shorter than the duration of the cardiac cycle.

[0016] During each cardiac cycle, partial activation of the receiving device of the second device is sufficient for the purpose of system synchronization, because the synchronization interval takes into account the time stamp associated with the detection of one of the electrical waves of the PQRS complex. Detection of one of the electrical waves of the PQRS complex allows for the identification of cardiac events. Therefore, the synchronization interval is determined based on physiological information useful for system synchronization and related to the patient's heart rhythm. Thus, the synchronization interval is advantageously adjusted according to the patient's physiological characteristics.

[0017] Therefore, this method makes it possible to reduce the time period during which the receiving device of the second device must be activated to allow wireless communication. This, in turn, makes it possible to save power requirements on the second device and thus extend its lifespan.

[0018] The present invention related to the communication method can be further improved due to the following embodiments.

[0019] According to one embodiment, for a cardiac cycle, a first time marker can be determined to mark the transmission of a synchronization signal by the transmitter of a first device, and a second time marker can be determined to mark the reception of the synchronization signal by the receiver of a second device. The synchronization interval of the first device for subsequent cardiac cycles can be determined based on the first time marker, and the synchronization interval of the second device for subsequent cardiac cycles can be determined based on the second time marker.

[0020] Therefore, the synchronization interval of the second device is a function of a second time marker relating to the patient’s physiological characteristics (such as the P wave), where the P wave is one of the electrical waves of the PQRST complex.

[0021] According to one embodiment, during the synchronization interval of the second device, the receiving device of the second device can be activated during multiple predefined activation time slots and can be deactivated during multiple predefined deactivation time slots. The multiple predefined activation time slots of the second device are distributed over the synchronization interval of the second device so as to synchronize with the signal pulse time slots of the first device according to a first time marker and a second time marker.

[0022] This allows for a further advantageous reduction in the power consumption of the receiving device of the second device, since the receiving device is not activated over the entire synchronization interval but only on a time-slot-by-slot basis. This does not interfere with the reception of the synchronization signal in any way, because the activation time slot is advantageously adjusted relative to the first time marker, which marks the first device's transmission of the synchronization signal.

[0023] According to one embodiment, the transmitter device of the first device can be configured to send a single synchronization signal for each cardiac cycle.

[0024] Therefore, the communication method does not require the first device to send a series of pulses. In fact, this method allows a single synchronization signal sent by the first device to "fall into" the active time slot of the receiving device of the second device due to the synchronization of the first and second time markers.

[0025] According to one embodiment, each predefined activation slot may have the same duration, and each predefined deactivation slot may have the same duration, and each predefined activation and deactivation slot may alternately take over from each other during the synchronization interval.

[0026] The alternation of activation and deactivation time slots is therefore periodic, which further increases the likelihood that the synchronization signal will be received during the synchronization interval.

[0027] According to one embodiment, the duration of activating a time slot can be shorter than or equal to the duration of deactivating a time slot.

[0028] This can further reduce the power consumption of the receiving device in the second device.

[0029] According to one embodiment, the duration of the activation slot can be expressed as between 0.3% and 50% of the duration of the deactivation slot, particularly 5% to 10%.

[0030] This allows for the minimization of power consumption in the receiving device of the second equipment.

[0031] According to one embodiment, during this period, the transmitter device of the first device can be configured to transmit a pulse of synchronization signal for a duration corresponding to 25% to 80%, particularly 50%, of the duration of the activation time slot.

[0032] Therefore, the active time slot corresponding to the time slot when the receiving device of the second device is activated to "listen" and detect the synchronization signal is longer than the transmission duration of the synchronization signal. Consequently, there is a greater chance that the reception of the synchronization signal will occur during the active time slot of the second device.

[0033] According to one embodiment, the first time marker can mark the start or end of the transmission of the synchronization signal or a predetermined time during the transmission of the synchronization signal.

[0034] Therefore, the adjustment of the synchronization interval of the second device using the synchronization interval of the first device can be improved because the "timing" of the first time marker is defined more precisely.

[0035] According to one embodiment, in step A), the predefined radio wave detected by means of the controller of the first device can correspond to the P wave of the PQRS composite wave.

[0036] The detection of the P wave is particularly suitable because it marks depolarization during atrial contraction and thus constitutes physiologically relevant information about atrioventricular delay and synchrony.

[0037] According to one embodiment, in step A), a predefined electrical wave can be detected by means of the controller of the first device by analyzing an electrogram, an electrocardiogram, data measured by an accelerometer, data measured by a cardioid impedance device, or data measured by an acoustic sensor.

[0038] Therefore, this method can be advantageously implemented using different detection devices.

[0039] According to one embodiment, during at least two consecutive cardiac cycles, the first device and the second device can communicate with each other asynchronously during steps A and B, and the receiving device of the second device is activated continuously during at least two consecutive cardiac cycles.

[0040] Thus, the first and second devices are configured to independently determine time stamps in order to determine and adjust the synchronization interval.

[0041] According to one embodiment, the controller of the second device can be configured to activate the receiving device of the second device during the remaining time of the synchronization interval of the second device after receiving the synchronization signal.

[0042] This allows for the minimization of power consumption in the receiving device of the second equipment.

[0043] According to one embodiment, the controller of the second device can be configured to send an alarm signal to the receiving device of the first device via the transmitter device of the second device when the second device does not receive a synchronization signal during the synchronization interval of the second device.

[0044] Therefore, the first device is warned that the second device, configured to be implanted in the right ventricle, has not yet received information regarding the detection of the predefined electrical waves. The first device has already sent a synchronization signal (which has not yet been received by the second device), and the first device can see that the signal has been lost during its journey. Local pacing of the right atrium may then be necessary.

[0045] The object of the present invention is also achieved by a system of multiple implantable medical devices. The system includes: a first device comprising at least one detection device, a transmitter device, and a controller configured to analyze signals representing atrial activity. The system includes a second device independent of the first implantable medical device, the second device comprising at least one receiver and a controller. The receiver of the second device is configured to be activated and deactivated by the controller of the second device. The controllers of the first device and the second device are configured to implement the method according to the above embodiments.

[0046] Therefore, the multi-implantable device system was improved because the receiver of the second device is not continuously activated, but only during a synchronization interval that is shorter than the duration of a cardiac cycle.

