A system with at least two devices

Abstract

The present invention is directed to a system 10 comprising a first intracardiac device 100 for implantation in the heart 20 of a patient 30 and at least one second implantable device 200, preferably the second device for implantation in the atrium of the patient, which can be designed to reduce electronic components, to be miniaturized and to increase the lifetime of the device. The first intracardiac device 100 comprises a first processing unit 120 for controlling a first signal generator unit 124, a first data memory 122 with a predetermined first signal parameter for a first therapeutic signal, and a first measuring unit 126 for determining at least one physical value and at least one second physical value, and the second device 200 comprises a second processing unit for controlling a second signal generator unit, a second data memory with a predetermined second signal parameter for a second therapeutic signal, and a second measuring unit for determining at least one third physical value. The present invention further describes a method of operation of such a system.

Description

[Technical field]

[0001] System Comprising at Least Two Devices and Method of Operation of Such a System - Patent application The present invention is generally directed to a system comprising a first intracardiac device for implantation within a patient's heart and at least one second implantable device, e.g., an intracardiac device, and a method of operation of such a system. [Background technology]

[0002] Active intracardiac devices, such as implantable intracardiac pacemakers (also known as implantable leadless pacemakers (ILPs)), are well-known miniature medical devices that are implanted entirely within the chambers of the heart, either the ventricles or the atria of the patient. They are considered the future of cardiac pacing. Intracardiac pacemakers are used, for example, for patients suffering from bradycardia, whose hearts beat too slowly to meet the physiological needs of the patient. Intracardiac devices can apply electrical stimulation to the heart in the form of pulses to generate a physiologically appropriate heart rate and / or in the form of rapid pacing or shocks for cardioversion or defibrillation to restore a more normal heart rhythm. Active intracardiac devices can provide, for example, antitachycardia pacing (ATP), i.e., pacing the heart using a stimulation rate higher than the tachycardia rate to stop the tachycardia. Alternative or additional functions of intracardiac devices include providing other electrical or electromagnetic signals to the heart or surrounding tissue, as well as sensing electrical or electromagnetic signals or other physiological parameters of the heart and / or surrounding tissue.Due to significant size constraints on the devices, the battery capacity of these devices is small.

[0003] However, there are situations where a patient suffers from a variety of cardiac arrhythmias that require separate cardiac therapy. In such cases, a system of implantable devices comprising at least two medical devices and / or medical units may be implanted.

[0004] US Patent No. 5,999,336 discloses a dual-chamber, leadless pacing system with at least one atrial pacing device and at least one ventricular pacing device, in which signals are sent from the atrial pacing device to the ventricular pacing device or from the ventricular pacing device to the atrial pacing device to adjust the pacing rate, where the respective pacing rates are adjusted based on the received signals. In this case, a separate communication unit of the atrial or ventricular pacing device, including appropriate hardware (e.g., antenna), firmware, software, or any combination thereof, consumes energy while communicating with each other pacing device.

[0005] As mentioned before, new technology comes with many challenges. Due to size constraints of intracardiac devices, the requirements for energy consumption and use of electronic components are dramatically increased. There are solutions available that implement basic VVIR functionality in ventricular ILP, where the rate response functionality is based on accelerometers. This allows adjusting the ventricular pacing rate in cases where the patient is in atrial fibrillation. VVI(R) is one of the more commonly used pacing forms. VVI(R) is ventricular demand pacing. The ventricles are paced and sensed, and the pulse generator inhibits the pacing output in response to sensed ventricular events. This form of pacing is primarily suited for patients with atrial fibrillation and slow ventricular response, as it prevents ventricular bradycardia. However, because the pulse generator paces and senses only in the ventricles, there can be a loss of AV synchrony (i.e., the physiological state of atrial electrical activity followed by ventricular electrical activity, the interval between which is necessary for impulse conduction from the atria to the ventricles), potentially resulting in pacemaker syndrome.

[0006] Intracardiac devices intended to be implanted in the atria of the heart require special design considerations: the available volume for device placement is smaller than in the ventricles, and the atrial tissue is significantly thinner compared to the ventricles. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] US Patent Application Publication No. 2016 / 0067490 Summary of the Invention [Problem to be solved by the invention]

[0008] Thus, there is a need for implantable intracardiac devices to better address the requirements for energy consumption, tissue properties, and available space. [Means for solving the problem]

[0009] The above problem is solved by means of a system comprising the features of claim 1 and a method of operation comprising the features of claim 7.

