Medical device system and method for determining bundle of his pacing capture

Abstract

In a medical device system, a computer is configured to receive surface electrical signals from an electrode device comprising multiple external electrodes. The computer generates electrical asynchrony data from the surface electrical signals during the delivery of His bundle pacing pulses and identifies valid His bundle captures based on the electrical asynchrony data. The computer generates an indication of His bundle capture in response to the identification of a valid His bundle capture.

Description

Technical Field

[0001] This disclosure relates to medical device systems and methods for determining His bundle capture and establishing His bundle capture detection thresholds. Background Technology

[0002] During normal sinus rhythm (NSR), the heartbeat is regulated by electrical signals generated by the sinoatrial (SA) node located in the wall of the right atrium. Each atrial depolarization signal generated by the SA node propagates through the atrium, causing atrial depolarization and contraction, and reaches the atrioventricular (AV) node. The AV node responds by propagating the ventricular depolarization signal through the His bundle of the interventricular septum, and subsequently to the bundle branches of the right and left ventricles and Purkinje muscle fibers.

[0003] Patients with conduction system abnormalities, such as poor AV junction conduction or SA junction dysfunction, may receive pacemakers to restore a more normal heart rhythm and AV synchrony. Ventricular pacing can be performed to maintain the ventricular rate in patients with atrioventricular conduction abnormalities. A univentricular pacemaker can be coupled to a transvenous ventricular lead carrying an electrode placed in the right ventricle, such as at the apex of the right ventricle. The pacemaker itself is typically implanted in a subcutaneous pouch, with the transvenous ventricular lead tunneling into the pouch.

[0004] A dual-chamber pacemaker is available, comprising a transvenous atrial lead carrying an electrode placed in the right atrium and a transvenous ventricular lead carrying an electrode placed in the right ventricle via the right atrium. The dual-chamber pacemaker senses both atrial and ventricular electrical signals and can provide both atrial and ventricular pacing as needed to promote normal atrial and ventricular rhythms and to promote AV synchrony in the presence of AV junctions or other conduction abnormalities.

[0005] Ventricular pacing at the right ventricular apex using a standard transvenous lead to position an endocardial electrode near the right ventricular apex has been found to be associated with an increased risk of atrial fibrillation and heart failure. Alternative pacing sites, such as His bundle pacing, have been investigated or proposed. His bundle cardiac pacing has been proposed to provide ventricular pacing along the heart's natural conduction system in patients with conduction defects above the His bundle (e.g., AV block). Ventricular pacing via the His bundle allows cardioversion along the heart's natural conduction system (including Purkinje fibers) and is hypothesized to promote physiologically more normal electromechanical synchrony than other pacing sites, such as the ventricular apex. Summary of the Invention

[0006] The techniques disclosed herein generally relate to establishing a His bundle capture detection threshold for detecting His bundle capture during cardiac pacing, for example, via an implantable pacemaker configured as a His bundle pacing device. A medical device system comprising electrode devices for sensing surface cardiac electrical signals and a computing device for receiving the cardiac electrical signals is configured to determine at least one metric of electrical asynchrony of ventricular depolarization during His bundle pacing. The evaluation of electrical asynchrony by the computing device is used to verify effective His bundle capture based on a relatively low metric of electrical asynchrony, indicating capture and conduction along the intrinsic ventricular conduction system (including both the right and left bundle branches). The His bundle pacing device is configured to deliver His bundle pacing pulses and sense cardiac electrical signals to determine the characteristics of the QRS waveform of the cardiac electrical signals received by the His bundle pacing device. When effective His bundle capture is verified by the computing device based on a metric of ventricular asynchrony, the His bundle pacing device establishes a His bundle capture detection threshold based on the value of the determined QRS waveform characteristics. The His bundle pacing device operating according to the technology disclosed herein delivers His bundle pacing and monitors His bundle capture by determining the characteristics of the QRS waveform of the cardiac electrical signal and comparing said characteristics with an established His bundle capture detection threshold. The His bundle pacing device can adjust cardiac pacing control parameters based on capture monitoring to maintain His bundle capture.