[0047] During each cardiac cycle, partial activation of the receiving device of the second device is sufficient for the purpose of system synchronization, because the synchronization interval takes into account the time stamp associated with the detection of one of the electrical waves of the PQRS complex. Detection of one of the electrical waves of the PQRS complex enables the identification of cardiac events. Therefore, the synchronization interval is determined based on physiological information useful for system synchronization and related to the patient's heart rhythm. Thus, the synchronization interval is advantageously adjusted according to the patient's physiological characteristics.

[0048] According to one embodiment, the first implantable medical device may be an implantable subcutaneous medical device, an event loop recorder, or a leadless pacemaker, and the second medical device may be a leadless pacemaker.

[0049] Therefore, this system is suitable for biventricular synchronous therapy. Specifically, it is suitable for biventricular synchronous therapy with an implantable leadless pacemaker in the right atrium and an implantable leadless pacemaker in the right ventricle.

[0050] The invention and its advantages will be illustrated in more detail below by way of preferred embodiments and with particular reference to the following drawings, wherein:

[0051] Figure 1 This refers to a multi-device system 10 according to a first embodiment of the present invention.

[0052] Figure 2 A standard diagram schematically representing the PQRST composite wave:

[0053] Figure 3 This refers to a multi-device system 40 according to a second embodiment of the present invention.

[0054] Figure 4 This refers to a multi-device system 60 according to a third embodiment of the present invention.

[0055] Figure 5 A diagram illustrating the communication method according to a first embodiment of the present invention.

[0056] Figure 6 A diagram illustrating the communication method according to a second embodiment of the present invention.

[0057] Figure 7 This is a flowchart describing the initialization steps of a method implemented by a first device.

[0058] Figure 8 A flowchart is provided to illustrate the operational steps of the method implemented by the first device.

[0059] Figure 8a Commentary Figure 8 This is a step in the flowchart shown in the image.

[0060] Figure 9 This is a flowchart describing the initialization steps of a method implemented by a second device.

[0061] Figure 10 This is a flowchart describing the operational steps of a method implemented by a second device.

[0062] Figure 10a Commentary Figure 10 This is a step in the flowchart shown in the image.

[0063] Figure 11 This represents another variation of the first and second embodiments of the present invention.

[0064] The invention will now be described in more detail by way of example and with reference to the accompanying drawings. The described embodiments are merely possible configurations, and it should be remembered that the individual features described above may be provided independently of each other or may be omitted together in implementing the invention.

[0065] This invention relates to a communication method for a system of multiple implantable medical devices, and such a system.

[0066] First refer to Figure 1 , 3 Examples of such systems with multiple implantable medical devices are described in sections 4 and 4.

[0067] Then refer to Figures 5 to 10 This invention describes a communication method that can be implemented by a system of multiple implantable medical devices.

[0068] Figure 1 This refers to a multi-device system 10 comprising two implantable devices 20 and 21 according to a first embodiment of the present invention.

[0069] Figure 1 The multi-device system 10, as shown in the figure, includes a subcutaneous implantable device 20 and a leadless spontaneous pacemaker 21 implanted in the right ventricle (RV).

[0070] Figure 1 The subcutaneous implantable device 20, as shown in the image, includes a housing 22 and a subcutaneous lead 24, which is equipped with three electrodes 26, 28, and 30, and a defibrillation electrode 32. Although in Figure 1 While not visible from the inside, housing 22 includes transmitter devices, such as radio frequency (RF) transmitter devices or those using in-body communication connections, and a controller. Housing 22 may also include receiver devices.

[0071] In one variant, an event recorder or implantable circuit recorder comprising at least a pair of electrodes may be used instead of the subcutaneous implantable device 20.

[0072] The subcutaneous implantable device 20 is configured to detect atrial activity using any of the methods known in the prior art, such as electrocardiography (ECG), impedance cardiography, acoustic sensors, and / or accelerometers.

[0073] In a first embodiment of the invention, the subcutaneous implantable device 20 is configured to analyze data representing ECG. Analysis of the ECG-representing data enables the detection of at least one of the five P, Q, R, S, and T waves of the PQRST complex, which are electrophysiological characteristics. Figure 2 An example of the PQRST complex is shown. The subcutaneous implantable device 20 is specifically configured to identify a time marker corresponding to the electrical wave detection of the PQRST complex. Detection of the P wave is preferred because it marks atrial depolarization and thus constitutes physiologically relevant information about atrioventricular delay and synchronization.

[0074] For example, the detection of P waves can be determined by identifying local maxima.

[0075] The leadless automatic pacemaker 21 includes a tip electrode 23 disposed at the distal end 25 of the device 21 and a ring electrode 27 disposed toward the proximal end 29 of the device 21. Electrodes 23 and 27 may form a receiver dipole or a transmitter dipole. It should be noted that the invention is not limited to the use of tip and ring electrodes, but can be implemented using any type of electrode included in leadless automatic pacemakers.

[0076] The tip electrode 23 can be a detection electrode or a pacing electrode. In one variant, electrode 23 is both a detection electrode and a pacing electrode.

[0077] Although Figure 1 The body 31 of the invisible, leadless autonomous pacemaker 21 may encapsulate a battery cell, a controller, and a receiving device, such as an RF receiver or using an in-body communication connection. The body 31 may also include a transmitter device.

[0078] The receiver of the leadless automatic pacemaker 21 is configured to communicate wirelessly with the transmitter of the subcutaneous implantable device 20, particularly via an in vivo communication connection.

[0079] The subcutaneous implantable device 21 can be configured to detect cardiac activity using any of the methods known in the art, such as electrocardiography (ECG), electrogrammography (EGM), impedance cardiography, acoustic sensors, and / or accelerometers.

[0080] In one variant, wireless communication between devices 20 and 21 can also be achieved using other wireless communication methods such as in-body communication or inductive coupling.

[0081] In system 10, the leadless automatic pacemaker 21 is thus configured to receive signals transmitted from the subcutaneous implantable device 20. Specifically, this can be a synchronization signal containing timing information related to atrial depolarization. This synchronization signal enables synchronization of ventricular contraction. The synchronization signal can be used to deliver pacing to the right ventricle based on the patient's physiological cardiac activity detected by the subcutaneous implantable device 20.

[0082] Figure 3 A multi-device system 40 comprising two implantable devices 21, 41 according to a second embodiment of the present invention has been described.

[0083] I will not describe in detail what has already been used. Figure 1 The elements described herein have the same reference numerals and are referenced to the descriptions thereon.

[0084] Implantable device 21 corresponds to the referenced Figure 1 The leadless automatic pacemaker 21 is described and referenced.