[0010] Specifically, the system of the invention comprises a first intracardiac device for implantation in the patient's heart and at least one second implantable device, e.g. an intracardiac device. Thus, the system can be a dual chamber system, where the first intracardiac device and the at least one second intracardiac device can each form a single chamber device. Alternatively, the first intracardiac device and the at least one second intracardiac device can each form a dual chamber device. For example, the first intracardiac device can realize a treatment related to a ventricle of the patient's heart and can be implanted in a ventricular wall of the heart, and the second intracardiac device can realize a treatment related to an atrium of the patient's heart and can be implanted in an atrial wall of the heart. Alternatively, the at least one second device can be another implantable device, e.g. a device located completely in the body or located outside the patient's body partially in the body and carrying the first intracardiac device. The first intracardiac device comprises a first processing unit for controlling the first signal generator unit, a first measuring unit for determining at least one first bodily value and a second bodily value, and a first data memory with a predetermined first signal parameter for the first therapeutic signal. The first bodily value and the second bodily value can be the same physical or chemical measure or can be different physical or chemical measures. The second implantable device comprises a second processing unit for controlling the second signal generator unit and a second data memory with a second predetermined signal parameter for the second therapeutic signal. The second device can further comprise a second measuring unit for determining at least one third bodily value. The first processing unit, the first signal generator unit, the first measuring unit, and the first data memory are all electrically connected and stored within a housing of the first intracardiac device. The second processing unit, the second signal generator unit, the second measurement unit, and the second data memory are all electrically connected and housed within a housing of the second device.The first processing unit and / or the second processing unit may include hardware to assist in signal processing (eg, scaling, filtering, rectification).

[0011] According to the invention, the first signal generator unit is adapted to send a first electric and / or electromagnetic therapeutic signal to the patient's heart with at least one first signal parameter and an information transfer parameter, where the at least one first signal parameter of the first therapeutic signal is obtained from a first data memory based on at least one determined first physical value, where the information transfer parameter is determined by a first processing unit based on a determined second physical value. The first therapeutic signal is provided by the first signal generator and comprises a time-dependent varying electric and / or electromagnetic field applied to the patient's cardiac tissue, e.g. a pacing signal, for a therapy aimed at improving the patient's health condition. The electric and / or electromagnetic field may for example be applied by electrodes protruding from the first intracardiac device and fixed in the tissue of the respective cardiac chamber of the heart. The electrodes are electrically connected to the first signal generator unit. The first therapeutic signal is characterized by its first signal parameters, such as for example its start time position, its amplitude and / or frequency (rate) of the signal, and also the signal morphology. The first signal parameters are obtained from a first data memory, where the selected first signal parameters are predefined signal parameters stored in the first data memory. The first signal parameters are selected by the first processing unit from a data matrix comprising for example predefined signal parameters related to possible measurable first physical values. According to the at least one first physical value determined by the first measuring unit, the appropriate at least one first signal parameter is selected from the data matrix. Thus, the first signal parameter is selected from a data matrix comprising predefined signal parameters based on the most recently measured first physical value (i.e. a vital sign of the patient's body, such as heart rate). According to the present invention, the therapeutic signal further realises an information transfer parameter determined by the first processing unit based on the determined second physical value.The information transfer parameters are determined by the first processing unit based on the second physical values ​​determined by the first measuring unit, for example calculated or derived from a respective data matrix of the first data memory comprising the predetermined information transfer parameters. For example, the second physical values ​​can be activity values ​​determined by an accelerometer and / or an impedance sensor of the first measuring unit, thereby assessing the patient's activity.

[0012] The second device can determine the information transfer value provided with the first therapeutic signal and associate some information with the determined value of the information transfer parameter. For example, the second device compares the predefined therapeutic signal and / or the predefined first parameter of the therapeutic signal contained in the first data memory against the most recently (i.e. immediately before) measured therapeutic signal or the determined first parameter of such therapeutic signal of the first intracardiac device. According to the invention, the second signal generator is adapted to send a second electric and / or electromagnetic therapeutic signal, for example to the patient's heart, where at least one second signal parameter of the second therapeutic signal is obtained from the second data memory based on at least one determined third physical value and further based on the determined information transfer parameter of the first electric and / or electromagnetic therapeutic signal most recently provided by the first intracardiac device. The second electric and / or electromagnetic therapeutic signal can include a time-dependent varying electric and / or electromagnetic field applied to the patient's cardiac tissue, for example a pacing signal, for a treatment aimed at improving the patient's health condition. The electric and / or electromagnetic fields may be applied by electrodes protruding from a second device, e.g. an intracardiac device, and fixed in the tissue of the respective cardiac chamber of the heart. The electrodes are electrically connected to a second signal generator unit. The second therapeutic signal is characterized by its second signal parameters, e.g. its start time position, its amplitude and / or frequency (rate) of the signal, as well as the signal morphology. The second signal parameters are obtained from a second data memory, where the selected second signal parameters are predefined signal parameters stored in the second data memory. The second signal parameters are selected by the second processing unit from a data matrix, e.g. comprising predefined signal parameters related to possible measurable third physical values. According to the at least one third physical value determined by the second measurement unit, the appropriate at least one second signal parameter is selected from the data matrix. Thus, the second signal parameter is selected from a data matrix comprising predefined signal parameters for the second therapeutic signal based on the last measured third physical value (i.e. the patient's body vital sign, e.g. heart rate).The at least one second signal parameter is further adapted according to the determined signaling parameter before applying the second therapeutic signal to the patient. For example, the second processing unit uses the at least one signal parameter obtained from the second data memory to increase, decrease or maintain at least one parameter of the at least one second signal parameter according to the most recently provided first therapeutic signal (i.e., immediately prior to providing the first therapeutic signal) and the most recently determined signaling parameter from this signal.

