Reducing far field oversensing via integrated bipolar lead

Abstract

An example system includes an implantable medical device (IMD) configured to: acquire an integrated bipolar electrogram (EGM) signal of the first chamber sensed via a first lead implanted in a first chamber of the heart; and at least one of: identifying an intrinsic event of the second chamber sensed via a second lead implanted in a second chamber of the heart; or identifying a pacing event of the second chamber sensed via the second lead; and processing circuitry configured to: generate a time window of the EGM signal based on one or more of the identified intrinsic event or the identified pacing event; determine a value of a characteristic of the EGM signal during the time window; determine that the value of the characteristic satisfies a far-field activity threshold; and adjust a sensitivity threshold of the IMD based on the determination that the value of the characteristic satisfies the far-field activity threshold.

Description

[0001] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 593,655, filed October 27, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This disclosure generally relates to medical device systems, and more specifically to cardiac monitoring and / or treatment delivery by implantable medical devices. Background Technology

[0003] Some types of implantable medical devices (such as pacemakers or implantable cardioverter-defibrillators) deliver electrical therapy to a patient's heart via electrodes through one or more implantable leads. The electrical therapy can be delivered to the heart in the form of pulses for pacing or electric shocks for cardioversion or defibrillation. In some cases, the implantable medical device can sense the heart's inherent depolarization and control the delivery of electrical therapy to the heart based on this sensing. Summary of the Invention

[0004] Generally, this disclosure describes example techniques related to adjusting sensitivity thresholds to prevent or reduce the possibility of oversensing far-field activity in integrated bipolar leads in multi-chamber systems (e.g., systems including leads implanted in multiple chambers of the heart). Integrated bipolar leads may include integrated bipolar leads implanted within the ventricle, and the techniques of this disclosure can be used to reduce oversensing of atrial far-field activity. For example, an implantable medical system may include an implantable medical device (IMD), such as a pacemaker, implantable cardioverter defibrillator (ICD), or implantable cardiac resynchronization therapy (CRT), coupled to a ventricular integrated bipolar lead configured to be implanted in the ventricle of a patient's heart and configured to sense the patient's ventricular electrocardiogram (EGM) signal via the ventricular integrated bipolar lead. The implantable medical system may further couple to an atrial lead configured to be implanted in the patient's atrium and configured to sense the patient's atrial EGM signal via the atrial lead. IMD can identify atrial intrinsic events (e.g., depolarization) and / or indications of atrial pacing events in a patient based on atrial cardiac EGM signals from the atrial leads.

[0005] The IMD can be configured to generate a time window for the ventricular EGM signal based on the timing of one or more of the intrinsic atrial events or atrial pacing events. The IMD can determine the values ​​of one or more features of the ventricular EGM signal during this time window and determine whether the values ​​of one or more features of the ventricular EGM signal satisfy a far-field activity threshold. In response to the value of one or more features of the ventricular EGM signal satisfying the far-field activity threshold of the ventricular integrated bipolar lead, the IMD can adjust the sensitivity threshold of the ventricular integrated bipolar lead, such as increasing the sensitivity threshold, to reduce the likelihood of subsequent atrial oversensing (such as P-wave oversensing) instances in the ventricular EGM signal. In some examples, generating the time window based on one or more of the sensed atrial events or atrial pacing events can focus the determined values ​​of one or more features of the EGM signal during the time period (e.g., the time window) in which atrial cardiac activity and / or atrial sensing occur. This can help isolate and indicate features that may be caused by the ventricular integrated bipolar lead (implanted P-wave oversensing).

[0006] In one example, this disclosure describes a system comprising: an implantable medical device (IMD) configured to: acquire an integrated bipolar electrogram (EGM) signal of the first chamber sensed via a first lead implanted in a first chamber of a patient's heart; and at least one of: identifying an intrinsic event of the second chamber sensed via a second lead implanted in a second chamber of the patient's heart; or identifying a pacing event of the second chamber sensed via the second lead; and processing circuitry configured to: generate a time window of the integrated bipolar EGM signal of the first chamber based on one or more of the identified intrinsic event or the identified pacing event of the second chamber; determine a value of one or more features of the integrated bipolar EGM signal during the time window; determine that the value of the one or more features of the integrated bipolar EGM signal satisfies a far-field activity threshold; and adjust a sensitivity threshold of the IMD from a first value to a second value based on the determination that the value of the one or more features of the EGM signal satisfies the far-field activity threshold.

[0007] In another example, this disclosure describes an implantable medical device comprising: a sensing circuit configured to: acquire an integrated bipolar electrogrammage (EGM) signal of a first chamber sensed via a first lead implanted in a patient's heart, wherein the first lead includes an integrated bipolar lead; and identify an intrinsic event of a second chamber sensed via a second lead implanted in a second chamber of the heart; a treatment delivery circuit configured to perform a pacing event on the second chamber of the heart via the second lead; and a processing circuit configured to: generate a time window of the integrated bipolar EGM signal of the first chamber based on one or more of the identified intrinsic event or the identified pacing event of the second chamber; determine a value of one or more features of the integrated bipolar EGM signal during the time window; determine that the value of the one or more features of the integrated bipolar EGM signal satisfies a far-field activity threshold; and adjust a sensitivity threshold of the sensing circuit from a first value to a second value based on determining that the value of the one or more features of the EGM signal satisfies the far-field activity threshold.

[0008] In another example, this disclosure describes a method comprising: receiving an integrated bipolar electrogrammage (EGM) signal of a first chamber sensed via a first lead implanted in a first chamber of a patient's heart; receiving at least one of an identified intrinsic event of a second chamber sensed via a second lead implanted in a second chamber of the patient's heart or an identified pacing event of a second chamber sensed via the second lead; generating a time window for the integrated bipolar EGM signal of the first chamber based on one or more of the identified intrinsic event of the second chamber or the identified pacing event; determining a value of one or more features of the integrated bipolar EGM signal during the time window; determining that the value of the one or more features of the integrated bipolar EGM signal satisfies a far-field activity threshold; and adjusting a sensitivity threshold of an implantable medical device from a first value to a second value in response to determining that the value of the one or more features of the EGM signal satisfies the far-field activity threshold.

[0009] In another example, this disclosure describes a non-transitory computer-readable storage medium storing instructions that, when executed, cause processing circuitry to: receive an integrated bipolar electrogrammage (EGM) signal of the first chamber sensed via a first lead implanted in the patient's heart; receive at least one of an identified intrinsic event of the second chamber sensed via a second lead implanted in the patient's heart or an identified pacing event of the second chamber sensed via the second lead; generate a time window for the integrated bipolar EGM signal of the first chamber based on one or more of the identified intrinsic event or the identified pacing event of the second chamber; determine a value of one or more features of the integrated bipolar EGM signal during the time window; determine that the value of the one or more features of the integrated bipolar EGM signal satisfies a far-field activity threshold; and adjust a sensitivity threshold of the implantable medical device from a first value to a second value in response to determining that the value of the one or more features of the EGM signal satisfies the far-field activity threshold.

[0010] This summary is intended to provide an overview of the subject matter described in this disclosure. It is not intended to provide an exclusive or exhaustive explanation of the methods and systems described in detail in the following drawings and specification. Details of one or more aspects of this disclosure are set forth in the following drawings and specification. Attached Figure Description

[0011] Details of one or more examples of this disclosure are set forth in the following figures and description. Other features, objects, and advantages of this disclosure will be apparent from the description and figures, as well as from the claims.

[0012] Figure 1 This is a conceptual diagram illustrating an example medical device system according to some examples of this disclosure.

[0013] Figure 2 This further illustrates some examples according to this disclosure. Figure 1 A conceptual diagram of an implantable medical device (IMD).

[0014] Figure 3 These are examples illustrating some aspects of this disclosure. Figure 1 and Figure 2 Functional block diagram of an example configuration of an implantable medical device.

[0015] Figure 4 These are examples illustrating some aspects of this disclosure. Figure 1 A functional block diagram of an example configuration of external devices for a medical system.

[0016] Figure 5 This is a block diagram illustrating an example system according to some examples of this disclosure, the example system including external devices such as servers and coupled via a network to... Figure 1One or more computing devices, including the IMD and external devices shown.

[0017] Figure 6 This is a flowchart illustrating example techniques for adjusting sensitivity thresholds according to some examples of this disclosure.

[0018] Figure 7 This is a flowchart illustrating example techniques for adjusting sensitivity thresholds according to some examples of this disclosure.

[0019] Throughout the specification and drawings, similar reference characters represent similar elements. Detailed Implementation

[0020] Implantable medical systems include implantable medical devices (IMDs), such as pacemakers, implantable cardioverter-defibrillators (ICDs), or implantable cardiac resynchronization therapy (CRTs), which can provide treatment for maintaining and restoring a normal heart rhythm by pacing and / or by delivering electrical shocks for cardioversion or defibrillation. One or more electrical leads connected to the IMD can be inserted into or near the patient's heart. The leads deliver therapeutic current from the IMD to the heart tissue to stimulate the heart with low-energy pacing pulses or to cardioversion / defibrillate the heart with relatively high-energy electrical shocks. The IMD also uses the leads to sense electrical activity from the heart, such as electrogrammography (EGM) signals. Using EGM signals, the IMD can detect cardiac depolarization, repolarization, or other activity, and detect arrhythmias in which the IMD can deliver electrical therapy. In some examples, within the IMD, a sensing amplifier can amplify the EGM signal from the electrodes on the leads, and the IMD can use the amplified EGM signal to sense the intrinsic depolarization of the atria (called the P wave) and the intrinsic depolarization of the ventricles (called the R wave).

[0021] Implantable medical systems may also include one or more leads that are wholly or partially implanted in the patient and configured to couple to the IMD. In some examples, the implantable leads include integrated bipolar leads, wherein electrodes (e.g., coil electrodes) for delivering relatively high-energy electrical shocks act as the anode or cathode of a sensing vector (such as a sensing bipolar). The sensing bipolar of the integrated bipolar lead may have a larger (e.g., wider) spacing than conventional bipolar leads, which include, for example, two relatively closely spaced electrodes, such as a tip electrode and a loop electrode, or two closely spaced loop electrodes. Due to the larger inter-electrode spacing, the integrated bipolar lead can capture more far-field signals. In some examples, the integrated bipolar lead may include a defibrillator coil electrode connected to the loop electrode, wherein the combination of the defibrillator coil electrode and the loop electrode acts as the anode or cathode of the sensing bipolar of the integrated bipolar lead.

[0022] Therefore, integrated bipolar leads implanted in the ventricle may have a higher chance of atrial oversensing, especially those implanted in the left bundle branch region, septal region, or higher / closer to the atrium than conventional apical implantation. In some cases, the position of the integrated bipolar lead can be adjusted by the implanter at implantation to reduce the chance of oversensing atrial far-field activity by ventricularly implanted integrated bipolar leads. However, in some cases, ventricularly implanted integrated bipolar leads may sense atrial far-field activity over time, leading to atrial oversensing. For example, the lead position may change after implantation, such as due to patient movement, which may lead to increased atrial far-field activity sensed by the integrated bipolar lead implanted in the ventricle, potentially resulting in atrial oversensing. Atrial oversensing can lead to various undesirable outcomes, such as overdetection of tachyarrhythmias, suppression of cardiac resynchronization therapy (CRT), and / or loss of the optimal AV interval for CRT or other synchronized ventricular pacing.