[0085] In the second embodiment, a second leadless autonomous pacemaker 41 is used instead of the subcutaneous implantable medical device 20 of the first embodiment.

[0086] like Figure 3 As explained in the text, the leadless automatic pacemaker 41 is configured to be implanted in the right atrium (RA).

[0087] The autonomous leadless pacemaker 41 is configured to detect atrial activity using any method known in the art, such as electrocardiography (ECG), electrogrammography (EGM), impedance cardiography, acoustic sensors, and / or accelerometers.

[0088] The leadless automatic pacemaker 41 is configured to analyze data representing the ECG. By analyzing the data representing the ECG, at least one of the five P, Q, R, S, and T waves of the PQRST complex known in the prior art can be detected. Figure 2 An example of the PQRST complex wave is explained below. The leadless automatic pacemaker 41 is specifically configured to recognize a time stamp corresponding to the electrical wave detection of the PQRST complex wave.

[0089] Similar to the leadless autonomous pacemaker 21, the leadless autonomous pacemaker 41 includes a tip electrode 43 disposed at the distal end 45 of the pacemaker 41 and a ring electrode 47 disposed towards the proximal end 49 of the pacemaker 41. Electrodes 43 and 47 may form a receiver dipole or a transmitter dipole. It should be noted that the invention is not limited to the use of tip and ring electrodes, but can be implemented using any type of electrode included in leadless autonomous pacemakers.

[0090] The tip electrode 43 can be a detection electrode or a pacing electrode. In one variant, electrode 43 is both a detection electrode and a pacing electrode.

[0091] Although Figure 3 The body 51 of the leadless autonomous pacemaker 41, which is not visible in the foreground, may encapsulate a battery cell, a processor, a controller, and a transmitter device, such as an RF transmitter device. The body 51 may also include a receiver.

[0092] The transmitter device of the leadless self-standing pacemaker 41 is configured to communicate wirelessly with the receiver device of the leadless self-standing pacemaker 21, particularly by means of an in vivo communication connection.

[0093] In one variant, wireless communication between devices 21 and 41 can also occur using other wireless communication methods such as in-body communication or inductive coupling.

[0094] In one embodiment not shown, the system according to the invention includes a subcutaneous implantable device 20 and two leadless pacemakers 21, 41.

[0095] Figure 4 A multi-device system 60 comprising three implantable devices 21, 41, and 61 according to a third embodiment of the present invention has been described.

[0096] Detailed description of what has been used will not be provided. Figure 1 and 3 The elements described herein have the same reference numerals and are referenced to the descriptions thereon.

[0097] Compared to the second embodiment, the multi-device system 60 of the third embodiment includes a third implantable medical device 61. The multi-device system 60 is a so-called three-chamber resynchronization system type, also known as "CRT-P", for "cardiac resynchronization therapy pacemaker".

[0098] Implantable devices 21 and 41 correspond to the referenced Figure 1 and Figure 3 The leadless automatic pacemakers 21 and 41 are described and referenced.

[0099] The third device 61 is a leadless automatic pacemaker 61 implanted into the myocardial wall via an epicardial approach.

[0100] Reference Figure 1 , 3 In each embodiment of the invention described in section 4, the implantable devices 20, 21, 41, and 61 may include both a receiving device and a transmitting device, and are particularly suitable for RF communication. Therefore, each of the implantable devices 20, 21, 41, and 61 is configured to both transmit and receive signals in order to enable wireless communication in each of the systems 10, 40, and 60.

[0101] In addition, each of the implantable devices 20, 21 and 41 is able to determine the duration of the cardiac cycle.

[0102] The wireless communication method according to the invention relates to the synchronization of at least two implanted devices (such as 20, 21, 41, 61) included in a system (such as system 10, 40, or 60). The wireless communication method according to the invention is described below. Systems 10, 40, and 60 are each configured to implement the communication method. Specifically, the communication method is described below with respect to a system including a first device and a second device.

[0103] Figure 5 The operation of the communication method according to the first embodiment of the present invention is illustrated schematically.

[0104] Figure 5 Three time axes, 102, 104, and 106, are shown. The units for axes 102, 104, and 106 are expressed in milliseconds (ms).

[0105] The ECG is represented on time axis 102. The ECG interpreted on time axis 102 includes multiple PQRST complex waves for each of the depicted cardiac cycles. The duration of a complete cardiac cycle can be determined as the time between two consecutive identical waves. Figure 5 In this context, the duration of the cardiac cycle is represented by the interval PP, which is interpreted between two local maxima of the P wave representing the cardiac cycle. Figure 5 The annotation shows four consecutive cardiac cycles, from n=1 to n=4.

[0106] The PP interval represents the duration of a complete cardiac cycle and typically lasts about one second or more.

[0107] The first device is configured to analyze ECG 102 and determine the characteristics of the ECG in order to identify the waveform of the PQRS composite wave, particularly the P wave. This characteristic may be, for example, a local maxima assigned to the P wave. The first device may also be configured to record ECG 102.

[0108] The first device is configured to determine the duration of a cardiac cycle. This first device may be a subcutaneous implantable device 20, a recorder, or a leadless automatic pacemaker 41 configured for implantation in the right atrium (RA). Figure 5 The first device includes at least one transmitter device, for example, via an in-body communication connection.

[0109] The detection of the P wave in each PP cycle (see “Detection P1” to “Detection P4”) identified by the first device is shown on time axis 104.

[0110] Timeline 106 refers to, as referenced Figure 1 , Figure 3 and Figure 4 The second device in the described multi-device system may be a leadless automatic pacemaker 21 configured to be implanted in the right ventricle (RV). The second device may be configured to determine the duration of the cardiac cycle. The second device may therefore be able to deliver ventricular pacing.

[0111] Figure 5 The second device is independent of the first implantable medical device and includes at least one receiving device.

[0112] The method of the present invention is a method for wireless communication between a first device and a second device constituting a multi-device system, so as to allow the devices to synchronize with each other. The method is described below.

[0113] First, let's consider... Figure 5 The first cardiac cycle explained in the text is n=1. During this period, the first and second devices are not yet synchronized.

[0114] As described above, the first device is configured to analyze ECG and detect P waves. During the first cardiac cycle n=1, the P wave is detected by the first device and marked as "Detected P1" on time axis 104.