[0013] In one embodiment, the first and second measuring units are adapted to measure intracardiac electrocardiogram (IEGM) signals of the patient, including, for example, heart rate, PR interval, QT interval, ST interval, P wave duration, and T wave duration. Using the IEGM signals, the first and second measuring units can further sense pacing signals (e.g., their onset time location and their duration, as well as their frequency) from the respective other intracardiac devices. In addition, the first and second measuring units can be adapted to determine impedances for obtaining cardiac tissue properties. The first and second measuring units can further sense a plurality of signals indicative of multiple contractions of the ventricle, and a ventricular contraction rate can be determined from the plurality of signals. The sensed signals can include, for example, far-field R waves and / or heart sounds. Communication between at least two devices in this manner can be enabled by simply passively sensing electrical activity resulting from different devices in the heart. For example, a dual-chamber leadless pacer therapy with one device sensing and pacing in the ventricle and a second device sensing and pacing in the atrium can rely on each device sensing far-field activity from the electrically separated cardiac chambers to maintain synchronization with each other. The first measurement unit can further comprise an accelerometer sensor and / or an impedance sensor as shown below.

[0014] In one example, the first therapy signal is an electrical ventricular pacing signal, where the at least one first signal parameter of the first intracardiac device is a time location of a start of the ventricular pacing signal and / or its amplitude, and / or the second therapy signal is an electrical atrial pacing signal, where the signal parameter of the second device is an atrial pacing rate, an amplitude of the pacing signal, a duration of the pacing signal, and / or a time location of a start of the atrial pacing signal.

[0015] In one embodiment, the information transfer parameter is the amount of time of shortening or lengthening the predetermined first electrical and / or electromagnetic therapy signal interval, such as shortening or lengthening an AV delay value, and / or the rate of the predetermined first electrical and / or electromagnetic therapy signal. Furthermore, the VA interval may be modulated. The shortening or lengthening amount of time may be between -50ms and 50ms, preferably between -15ms and 15ms, and most preferably between -8ms and 8ms. A negative value is considered to be a shortening amount of time, and a positive value is considered to be a lengthening amount of time. In another embodiment, the shortening or lengthening amount of time is between -8ms and -3ms or between 3ms and 8ms. All the intervals mentioned above include their respective boundaries. The AV delay is the amount of time between the start time position of the atrial pacing signal and the start time position of the ventricular pacing signal. In this embodiment, a first intracardiac device, such as a ventricular ILP, may sense the start time position of the atrial pacing signal generated by a second device using a first measurement unit. In addition, a second device, such as an atrial ILP, can sense the time position of the start of the ventricular pacing signal generated by the first intracardiac device using a second measurement unit. The first and second devices are individually programmed with expected AV delays and / or pacing rates for a particular heart rate, which are stored in the first and second data memories. In the case where both devices "know" the patient's current heart rate, both devices can have an "expectation" of the timing of the ventricular pace to be produced, i.e., both devices know the "normal" AV delay and / or pacing rate. The shortening or lengthening of the "normal" AV delay and / or the change in pacing rate due to the ventricular ILP can be used to convey information to the atrial device. For example, if the ventricular device paces with a shortened AV delay than expected, i.e., if the ventricular ILP's pacing signal begins earlier or later by a certain amount of time, the atrial ILP detects the shortening and lengthening of the AV delay by comparing the measured AV delay against a predetermined AV delay stored in its data memory.If a shortening of the AV delay is determined, the second processing unit obtains information that the atrial pacing rate is increased. In contrast, if the atrial pacing rate is higher than that indicated by the accelerometer and / or impedance of the ventricular ILP, the ventricular ILP delays delivering the ventricular pace, which is an indication for the atrial ILP to decrease the pacing rate. Additionally or alternatively, in one embodiment, if a change in the ventricular pacing rate is detected, the atrial pacing is adapted accordingly to maintain synchronization of the pacing relative to each other. In this manner, in the case where a patient has a continuous atrial tachycardia, the two leadless pacemakers work asynchronously and the pacing rate indicated by the accelerometer and / or impedance-based sensor is available at the ventricular ILP, thereby enabling standard VVIR pacing.