[0023] Generally, this disclosure describes example techniques related to adjusting sensitivity thresholds to prevent or reduce the possibility of oversensing far-field activity via integrated bipolar leads in multi-chamber systems, such as ventricular-implanted integrated bipolar leads. For example, an IMD can monitor one or more characteristics of the EGM signal sensed by an atrial lead and a ventricular integrated bipolar lead, such as during a normal 1:1 rhythm. In some examples, the IMD can periodically determine one or more characteristics of one or more EGM signals sensed by a ventricular integrated bipolar lead. In some examples, the IMD can periodically determine the amplitude or other measure of a window portion of the EGM signal sensed by the ventricular integrated bipolar lead.

[0024] In some examples, the IMD can sense a patient's intrinsic atrial events and / or perform atrial pacing events on the patient via an atrial lead. The IMD can periodically perform windowing based on one or more of the intrinsic atrial events or atrial pacing events to generate a time window for the EGM signal sensed by the integrated bipolar lead. For example, the IMD can generate a time window for the EGM signal sensed via the integrated bipolar lead that extends from the time before the atrial event (e.g., up to 50 milliseconds (ms) before the intrinsic atrial event, between 20 ms and 70 ms before the intrinsic atrial event, or 50 ms before the intrinsic atrial event) to the time after the atrial event (e.g., up to 120 ms after the intrinsic atrial event, between 100 ms and 140 ms after the intrinsic atrial event, or 120 ms after the intrinsic atrial event). In some examples, the IMD can generate a time window for the EGM signal sensed by the integrated bipolar from the location or vicinity of the atrial pacing event to the location after the atrial pacing event, such as up to 170 ms after the atrial pacing event, between 150 ms and 190 ms after the atrial pacing event, or 170 ms after the atrial pacing event.

[0025] IMD can periodically determine the values ​​of one or more features of the EGM signal during the generated time window, such as P wave amplitude, peak-to-peak amplitude, maximum peak amplitude, minimum trough amplitude, transition rate, or other features. In some examples, IMD can compare the value of one or more features of the EGM signal to the baseline value of the corresponding feature of the EGM signal. In some examples, the baseline values ​​of one or more features of the EGM signal can be generated shortly after the ventricular integrated bipolar lead and atrial lead are implanted in the patient. In some examples, the baseline values ​​of one or more features of the EGM signal can be predetermined. The baseline values ​​of the EGM signal features can be configured to represent the measurements of those corresponding features when the ventricular integrated bipolar lead senses a minimum amount of atrial far-field activity.

[0026] In some examples, the IMD may periodically adjust the sensitivity threshold applied to signals sensed via an integrated bipolar lead implanted in the ventricle when the change in the value of one or more features of the EGM signal within the window (such as amplitude) relative to the baseline value of the corresponding feature of the EGM signal meets a change threshold and / or the value of one or more features of the EGM signal within the window meets a far-field activity threshold. For example, the IMD may increase the sensitivity threshold to reduce the likelihood of subsequent instances of atrial oversensing, i.e., the likelihood of misidentifying P-wave activity in the ventricular EGM signal as an R-wave. In some examples, the IMD may increase the sensitivity threshold by 10% to 50% of the current sensitivity threshold to reduce subsequent instances of atrial oversensing, such as P-wave oversensing. In some examples, the periodicity may be hourly, every 4 hours, every 6 hours, every 8 hours, every 12 hours, every 24 hours, or every 48 hours. In other examples, the periodicity may be other time periods not listed above.

[0027] Figure 1 An exemplary medical device system 10 associated with a patient 14 is illustrated. Medical device system 10 is an example of a medical device system configured to implement the exemplary techniques described herein for adjusting sensitivity thresholds to reduce the likelihood of far-field oversensing via integrated bipolar leads. In some examples, medical device system 10 includes an implantable medical device (IMD) 16 communicating with an external device 24. In the illustrated example, IMD 16 may be coupled to leads 18, 20, and 22. IMD 16 may be, for example, an implantable pacemaker that provides electrical signals to the heart 12 and senses the electrical activity of the heart 12 via electrodes coupled to one or more of the leads 18, 20, and 22. In some examples, IMD 16 may have cardioversion and / or defibrillation capabilities.

[0028] Leads 18, 20, and 22 extend into the heart 12 of the patient 14 to sense the electrical activity of the heart 12 and deliver electrical therapy to the heart 12. Figure 1 In the example shown, the right ventricle (RV) lead 18 extends through one or more veins (not shown), the superior vena cava (not shown), and the right atrium (RA) 26, and enters RV 28. The left ventricle (LV) coronary sinus lead 20 extends through one or more veins, the vena cava, and the right atrium 26, and enters the coronary sinus 30, reaching the region adjacent to the free wall of LV 32 of heart 12. The right atrium (RA) lead 22 extends through one or more veins and the vena cava, and enters RA 26 of heart 12.

[0029] In some examples, lead 18 may be referred to as a ventricular implantable integrated bipolar lead. In some examples, lead 22 may be referred to as an atrial lead. Although in Figure 1 The image shows the tip implantation location of the lead 18, but in some examples, the ventricular implantable integrated bipolar lead 18 can be implanted in other locations, such as near the left bundle branch, the ventricular septum, or more generally closer to the right atrium.

[0030] IMD 16 can be connected via an electrode coupled to at least one of leads 18, 20, and 22. Figure 1 (Not shown) to sense electrical signals accompanying depolarization and repolarization of the heart 12. In some examples, the IMD 16 can also sense electrical signals accompanying depolarization and repolarization of the heart 12 via extravascular electrodes (e.g., electrodes positioned outside the vascular system of the patient 14) (such as epicardial electrodes, external surface electrodes, subcutaneous electrodes, etc.). The electrodes used for sensing and pacing by the IMD 16 can be configured as monopolar or bipolar.

[0031] The natural electrical activation system of the human heart involves several sequential conduction pathways, starting at the sinoatrial (SA) node and continuing at the atrial level through the atrial conduction pathway via the Bachmann bundle and internodal tracts, followed by the atrioventricular (AV) node, the common bundle of His, the right and left bundle branches, and finally distributing to the distal myocardial terminals via the Purkinje fiber network. In a normal electrical activation sequence, the cardiac cycle begins with the generation of a depolarization wave at the SA node in the wall of RA 26. The depolarization wave is transmitted at the atrial level through the atrial conduction pathway via the Bachmann bundle and internodal tracts to the LA 33 septum. When the atrial depolarization wave reaches the AV node, the atrial septum, and the distal walls of right atrium 26 and left atrium 33, respectively, atrium 26 and atrium 33 may contract due to electrical activation. The convergence of right and left atrial depolarization waves manifests as the P wave of the PQRST complex of the cardiac EGM. A sensed P wave is detected when the amplitude of an atrial depolarization wave passing between a pair of monopolar or bipolar pacing / sensing electrodes located on or near RA 26 and / or LA 33 exceeds a threshold. A sensed P wave can also be referred to as an intrinsic atrial event.

[0032] During or after atrial systole, the AV junction causes the depolarization wave to distribute downwards below the His bundle of the ventricular septum. The depolarization wave can travel to the apical region of cardiac 12 and then upwards through the Purkinje fiber network. The convergence of right and left ventricular depolarization waves and the subsequent T wave accompanying repolarization of the depolarized myocardium can represent the QRST portion of the PQRST cardiac cycle complex. A sensed R wave can be detected when the amplitude of the QRS ventricular depolarization wave passing between bipolar or monopolar pacing / sensing electrode pairs located on or near RV 28 and / or LV 32 exceeds a threshold. Depending on the ventricle, the sensed R wave may also be referred to as a ventricular intrinsic event, an RV sensing event (RV... S ) or LV sensing events (LV S In this ventricle, the electrodes of one or more of leads 18, 20, and 22 are configured to sense under specific conditions.

[0033] In some examples, the IMD 16 provides defibrillation and / or cardioversion therapy via electrodes located on at least one of leads 18, 20, and 22. Based on signals sensed via one or more leads 18, 20, and 22, such as the detection of R waves, the IMD 16 can detect arrhythmias of heart 12, such as fibrillation or other tachyarrhythmias in ventricles 28 and 32, and deliver anti-tachyarrhythmic therapy to heart 12 in the form of an electric shock. In some examples, the IMD 16 can be programmed to deliver therapy (e.g., an electric shock with an increased energy level) until the tachyarrhythmia of heart 12 ceases. In examples where the IMD 16 provides anti-tachyarrhythmic electric shock therapy, the IMD 16 can detect tachyarrhythmias by employing any one or more tachyarrhythmia detection techniques known in the art.

[0034] In some examples, external device 24 may be a handheld computing device or a computer workstation. External device 24 may include a user interface for receiving input from a user. The user interface may include, for example, a keypad and a display, which may be, for example, a liquid crystal display (LCD) or a light-emitting diode (LED) display. The keypad may take the form of an alphanumeric keypad associated with specific functions or a reduced set of keys. External device 24 may additionally or alternatively include a peripheral pointing device (such as a mouse) through which the user can interact with the user interface. In some examples, the display of external device 24 may include a touchscreen display, and the user can interact with external device 24 through the display.

[0035] Users (such as physicians, technicians, or other clinicians) can interact with external device 24 to communicate with IMD 16. For example, users can interact with external device 24 to retrieve physiological or diagnostic information from IMD 16. Users can also interact with external device 24 to program IMD 16, for example, to select values ​​for operating parameters of IMD 16.

[0036] For example, a user can use external device 24 to retrieve information from IMD 16 regarding the rhythm of heart 12, its trend over time, or the occurrence of arrhythmias. Similarly, a user can use external device 24 to retrieve information from IMD 16 regarding other sensed physiological parameters of patient 14, such as sensed electrical activity, movement, posture, respiration, or chest impedance. As another example, a user can use external device 24 to retrieve information from IMD 16 regarding the performance or integrity of IMD 16 or other components of system 10, such as leads 18, 20, and 22, or the power supply to IMD 16. In such examples, physiological parameters of patient 14 and data regarding IMD 16 can be stored in the memory of IMD 16 for retrieval by the user. The user can use external device 24 to program parameters for treatment delivery performed by IMD 16 and / or parameters used by IMD 16 for depolarization and / or arrhythmia detection. In some examples, a user can activate certain features of the IMD 16 by entering a single command via an external device 24, such as pressing a single key or a combination of keys on the keypad or performing a single-point selection action using a pointing device.

[0037] The IMD 16 and external device 24 can communicate wirelessly using any technology known in the art. Examples of communication technologies may include, for example, radio frequency (RF) telemetry, which may be based on Bluetooth. ® WiFi or a medical implantable communication service (MICS) via an RF link established through an antenna, but other technologies are also considered. In some examples, the external device 24 may include a programming head that can be placed close to the patient's body near the IMD 16 implantation site to improve the quality or security of communication between the IMD 16 and the external device 24.