[0115] After the detection and identification of the P1 wave, the transmitter of the first device is configured to send a synchronization signal to the second device. The time marker P on time axis 104... ref1 n＝1 Corresponding to the mark Figure 5 The time stamp of the transmission of the synchronization signal in the first cardiac cycle explained in the text.

[0116] The synchronization signal is received by the receiving device of the second device and is marked by the time marker P on the time axis 106. ref2 n＝1 To give instructions.

[0117] Then, during the next cardiac cycle n=2, the P wave is detected and identified again by the first device and marked as "Detected P2" on time axis 104.

[0118] After the P2 wave is detected and identified, the transmitter of the first device is configured to send a synchronization signal to the second device. The time marker P on time axis 104... ref1 n＝2 Corresponding to the mark Figure 5 The time stamp of the transmission of the synchronization signal of the second cardiac cycle n=2 as explained in the middle.

[0119] The synchronization signal is received by the receiving device of the second device and is marked by the time marker P on the time axis 106. ref2 n＝2 To give instructions.

[0120] According to the present invention, in P ref1 n＝1 With P ref1 n＝2 Determine the duration of the first cardiac cycle n=1 between (see) Figure 5 The "P" in ref1 n＝1 P ref1 n＝2 (Interval). This allows for reference to a common reference between the first and second devices.

[0121] In one variation, the duration between "detection P1" and "detection P2" allows for the determination of the duration of the first cardiac cycle n=1 (see [link]). Figure 5 (The interval P1P2 in the text).

[0122] Then, during the next cardiac cycle n=3, the P wave is detected and identified again by the first device and marked as "Detected P3" on time axis 104.

[0123] After the P3 wave is detected and identified, the transmitter of the first device is configured to send a synchronization signal to the second device. The time marker P on time axis 104... ref1 n＝3 Corresponding to the mark Figure 5 The time stamp of the synchronization signal sent in the third cardiac cycle explained in the text.

[0124] The synchronization signal is received by the receiving device of the second device and is marked by the time marker P on the time axis 106. ref2 n＝3 To give instructions.

[0125] According to the present invention, and by means of a second cardiac cycle with a duration n=2 similar to the first cycle, in P ref1n＝2 and P ref1 n＝3 The interval is determined.

[0126] In one variant, the duration between "detection P2" and "detection P3" allows for the determination of the duration of the second cardiac cycle n+2.

[0127] The synchronization interval of the second device is 108, which can be determined from the time stamp P. ref2 n＝2The duration of the second cardiac cycle is determined with respect to the third cardiac cycle n=3. This synchronization interval 108 corresponds to the listening window, meaning that the receiving device of the second device is activated during synchronization interval 108 for the purpose of receiving the synchronization signal transmitted by the first device. Therefore, signals or messages can be received by the receiving device of the second device during synchronization interval 108.

[0128] The duration of the synchronization interval 108 is determined in a manner shorter than the duration of the second cardiac cycle. The duration of the synchronization interval 108 can be less than 0.8 s, specifically less than 0.4 s.

[0129] From reference D ref2 n＝3 The start of the indicated synchronization interval 108 is determined to be the time marker P of the previous cardiac cycle n+2. ref2 n＝2 The function.

[0130] Since the synchronization interval 108 is the time marker P of the previous cardiac cycle n+2. ref2 n＝2 The function of this allows the synchronization interval 108 to be arranged on the third cycle, so that the reception of the synchronization signal occurs during the synchronization interval 108.

[0131] The reception of the synchronization signal is achieved by the time stamp P. ref2 n＝3 To give instructions.

[0132] Start D ref2 n＝3 The determination of the duration of the synchronization interval 108 on the third cardiac cycle significantly takes into account the maximum acceleration between beats, which typically does not exceed 10% to 40% of the duration of the cardiac cycle, specifically 25% to 35%.

[0133] Furthermore, the determination of the synchronization interval 108 also takes into account the time taken for the myocardium to respond to atrial activity. This is a parameter that can be programmed by a physician to improve the physiological response of the heart. This parameter can correspond to 0-50% of the duration of the cardiac cycle, particularly 0-30%.

[0134] According to the present invention, the receiving device of the second device is activated during the synchronization interval 108 and deactivated by the controller of the second device outside the synchronization interval 108.

[0135] Therefore, the receiver of the second device is not continuously activated throughout the entire cardiac cycle, which allows for a reduction in the power consumption of the second device. In fact, the receiver of the second device consumes power whenever it is activated. By activating the receiver during the synchronization interval 108 rather than the entire cardiac cycle, the power consumption required for wireless communication for resynchronization purposes can be reduced because the power-on time of the receiver is limited to the duration of the synchronization interval 108.

[0136] However, this is not a matter of shutting down all the functions of the second device at once, which performs other functions, such as detection, timing, or pacing, in parallel with the functions of the receiving device.

[0137] The synchronization interval 110 of the first device can also be determined from the time marker P and the duration of the second cardiac cycle. The start of the synchronization interval 110 of the third cardiac cycle n+3 is determined by the time marker D. ref1 n＝3 Instructions. Therefore, specifically according to the time stamp P ref1 n＝2 To determine the start of synchronization interval 110 D ref1 n＝3 .

[0138] Based on the P-wave identifier, the synchronization interval 110 of the first device corresponds to the transmission window, that is, the interval during which a synchronization signal may be transmitted. For the third cardiac cycle n+3, the transmission of the synchronization signal is time-stamped by P. ref1 n＝3 instruct.

[0139] The fourth and subsequent cardiac cycles n+4 (in Figure 5 The synchronization intervals 108 and 110 (not shown in the diagram) are determined in the same manner as explained above for the third cardiac cycle.

[0140] The advantage of this method is that the communication intervals 108 and 110 are adjusted over time according to cardiac events (detection of P waves), and thus the communication intervals 108 and 110 are customized for the patient's physiological characteristics.

[0141] In an alternative scheme not shown, the synchronization interval 110 can be determined based on the time stamp P. ref1 n＝2 The duration of the second cardiac cycle is arranged on the third cycle n+3 in such a way that the detection of the P wave is not included in the synchronization interval 110. In this case, the synchronization interval 110 is shifted to the right of the time axis 104 relative to the first embodiment. In this alternative, the synchronization interval 108 is also shifted to the right of the time axis 104 relative to the first embodiment. This alternative is particularly suitable for sending synchronization messages containing datasets.

[0142] Please note that the first device may send a synchronization "signal" or "message". In this specification, a synchronization "signal" refers to a signal that includes information encoded on a single bit, while a synchronization "message" refers to a signal that includes information encoded on multiple bits.