[0016] The system of the present invention uses the therapeutic signal of the first intracardiac device to convey information to the second device, which adapts its therapeutic signal according to the received information. For example, the system of the present invention can increase or decrease the atrial pacing rate based on the changing AV delay of the ventricle and / or the changing pacing rate. Active communication using a separate communication channel (e.g., NF communication or Bluetooth communication) is not required for communication between the first intracardiac device and the second device. Therefore, since a separate communication channel is not used with this communication, there is no energy consumption with respect to such communication. The energy used in connection with the first therapeutic signal does not change significantly. In addition, since only a small shift in the starting time position of the first therapeutic signal contains information, no special modulation unit is required. The information transmission parameter does not change the therapeutic activity of the first therapeutic signal and does not affect the effectiveness of the treatment due to its small value compared to a typical near-field electrical signal, but is reliably measurable by the second measurement unit.

[0017] In one example, the signaling parameters take into account variability in the timing of the far-field signal, such as far-field atrial detection in the first intracardiac device (e.g., ventricular device). For example, the atrial and ventricular devices will likely detect atrial events at slightly different times due to the signal processing and detection mechanisms for far-field sensing in the ventricular device. This means that the AV delays measured by the second device (e.g., atrial intracardiac device) and the first intracardiac device (e.g., ventricular device) may be slightly different. This difference may be considered when setting a tolerance for increasing or decreasing the AV delay by the second device for purposes of communicating a pacing rate.

[0018] In one embodiment, the first physical value comprises intrinsic atrial activity and / or intrinsic ventricular activity and / or the third physical value comprises intrinsic ventricular activity. For example, the first measurement unit and the second measurement unit detect an ECG or IEGM of the patient's heart, for example detecting an IEGM with high resolution and high gain.

[0019] In one example, the first physical value can include intrinsic near-field ventricular electrical activity and / or intrinsic far-field atrial electrical activity, and / or atrial pacing provided by the second device, and the third physical value can include intrinsic near-field atrial electrical activity and / or intrinsic far-field ventricular electrical activity, and / or ventricular pacing provided by the first intracardiac device.

[0020] Alternatively or additionally, the first physical value includes intrinsic or paced atrial activity and / or intrinsic or paced ventricular electrical activity, and / or the third physical value includes intrinsic ventricular activity, intrinsic atrial activity, and / or intrinsic or paced atrial activity.

[0021] In one embodiment, the second physical value is a signal determined by an accelerometer sensor, where the accelerometer sensor is integrated into the first measurement unit. The accelerometer sensor is adapted to measure activity, for example, to determine a desired pacing rate, posture, and / or heart sound data. Alternatively or additionally, the second physical value is an impedance signal measured in a body tissue or in a body fluid, for example in blood in a ventricle of the heart. For example, the impedance caused by the pH value (i.e., acidity or alkalinity) of the patient's blood can be a characteristic parameter related to the patient's activity. The impedance sensor can be integrated into the first measurement unit.

[0022] In one embodiment, the second device allows the change of the second electrical and / or electromagnetic therapy signal previously applied to the patient's heart only if the second measurement unit receives confirmation or any confirmation of the most recently determined information transfer parameter. This confirmation is provided by at least one second transmission of the information transfer parameter consecutively (i.e. additionally two times, or even more than two times (e.g. three or four times consecutively)), thereby forming a set of at least two consecutive first therapy signals, both of which include the same information transfer parameter value. The number of consecutive first therapy signals including the same information transfer parameter value required for the change of the second therapy signal is predefined in each system. This is advantageous as it improves the safety and reliability of the system.

[0023] Furthermore, it is advantageous for the device communications to be visible to the clinician or the outside world. Existing surface ECG systems can be used to assess cardiac rhythm (such as AV delay or rate) and thus interpret signaling from either or both devices. This can improve troubleshooting or can be used to interpret how to program the first intracardiac device and at least one second device, such as, for example, how to program a rate response based on monitoring the AV delay.

[0024] Furthermore, the above problem is solved by a method of operation of a system comprising a first intracardiac device after implantation in a patient's heart and at least one second implantable device, e.g. an intracardiac device, wherein the first intracardiac device: a first processing unit for controlling the first signal generator unit, a first data memory having predetermined signal parameters for a first therapy signal, and a first measuring unit for determining at least one first physical value and at least one second physical value, the second intracardiac device comprises a second processing unit for controlling the second signal generator unit, a second data memory containing predetermined signal parameters for the second therapy signal, and a second measuring unit for determining at least one third signal value; Here, the method comprises the steps of: determining at least one first physical value by a first measuring unit of a first intracardiac device; determining at least one second physical value by a first measuring unit of the first intracardiac device; determining, by the first processing unit, an information transfer parameter based on the determined at least one second physical value; sending, by a first signal generator unit, a first electrical and / or electromagnetic therapy signal to the patient's heart using at least one first signal parameter and a communication parameter, wherein the at least one first signal parameter of the first therapy signal is obtained from a first data memory based on the at least one determined first physical value; determining, by the second intracardiac device, a signal delivery parameter of the first electrical and / or electromagnetic therapy signal provided by the first intracardiac device; determining at least one third physical value by a measuring unit of a second intracardiac device; The method includes a step of delivering a second electrical and / or electromagnetic therapy signal to the patient's heart by a second signal generating device, wherein at least one second signal parameter of the second therapy signal is obtained from a second data memory based on at least one determined third physical value, and further including a step of delivering the second electrical and / or electromagnetic therapy signal based on the determined information transmission parameter of the first electrical and / or electromagnetic therapy signal most recently provided by the first intracardiac device.