[0038] Figure 2 This is a conceptual diagram further illustrating an example configuration of the IMD 16 integrated with the heart 14. Figure 2 In the example, IMD 16 is coupled to leads 18 and 22. IMD 16 can be coupled to, for example... Figure 2 The two leads shown are as follows: Figure 1 The three leads shown may be different from the leads shown herein, but the IMD16 can still implement the techniques disclosed herein.

[0039] like Figure 2As shown, the proximal ends of leads 18 and 22 are connected to connector block 34 of IMD 16 to electrically couple electrodes on the leads to circuitry within housing 60 of IMD 16. In some examples, the proximal ends of leads 18 and 22 may include electrical contacts for corresponding electrical contacts within connector block 34 of IMD 16. Each lead of leads 18 and 22 includes an elongated insulated lead body that carries a plurality of conductors, such as conductors for each electrode on the lead, each of which can be connected to a corresponding contact at the proximal end of the lead. Bipolar electrode 42 is positioned adjacent to the distal end of lead 18 in right ventricle 28. Furthermore, bipolar electrodes 48 and 50 are positioned adjacent to the distal end of lead 22 in right atrium 26.

[0040] In some examples, lead 18 may be referred to as ventricular implantable integrated bipolar lead 18 or ventricular integrated bipolar lead 18. As will be described in more detail below, lead 18 may be configured to facilitate sensing of ventricular EGM by IMD 16 via an integrated bipolar pair including tip electrode 42 and elongated electrode 62. In some examples, lead 22 may be referred to as atrial lead 22.

[0041] Electrode 48 may be in the form of a ring electrode, and electrodes 42 and 50 may be in the form of helical tip electrodes, which are mounted, for example, within insulated electrode heads 52 and 56 using fixing screws. Some helical tip electrodes may include mechanisms for a deployable / retractable helix. In other examples, one or more of electrodes 42 and 50 may be in the form of small circular electrodes at the tip of a tin-plated lead or other fixing element. Leads 18 and 22 also include elongated electrodes 62 and 66, respectively, each of which may be in the form of a coil and may be configured to deliver relatively high-energy therapeutic shocks. Each of electrodes 42, 48, 50, 62, and 66 may be electrically coupled to a corresponding conductor within the lead body of its associated lead 18 and 22, and thereby coupled to a corresponding electrical contact in an electrical contact at the proximal end of leads 18 and 22.

[0042] exist Figure 2 In some examples, IMD 16 includes a housing electrode 58 that may be integrally formed with or otherwise coupled to the outer surface of the hermetically sealed housing 60 of IMD 16. In some examples, the housing electrode 58 is defined by an uninsulated portion of the outward-facing part of the housing 60 of IMD 16. Other divisions between the insulated and uninsulated portions of housing 60 may be used to define two or more housing electrodes. In some examples, the housing electrode 58 substantially encompasses the entire housing 60.

[0043] The IMD 16 can sense electrical signals accompanying the depolarization and repolarization of the heart 12 via electrodes 42, 48, 50, 62, and 66. These electrical signals are conducted from the electrodes to the IMD 16 via corresponding leads 18 and 22. The IMD 16 can sense these electrical signals via any bipolar combination of electrodes 40, 42, 48, 50, 62, and 66. For example, the IMD 16 can sense ventricular EGM via an integrated bipolar pair including a tip electrode 42 and an elongated electrode 62. Furthermore, any one of electrodes 42, 48, 50, 62, and 66 can be combined with a housing electrode 58 for unipolar sensing. The combination of electrodes used for sensing may be referred to as a sensing configuration or electrode vector.

[0044] In some examples, the IMD 16 delivers pacing pulses via a bipolar combination of electrodes 42, 48, 50, 62, and 66 to depolarize the myocardial tissue of the heart 12. In some examples, the IMD 16 delivers pacing pulses in a monopolar configuration with housing electrode 58 via any of electrodes 42, 48, and 50. Furthermore, the IMD 16 can deliver anti-tachyarrhythmic shocks, such as defibrillation shocks, to the heart 12 via any combination of extended electrodes 62 and 66 with housing electrode 58. The IMD 16 can also deliver cardioversion shocks to the heart 12 using electrodes 58, 62, and 66. Electrodes 62 and 66 can be made of any suitable conductive material, such as, but not limited to, platinum, platinum alloys, or other materials known to be suitable for use in implantable defibrillation electrodes.

[0045] Figure 1 and Figure 2 The configuration of system 10 shown is merely an example. In other examples, the system may include external vascular leads and electrodes as alternatives to or supplements to the transvenous leads 18 and 22 shown. Furthermore, the IMD 16 need not be implanted in the patient. In examples where the IMD 16 is not implanted in the patient, the IMD 16 may sense electrical signals and / or deliver anti-tachyarrhythmic shocks and other therapies to the heart 12 via percutaneous leads extending through the patient's skin to various locations inside or outside the heart 12.

[0046] Some additional or alternative examples of IMD 16 are described in the following documents: U.S. Patent No. 7,236,828, entitled “IMPLANTABLE CARDIOVERTER DEFRIBILLATOR WITH AUTOMATICALLY SENSING CONFIGURATION”, published June 26, 2007 by Casavant et al.; U.S. Patent No. 7,953,488, entitled “PRE-QUALIFICATION OF AN ALTERNATE SENSING CONFIGURATION”, published May 31, 2011 by Casavant et al.; and / or entitled “SYSTEM AND METHOD FOR IDENTIFYING AND RESPONDING TO P-WAVE OVERSENSING IN ACARDIAC”, published December 30, 2021 by Zhang et al. U.S. Patent Publication No. 2021 / 0402197, entitled "SYSTEM (System and Method for Identifying and Responding to P Wave Oversensing in the Cardiac System)," the entire contents of each of these patents are incorporated herein by reference.

[0047] Figure 3 yes Figure 1 and Figure 2 A functional block diagram of an exemplary configuration of the IMD 16 is provided. In the illustrated example, the IMD 16 includes a memory 70, processing circuitry 80, sensing circuitry 82, one or more accelerometers 84, treatment delivery circuitry 86, telemetry circuitry 88, and a power supply 90, one or more of which may be disposed within a housing 60 of the IMD 16. In some examples, the memory 70 includes computer-readable instructions that, when executed by the processing circuitry 80, cause the IMD 16 and the processing circuitry 80 to perform various functions categorized herein as belonging to the IMD 16 and the processing circuitry 80. The memory 70 may include any volatile memory, non-volatile memory, magnetic memory, optical memory, or dielectric memory, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), electrically erasable programmable ROM (EEPROM), flash memory, or any other digital medium. Sensed physiological parameters of the patient 14 (e.g., EGM or ECG signals or atrial events) may be stored in the memory 70.

[0048] Processing circuitry 80 may include one or more of the following: a microprocessor, a controller, a digital signal processing circuit (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or equivalent discrete or integrated logic circuitry. In some examples, processing circuitry 80 may include multiple components, such as any combination of the following: one or more microprocessors, one or more controllers, one or more DSPs, one or more ASICs, or one or more FPGAs, and other discrete or integrated logic circuitry. The functionality attributed herein to processing circuitry 80 may be embodied in software, firmware, hardware, or any combination thereof. According to the technology described herein, processing circuitry 80 can be configured to generate a time window for an integrated bipolar EGM signal based on one or more of an intrinsic atrial event or an atrial pacing event, determine the value of one or more features of the EGM signal during the time window, determine that the value of the one or more features of the EGM signal satisfies a far-field activity threshold, and, in response to determining that the value of the one or more features of the EGM signal satisfies the far-field activity threshold, adjust the value of a sensitivity threshold for depolarization of a desired chamber (e.g., R wave) in the integrated bipolar EGM, used by processing circuitry 80 and / or sensing circuitry 82, for example, adjusting the sensitivity threshold from a first value to a second value. The second value may be higher than the first value, which may make the threshold less sensitive to depolarization.

[0049] Sensing circuit 82 is configured to monitor signals from at least one of electrodes 42, 48, 50, 58, 62, or 66 to monitor the electrical activity of heart 12, for example, via an EGM signal. For example, sensing circuit 82 may utilize electrodes 48, 50, and 66 within RA 26 to sense intrinsic atrial events (e.g., P waves). In some examples, sensing circuit 82 includes switching circuitry to select which of the available electrodes is used to sense the electrical activity of heart 12. For example, processing circuitry 80 may select the electrodes used as sensing electrodes via the switching circuitry within sensing circuitry 82, for example, by providing a signal via a data / address bus. In some examples, sensing circuitry 82 includes one or more sensing channels, each of which may include an amplifier. In response to a signal from processing circuitry 80, the switching circuitry of sensing circuitry 82 may couple the output from the selected electrode to one of the sensing channels.

[0050] In some examples, one channel of sensing circuitry 82 may include an R-wave amplifier that receives signals from selected electrode pairs 42, 62, and electrode 60 for pacing and sensing in RV 28 of heart 12. According to the techniques of this disclosure, sensing circuitry 82 may include an R-wave amplifier that receives signals from integrated bipolar electrode pairs 42 and 62, i.e., integrated bipolar ventricular EGM signals, and detects R-waves within the signals. In some examples, the R-wave amplifier may take the form of an automatic gain control amplifier that provides an adjustable sensing threshold based on the R-wave amplitude of the measured heart rate. According to the techniques of this disclosure, processing circuitry 80 may adjust parameters of the adjustable sensing threshold in response to a window portion of the integrated bipolar ventricular EGM signal satisfying a far-field activity threshold, for example, to increase the threshold and make the threshold less sensitive to waves in the integrated bipolar ventricular EGM signal.

[0051] In addition, in some examples, one channel of the sensing circuit 82 may include a P-wave amplifier that receives signals from electrodes 48 and 50 for pacing and sensing in the RA 26 for the heart 12. In some examples, the P-wave amplifier may take the form of an automatic gain control amplifier that provides an adjustable sensing threshold based on the P-wave amplitude of the measured heart rate. Examples of R-wave amplifiers and P-wave amplifiers are described in U.S. Patent No. 5,117,824, entitled “APPARATUS FORMONITORING ELECTRICAL PHYSIOLOGIC SIGNALS”, published June 2, 1992, by Keimel et al., the entire contents of which are incorporated herein by reference. Other amplifiers may also be used. Furthermore, in some examples, one or more sensing channels of sensing circuit 82 may be selectively coupled to housing electrode 58 or extended electrode 62 or 66, together with or in place of one or more electrodes 42, 48, or 50, for example for unipolar or integrated bipolar sensing of R-wave or P-wave in any of the chambers 26, 28, or 32 of heart 12.