[0143] Therefore, the difference between the synchronization “signal” and the synchronization “message” is related to how the timing information of P-wave detection is encoded.

[0144] In the synchronization message, the timing of the P-wave detection is encoded, thus allowing more detailed information to be sent to the second device.

[0145] In the synchronization signal, the timing information for P-wave detection is implicit in the timing of the signal transmission. Thus, a signal containing information encoded on a single bit can be transmitted.

[0146] The time stamp P for each period n ref1 and P ref2 Used as a time reference to synchronize synchronization intervals 108 and 110. Specifically, time stamp P is used. ref1 and P ref2 This ensures that the synchronization intervals 108 and 110 overlap or even align.

[0147] Therefore, time stamp P ref2 Used to adjust the activation of the receiving device of the second device.

[0148] Figure 6 The operation of the communication method according to the second embodiment of the present invention is illustrated schematically.

[0149] With similar Figure 5 In this way, Figure 6 This represents three time axes: 202, 204, and 206. The units for axes 202, 204, and 206 are expressed in milliseconds (ms).

[0150] The ECG is shown on time axis 202. The ECG includes the PQRST complex. The duration of a complete cardiac cycle can be determined as the duration between two consecutive identical waves.

[0151] As shown on timeline 204 (reference) Figure 1 , 3 The synchronization interval 210 of the first device in the multi-device system described in section 4.

[0152] As shown on timeline 206 (reference) Figure 1 , 3 The synchronization interval 208 of the second device in the multi-device system described in section 4. This second device may be a leadless spontaneous pacemaker 21 configured to be implanted in the right ventricle (RV). The second device may therefore be able to deliver ventricular pacing.

[0153] Figure 6 The second device is independent of the first implantable medical device and includes at least one receiving device.

[0154] For cardiac cycle n, the synchronization interval 208 of the second device is determined in the same manner as described for the synchronization interval 108 of the second device in the third cycle of the first embodiment (see [link]). Figure 5 In other words, Figure 6 The second device's synchronization interval 208, as explained in the middle, begins D. ref2 n It is the second time marker P of the previous cardiac cycle n-1.ref2 n-1 function ( Figure 6 (Not indicated in the text).

[0155] Similarly, for cardiac cycle n, the synchronization interval 210 of the first device is determined in the same manner as described for the synchronization interval 110 of the first device in the third cycle of the first embodiment (see [link]). Figure 5 In other words, Figure 6 The first device's synchronization interval 210, as explained in the middle, begins D. ref1 n It is the first time marker P of the previous cardiac cycle n-1. ref1 n-1 function ( Figure 6 (Not shown in the image).

[0156] During synchronization interval 208, the transmitter device of the first device can transmit via, as Figure 6 Rest period T depicted on timeline 204 off Interval duration T bit The pulse. During the rest period T off During this period, the transmitter device does not send pulses. Duration T bit It can be equal to 500 microseconds (μs) and "T off "It can be equal to 9.5 milliseconds (ms)."

[0157] Once detected by Figure 6 The transmitter of the first device immediately uses the P-wave indicated by "Detect P" in the code. bit The first available time slot is defined for sending the synchronization signal. Therefore, although Figure 6 Represents multiple Ts bit The transmitter device uses only one time slot to send the synchronization signal.

[0158] In other words, when the first device detects a P-wave, the transmitter of the first device is configured to send a synchronization signal to the first T-block after detecting the P-wave. bit , its origin Figure 6 Block T in bit P Indication. The transmission of the synchronization signal is indicated by the time stamp P. ref1 n To mark. Time stamp P ref1 n It can indicate the start or end of signal transmission.

[0159] To further reduce the power consumption of the second device, in the second communication mode, the receiving device of the second device is activated by the controller at each interval during the synchronization interval 208 and then deactivated.

[0160] The synchronization interval 208 of the second device therefore includes multiple activation time slots “m”. on "and multiple deactivation slots" m offIn other words, the synchronization interval 208 comprises a series of blocks "m", each block containing time slots m. on and time slot m off , such as in Figure 6 The explanation is on timeline 206.

[0161] In the activation time slot "m on During this period, the receiving device is activated and configured to receive signals, particularly the synchronization signal sent by the first device.

[0162] In the deactivation slot "m off During this period, the receiver is deactivated, meaning it is turned off and does not consume any energy.

[0163] exist Figure 6 In the example, each activation slot "m on "They have the same duration."

[0164] exist Figure 6 In the example, each deactivation slot "m off "They have the same duration."

[0165] Each time slot m on The duration can be equal to or shorter than each time slot m off The duration.

[0166] The synchronization intervals 208 and 210 of cardiac cycle n are based on the time stamp P of the previous cardiac cycle n-1. ref2 n-1 and P ref1 n-1 Synchronize with each other, as shown in the reference. Figure 5 As explained.

[0167] In addition, the second time marker P based on the previous cardiac cycle n-1 ref2 n-1 and the first time marker P ref1n-1 The second device has multiple predefined activation slots m on With multiple time slots T of the first device bit synchronous.

[0168] like Figure 6 The interpretation in the text is that it is composed of "m" on P "During the indicated activation time slot, the receiver of the second device receives a synchronization signal. The signal reception is determined by time stamp P." ref2 n Use it to mark.

[0169] Activation slot m on The duration can represent a deactivation slot m off The duration is between 0.3% and 50%. Activation slot m on The duration depends on the receiver quality and the time required for it to detect the synchronization signal. Specifically, the activation time slot mon The duration can represent the deactivation slot m off The duration is between 5% and 10%.

[0170] When considering the synchronization interval of approximately 350ms, the ratio of 208 to m is... on =10% (m=m) on +m off The results show that improving the activation period of the receiver in the second device for synchronization purposes can reduce power consumption by 0.1% to 3.5%. For example, block m can be equal to a duration of 10 ms, where block m includes a 1 ms time slot m. on and 9ms time slot m off .

[0171] In the favorable variant, once the time stamp P is determined... ref2 n Then, the receiver of the second device is activated during the remaining time of a given cardiac cycle to conserve further power. Figure 6 In the example, this will result in the output from module m on P The receiving device is deactivated from the start until the end of the cardiac cycle n.

[0172] Figure 7 The initialization steps of the method implemented by the first device are explained with the help of flowchart 300. These initialization steps are implemented asynchronously relative to the second device. The method steps in flowchart 300 are applicable to reference... Figure 5 and Figure 6 The described embodiments.