[0007] In one example, this disclosure provides a medical device system including an electrode device having a plurality of external electrodes and a computing device coupled to the electrode device, the external electrodes being configured to monitor electrical signals on a patient's body surface. The computing device includes a processing circuitry system and is configured to generate cardiac electrical asynchrony data based on the body surface electrical signals received from the external electrodes during the delivery of His bundle pacing pulses, and to identify valid capture asynchrony data via the His bundle pacing pulses based on the electrical asynchrony data. Valid His bundle capture includes capture of both the left and right branches of the His bundle. The computing device is also configured to generate an indication of His bundle capture in response to the identification of valid His bundle capture.

[0008] In another example, this disclosure provides a method performed by a medical device system. The method includes receiving surface electrical signals from an electrode device having multiple external electrodes by a computing device, generating electrical asynchrony data by the computing device during the delivery of His bundle pacing pulses, and identifying a valid His bundle capture based on the electrical asynchrony data. The method also includes generating an indication of His bundle capture by the computing device in response to identifying a valid His bundle capture.

[0009] In yet another example, this disclosure provides a non-transitory computer-readable storage medium comprising a set of instructions, when executed by a processor of a computing device, to cause the computing device to receive surface electrical signals from an electrode device having a plurality of external electrodes, to generate electrical asynchrony data based on the surface electrical signals received from the external electrodes during the delivery of His bundle pacing pulses, and to identify a valid His bundle capture based on the electrical asynchrony data. These instructions also cause the computing device to generate an indication of His bundle capture in response to the identification of a valid His bundle capture.

[0010] Details of one or more aspects of this disclosure are set forth in the accompanying drawings and the following description. Other features, objects, and advantages described in this disclosure will become apparent from the description and drawings and from the claims. Attached Figure Description

[0011] Figure 1 This is a conceptual diagram of a medical device system that includes a His bundle pacing device capable of pacing and sensing in a patient's heart.

[0012] Figure 2 This is a conceptual diagram of a leadless intracardiac pacemaker configured as a His bundle pacing device.

[0013] Figure 3 This is a schematic diagram of a circuit system that can be encapsulated within a His bundle pacing device configured to perform His bundle pacing and capture detection, based on an example.

[0014] Figure 4 This is a conceptual diagram of a medical device system that includes a computer device for generating electrical activation information of the patient's heart during His bundle pacing via the His bundle pacing device.

[0015] Figure 5 It is based on another example Figure 4 A conceptual diagram of the electrode device.

[0016] Figure 6 This is based on an example of pacing during His bundle stimulation. Figure 4 A flowchart of a method for identifying His bundle capture using computing devices.

[0017] Figure 7 Depicting according to from Figure 4 or Figure 5 A method for determining the electrical activation time by receiving at least one QRS waveform of a given surface potential signal from the electrodes of an electrode device.

[0018] Figure 8 It is based on an example. Figure 4 The flowchart illustrates the method for establishing a capture detection threshold, executed collaboratively by the system and the His bundle pacing device.

[0019] Figure 9 This is a diagram of cardiac electrical signals that can be generated by a His bundle pacemaker.

[0020] Figure 10 This is a flowchart of an example method for monitoring and maintaining His bundle capture by delivering a His bundle pacing device for His bundle pacing therapy. Detailed Implementation

[0021] This article describes a medical device system for delivering His bundle pacing and for detecting and monitoring His bundle capture. Cardiac tissue is “captured” when an electrical pacing pulse delivers sufficient electrical energy to induce depolarization. This depolarization of cardiac tissue is sometimes referred to as an electrically “evoked response,” followed by mechanical contraction of one or more ventricles. For the heart to be effectively captured and paced to achieve the desired therapeutic effect, the cardiac pacing pulse needs to have a pulse energy equal to or greater than the capture threshold of the cardiac tissue at the pacing site. A pacing capture threshold test can be performed to determine the minimum pacing pulse voltage amplitude for a given pacing pulse width (or the minimum pulse width for a given voltage amplitude) that induces an evoked response. Determining the pacing capture threshold allows for appropriate programming of the pacing pulse amplitude and pulse width to promote effective pacing and avoid capture loss. Capture monitoring by the pacemaker during continuous pacing allows for automatic adjustment of the pacing pulse amplitude and / or width to maintain capture when capture loss is detected.