[0052] In some examples, sensing circuitry 82 includes a channel comprising an amplifier having a relatively wider passband than an R-wave or P-wave amplifier. Selected signals chosen for coupling to this broadband amplifier can be provided to a multiplexer and subsequently converted by an analog-to-digital converter into multi-bit digital signals for storage as an EGM in memory 70. In some examples, the storage of such an EGM in memory 70 can be under the control of direct memory access circuitry. Processing circuitry 80 may employ digital signal analysis techniques to characterize the digitized signals stored in memory 70 to detect and classify the patient's heart rhythm from the electrical signals. Processing circuitry 80 may detect and classify the patient's heart rhythm by employing any of the numerous signal processing methods known in the art. In some examples, sensing 82 stores an integrated bipolar EGM (e.g., a ventricular integrated bipolar EGM) in memory 70 for windowing and further processing by processing circuitry 80 according to the techniques of this disclosure.

[0053] The signal generated by the sensing circuit 82 may include, for example, an RA event signal indicating via implanted RA 26 ( Figure 1 P waves were detected by electrodes within the implanted LA 33; LA event signals indicated by the implanted LA 33 ( Figure 1 The electrodes within the RV 28 detect a P wave; an RV event signal indicating that an R wave is detected via an electrode implanted within the RV 28; or an LV event signal indicating that an R wave is detected via an electrode implanted within the LV 32.

[0054] In some examples, IMD 16 may include one or more additional sensors, such as accelerometer 84. In some examples, accelerometer 84 may include one or more triaxial accelerometers. Signals generated by accelerometer 84 may indicate, for example, the overall body movement of patient 14, such as patient posture or activity level. Regardless of the configuration of accelerometer 84, processing circuitry 80 may determine patient parameter values ​​based on signals obtained from these accelerometers. Accelerometer 84 may generate signals and provide these signals to processing circuitry 80 to make determinations about the posture and activity level of patient 14 at a given time. Processing circuitry 80 may then use the determined posture and activity level to further determine whether patient 14 is awake or asleep, and if patient 14 is determined to be awake, further determine whether patient 14 is resting or exercising.

[0055] The therapeutic delivery circuit 86 is electrically coupled to electrodes 42, 48, 50, 58, 62, and 66, for example, via conductors of the corresponding leads 18, 20, 22, or, in the case of housing electrodes 58, via an electrical conductor disposed within the housing 60 of the IMD 16. The therapeutic delivery circuit 86 is configured to generate and deliver electrotherapy.

[0056] In some examples, the treatment delivery circuit 86 is configured to deliver a cardioversion or defibrillation shock to the heart 12. Pacing stimulation, cardioversion shock, and defibrillation shock may be in the form of pulses. In other examples, the treatment delivery circuit 86 may deliver one or more of these types of stimulation in the form of other signals, such as sine waves, square waves, or other substantially continuous time signals.

[0057] The treatment delivery circuit 86 may include switching circuitry, and the processing circuitry 80 may use this switching circuitry to select, for example, which of the available electrodes to deliver shock pulses or pacing pulses (e.g., via a data / address bus). The switching circuitry may include a switch array, a switch matrix, a multiplexer, or any other type of switching device suitable for selectively coupling treatment energy to the selected electrodes. In other examples, the processing circuitry 80 may select a subset of electrodes 42, 48, 50, 58, 62, and 66 to deliver treatment to the heart 12 without the switching circuitry.

[0058] The processing circuitry 80 may include pacemaker timing and control circuitry, which may be embodied in hardware, firmware, software, or any combination thereof. The pacemaker timing and control circuitry may include dedicated hardware circuitry (such as an ASIC) separate from other components of the processing circuitry 80 (such as a microprocessor), or software modules executed by components of the processing circuitry 80 (e.g., a microprocessor or an ASIC).

[0059] In some examples, the arrhythmia detection method may include any suitable rapid arrhythmia detection algorithm. In one example, the processing circuitry 80 may utilize all or a subset of the rule-based detection methods described in U.S. Patent No. 5,545,182, entitled "PRIORITIZED RULE BASED METHOD AND APPARATUS FOR DIAGNOSIS AND TREATMENT OF ARRHYTHMIAS" by Olson et al., published August 13, 1996, or in U.S. Patent No. 5,755,736, entitled "PRIORITIZED RULE BASED METHOD AND APPARATUS FOR DIAGNOSIS AND TREATMENT OF ARRHYTHMIAS" by Gillberg et al., published May 26, 1998. The entire contents of U.S. Patent No. 5,545,182 to Olson et al. and U.S. Patent No. 5,755,736 to Gillberg et al. are incorporated herein by reference. However, in other examples, the processing circuit 80 may employ other arrhythmia detection methods.

[0060] If IMD 16 is configured to generate a defibrillation shock and deliver it to the heart 12, the treatment delivery circuit 86 may include a high-voltage charging circuit and a high-voltage output circuit. When processing circuit 80 determines that a cardioversion or defibrillation shock needs to be generated, processing circuit 80 may employ an escape interval counter to control the timing of such cardioversion and defibrillation shock and the associated refractory period. In response to the detection of atrial or ventricular fibrillation or rapid arrhythmia requiring a cardioversion pulse, processing circuit 80 may activate a cardioversion / defibrillation control circuit (not shown), which may be a hardware component of processing circuit 80 and / or firmware or software module executed by one or more hardware components of processing circuit 80. The cardioversion / defibrillation control circuit may initiate the charging of the high-voltage capacitor of the high-voltage charging circuit of treatment delivery circuit 86 under the control of the high-voltage charging control line.

[0061] Processing circuit 80 can monitor the voltage on the high-voltage capacitor, for example, via a voltage charge and potential (VCAP) line. In response to the voltage on the high-voltage capacitor reaching a predetermined value set by processing circuit 80, processing circuit 80 can generate a logic signal to terminate charging. Thereafter, the timing of the delivery of defibrillation or cardioversion pulses by treatment delivery circuit 86 is controlled by cardioversion / defibrillation control circuitry (not shown) of processing circuit 80. After delivery of fibrillation or tachycardia treatment, processing circuit 80 can cause treatment delivery circuit 86 to return to cardiac pacing function and wait for the next consecutive interruption due to pacing or sensed atrial or ventricular depolarization.

[0062] The treatment delivery circuit 86 can deliver cardioversion or defibrillation shocks by means of an output circuit that determines whether a monophasic or biphasic pulse is delivered, whether the housing electrode 58 is used as a cathode or an anode, and which electrodes are involved in the delivery of the cardioversion or defibrillation pulse. Such functionality can be provided by one or more switches or switching circuits of the treatment delivery circuit 86.

[0063] Telemetry circuit 88 includes any suitable hardware, firmware, software, or any combination thereof for use with external devices such as 24 ( Figure 1 The telemetry circuit 88 communicates with another device. Under the control of the processing circuit 80, the telemetry circuit 88 can receive downlink telemetry from the external device 24 and send uplink telemetry to the external device via an antenna that can be internal or external. The processing circuit 80 can provide the telemetry circuit within the telemetry circuit 88 with data and control signals to be uplinked to the external device 24, for example, via an address / data bus. In some examples, the telemetry circuit 88 can provide the received data to the processing circuit 80 via a multiplexer.

[0064] In some examples, processing circuitry 80 may transmit atrial and ventricular cardiac signals (e.g., EGM signals) generated by atrial and ventricular sensing amplifier circuitry within sensing circuitry 82 to external device 24. Other types of information may also be transmitted to external device 24, such as indications of meeting far-field activity thresholds and / or adjusting sensitivity thresholds. External device 24 may query IMD 16 to receive cardiac signals. Processing circuitry 80 may store cardiac signals in memory 70 and retrieve stored cardiac signals from memory 70. Processing circuitry 80 may also generate and store tag codes indicating different cardiac episodes detected by sensing circuitry 82 and transmit the tag codes to external device 24. An example pacemaker with tag channel capability is described in Markowitz’s U.S. Patent No. 4,374,382, entitled “MARKER CHANNEL TELEMETRY SYSTEM FOR A MEDICAL DEVICE,” published February 15, 1983, the entire contents of which are incorporated herein by reference.

[0065] Telemetry circuit 88 includes any suitable hardware, firmware, software, or any combination thereof for use with external devices such as 24 ( Figure 1 The telemetry circuit 88 communicates with another device. Under the control of the processing circuit 80, the telemetry circuit 88 can receive downlink telemetry from the external device 24 and send uplink telemetry to the external device via an antenna that can be internal or external. The processing circuit 80 can provide the telemetry circuit within the telemetry circuit 88 with data and control signals to be uplinked to the external device 24, for example, via an address / data bus. In some examples, the telemetry circuit 88 can provide the received data to the processing circuit 80 via a multiplexer.

[0066] The various components of the IMD 16 are coupled to a power source 90, which may include a rechargeable or non-rechargeable battery. The non-rechargeable battery may be selected to last for several years, while the rechargeable battery may be inductively charged from an external device, for example, on a daily or weekly basis.

[0067] Figure 4 This is a functional block diagram of example external device 24. (Example:) Figure 4 As shown, external device 24 includes processing circuitry 100, memory 102, user interface 104, telemetry circuitry 106, and power supply 108. External device 24 may be a dedicated hardware device with dedicated software for interacting with IMD 16. Alternatively, external device 24 may be an off-the-shelf computing device running an application that enables external device 24 to interact with IMD 16.

[0068] Users can use external device 24 to select programmable parameters for controlling monitoring and delivery of treatments performed by IMD 16, and to retrieve information collected by IMD regarding the condition of patient 14 or the performance of IMD 16. Users can interact with external device 24 via user interface 104, which may include a display presenting a graphical user interface to the user, and a keypad or other mechanism for receiving input from the user.

[0069] Processing circuitry 100 may take the form of one or more microprocessors, DSPs, ASICs, FPGAs, programmable logic circuits, etc., and the functions attributed herein to processing circuitry 102 may be embodied in hardware, firmware, software, or any combination thereof. Memory 102 may store instructions that cause processing circuitry 100 to provide the functions attributed herein to external device 24, as well as information used by processing circuitry 100 to provide the functions attributed herein to external device 24. Memory 102 may include any fixed or removable magnetic, optical, or electrical medium, such as RAM, ROM, CD-ROM, hard disk or floppy disk, EEPROM, etc. Memory 102 may also include a removable memory portion that can be used to provide memory updates or increases in memory capacity. Removable memory may also allow patient data to be easily transferred to another computing device or removed before external device 24 is used to program treatment for another patient. Memory 102 may also store information such as stimulation parameter values ​​that control treatment delivery via IMD 16.

[0070] External device 24 can communicate wirelessly with IMD 16, such as using RF communication or proximity sensing interaction. This wireless communication is possible through the use of telemetry circuitry 106, which can be coupled to an internal or external antenna. The external antenna coupled to external device 24 can correspond to a programming head that can be placed on the IMD 12, as referenced above. Figure 1 As stated above.

[0071] Telemetry circuit 106 can be similar to telemetry circuit 88 of IMD 16. Figure 3 Telemetry circuit 106 can also be configured to communicate with another computing device via wireless communication technology or directly via a wired connection. Examples of local wireless communication technologies that can be used to facilitate communication between external device 24 and another computing device include RF communication according to the 802.11 or Bluetooth specification set, and infrared communication according to, for example, the IrDA standard or other standards or proprietary telemetry protocols. In this way, other external devices can be able to communicate with external device 24 without establishing a secure wireless connection.