[0173] like Figure 7 As illustrated in the flowchart, initialization 302 includes detecting a time stamp of the cardiac cycle in step 304. This time stamp corresponds to the detection of a predefined wave of the PQRST complex. As previously stated, the first device is indeed configured to analyze data representing the ECG.

[0174] Preferably, the time stamp corresponds to the detection of the P wave, which is the first detectable wave of the PQRST complex. The P wave appears when the stimulus (or pulse) propagates to the atrial myocardium, causing atrial depolarization.

[0175] Therefore, in the following text, reference is made to the detection of the P wave, as indicated in step 304 of flowchart 300. Figure 7 In this embodiment, the P-wave is selected as a predefined radio wave. It should be remembered that the selection of the P-wave is not limiting; another wave of the PQRST composite wave, particularly the R-wave, can be considered.

[0176] If a P-wave is detected in step 304, a synchronization signal is sent to the second device in step 306.

[0177] The synchronization signal thus indicates the timing of P wave detection. The synchronization signal for each cardiac cycle can indicate the detection of atrial depolarization, particularly right atrial depolarization.

[0178] In step 308, following step 306, a time vector representing the timing of the synchronization signal transmitted in step 306 is saved. The time vector can be stored in a first-in, first-out (FIFO) memory. In other words, a time stamp marking the transmission of the synchronization signal is determined in step 308.

[0179] Then, in step 310, the time vector is incremented in the counter in such a way that when multiple "n" time markers of n cardiac cycles (and thus the same number as the time vector) are incremented in step 312, they can be compared with each other to define the so-called P based on the n time markers. ref1 Reference time stamp.

[0180] Therefore, in step 314, the reference time marker P for the transmission of the marker synchronization signal is performed by taking into account the timing of detecting the P wave over n cardiac cycles (e.g., by calculating the average of n cardiac cycles), particularly when n is greater than or equal to 3. ref1 The determination of a cardiac cycle is predicated on the assumption that the n cardiac cycles are considered regular. A cardiac cycle is considered normal when the acceleration between the maximum cycles does not exceed 25%. For example, for a 1-second average cardiac cycle (which can be defined by the interval PP), an interval PP with a duration greater than or equal to 750 ms is considered stable.

[0181] If no P wave is detected in step 304, then in step 316, it is verified that the duration of the cardiac cycle has not yet expired. The duration of the cardiac cycle can be determined, for example, by the duration between two consecutive time markers sent by the marker signal or between two consecutive P waves. Note that a predetermined "initialization" interval PP can be used during the initialization phase.

[0182] According to the present invention, the duration of the cardiac cycle can also be determined by a detection device via a first device and / or a second device, which, for example, allows for the acquisition of an ECG graph.

[0183] If it is determined in step 316 that the duration of the cardiac cycle has not expired, then in step 304 the first device continues to analyze the ECG.

[0184] Conversely, if the cardiac cycle time is deemed to have expired in step 316, the time vector is reset in step 318, and the process returns to the first initialization step 302.

[0185] Following the initialization step of the method, in step 314 of flowchart 300, a reference time marker P is determined to indicate the timing for transmitting a synchronization signal after the detection of the P wave.ref1 .

[0186] For example, refer to time stamp P ref1 like Figure 5 and Figure 6 What is represented.

[0187] Figure 8 Commentary Figure 7 The flowchart 300 continues, that is, the method operation steps after step 314, in which the reference time marker P is determined. ref1 Therefore, through Figure 8 The steps of the described method are applicable to the reference. Figure 5 and Figure 6 The described embodiments.

[0188] During the operational steps of this method, the synchronization interval of the first device is used. (Already combined) Figure 5 and Figure 6 Such synchronization intervals of 110 and 210 are described, see reference. Figure 5 and 6 .

[0189] If a P wave of the next cardiac cycle n+1 is detected in step 320, a corresponding synchronization signal is sent to the second device in step 322. The synchronization signal carries physiological information related to the detection of the PQRST complex and enables the delivery of synchronized therapy.

[0190] In step 324, following the transmission of the synchronization signal in step 322, a time vector representing the time of transmission of the synchronization signal in step 322 is saved. The time vector can be saved in a FIFO-type memory.

[0191] Then, in step 326, it is verified whether the synchronization intervals 110 and 210 of cardiac cycle n+1 have expired. If not, the first device remains activated and waits to detect the P wave of cardiac cycle n+1 in order to send a synchronization signal.

[0192] If a P-wave is detected in step 320, a synchronization signal is sent in step 322. Then, if it is confirmed in step 326 that the duration of synchronization intervals 110 and 210 has expired, the first device is configured to activate the receiving device in step 328.

[0193] The following is for reference Figure 8 Let's further describe step 328.

[0194] like Figure 8aAs explained, the transmitter of the first device is configured to be activated during synchronization intervals 110 and 210. Furthermore, the first device may also include a receiver configured to be activated during an interval 329, which is shorter than the synchronization intervals 110 and 210. The receiver of the first device can be activated with a predetermined offset Δ. d Activated, starting from the end of synchronization intervals 110 and 210, 110a and 210a respectively, as follows. Figure 8a The explanations are provided on timelines 104 and 204.

[0195] During interval 329, the receiving device of the first device is activated to detect any possible alarm signals transmitted by the second device. (See below for reference.) Figure 9 and Figure 10 The alarm signal is further described as being transmitted by a second device.

[0196] If the receiving device of the first device receives an alarm signal in step 330, then in step 332 it is determined whether to reset the method and send a control signal to request pacing delivery to the right atrium (step 334) or simply reset the method without requesting pacing delivery (step 336).

[0197] In step 338, if no alarm signal is detected during interval 329, the first device continues to operate in a near-synchronous manner using synchronization intervals 110 and 210 for wireless communication with the second device.

[0198] therefore, Figure 7 and Figure 8 The flowchart 300 in the explanation represents the algorithm implemented by the first device of the multi-device system.

[0199] The multi-device system according to the invention includes at least one second device configured to be implanted in the right ventricle, and wherein an algorithm is also implemented. The second device is independent of the first device. However, the second device implements an algorithm complementary to that of the first device. The algorithm implemented by the second device is described below with reference to flowchart 400, as follows... Figure 9 and Figure 10 The explanation is in Chinese.

[0200] Figure 9 and Figure 10 Flowchart 400 shows the method implemented by the second device.