[0025] The above method has the advantages as explained in relation to the above system. The embodiments mentioned and explained above in relation to the system also apply to the above presented method.

[0026] The invention will now be described in more detail with reference to the accompanying schematic drawings. [Brief description of the drawings]

[0027] [Figure 1] 1 is a cross-sectional view of a patient's heart illustrating a first embodiment of the system of the present invention. [Diagram 2] FIG. 2 is a functional block diagram of a first intracardiac device of the embodiment shown in FIG. 1. [Diagram 3] 13 is a graph illustrating an example of AV delay modulation of a ventricular device to relay pace rate information to an atrial device. [Figure 4] Graph showing atrial signals over time: in the first column is the ECG signal, in the second column is the RA signal, and in the third column is the near-field RV signal. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] FIGURE 1 shows an illustrative leadless pacing system 10 implanted in a heart 20 of a patient 30. The leadless pacing system 10 includes a ventricular leadless cardiac pacemaker device 100 (hereinafter "ventricular device 100") and an atrial leadless cardiac pacemaker device 200 (hereinafter "atrial device 200"). The ventricular device 100 can be configured to be implanted in a right ventricle 21 of the heart to pace the ventricle, sense intrinsic ventricular depolarization, and inhibit ventricular pacing in response to a sensed ventricular depolarization. The atrial device 200 can be implanted in a right atrium 22 of the heart 20 and configured to monitor electrical activity of and / or deliver electrical therapy to the heart 20. A programmer may be used to program the ventricular device 100 and / or the atrial device 200 and to retrieve data from the ventricular device 100 and / or the atrial device 200.

[0029] FIG. 2 shows a functional block diagram of an example ventricular device 100 configured to be implanted in the ventricle 21 ( FIG. 1 ). The ventricular device 100 includes a first processing unit 120, a first data memory 122, a first signal generator unit 124, a first measurement unit 126, a first communication unit 128, and a first power source 132. The first power source 132 can include a battery, such as a rechargeable battery or a non-rechargeable battery. The units included in the ventricular device 100 are representative of functionality that may be included in the ventricular device 100 of the present disclosure. Similar or identical units and functionality may be included in a ventricular pacemaker device that may be provided as part of a dual-chamber leadless pacemaker system for implantation and used in at least one atrium and at least one ventricle of the heart 20. The units of the present disclosure may include any discrete and / or integrated electronic circuitry implementing analog and / or digital circuitry capable of producing the functionality attributed to the units herein. For example, the units may include analog circuits, such as, for example, amplifier circuits, filter circuits, and / or other signal conditioning circuits. The units may further include digital circuits, such as, for example, combinatorial or sequential logic circuits, memory devices, etc. The first data memory 122 may include any volatile, non-volatile, magnetic, or electronic medium, such as a random access memory (RAM), a read-only memory (ROM), a non-volatile RAM (NVRAM), an electrically-erasable programmable ROM (EEPROM), a flash memory, or any other memory device. Furthermore, the first memory unit 122 may include instructions that, when executed by one or more processing circuits, cause the units to perform various functions attributed to the units herein. The functions attributed to the units herein may be embodied as one or more processors, hardware, firmware, software, or any combination thereof.The description of different features as units is intended to highlight different functional aspects and does not necessarily imply that these units must be realized by separate hardware or software components. Rather, functionality associated with one or more units may be performed by separate hardware or software components or may be integrated into common or separate hardware or software components. The first processing unit 120 may be in communication with a first data memory 122. The first data memory 122 may include computer-readable instructions that, when executed by the processing unit 120, cause the processing unit 120 to perform various functions attributed to the processing unit 120 herein. For example, the memory 122 may include pacing instructions and first signal parameters for a first therapy signal, such as a baseline ventricular pacing rate, a baseline ventricular pacing interval, and a baseline AV delay. The pacing instructions and the first signal parameters may be updated by a programmer using the communication unit 128.