[0072] Power source 108 is configured to deliver operating power to components of external device 24. Power source 108 may include a battery and power generation circuitry to generate operating power. In some embodiments, the battery may be rechargeable to allow for extended operation. Recharging can be achieved by electrically coupling power source 108 to a bracket or plug connected to an AC outlet. Alternatively, recharging can be accomplished via proximal end inductive interaction between an external charger and an inductive charging coil within external device 24. In other embodiments, conventional batteries (e.g., nickel-cadmium or lithium-ion batteries) may be used. Additionally, external device 24 may be directly coupled to an AC outlet to power external device 24. Power source 108 may include circuitry for monitoring remaining power within the battery. Thus, user interface 104 can provide a current battery level indicator or a low battery level indicator when the battery needs replacement or recharging. In some cases, power source 108 may be able to estimate the remaining operating time using the current battery.

[0073] In some examples, the processing circuitry 100 and memory 102 of external device 24 may be configured to provide some or all of the functions attributable to the processing circuitry 80 and memory 70 of IMD 16. In some examples, the processing circuitry 100 may be configured to generate a time window for the integrated bipolar EGM signal, determine the values ​​of one or more characteristics of the EGM signal during that time window, and adjust the sensitivity threshold for detecting near-field depolarization by IMD 16, as described herein with respect to the processing circuitry 80 of IMD 16.

[0074] Figure 5 To illustrate a block diagram of an example system 110, the system includes an external device 112 such as a server and a device coupled to via a network 120. Figure 1 The IMD 16 and one or more computing devices 114A to 114N of the external device 24 are shown. In this example, the IMD 16 uses telemetry circuitry 88 ( Figure 3 It communicates with external device 24 via a first wireless connection and with access point 122 via a second wireless connection. Figure 5 In the example, access point 122, external device 24, external device 112, and computing devices 114A to 114N are interconnected via network 120 and are able to communicate with each other. In some cases, one or more of access point 122, external device 24, external device 112, and computing devices 114A to 114N may be coupled to network 120 via one or more wireless connections. IMD 16, external device 24, external device 112, and computing devices 114A to 114N may each include one or more processing circuits capable of performing various functions and operations (as described herein), such as one or more microprocessors, DSPs, ASICs, FPGAs, programmable logic circuits, etc.

[0075] Access point 122 may include a device connected to network 120 via any of a variety of connections, such as dial-up, digital subscriber line (DSL), or cable modem connections. In other examples, access point 122 may be coupled to network 120 via different forms of connections, including wired or wireless connections. In some examples, access point 122 may communicate with external device 24 and / or IMD 16. Access point 122 may be located in the same place as patient 14 (e.g., in the same room or location as patient 14) or may be located away from patient 14. For example, access point 122 may be a home monitor located in the patient's home or a portable monitor that is easy for patient 14 to carry.

[0076] During operation, the IMD 16 can collect, measure, and store various forms of diagnostic data. For example, as previously described, the IMD 16 can collect EGM signals, generate a time window for the integrated bipolar EGM signal, determine the values ​​of one or more characteristics of the integrated bipolar EGM signal during that time window, and adjust the sensitivity thresholds used to detect R-waves or other near-field depolarizations. In some cases, the IMD 16 can directly analyze the collected diagnostic data and generate any corresponding reports or alarms. However, in other cases, the IMD 16 can wirelessly or via access point 122 and network 110 transmit diagnostic data to external device 24, access point 122, and / or external device 112 for remote processing and analysis.

[0077] For example, IMD 16 can send data to external device 24 via processing circuit 80. Figure 3 Based on the generated system integrity indication, external device 24 can take further steps to determine whether one or more of leads 18, 20, and 22 may have a potential condition. For example, external device 24 may initiate a lead impedance test, or IMD 16 may provide lead impedance information (if such information is available). In another example, IMD 16 may provide external device 112 with collected EGM data, system integrity indications, and any other relevant physiological or systemic data via access point 122 and network 120. External device 112 includes one or more processing circuits 118. In some cases, external device 112 may request such data, and in other cases, IMD 16 may provide such data to external device 112 automatically or periodically. Upon receiving diagnostic data via input / output device 116, external device 112 is able to analyze the data and generate reports or alarms when it determines that one or more of leads 18, 20, and 22 or the patient 14 may have a potential condition.

[0078] In one example, external device 112 may include a secure storage site for information collected from IMD 16 and / or external device 24. In this example, network 120 may include the Internet; and trained professionals (such as clinicians) may use computing devices 114A to 114N to securely access the data stored on external device 112. For example, a trained professional may need to enter a username and password to access the information stored on external device 112. In one embodiment, external device 112 may be a CareLink server provided by Medtronic, Inc., Minneapolis, Minnesota.

[0079] In some examples, the processing circuitry and memory of one or more of the access point 122, server 112, or computing device 114, such as processing circuitry 118 and the memory of server 112, may be configured to provide some or all of the functions attributed to processing circuitry 80 and memory 70 of IMD 16. In some examples, processing circuitry 118 may be configured to generate a time window for an integrated bipolar EGM signal based on one or more of an intrinsic atrial event or an atrial pacing event, determine the value of one or more features of the EGM signal during that time window, determine that the value of the one or more features of the EGM signal satisfies a far-field activity threshold, and, in response to determining that the value of the one or more features of the EGM signal satisfies the far-field activity threshold, adjust the value of a sensitivity threshold used by processing circuitry 118 to sense depolarization of a desired chamber (e.g., R wave) in the integrated bipolar EGM, for example, adjusting the sensitivity threshold from a first value to a second value. The second value may be higher than the first value, which may make the threshold less sensitive to depolarization.

[0080] Figures 6 to 7 This is a flowchart illustrating various techniques related to adjusting sensitivity thresholds (such as ventricular sensitivity thresholds) according to examples of this disclosure. As described herein, one or more components of system 10 may be used to employ... Figures 6 to 7 The technology shown, the one or more components, have been described above regarding Figures 1 to 5 It has been described. Although it is described as being executed by the processing circuitry 80 of the IMD16, Figures 6 to 7 The technology can be executed, in whole or in part, through the processing circuitry and memory of other devices in the medical device system, as described herein.

[0081] Figure 6 This is a flowchart illustrating an exemplary technique for operating a medical system 10 to adjust a sensitivity threshold for detecting near-field depolarization in an EGM signal sensed by an integrated bipolar lead. Figure 6The example shown is the detection of the R wave via a ventricular integrated bipolar lead, but the example operation in this figure can be applied to other example ventricular and near-field waves. For example... Figure 6 As indicated, processing circuitry 80 may receive at least one of a sensed ventricular integrated bipolar EGM signal and an indication of an identified atrial intrinsic event or an identified atrial pacing event (600). In some examples, ventricular integrated bipolar lead 18 may be configured to sense the ventricular integrated bipolar EGM signal, and atrial lead 22 may be configured to identify an atrial intrinsic event of patient 14 and / or identify an atrial pacing event in patient 14. In some examples, processing circuitry 80 may be configured to receive an indication of an identified atrial pacing event via atrial lead 22 and / or treatment delivery circuitry 86. In some examples, the indication of an identified atrial pacing event may be generated by processing circuitry 80 itself.

[0082] Processing circuit 80 can generate a time window (602) for the integrated bipolar EGM signal based on one or more of the identified atrial intrinsic events or identified atrial pacing events. For example, processing circuit 80 can use an atrial intrinsic event sensed by atrial lead 22 to generate a time window for the integrated bipolar EGM signal sensed by ventricular integrated bipolar lead 18. For example, the time window can begin at a time before the atrial event, such as up to 50 milliseconds (ms) before the identified atrial intrinsic event, and end at a time after the atrial event, such as up to 120 ms after the identified atrial intrinsic event. In some examples, processing circuit 80 can use an identified atrial pacing event to generate a time window for the EGM signal sensed by ventricular integrated bipolar lead 18. For example, processing circuit 80 can generate a time window for the ventricular integrated bipolar EGM signal from the time of the identified atrial pacing event to a time after the atrial pacing event (such as up to 170 ms after the identified atrial pacing event).

[0083] Processing circuitry 80 can determine the values ​​(604) of one or more characteristics of the integrated bipolar EGM signal during a time window. In some examples, the one or more characteristics may include one or more of the following: the amplitude of the P wave of the integrated bipolar EGM signal during the time window, the amplitude of the R wave of the integrated bipolar EGM signal during the time window, the peak-to-peak amplitude of the integrated bipolar EGM signal during the time window, the maximum peak amplitude of the integrated bipolar EGM signal during the time window, the minimum trough amplitude of the integrated bipolar EGM signal during the time window, the maximum amplitude of the rectified version of the integrated bipolar EGM during the time window, and / or the slewing rate of the integrated bipolar EGM signal during the time window. In some examples, the values ​​of the one or more characteristics of the integrated bipolar EGM signal during the time window may correspond to values ​​of atrial far-field activity sensed by the integrated bipolar leads 18, for example, via electrodes 42 and 62.

[0084] Processing circuitry 80 can determine whether the value of one or more characteristics of a window portion of the integrated bipolar EGM signal satisfies a far-field activity threshold (606) (e.g., "yes" or "no"). The far-field activity threshold can be determined based on the current value of a sensitivity threshold. In some examples, the far-field activity threshold can be a P-wave salience threshold. For example, processing circuitry 80 can calculate the far-field activity threshold by applying a factor to the value of the sensitivity threshold (such as the current value of the sensitivity threshold). In some examples, this factor can be between 0.1 and 1.5. In some examples, this factor can be between 0.7 and 0.9. In other examples, the factor can be a different amount than between 0.7 and 0.9. For example, if the factor is 0.75 (e.g., 75% of the sensitivity threshold) and the value of a characteristic of the EGM signal (such as amplitude) is 0.80 of the sensitivity threshold (e.g., 80%), then processing circuitry 80 determines that the value of one or more characteristics (e.g., amplitude) of a window portion of the integrated bipolar EGM signal satisfies far-field activity ("yes" of 606). For example, if the sensitivity threshold factor is 0.75 (e.g., 75% of the sensitivity threshold), and the value of a feature of the integrated bipolar EGM signal (such as the P-wave amplitude) is 0.30 of the sensitivity threshold (e.g., 30%), then the processing circuit 80 determines that the value of one or more features of the integrated bipolar EGM signal (e.g., the P-wave amplitude) does not meet the far-field activity threshold (606 "No").

[0085] In response to the processing circuit 80 determining that the value of one or more features of the window portion of the integrated bipolar EGM signal does not meet the far-field activity threshold, the processing circuit 80 determines to maintain the sensitivity threshold at its current value (607).

[0086] In response to the processing circuit 80 determining that the value of one or more features of the window portion of the integrated bipolar EGM signal meets the far-field activity threshold, the processing circuit 80 adjusts the sensitivity threshold from a first value to a second value (608). In some examples, the second value of the sensitivity threshold is greater than the first value of the sensitivity threshold. For example, if the first value of the sensitivity threshold is set to 0.3, the processing circuit 80 may adjust the sensitivity threshold to a second value of 0.45.