[0201] Figure 9 Flowchart 400 illustrates the initialization steps of a method implemented by a second device. These initialization steps are implemented asynchronously relative to the first device. The steps of the method in flowchart 400 can be applied to reference... Figure 5 and Figure 6 The described embodiments.

[0202] During these initialization steps implemented by the second device, the receiving device of the second device is continuously activated because the timing of receiving the synchronization signal has not yet been estimated.

[0203] First, such as Figure 9 As illustrated in the flowchart, initialization 402 includes activating the receiving device of the second device in step 404.

[0204] In step 406, it is analyzed whether the receiving device of the second device has received a synchronization signal.

[0205] If a synchronization signal is indeed received, then in step 408, a time vector representing the timing of receiving the synchronization signal in step 406 is saved. The time vector can be saved in a FIFO-type memory.

[0206] Then, in step 410, the time vectors are incremented in the counter in such a way that when multiple n time vectors of n cardiac cycles (and thus as many as the received synchronization signals) have been incremented in step 412, they can be compared with each other in order to define a so-called reference time stamp P for the second device. ref2 .

[0207] Therefore, in step 414, the reference time stamp P is executed by taking into account the timing of receiving the synchronization signal for n cardiac cycles. ref2 The determination of n, specifically, requires that n be greater than or equal to 3, provided that n cardiac cycles are considered regular cardiac cycles. A cardiac cycle is considered normal when the maximum inter-cycle acceleration does not exceed 25%. For example, for a 1-second average cardiac cycle (which can be defined by the interval PP), an interval PP with a duration greater than or equal to 750 ms is considered stable. Specifically, the reference time marker P... ref2 It can be determined by averaging the timing of receiving synchronization signals over n cardiac cycles.

[0208] If no synchronization signal is received in step 406, then in step 418, it is verified that the duration of the considered cardiac cycle has not yet expired. The duration of the cardiac cycle can be determined, for example, by the duration between two consecutive P waves.

[0209] Therefore, the second device can be configured to estimate the duration of the cardiac cycle using timing information contained in two consecutively received synchronization signals.

[0210] In one variant, the second device may include a detection device, for example, that allows obtaining an ECG plot and deriving the cardiac cycle duration from the plot. If, in step 418, the cardiac cycle duration is deemed not to have expired, then in step 406 the second device continues to wait for the reception of a synchronization signal.

[0211] Conversely, if the cardiac cycle time is deemed to have expired in step 418, the time vector is reset in step 420, and the process returns to step 406.

[0212] Following the initialization step of this method, the reference time stamp P is determined in step 414 of flowchart 400. ref2 This reference time marker indicates the timing of the received synchronization signal and is related to the detection of P waves in the atrium.

[0213] For example, in Figure 5 and Figure 6 The reference time marker P is represented on time axes 106 and 206. ref2 .

[0214] Figure 10 Commentary Figure 9 The flowchart 400 continues, that is, the operation steps of the method after step 414, in which the reference time marker P is determined. ref2 According to the second embodiment, during the operation steps of the method, particularly starting from step 422 described below, the receiving device of the second device is no longer continuously activated, but is activated intermittently during the synchronization interval 208. Regarding the block m of the synchronization interval 208... on The activation of the receiving device during each interval of the period, for Figure 6 Refer to the description.

[0215] like Figure 10 As explained, in step 422 following step 414, the second device is relative to the reference time marker P determined in step 414. ref2 The value is updated and the synchronization interval is adjusted to 208. The synchronization interval 208 of cardiac cycle n is based on the reference time marker P determined in the previous cardiac cycle n-1. ref2 The value or a reference timescale P determined from multiple previous cardiac cycles. ref2 Adjusted using the average value.

[0216] In step 424, in multiple activation slots m on During this period, the receiving device is activated at synchronization interval 208, such as... Figure 6 As explained in the text.

[0217] In step 424, it is analyzed whether the synchronization signal sent by the first device is received by the receiving device of the second device.

[0218] If a synchronization signal is indeed received, then in step 426, a time vector representing the timing of the received synchronization signal is saved. The time vector can be saved in a first-in-first-out (FIFO) type memory.

[0219] In step 414, a time vector is used to update the timing of the synchronization signal reception; that is, the reference time stamp P used for the next cardiac cycle is updated. ref2 Therefore, refer to time stamp P ref2 Updated jump by jump, because it is based on the reference time stamp P of the previous beat. ref2 For example, it can be calculated based on two previous cardiac cycles n-2 and n-1 that precede the cardiac cycle n under consideration.

[0220] If no synchronization signal is received in step 424, then in step 428, it is verified that the duration of synchronization interval 208 has not expired.

[0221] If the duration of synchronization interval 208 has not expired in step 428, the second device continues to wait for the synchronization signal to be received in step 424.

[0222] Conversely, if the synchronization interval 208 expires in step 428 without a signal notification being received, the second device is configured to send an alarm signal in step 430. For this purpose, the second device also includes a transmitter.

[0223] Note that the second device is unaware of the reason for the failure to receive the signaling signal. This could be a communication failure, or the first device failing to detect the P-wave. In either case, the second device sends an alarm signal in step 430.

[0224] The following is for reference Figure 10a Let's further describe step 430.

[0225] In step 430, the second device is configured to activate the transmitter device. For example... Figure 10a As shown, the transmitter of the second device is activated during an interval 431 that is shorter than the synchronization interval 208.

[0226] In such Figure 10a After the end 208b of the synchronization interval 208 represented on the time axis 206, it can be offset by a predetermined Δ dd Send an alarm signal.

[0227] Therefore, during interval 431, the transmitter of the second device is activated to send an alarm signal to the first device. The activation interval 431 of the transmitter of the second device is shorter than the activation interval 329 of the receiver of the first device.

[0228] The activation interval 431 of the transmitter device of the second device can be used for two purposes: both are used to notify the first device of communication failure (due to the lack of a synchronization signal) - the first device knows that its transmitter device has indeed sent a synchronization signal, or that artificial and local pacing of the right atrium is required.

[0229] The communication method of the present invention allows for the synchronization of treatments delivered by multiple device systems and can save a significant amount of energy.

[0230] However, patients equipped with such multi-device systems may experience episodes where their atrial activity becomes rapid and irregular (known as supraventricular tachyarrhythmia). In such cases, treatment delivered to the ventricles must be independent of atrial activity.