[0022] Effective His bundle capture occurs when the His bundle is captured and induces depolarization, which is conducted via the bundle branching system to both the right and left ventricles, thereby increasing the electrical synchronicity of the two ventricles. Increased electrical synchronicity (or decreased electrical asynchrony) between the right and left ventricles is evidenced by a narrowing or relative narrowing of the QRS waveform width of the cardiac electrical signal. Effective His bundle capture can occur when ventricular myocardial tissue near the His bundle pacing electrode is captured or not captured. Ineffective His bundle capture occurs when His bundle capture is not achieved or when the His bundle is partially captured, causing conduction along only a portion of the bundle branching system, such as only along the right bundle branch or only along the left bundle branch. Ineffective His bundle capture is evidenced by a wide QRS waveform and can occur with or without capture of nearby ventricular myocardial tissue. In some cases, complete capture loss occurs when the His bundle pacing pulse output is less than both the His bundle capture threshold and the myocardial capture threshold, or when the intrinsic R wave conducts earlier than the His bundle pacing pulse.

[0023] When pacing pulses are delivered from electrodes located in the heart to pace the His bundle, it is possible to capture only the His bundle tissue, capture both the His bundle and the surrounding ventricular myocardium, or capture the surrounding ventricular myocardium without capturing the His bundle. Capturing only the His bundle is referred to as “selective” His bundle (SHB) capture. Capturing both the His bundle and the surrounding ventricular myocardium is referred to as “non-selective” His bundle (NSHB) capture. Both SHB and NSHB captures can be effective His bundle captures because conduction along both the right and left bundle branches can lead to increased electrical synchronicity, as demonstrated by a narrow QRS waveform width. A narrow QRS waveform width is a QRS width that is smaller than a predefined threshold and / or smaller than a previously determined QRS waveform width when His bundle pacing is not delivered. When His bundle pacing is not delivered, the QRS waveform may appear alongside the inherently conducted R wave or ventricular myocardial pacing. In both cases, the QRS waveform is expected to be wider than during effective His bundle pacing.

[0024] Capturing peripheral ventricular myocardium without capturing the His bundle is referred to herein as ventricular myocardial (VM) capture and is considered an ineffective His bundle capture. In other cases, His bundle pacing is ineffective when only the right bundle branch is captured, only the left bundle branch is captured, or atrial capture occurs instead of the His bundle. Sometimes, fusion may occur when the His bundle pacing pulse captures the His bundle and inherent depolarization occurs simultaneously. These different types of effective and ineffective His bundle captures can cause one or more characteristics of the QRS waveform of the cardiac electrical signal sensed by the His bundle pacing device to change. Therefore, a capture detection threshold, as sensed by the His bundle pacing device, is established to distinguish between effective and ineffective His bundle captures, enabling the His bundle pacing device to reliably detect effective His bundle captures and provide an appropriate response when no effective His bundle capture is detected, for example, to adjust the His bundle pacing therapy.