[0087] In some examples, a window portion of the integrated bipolar EGM signal that satisfies a far-field activity threshold may indicate that the ventricular integrated bipolar lead 18 is oversensing atrial far-field activity, such as due to the location or movement of the integrated bipolar lead 18 near the atrium. Sensing atrial far-field activity above a threshold (such as a sensitivity threshold) by the ventricular integrated bipolar lead 18 may lead to atrial oversensing. Atrial oversensing can cause various negative problems, such as overdetection of tachyarrhythmias, suppression of pacing (such as cardiac resynchronization therapy (CRT)), and / or loss of the optimal AV interval for CRT. In some examples, adjusting the sensitivity threshold in response to determining that the value of one or more characteristics of the window portion of the integrated bipolar EGM signal satisfies the far-field activity threshold can prevent or reduce the likelihood of atrial oversensing due to oversensing of far-field activity (such as atrial far-field activity) by the integrated bipolar lead (such as the ventricular integrated bipolar lead 18) in a multi-chamber device, which may reduce overdetection of events such as tachyarrhythmias, CRT suppression, and / or loss of the optimal AV interval for CRT.

[0088] In some examples, generating a time window based on one or more of the atrial intrinsic events or atrial pacing events can focus determined values ​​of one or more features of the integrated bipolar EGM signal during the time period (e.g., the time window) in which atrial cardiac activity occurs. This can help isolate and indicate atrial oversensitization caused by the ventricular integrated bipolar lead 18, such as P-wave oversensitization. In some examples, to avoid increasing the sensitivity threshold too much, there may be a maximum amount of adjustable (e.g., increasing) sensitivity threshold to minimize the risk of undersensitized cardiac events such as tachyarrhythmias.

[0089] Figure 7 This is a flowchart illustrating an exemplary technique for adjusting the sensitivity threshold for detecting near-field depolarization in an EGM signal sensed by a ventricular integrated bipolar lead in a medical system 10. Figure 7 As indicated, processing circuitry 80 may receive an indication (700) of at least one of a sensed ventricular integrated bipolar EGM signal and an indication of an identified atrial intrinsic event or an identified atrial pacing event. In some examples, ventricular integrated bipolar lead 18 may be configured to sense the ventricular integrated bipolar EGM signal, and atrial lead 22 may be configured to identify an atrial intrinsic event of patient 14 and / or an atrial pacing event in patient 14. In some examples, processing circuitry 80 may be configured to receive an indication of an identified atrial pacing event via atrial lead 22 and / or treatment delivery circuitry 86. In some examples, the indication of an identified atrial pacing event may be generated by processing circuitry 80 itself.

[0090] Processing circuitry 80 can generate a time window (702) for the integrated bipolar EGM signal based on one or more of the identified atrial intrinsic events or identified atrial pacing events. For example, the time window may begin at a time before the atrial event, such as up to 50 milliseconds (ms) before the identified atrial intrinsic event, and end at a time after the atrial event, such as up to 120 ms after the identified atrial intrinsic event. In some examples, processing circuitry 80 can generate a time window for the integrated bipolar EGM signal from the time of the identified atrial pacing event to the time after the atrial pacing event (e.g., up to 170 ms after the identified atrial pacing event).

[0091] Processing circuit 80 can determine the values ​​(704) of one or more features of the integrated bipolar EGM signal during a time window. Processing circuit 80 can determine the change in the value of one or more features of the integrated bipolar EGM signal relative to the baseline value of the corresponding feature during this time window (706). For example, processing circuit 80 can compare the value of the one or more features of the integrated bipolar EGM signal with the corresponding baseline value of the one or more features to determine the change in the value of the one or more features of the EGM signal. In some examples, the baseline values ​​of the features of the integrated bipolar EGM signal can be generated shortly after the ventricular integrated bipolar lead 18 and the atrial lead 22 are implanted in the patient. In some examples, the baseline values ​​of the features of the integrated bipolar EGM signal can be predetermined, for example, not necessarily patient-specific fixed values. The baseline values ​​of the features of the integrated bipolar EGM signal can be configured to represent the measurements of those corresponding features when the ventricular integrated bipolar lead 18 senses a minimum amount of atrial far-field activity.

[0092] In some examples, the one or more characteristics may include one or more of the following: the amplitude of the P wave of the integrated bipolar EGM signal during the time window; the amplitude of the R wave of the integrated bipolar EGM signal during the time window; the peak-to-peak amplitude of the integrated bipolar EGM signal during the time window; the maximum peak amplitude of the integrated bipolar EGM signal during the time window; the minimum trough amplitude of the integrated bipolar EGM signal during the time window; the maximum amplitude of the rectified version of the integrated bipolar EGM during the time window; and / or the slew rate of the integrated bipolar EGM signal during the time window. In some examples, the values ​​of the one or more characteristics of the integrated EGM signal during the time window may correspond to values ​​of atrial far-field activity sensed by the integrated bipolar leads 18, for example, via electrodes 42 and 66.

[0093] Processing circuit 80 can determine whether a change in the value of one or more characteristics of a window portion of the integrated bipolar EGM signal satisfies a change threshold, and whether the value of one or more characteristics of the EGM signal satisfies a threshold (708) (e.g., "yes" or "no"). The comparison of the far-field activity threshold and the one or more characteristics of the window portion of the integrated bipolar EGM signal can be made as described above relative to... Figure 6 As stated in 606.

[0094] In some examples, the change threshold can be between 10% and 50% of the baseline value. For example, if the change threshold is 10% of the baseline value, and if the value of a feature of the window portion of the integrated bipolar EGM signal (such as the P-wave amplitude) differs from the baseline value by more than 10% (e.g., the P-wave amplitude is more than 10% larger than the baseline P-wave amplitude), then the change in the value of that one or more features of the EGM signal satisfies the change threshold ("Yes" in 708). For example, if the change threshold is 10% of the baseline value, and if the value of a feature of the window portion of the integrated bipolar EGM signal (such as the P-wave amplitude) differs from the baseline value by less than 10% (e.g., the difference between the P-wave amplitude and the baseline P-wave amplitude is less than 10%), then the change in the value of that one or more features of the window portion of the integrated bipolar EGM signal does not satisfy the change threshold ("No" in 708).

[0095] In response to the processing circuit 80 determining that the value of one or more features of the EGM signal does not meet the far-field activity threshold and / or the change in the value of one or more features of the window portion of the integrated bipolar EGM signal does not meet the change threshold, the processing circuit 80 determines to maintain the sensitivity threshold at its current value (709).

[0096] In response to processing circuit 80 determining that the change in the value of one or more features of a window portion of the integrated bipolar EGM signal satisfies a change threshold and that the value of one or more features of the window portion of the integrated bipolar EGM signal satisfies a far-field activity threshold, processing circuit 80 adjusts the sensitivity threshold from a first value to a second value (710). In some examples, the second value of the sensitivity threshold is greater than the first value of the sensitivity threshold. For example, if the first value of the sensitivity threshold is set to 0.3, processing circuit 80 may adjust the sensitivity threshold to a second value of 0.45. In some examples, a window portion of the integrated bipolar EGM signal that satisfies the far-field activity threshold may indicate that the ventricular integrated bipolar lead 18 is oversensing atrial far-field activity, such as due to the location or movement of the integrated bipolar lead 18 near the atrium. The ventricular integrated bipolar lead 18 sensing atrial far-field activity above a threshold (such as the sensitivity threshold) may lead to atrial oversensing. Atrial oversensing can lead to various negative problems, such as overdetection of tachyarrhythmias, suppression of CRT, and / or loss of the optimal AV interval for CRT. In some examples, adjusting the sensitivity threshold in response to determining that a change in the value of one or more features of a window portion of the integrated bipolar EGM signal satisfies a change threshold and that the value of one or more features of a window portion of the integrated bipolar EGM signal satisfies a far-field activity threshold can prevent or reduce the likelihood of oversensing far-field activity (such as atrial far-field activity) by the integrated bipolar leads. In some examples, to avoid increasing the sensitivity threshold too much, there may be a maximum amount of adjustable (e.g., increasing) sensitivity threshold to minimize the risk of undersensing cardiac events (such as tachyarrhythmias).

[0097] In one or more examples, the functionality described in this disclosure may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functionality may be stored as one or more instructions or code on a computer-readable medium and executed by a hardware-based processing unit. The computer-readable medium may include a computer-readable storage medium forming a tangible, non-transitory medium. The instructions may be executed by one or more processing circuitry, such as one or more DSPs, ASICs, FPGAs, general-purpose microprocessors, or other equivalent integrated or discrete logic circuitry. Therefore, the term "processing circuitry" as used herein may refer to one or more of the foregoing structures or any other structure suitable for implementing the techniques described herein.

[0098] The techniques described in this disclosure can be implemented, at least in part, in hardware, software, firmware, or any combination thereof. For example, aspects of these techniques can be implemented in one or more microprocessors, DSPs, ASICs, FPGAs, or any other equivalent integrated or discrete logic QRS circuits, and any combination of such components embodied in external devices, such as physician or patient programmers, simulators, or other devices. The terms “processor” and “processing circuit” can generally refer to any of the aforementioned logic circuits, alone or in combination with other logic circuits, or any other equivalent circuit, alone or in combination with other digital or analog circuits.

[0099] For each aspect implemented in software, at least some of the functionality of the systems and apparatus described in this disclosure may be embodied in instructions on a computer-readable storage medium, such as RAM, DRAM, SRAM, magnetic disk, optical disk, flash memory, or various forms of EPROM or EEPROM. Executable instructions are provided to support one or more aspects of the functionality described in this disclosure.

[0100] Furthermore, in some aspects, the functionality described herein can be housed within dedicated hardware and / or software modules. Describing different features as modules or units is intended to highlight different functional aspects and does not necessarily imply that such modules or units must be implemented by separate hardware or software components. Rather, the functionality associated with one or more modules or units can be performed by separate hardware or software components, or integrated within common or separate hardware or software components. Additionally, these techniques can be fully implemented in one or more circuit or logic elements. The techniques disclosed herein can be implemented in a variety of devices or apparatuses, including IMDs, external programmers, combinations of IMDs and external programmers, integrated circuits (ICs), or a set of ICs and / or discrete circuits residing in IMDs and / or external programmers.

[0101] The following embodiments can be implemented in various aspects of the technology.

[0102] Example 1: A system comprising: an implantable medical device (IMD) configured to: acquire an integrated bipolar electrogram (EGM) signal of the first chamber sensed via a first lead implanted in a first chamber of a patient's heart; and at least one of: identifying an intrinsic event of the second chamber sensed via a second lead implanted in a second chamber of the patient's heart; or identifying a pacing event of the second chamber sensed via the second lead; and processing circuitry configured to: generate a time window of the integrated bipolar EGM signal of the first chamber based on one or more of the identified intrinsic event or the identified pacing event of the second chamber; determine values ​​of one or more features of the integrated bipolar EGM signal during the time window; determine that the values ​​of the one or more features of the integrated bipolar EGM signal satisfy a far-field activity threshold; and adjust a sensitivity threshold of the IMD from a first value to a second value based on determining that the values ​​of the one or more features of the EGM signal satisfy the far-field activity threshold.