[0030] The first processing unit 120 can communicate with a first signal generator unit 124 and a first measurement unit 126. The first signal generator unit 124 and the first measurement unit 126 are electrically coupled to the electrodes 111, 112. The first measurement unit 126 is configured to monitor signals from the electrodes 111, 112 for monitoring electrical activity of the heart 20. Furthermore, the first measurement unit 126 may include an accelerometer and / or a pressure sensor and / or an impedance sensor. The first signal generator unit 124 is configured to send electrical stimuli to the ventricle 21 via the electrodes 111, 112.

[0031] The first processing unit 120 can control the first signal generator unit 124 to generate and deliver electrical stimuli to the ventricle 21 via the electrodes 111, 112. The electrical stimuli can include pacing pulses. The first processing unit 120 can control the first signal generator unit 124 to provide electrical stimulation therapy according to one or more ventricular therapy programs, including pacing instructions and pacing values, which can be stored in the first data memory 122.

[0032] The first measurement unit 126 may include circuitry to acquire electrical signals from a sensor. The electrical signals acquired by the first measurement unit 126 may include intrinsic cardiac electrical activity, such as intrinsic ventricular electrical activity and / or intrinsic ventricular cardiac electrical activity. The first measurement unit 126 may filter, amplify, and digitize the acquired electrical signals to generate raw digital data. The first processing unit 120 may receive the digitized data generated by the first measurement unit 126. In some instances, the first processing unit 120 may perform various digital signal processing operations on the raw data, such as digital filtering.

[0033] The processing unit 120 can sense a cardiac event based on the data received from the first measurement unit 126. For example, the first processing unit 120 can determine a ventricular event based on the data received from the first measurement unit 126. In some instances, the first processing unit 120 can determine ventricular activity based on the data received from the first measurement unit 126. For example, the first processing unit 120 can detect a far-field R-wave (FFRW) indicative of ventricular activity based on the data received from the first measurement unit 126.

[0034] The ventricular device 100 can include a housing, fixation tines, and electrodes 111, 112. The housing can have a pill-shaped cylindrical form factor in some instances. The fixation tines are configured to connect (e.g., anchor) the ventricular device 100 to the heart 20. The fixation tines can be fabricated from a shape memory material, such as Nitinol. In some instances, the fixation tines can connect the ventricular device 100 to the heart 20 in one of the chambers of the heart 20. For example, as shown and described herein with reference to FIG. 1 , the fixation tines can be configured to anchor the ventricular device 100 to the heart 20 in the right ventricle 21. Although the ventricular device 100 includes multiple fixation tines configured to anchor the ventricular device 100 to cardiac tissue in the right ventricle, it is contemplated that other types of fixation mechanisms can be used to anchor a leadless device according to the present disclosure to cardiac tissue in other chambers of the patient's heart 20.

[0035] The ventricular device 100 may include one or more electrodes 111, 112 for sensing electrical activity of the heart 20 and / or delivering electrical stimuli to the heart 20. The ventricular device 100 includes two electrodes 111, 112, although in other instances more than two electrodes may be included in the ventricular device. The electrodes 111, 112 may be spaced apart a sufficient distance to allow for detection of various electrical signals generated by the heart 20, such as P-waves generated by the atria and FFRW generated by the ventricles. The housing houses the electronic components of the ventricular device 100. The electronic components may include any discrete and / or integrated electronic circuitry implementing analog and / or digital circuits capable of providing the functionality attributed to the ventricular device 100 described above.

[0036] The first communication unit 128 can enable the leadless device 100 to communicate with other electronic devices, such as a programmer or other external patient monitor. In some instances, the housing 108 can house an antenna for wireless communication. The housing can further include a first power source 132.

[0037] The structure of the atrial device 200 may be similar to that of the ventricular device 100 described above. For example, the atrial device 100 may have a housing, fixed tines, and electrodes similar to the housing, fixed tines, and electrodes of the ventricular device 100. In addition, the atrial device 200 may have a second processing unit similar to the first processing unit 120, a second data memory similar to the first data memory 122, a second signal generating unit similar to the first signal generating unit 124, and a second measurement unit similar to the first measurement unit 126, but the accelerometer and / or impedance sensor and / or any other sensor used to determine the patient's activity level for the rate response are not required in the atrial device. Furthermore, the atrial device 200 may include a second communication module similar to the first communication unit 128 for communicating with a programmer or other external patient monitor.