[0025] This document discloses an apparatus and technique for establishing a patient-specific capture detection threshold for the characteristics of a QRS waveform applied by a His bundle pacing device, which allows for highly deterministic and reliable detection of effective His bundle capture. Reliable detection of effective His bundle capture enables the His bundle pacing device to adjust the pacing pulse output to maintain effective His bundle capture, thereby improving the therapeutic effect of His bundle pacing. Reliable detection of effective His bundle capture allows the pacemaker to adjust the pacing pulse amplitude to a safety margin greater than the His bundle pacing capture threshold, while avoiding unnecessarily high pulse outputs that increase the current consumption of the pacemaker power supply. Note that, as used herein, "His bundle pacing capture threshold" refers to the pacing pulse output or energy, such as the pacing pulse voltage amplitude and pacing pulse width, i.e., the minimum pacing pulse output required to capture the His bundle. On the other hand, "His bundle capture detection threshold" is a value of cardiac electrical signal characteristics (e.g., QRS waveform characteristics, such as the QRS waveform width, QRS waveform area, or QRS waveform delay time following the His pacing pulse) that corresponds to effective capture of the His bundle by the pacing pulse.

[0026] Figure 1 This is a conceptual diagram of an implantable medical device (IMD) system 10 capable of pacing and sensing in a patient's heart 8. The IMD system 10 includes an IMD 14 connected to the patient's heart 8 via transvenous leads 16, 17, and 18. The IMD 14 is configured for His bundle pacing and is also referred to herein as a "His bundle pacing device." Figure 1 In the example, IMD 14 is a dual-chamber device capable of pacing both the right atrium (RA) and the ventricle via the His bundle. Housing 15 encapsulates and is coupled below. Figure 3 The various circuits and components described correspond to an internal circuit system for sensing cardiac signals from the heart 8, detecting arrhythmias, controlling therapy delivery, and monitoring His bundle capture using the techniques disclosed herein.

[0027] The IMD 14 includes a connector block 12, which can be configured to receive the proximal ends of an RA lead 16, an optional right ventricular (RV) lead 17, and a His pacing lead 18, all of which are venously advanced to position electrodes for sensing and stimulation, respectively, near the RA, RV, and His bundle. The RA lead 16 is positioned such that its distal end is near the right atrium and superior vena cava. The RA lead 16 is equipped with pacing and sensing electrodes 20 and 22, shown as a tip electrode 20 and a ring electrode 22 spaced proximally from the tip electrode 20. Electrodes 20 and 22 provide sensing and pacing in the right atrium and are each connected to a corresponding insulated conductor extending within the elongated body of the RA lead 16. Each insulated conductor is coupled at its proximal end to a connector carried by a proximal lead connector 40.

[0028] The His lead 18 is advanced within the right atrium to position electrodes 32 and 34 near the His bundle for pacing and sensing. The His lead tip electrode 32, which may be a helical electrode, is advanced to the lower end of the interatrial septum, below the AV node, and near the tricuspid annulus to position the tip electrode 32 within or near the His bundle. A loop electrode 34, proximal to the tip electrode 32, serves as a return electrode, together with the cathode tip electrode 32, for pacing the right and left ventricles via the natural ventricular conduction system extending from the His bundle. An intracardiac electrocardiogram (EGM) signal can be generated by the IMD 14 based on cardiac electrical signals sensed using the tip electrode 32 and loop electrode 34 using the His lead 18, and received by a sensing circuitry system included in the IMD 14. As described below, the EGM signal generated from the cardiac electrical signals received via the His lead 18 can be used to detect His bundle capture and distinguish His bundle capture loss. Electrodes 32 and 34 are coupled to corresponding insulated conductors extending within the elongated body of His lead 18, which provide electrical connection to the proximal lead connector 44 coupled to connector block 12.

[0029] In some examples, IMD 14 may optionally be coupled to RV lead 17 for positioning electrodes within the RV to sense cardiac signals within the RV and deliver pacing or shock pulses within the RV. For these purposes, RV lead 17 is equipped with pacing and sensing electrodes, shown as tip electrode 28 and loop electrode 30. RV lead 17 is also shown carrying defibrillator electrodes 24 and 26, which may be elongated coil electrodes for delivering high-voltage CV / DF pulses. Defibrillator electrode 24 may be referred to as an “RV defibrillator electrode” or “RV coil electrode” because it may be carried along RV lead 17 such that it is substantially positioned within the right ventricle when the distal pacing and sensing electrodes 28 and 30 are positioned for pacing and sensing of the right ventricle. Defibrillator electrode 26 may be referred to as a “superior vena cava (SVC) defibrillator electrode” or “SVC coil electrode” because it may be carried along RV lead 17 such that it is at least partially positioned along the SVC as the distal end of RV lead 17 is advanced within the right ventricle.