[0103] Example 2: According to the system of Example 1, wherein the processing circuit is further configured to: compare the value of one or more features of the integrated bipolar EGM signal with a corresponding baseline value of the one or more features to determine a change in the value of the one or more features of the integrated bipolar EGM signal; and determine that the change in the value of the one or more features of the integrated bipolar EGM signal satisfies a change threshold, wherein adjusting the sensitivity threshold includes: adjusting the sensitivity threshold based on determining that the change in the value of the one or more features of the integrated bipolar EGM signal satisfies a change threshold and that the value of the one or more features of the integrated bipolar EGM signal satisfies a far-field activity threshold.

[0104] Example 3: The system according to any one of Examples 1 to 2, wherein the first chamber is a ventricle of the heart and the second chamber is an atrium of the heart.

[0105] Example 4: The system according to any one of Examples 1 to 3, wherein the one or more features of the integrated bipolar EGM signal include at least one of the following: the P-wave amplitude of the integrated bipolar EGM signal, the peak-to-peak amplitude of the integrated bipolar EGM signal, the maximum peak amplitude of the integrated bipolar EGM signal, the minimum valley amplitude of the integrated bipolar EGM signal, or the slew rate of the integrated bipolar EGM signal.

[0106] Example 5: According to the system described in Example 4, the one or more features of the EGM signal include the P-wave amplitude of the integrated bipolar EGM signal.

[0107] Example 6: The system according to any one of Examples 1 to 5, wherein the value of one or more features of the integrated bipolar EGM signal corresponds to the value of far-field activity of the second chamber sensed via the first lead in the first chamber.

[0108] Example 7: The system according to any one of Examples 1 to 6, wherein the far-field activity threshold is based on the first value of the sensitivity threshold.

[0109] Example 8: The system according to Example 7, wherein the far-field activity threshold is based on the first value of applying a factor to the sensitivity threshold.

[0110] Example 9: The system according to Example 8, wherein the factor is between 0.7 and 0.9.

[0111] Example 10: The system according to any one of Examples 1 to 9, wherein the second value of the sensitivity threshold is greater than the first value of the sensitivity threshold.

[0112] Example 11: The system according to Example 10, wherein the second value of the sensitivity threshold is at least 50% greater than the first value of the sensitivity threshold.

[0113] Example 12: The system according to any one of Examples 1 to 11, wherein the processing circuit is configured to generate the time window of the integrated bipolar EGM signal based on the inherent event.

[0114] Example 13: The system according to Example 12, wherein the time window begins before the inherent event and ends after the inherent event, wherein the time before the inherent event is before the inherent event and the time after the inherent event is after the inherent event.

[0115] Example 14: According to the system described in Example 13, the inherent event pre-time is up to 50 milliseconds before the inherent event, and the inherent event post-time is up to 120 milliseconds after the inherent event.

[0116] Example 15: The system according to any one of Examples 1 to 11, wherein the processing circuit is configured to generate the time window of the integrated bipolar EGM signal based on the pacing event.

[0117] Example 16: The system according to Example 15, wherein the time window begins at the time of the pacing event and ends at a predetermined time after the pacing event.

[0118] Example 17: The system according to Example 16, wherein the predetermined time is as long as 170 milliseconds.

[0119] Example 18: The system according to any one of Examples 1 to 17, the system further comprising: a first lead configured to be implanted in a first chamber of the heart; and a second lead configured to be implanted in a second chamber of the heart.

[0120] Example 19: The system according to any one of Examples 1 to 18, wherein the first lead is an integrated bipolar lead, the integrated bipolar lead comprising two electrodes configured to serve as an anode and a cathode of a sensing bipolar, respectively.

[0121] Example 20: An implantable medical device comprising: a sensing circuit configured to: acquire an integrated bipolar electrogrammage (EGM) signal of the first chamber sensed via a first lead implanted in a patient's heart, wherein the first lead includes an integrated bipolar lead; and identify an intrinsic event of the second chamber sensed via a second lead implanted in the second chamber of the heart; a treatment delivery circuit configured to perform a pacing event on the second chamber of the heart via the second lead; and a processing circuit configured to: generate a time window of the integrated bipolar EGM signal of the first chamber based on one or more of the identified intrinsic event or the identified pacing event of the second chamber; determine values ​​of one or more features of the integrated bipolar EGM signal during the time window; determine that the values ​​of the one or more features of the integrated bipolar EGM signal satisfy a far-field activity threshold; and adjust a sensitivity threshold of the sensing circuit from a first value to a second value based on determining that the values ​​of the one or more features of the EGM signal satisfy the far-field activity threshold.

[0122] Example 21: The implantable medical device according to Example 20, wherein the processing circuit is further configured to: compare the value of one or more features of the integrated bipolar EGM signal with a corresponding baseline value of the one or more features to determine a change in the value of the one or more features of the integrated bipolar EGM signal; and determine that the change in the value of the one or more features of the integrated bipolar EGM signal satisfies a change threshold, wherein adjusting the sensitivity threshold includes: adjusting the sensitivity threshold based on determining that the change in the value of the one or more features of the integrated bipolar EGM signal satisfies a change threshold and that the value of the one or more features of the integrated bipolar EGM signal satisfies a far-field activity threshold.

[0123] Example 22: An implantable medical device according to any one of Examples 20 to 21, wherein the first chamber is a ventricle of the heart and the second chamber is an atrium of the heart.

[0124] Example 23: An implantable medical device according to any one of Examples 20 to 22, wherein the one or more features of the integrated bipolar EGM signal include at least one of the following: the P-wave amplitude of the integrated bipolar EGM signal, the peak-to-peak amplitude of the integrated bipolar EGM signal, the maximum peak amplitude of the integrated bipolar EGM signal, the minimum trough amplitude of the integrated bipolar EGM signal, or the slew rate of the integrated bipolar EGM signal.

[0125] Example 24: The implantable medical device according to Example 23, wherein one or more features of the EGM signal include the P-wave amplitude of the integrated bipolar EGM signal.

[0126] Example 25: An implantable medical device according to any one of Examples 20 to 24, wherein the value of one or more features of the integrated bipolar EGM signal corresponds to the value of far-field activity of the second chamber sensed via the first lead in the first chamber.

[0127] Example 26: An implantable medical device according to any one of Examples 20 to 25, wherein the far-field activity threshold is based on the first value of the sensitivity threshold.

[0128] Example 27: An implantable medical device according to Example 26, wherein the far-field activity threshold is based on the first value of applying a factor to the sensitivity threshold.

[0129] Example 28: The implantable medical device according to Example 27, wherein the factor is between 0.7 and 0.9.

[0130] Example 29: An implantable medical device according to any one of Examples 20 to 28, wherein the second value of the sensitivity threshold is greater than the first value of the sensitivity threshold.

[0131] Example 30: The implantable medical device according to Example 29, wherein the second value of the sensitivity threshold is at least 50% greater than the first value of the sensitivity threshold.

[0132] Example 31: An implantable medical device according to any one of Examples 20 to 30, wherein the processing circuitry is configured to generate the time window of the integrated bipolar EGM signal based on the inherent event.

[0133] Example 32: The implantable medical device according to Example 31, wherein the time window begins before the inherent event and ends after the inherent event, wherein the time before the inherent event is before the inherent event and the time after the inherent event is after the inherent event.

[0134] Example 33: The implantable medical device according to Example 32, wherein the pre-inherent event time is up to 50 milliseconds before the inherent event and the post-inherent event time is up to 120 milliseconds after the inherent event.

[0135] Example 34: An implantable medical device according to any one of Examples 20 to 30, wherein the processing circuit is configured to generate the time window of the integrated bipolar EGM signal based on the pacing event.

[0136] Example 35: An implantable medical device according to Example 34, wherein the time window begins at the time of the pacing event and ends at a predetermined time after the pacing event.

[0137] Example 36: The implantable medical device according to Example 35, wherein the predetermined time is up to 170 milliseconds.

[0138] Example 37: An implantable medical device according to any one of Examples 20 to 36, the implantable medical device further comprising: a first lead wire configured to be implanted in a first chamber of the heart; and a second lead wire configured to be implanted in a second chamber of the heart.

[0139] Example 38: An implantable medical device according to any one of Examples 20 to 36, wherein the first lead is an integrated bipolar lead, the integrated bipolar lead comprising two electrodes configured to serve as an anode and a cathode, respectively, for sensing bipolarity.

[0140] Example 39: A method comprising: receiving an integrated bipolar electrogrammage (EGM) signal of the first chamber sensed via a first lead implanted in a first chamber of a patient's heart; receiving at least one of an identified intrinsic event of the second chamber sensed via a second lead implanted in a second chamber of the patient's heart or an identified pacing event of the second chamber sensed via the second lead; generating a time window of the integrated bipolar EGM signal of the first chamber based on one or more of the identified intrinsic event of the second chamber or the identified pacing event; determining a value of one or more features of the integrated bipolar EGM signal during the time window; determining that the value of the one or more features of the integrated bipolar EGM signal satisfies a far-field activity threshold; and adjusting a sensitivity threshold of an implantable medical device from a first value to a second value in response to determining that the value of the one or more features of the EGM signal satisfies the far-field activity threshold.

[0141] Example 40: According to the method of Example 39, the method further includes: comparing the value of one or more features of the integrated bipolar EGM signal with a corresponding baseline value of the one or more features to determine a change in the value of the one or more features of the integrated bipolar EGM signal; and determining that the change in the value of the one or more features of the integrated bipolar EGM signal satisfies a change threshold, wherein adjusting the sensitivity threshold includes: adjusting the sensitivity threshold based on determining that the change in the value of the one or more features of the integrated bipolar EGM signal satisfies a change threshold and that the value of the one or more features of the integrated bipolar EGM signal satisfies a far-field activity threshold.

[0142] Example 41: The method according to any one of Examples 39 to 40, wherein the first chamber is a ventricle of the heart and the second chamber is an atrium of the heart.

[0143] Example 42: According to any one of Examples 39 to 41, the one or more features of the integrated bipolar EGM signal include at least one of the following: the P-wave amplitude of the integrated bipolar EGM signal, the peak-to-peak amplitude of the integrated bipolar EGM signal, the maximum peak amplitude of the integrated bipolar EGM signal, the minimum valley amplitude of the integrated bipolar EGM signal, or the slew rate of the integrated bipolar EGM signal.

[0144] Example 43: According to the method of Example 42, the one or more features of the EGM signal include the P-wave amplitude of the integrated bipolar EGM signal.

[0145] Example 44: The method according to any one of Examples 39 to 43, wherein the value of one or more features of the integrated bipolar EGM signal corresponds to the value of far-field activity of the second chamber sensed via the first lead in the first chamber.

[0146] Example 45: The method according to any one of Examples 39 to 44, wherein the far-field activity threshold is based on the first value of the sensitivity threshold.