[0038] FIG. 3 shows an example of how AV delay information can be used to trigger atrial pacing rate changes. The atrial device 200 can at least sense intrinsic atrial activity, ventricular activity (from the far field), and pace atrial heart tissue. The ventricular device 100 can at least sense ventricular activity, pace ventricular tissue, trigger ventricular pacing based on detection of atrial activity (from the far field), and provide a desired atrial pacing rate based on signals provided by the accelerometer and / or impedance sensor of the first measurement unit 126 of the ventricular device 100. Both devices 100, 200 are individually programmed, including the expected AV delay for a particular heart rate as determined by the first measurement unit 126. Both devices 100 and 200 "know" the current heart rate of the patient 30 and have an "expectation" of the timing of the ventricular pace that will result. The reason is that these signal parameters are stored in the first and second data memories. Thus, the information transfer parameter in the form of a lengthening or shortening of a predetermined (expected) AV delay by the ventricular device 100 is used to convey simple information to the atrial device when the first therapy signal is applied by the first signal generator unit 124. This is used as information that the atrial pacing rate of the atrial device 200 needs to be increased, for example, if the ventricular device 100 paces with a shorter AV delay than expected. In contrast, if the atrial pacing is higher than indicated by the accelerometer and / or impedance sensor, the ventricular device 100 will delay delivering the ventricular pace, i.e., lengthen the AV delay, which is an indication for the atrial device 200 to reduce its pacing rate. The example of FIG. 3 illustrates a scenario where the accelerometer and / or impedance sensor in the ventricular device first indicates the need to reduce the atrial pacing rate to meet the demands.A decrease in the rate determined by the accelerometer and / or by the impedance causes an increase in the difference of the AV delay from the expected value in 5 ms steps, thereby triggering a decrease in the atrial pacing rate at a constant rate until the AV delay returns to the expected value, which is when the atrial pacing rate matches the rate determined by the accelerometer and / or by the impedance. After a certain period of constant atrial pacing rate, the rate determined by the accelerometer and / or by the impedance increases, thereby causing a certain period of AV delay shortened by 5 ms from the expected value, thereby triggering an increase in the atrial pacing rate. When the AV delay returns to the expected value, the atrial pacing rate stabilizes. In the case where the patient develops a series of atrial tachycardias, the two devices 100, 200 will work asynchronously and the pacing rate indicated by the first measurement unit 126 based on the accelerometer and / or impedance will be available to the ventricular device 100, thereby allowing standard VVIR pacing.

[0039] In addition, the proposed solution, based on the regular programming of a shortened AV delay at higher pacing rates, is inherently safe. In order to transmit information to the atrial device 200 for a further increase in the desired atrial pacing rate, the ventricular device 100 is required to further shorten the paced AV delay. It is believed that the signaling parameters (i.e., values ​​of shortening or lengthening of the AV delay) used to convey the change in atrial pacing rate must be within a predefined range of values ​​(e.g., expected AV delay changes that are an amount of time between 3 ms and 8 ms (lengthening) and between −8 ms and −3 ms (shortening) are considered as signals. AV delay changes that are not within these expected ranges are considered as noise). In one embodiment, the signaling using the signaling parameters must be repeated in a specific sequence to be a valid input for the atrial device 200, e.g., three times in a row.

[0040] In another example, communication between multiple leadless (intracardiac) pacing devices in this manner can be enabled by simply passively sensing electrical activity originating from each other device in the heart. Dual-chamber leadless pacer therapy with a ventricular device 100 sensing and pacing in the ventricle and an atrial device 200 pacing and pacing in the atrium relies on each device sensing far-field activity from the electrically separated cardiac chambers to maintain synchronization with each other. For VDD therapy, far-field atrial activity is sensed by the ventricular device, and preliminary preclinical data also indicates that far-field electrical signals from ventricular activity are present in the atria. An example ventricular far-field signal recorded in the atrium is shown in FIG. 4 (see second column and arrow). In this example, the communication parameters can be, for example, pacing time and / or pacing rate.

[0041] A technical advantage of the present invention is the ability to achieve atrial rate-responsive pacing in a leadless pacemaker system consisting of two independent devices 100, 200. The atrial device 200 can be designed to be simpler (fewer electronic components), smaller, and to extend device lifetime without compromising patient therapy. Furthermore, duplication of device functionality, such as accelerometer and / or impedance sensor based rate response, for example in the atrial device 200, is avoided. Instead, the ventricular device 100 calculates the ventricular pacing rate and communicates this information to the atrial device 200.

Claims

1. A system (10) comprising a first intracardiac device (100) for implantation in a heart (20) of a patient (30) and at least one second implantable device (200), the first intracardiac device (100) comprises a first processing unit (120) for controlling a first signal generator unit (124), a first data memory (122) having predetermined first signal parameters for a first therapy signal, and a first measuring unit (126) for determining at least one first physical value and at least one second physical value, said second device (200), for example an intracardiac device, comprising a second processing unit for controlling a second signal generator unit, a second data memory having predetermined second signal parameters for a second therapy signal, and a second measuring unit for determining at least one third physical value, the first signal generator unit (124) is adapted to send a first electrical and / or electromagnetic therapy signal to the patient's heart (20), the first electrical and / or electromagnetic therapy signal having at least one first signal parameter and an information transfer parameter, the at least one first signal parameter of the first therapy signal being obtained from the first data memory (122) based on the at least one determined first physical value, and the information transfer parameter being determined by the first processing unit (120) based on the determined second physical value; The system (10) is adapted to deliver a second electrical and / or electromagnetic therapy signal, for example to the patient's heart (20), and at least one second signal parameter of the second therapy signal is obtained from a second data memory based on the at least one determined third physical value, and further based on the determined information transmission parameter of the first electrical and / or electromagnetic therapy signal most recently provided by the first intracardiac device (100).