[0231] In addition, patients with atrial arrhythmias need to temporarily disconnect bichat (or trichat) therapy in order to desynchronize the ventricles (or multiple ventricles) with the atria.

[0232] Figure 11 Alternative variations of the first and second embodiments that are advantageously adapted to the above-described cardiac rhythm disorders are explained.

[0233] Figure 11 based on Figure 5 Figure 100 shows that so-called start intervals 260 and 262 are added to each of the time axes 104 and 106 before the synchronization intervals 208 and 210 for each of the first and second devices.

[0234] During the start interval 260, the transmitter of the first device is configured to send a start authorization signal to the receiver of the second device.

[0235] Therefore, during the startup interval 262, the receiving device of the second device is configured to receive the startup authorization signal sent by the second device.

[0236] Startup intervals 260 and 262 allow or disallow communication between the first and second devices.

[0237] It is also possible that the first device waits for a reception confirmation signal sent by the transmitter of the second device to ensure that the information is correctly received by the second device.

[0238] This prevents unnecessary energy dissipation to activate the receiver of the second device during an arrhythmia episode.

[0239] The start intervals 260 and 262 can also more simply provide a “switch” function, allowing them to switch from a single-chamber operation mode (that is, a mode in which these devices are not synchronized) to a dual-chamber operation mode (which requires these devices to be synchronized).

[0240] The wireless communication method and the multi-device system configured to implement the method of the present invention allow for the adjustment and adaptation of communication windows to the patient's electrophysiological rhythm, these communication windows corresponding to synchronization intervals. In practice, each device in the system is capable of determining a time stamp associated with the detection of a P wave (or any other wave of the PRQST complex) and can rearrange the communication windows according to the time stamp thus determined for each cardiac cycle.

Claims

1. A communication method in a system comprising a plurality of implantable medical devices, wherein a first device includes at least one means for detecting a signal representing atrial activity, a transmitter means, and a controller configured to analyze the signal representing the atrial activity; and a second device independent of the first implantable medical device, the second device including at least one receiver and the controller, wherein the method comprises: A) Steps for time synchronization between the first device and the second device. By sending the synchronization signal from the transmitter device of the first device to the second device, After the controller of the first device identifies a predefined wave of a PQRS complex representing atrial activity, the synchronization signal is transmitted. B) Steps used to determine the duration of the cardiac cycle, following steps A and B: C) The step of determining the synchronization interval of the second device, wherein the duration of the synchronization interval is determined to be shorter than the duration of the cardiac cycle, and the start of the synchronization interval is determined based on the synchronization signal. D) A step for activating the receiving device of the second device during the synchronization interval, wherein the receiving device of the second device is deactivated by the controller of the second device outside the synchronization interval.

2. The method as described in claim 1, characterized in that, For the cardiac cycle, a first time marker is determined by marking the transmission of the synchronization signal via the transmitter device of the first device, and A second time marker is determined by the receiving device of the second device for receiving the synchronization signal, and a synchronization interval for subsequent cardiac cycles of the first device is determined based on the first time marker, and a synchronization interval for subsequent cardiac cycles of the second device is determined based on the second time marker.

3. The method as described in claim 2, characterized in that, During the synchronization interval of the second device: The receiving device of the second device can be activated during a plurality of predefined activation time slots and deactivated during a plurality of predefined deactivation time slots, the plurality of predefined activation time slots of the second device being distributed over the synchronization interval of the second device in such a way that they are synchronized with the signal pulse time slots of the first device according to the first time marker and the second time marker.

4. The method as described in claim 3, characterized in that, The transmitter device of the first device is configured to send a single synchronization signal for each cardiac cycle.

5. The method as described in claim 3 or 4, characterized in that: - Each of the predefined activation slots has the same duration and - Each of the predefined deactivation slots has the same duration and - Each of the predefined activation slot and the predefined deactivation slot alternately follows each other during the synchronization interval.

6. The method as described in claim 5, characterized in that, The duration of the activation time slot is shorter than or equal to the duration of the deactivation time slot.

7. The method as described in claim 6, characterized in that, The duration of an active slot is between 0.3% and 50% of the duration of a deactivated slot.

8. The method as described in claim 7, characterized in that, The duration of the activation slot is between 5% and 10% of the duration of the deactivation slot.

9. The method as described in claim 3, characterized in that, During this period, the transmitter device of the first device is configured to transmit a pulse of synchronization signal for a duration corresponding to 25% to 80% of the duration of the activation time slot.

10. The method as described in claim 9, characterized in that, During this period, the transmitter device of the first device is configured to transmit a pulse of synchronization signal for a duration corresponding to 50% of the duration of the activation time slot.

11. The method as described in claim 2, characterized in that, The first time marker marks the start or end of the transmission of the synchronization signal or a predetermined time during the transmission of the synchronization signal.

12. The method as described in claim 1, characterized in that, In step A), the predefined radio wave detected by the controller of the first device corresponds to the P wave of the PQRS composite wave.

13. The method as described in claim 1, characterized in that, In step A), the predefined electrical waves are detected by means of the controller of the first device, by means of analyzing electrograms, electrocardiograms, data measured by accelerometers, data measured by cardioid impedance, or data measured by acoustic sensors.

14. The method as described in claim 1, characterized in that, During at least two consecutive cardiac cycles, the first device and the second device communicate with each other asynchronously during steps A and B, and the receiving device of the second device is continuously activated during at least two consecutive cardiac cycles.

15. The method as described in claim 1, characterized in that, The controller of the second device is configured to deactivate the receiving device of the second device during the remaining time of the synchronization interval of the second device after receiving the synchronization signal.

16. The method as described in claim 1, characterized in that, The controller of the second device is configured to send an alarm signal to the receiving device of the first device via the transmitter device of the second device when the second device does not receive a synchronization signal during the synchronization interval of the second device.

17. A system comprising multiple implantable medical devices, comprising at least: A first device includes at least one detection device, a transmitter device, and a controller configured to analyze signals representing atrial activity; as well as A second device, independent of the first implantable medical device, the second device comprising at least a receiver and a controller. The receiving device of the second device is configured to be activated and deactivated by the controller of the second device. The controller of the first device and the controller of the second device are configured to implement the method according to any one of claims 1-16.

18. The system of multiple implantable medical devices as described in claim 17, characterized in that... The first implantable medical device is a subcutaneous implantable medical device, an event circuit recorder, or a leadless pacemaker, and The second medical device is a leadless pacemaker.

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