[0147] Example 46: The method according to Example 45, wherein the far-field activity threshold is based on the first value of applying a factor to the sensitivity threshold.

[0148] Example 47: The method according to Example 46, wherein the factor is between 0.7 and 0.9.

[0149] Example 48: The method according to any one of Examples 39 to 47, wherein the second value of the sensitivity threshold is greater than the first value of the sensitivity threshold.

[0150] Example 49: According to the method of Example 48, the second value of the sensitivity threshold is up to 50% greater than the first value of the sensitivity threshold.

[0151] Example 50: The method according to any one of Examples 39 to 49, the method further comprising generating the time window of the integrated bipolar EGM signal based on the inherent event.

[0152] Example 51: According to the method of Example 50, the time window begins before the inherent event and ends after the inherent event, wherein the time before the inherent event is before the inherent event and the time after the inherent event is after the inherent event.

[0153] Example 52: According to the method of Example 51, the inherent event pre-time is up to 50 milliseconds before the inherent event, and the inherent event post-time is up to 120 milliseconds after the inherent event.

[0154] Example 53: The method according to any one of Examples 39 to 49, the method further comprising generating the time window of the integrated bipolar EGM signal based on the pacing event.

[0155] Example 54: According to the method of Example 53, wherein the time window begins at the time of the pacing event and ends at a predetermined time after the pacing event.

[0156] Example 55: The method according to Example 54, wherein the predetermined time is as long as 170 milliseconds.

[0157] Example 56: The method according to any one of Examples 39 to 55, wherein the first lead is an integrated bipolar lead, the integrated bipolar lead comprising two electrodes configured to serve as an anode and a cathode of a sensing bipolar, respectively.

[0158] Example 57: A non-transitory computer-readable storage medium storing instructions that, when executed, cause processing circuitry to: receive an integrated bipolar electrogrammage (EGM) signal of the first chamber sensed via a first lead implanted in a patient's heart; receive at least one of an identified intrinsic event of the second chamber sensed via a second lead implanted in the patient's heart or an identified pacing event of the second chamber sensed via the second lead; generate a time window for the integrated bipolar EGM signal of the first chamber based on one or more of the identified intrinsic event or the identified pacing event of the second chamber; determine a value of one or more features of the integrated bipolar EGM signal during the time window; determine that the value of the one or more features of the integrated bipolar EGM signal satisfies a far-field activity threshold; and adjust a sensitivity threshold of an implantable medical device from a first value to a second value in response to determining that the value of the one or more features of the EGM signal satisfies the far-field activity threshold.

[0159] Example 58: The storage medium according to Example 57, wherein the processing circuitry further comprises: comparing the value of one or more features of the integrated bipolar EGM signal with a corresponding baseline value of the one or more features to determine a change in the value of the one or more features of the integrated bipolar EGM signal; and determining that the change in the value of the one or more features of the integrated bipolar EGM signal satisfies a change threshold, wherein adjusting the sensitivity threshold from the first value to the second value includes adjusting the sensitivity threshold based on determining that the change in the value of the one or more features of the integrated bipolar EGM signal satisfies a change threshold and that the value of the one or more features of the integrated bipolar EGM signal satisfies a far-field activity threshold.

[0160] Example 59: The storage medium according to any one of Examples 57 to 58, wherein the first chamber is a ventricle of the heart and the second chamber is an atrium of the heart.

[0161] Example 60: The storage medium according to any one of Examples 57 to 59, wherein the one or more features of the integrated bipolar EGM signal include at least one of the following: the P-wave amplitude of the integrated bipolar EGM signal, the peak-to-peak amplitude of the integrated bipolar EGM signal, the maximum peak amplitude of the integrated bipolar EGM signal, the minimum valley amplitude of the integrated bipolar EGM signal, or the slew rate of the integrated bipolar EGM signal.

[0162] Example 61: The storage medium according to Example 60, wherein one or more features of the EGM signal include the P-wave amplitude of the integrated bipolar EGM signal.

[0163] Example 62: A storage medium according to any one of Examples 57 to 61, wherein the value of one or more features of the integrated bipolar EGM signal corresponds to the value of far-field activity of the second chamber sensed via the first lead in the first chamber.

[0164] Example 63: A storage medium according to any one of Examples 57 to 62, wherein the far-field activity threshold is based on the first value of the sensitivity threshold.

[0165] Example 64: The storage medium according to Example 63, wherein the far-field activity threshold is based on the first value of applying a factor to the sensitivity threshold.

[0166] Example 65: The storage medium according to Example 64, wherein the factor is between 0.7 and 0.9.

[0167] Example 66: A storage medium according to any one of Examples 57 to 65, wherein the second value of the sensitivity threshold is greater than the first value of the sensitivity threshold.

[0168] Example 67: The storage medium according to Example 66, wherein the second value of the sensitivity threshold is up to 50% greater than the first value of the sensitivity threshold.

[0169] Example 68: A storage medium according to any one of Examples 57 to 67, wherein the processing circuitry further generates the time window of the integrated bipolar EGM signal based on the inherent event.

[0170] Example 69: The storage medium according to Example 68, wherein the time window begins before the inherent event and ends after the inherent event, wherein the time before the inherent event is before the inherent event and the time after the inherent event is after the inherent event.

[0171] Example 70: The storage medium according to Example 69, wherein the inherent event pre-time is up to 50 milliseconds before the inherent event and the inherent event post-time is up to 120 milliseconds after the inherent event.

[0172] Example 71: The storage medium according to any one of Examples 57 to 67, wherein the processing circuitry further generates the time window of the integrated bipolar EGM signal based on the pacing event.

[0173] Example 72: The storage medium according to Example 71, wherein the time window begins at the time of the pacing event and ends at a predetermined time after the pacing event.

[0174] Example 73: The storage medium according to Example 72, wherein the predetermined time is as long as 170 milliseconds.

[0175] Example 74: A storage medium according to any one of Examples 57 to 73, wherein the first lead is an integrated bipolar lead, the integrated bipolar lead comprising two electrodes configured to serve as an anode and a cathode, respectively, for sensing bipolarity.

[0176] Various embodiments have been described. These and other embodiments are within the scope of the appended claims.

Claims

1. A system comprising: an implantable medical device (IMD) configured to: obtain an integrated bipolar electrogram (EGM) signal of a first chamber of a heart of a patient sensed via a first lead implanted in the first chamber; and at least one of: identify an intrinsic event of a second chamber of the heart of the patient sensed via a second lead implanted in the second chamber; or identify a paced event of the second chamber sensed via the second lead; processing circuitry configured to: generate a time window of the integrated bipolar EGM signal of the first chamber based on one or more of the identified intrinsic events or the identified paced events of the second chamber; determine a value of one or more features of the integrated bipolar EGM signal during the time window; determine that the value of the one or more features of the integrated bipolar EGM signal satisfies a far-field activity threshold; and based on determining that the value of the one or more features of the EGM signal satisfies the far-field activity threshold, adjust a sensitivity threshold of the IMD from a first value to a second value.

2. The system of claim 1, wherein the processing circuitry is further configured to: compare the value of the one or more features of the integrated bipolar EGM signal to a respective baseline value of the one or more features to determine a change in the value of the one or more features of the integrated bipolar EGM signal; and determine that the change in the value of the one or more features of the integrated bipolar EGM signal satisfies a change threshold, wherein adjusting the sensitivity threshold comprises: adjust the sensitivity threshold based on determining that the change in the value of the one or more features of the integrated bipolar EGM signal satisfies a change threshold and the value of the one or more features of the integrated bipolar EGM signal satisfies the far-field activity threshold.

3. The system of any of embodiments 1-2, wherein the first chamber is a ventricle of the heart and the second chamber is an atrium of the heart.

4. The system of any of claims 1-3, wherein the one or more features of the integrated bipolar EGM signal comprise at least one of a P-wave amplitude of the integrated bipolar EGM signal, a peak-to-peak amplitude of the integrated bipolar EGM signal, a maximum peak amplitude of the integrated bipolar EGM signal, a minimum trough amplitude of the integrated bipolar EGM signal, or a slew rate of the integrated bipolar EGM signal.

5. The system of any of claims 1-4, wherein the value of the one or more features of the integrated bipolar EGM signal corresponds to a value of far-field activity of the second chamber sensed via the first lead in the first chamber.

6. The system of any of claims 1-5, wherein the far-field activity threshold is based on the first value of the sensitivity threshold.

7. The system of any of claims 1-6, wherein the second value of the sensitivity threshold is greater than the first value of the sensitivity threshold.

8. The system according to any one of claims 1 to 7, wherein the processing circuitry is configured to generate the time window of the integrated bipolar EGM signal based on the inherent event.

9. The system according to any one of claims 1 to 7, wherein the processing circuitry is configured to generate the time window of the integrated bipolar EGM signal based on the pacing event.

10. The system according to any one of claims 1 to 9, further comprising: The first lead is configured to be implanted in the first chamber of the heart; and The second lead is configured to be implanted in the second chamber of the heart.

11. An implantable medical device, the implantable medical device comprising: The sensing circuit is configured to: An integrated bipolar electrogram (EGM) signal of the first chamber is obtained via a first lead implanted in the first chamber of the patient's heart, wherein the first lead includes an integrated bipolar lead; as well as Identify inherent events of the second chamber sensed via a second lead implanted in the second chamber of the heart; A treatment delivery circuit configured to perform a pacing event in the second chamber of the heart via the second lead; and Processing circuit, the processing circuit being configured to: The time window for generating the integrated bipolar EGM signal of the first chamber is based on one or more of the identified intrinsic events of the second chamber or the pacing events. Determine the values ​​of one or more characteristics of the integrated bipolar EGM signal during the time window; The value of one or more features of the integrated bipolar EGM signal is determined to satisfy a far-field activity threshold; as well as Based on the determination that the value of one or more features of the EGM signal satisfies the far-field activity threshold, the sensitivity threshold of the sensing circuit is adjusted from a first value to a second value.

12. The implantable medical device of claim 11, wherein the processing circuit is further configured to: The values ​​of one or more features of the integrated bipolar EGM signal are compared with corresponding baseline values ​​of the one or more features to determine the changes in the values ​​of the one or more features of the integrated bipolar EGM signal; and Determine that the change in the value of one or more features of the integrated bipolar EGM signal satisfies a change threshold. wherein adjusting the sensitivity threshold comprises: The sensitivity threshold is adjusted based on determining that the changes in the values ​​of one or more features of the integrated bipolar EGM signal satisfy a change threshold and that the values ​​of one or more features of the integrated bipolar EGM signal satisfy a far-field activity threshold.

13. The implantable medical device according to any one of claims 11 to 12, wherein the value of one or more features of the integrated bipolar EGM signal corresponds to the value of far-field activity of the second chamber sensed via the first lead in the first chamber.

14. The implantable medical device according to any one of claims 11 to 13, wherein the processing circuitry is configured to generate the time window of the integrated bipolar EGM signal based on the inherent event.

15. The implantable medical device according to any one of claims 11 to 13, wherein the processing circuitry is configured to generate the time window of the integrated bipolar EGM signal based on the pacing event.

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