2. 2. The system of claim 1, wherein the first therapy signal is an electrical ventricular pacing signal and the at least one first signal parameter of the first intracardiac device is a time position of the start of the ventricular pacing signal, its amplitude, and / or a ventricular pacing rate; and / or the second therapy signal is an electrical atrial pacing signal and the second signal parameter of the second device is an atrial pacing rate, an amplitude of the pacing signal, and a time position of the start of the atrial pacing signal.

3. 3. The system of claim 1, wherein the information transfer parameter is an amount of time of shortening or lengthening a predetermined first electrical and / or electromagnetic therapy signal interval, such as shortening or lengthening an AV delay value, and / or a rate of the predetermined first electrical and / or electromagnetic therapy signal.

4. 3. The system of claim 1 or 2, wherein the first physical value comprises intrinsic atrial activity and / or intrinsic ventricular activity and / or the third physical value comprises intrinsic ventricular activity and / or intrinsic atrial activity.

5. 3. The system according to claim 1 or 2, wherein the second physical value is a signal determined by an accelerometer sensor and / or an impedance sensor of the first measuring unit (126).

6. 3. The system of claim 1, wherein the second device (200) allows a change in the second electrical and / or electromagnetic therapy signal previously applied to the patient's heart (20) only if the second measurement unit receives confirmation of the most recently determined communication parameter.

7. 1. A method of operation of a system (100) comprising a first intracardiac device (100) and at least one second implantable device (200) after implantation in a heart (20) of a patient (30), comprising: the first intracardiac device (100) comprises a first processing unit (120) for controlling a first signal generator unit (124), a first data memory (122) having predetermined first signal parameters for a first therapy signal, and a first measuring unit (126) for determining at least one first physical value and at least one second physical value, said second device (200), for example an intracardiac device, comprising a second processing unit for controlling a second signal generator unit, a second data memory having predetermined second signal parameters for a second therapy signal, and a second measuring unit for determining at least one third physical value, The method comprises: determining at least one first physical value by the first measuring unit (126) of the first intracardiac device (100); determining at least one second body value by the first measuring unit (126) of the first intracardiac device (100); determining, by the first processing unit (120), an information transfer parameter based on the determined at least one second physical value; sending, by the first signal generator unit (124), a first electrical and / or electromagnetic therapy signal to the patient's heart (20) using at least one first signal parameter and the communication parameter, wherein the at least one first signal parameter of the first therapy signal is obtained from the first data memory (122) based on the at least one determined first physical value; determining, by the second device (200), the signaling parameters of the first electrical and / or electromagnetic therapy signal provided by the first intracardiac device (100); determining at least one third body value by said measuring unit of said second device (200); delivering, by the second signal generator, a second electrical and / or electromagnetic therapy signal, e.g., to the patient's heart (20), wherein at least one second signal parameter of the second therapy signal is obtained from a second data memory based on the at least one determined third physical value, and further based on the determined signal transmission parameter of the first electrical and / or electromagnetic therapy signal most recently provided by the first intracardiac device (100); A method of operation, including:

8. 8. The method of claim 7, wherein the first therapy signal is an electrical ventricular pacing signal and the at least one first signal parameter of the first intracardiac device is a time position of the start of the ventricular pacing signal, its amplitude, and / or a ventricular pacing rate; and / or the second therapy signal is an electrical atrial pacing signal and the second signal parameter of the second device is an atrial pacing rate, an amplitude of the pacing signal, and a time position of the start of the atrial pacing signal.

9. 9. The method of claim 7 or 8, wherein the information transfer parameter is an amount of time of shortening or lengthening of a predetermined first electrical and / or electromagnetic therapy signal interval, such as shortening or lengthening of an AV delay value, and / or a rate of the predetermined first electrical and / or electromagnetic therapy signal.

10. 9. The method of claim 7 or 8, wherein the first physical value comprises intrinsic atrial activity and / or intrinsic ventricular activity, and / or the third physical value comprises intrinsic ventricular activity.

11. 9. The method according to claim 7 or 8, wherein the second physical value is a signal determined by an accelerometer sensor and / or an impedance sensor of the first measuring unit (126).

12. 9. The method according to claim 7 or 8, wherein the second device (200) allows a change in the second electrical and / or electromagnetic therapy signal previously applied to the patient's heart (20) only if the second measurement unit receives confirmation of the most recently determined communication parameter.

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