[0030] Each of electrodes 24, 26, 28, and 30 is connected to a corresponding insulated conductor extending within the body of RV lead 17. The proximal end of the insulated conductor is coupled to a corresponding connector, such as a DF-4 connector, carried by proximal lead connector 42, for providing electrical connection to IMD 14. Housing 15 can be used as an active electrode together with RV coil electrode 24 or SVC coil electrode 26 during CV / DF shock delivery. In some examples, housing 15 can be used as a return electrode in a unipolar sensing or pacing configuration, wherein any of the electrodes is carried by leads 16, 17, and 18.

[0031] It should be understood that, although IMD 14 is in Figure 1The illustration shows an implantable cardioverter-defibrillator (IMD) capable of delivering both low-pressure cardiac pacing therapy and high-pressure cardiac cardioversion and defibrillation (CV / DF) shocks. In other examples, IMD 14 can be configured as a dual-chamber pacemaker, connected only to the RA lead 16 and His lead 18, without CV / DF shock delivery capability or connection to a third lead, such as the RV lead 17. In yet another example, IMD 14 can be a single-chamber device connected only to the His lead 18 for delivering pacing pulses to the ventricle to at least maintain a minimum ventricular rate, thus eliminating both the RA lead 16 and the RV lead 17.

[0032] External device 50 is shown communicating telemetry with IMD 14 via communication link 60. External device 50 may include processor 52, memory 53, display unit 54, user interface 56, and telemetry unit 58. Processor 52 controls the operation of the external device and processes data and signals received from IMD 14. Display unit 54, which may include a graphical user interface, displays data and other information to the user for viewing parameters of IMD operation and programming, as well as cardiac electrical signals retrieved from IMD 14. Data obtained from IMD 14 via communication link 60 may be displayed on display 54. For example, clinicians may view cardiac electrical signals received from IMD 14 and / or the results of His capture threshold tests and monitoring, or data derived therefrom.

[0033] User interface 56 may include a mouse, touchscreen, keyboard, etc., enabling a user to interact with external device 50 to initiate a telemetry session with IMD 14 for retrieving and / or transmitting data to IMD 14, including programmable parameters for controlling His beam capture determination, as described herein. Telemetry unit 58 includes a transceiver and antenna configured for bidirectional communication with telemetry circuitry included in IMD 14, and is configured to operate in conjunction with processor 52 for transmitting and receiving data relating to IMD functionality via communication link 60, which may include data relating to His beam capture detection thresholds.

[0034] Can be used as A communication link 60 is established between the IMD 14 and the external device 50 via Wi-Fi or a Medical Implantable Communication Service (MICS) or other RF or communication frequency bandwidth or communication protocol wireless radio frequency (RF) link. Data stored or retrieved by the IMD 14, including physiological signals or associated data derived therefrom, device diagnostic results, and the history of detected cardiac rhythm episodes and delivered therapies, can be retrieved by the external device 50 from the IMD 14 upon request.

[0035] External device 50 may be embodied as a programmer used in a hospital, clinic, or physician's office to retrieve data from IMD 14 and program the operating parameters and algorithms in IMD 14 to control IMD functions. External device 50 may alternatively be embodied as a home monitor or a handheld device. External device 50 can be used to program cardiac signal sensing parameters, heart rate monitoring parameters, and therapy control parameters used by IMD 14. (See below for further details.) Figure 4 The external device 50 may be embodied as a computing device coupled to the electrode device for analyzing surface cardiac electrical signals to identify effective His bundle capture by the IMD 14. In other examples, the external device 50 is... Figure 4 The computing device communicates with IMD 14 to transmit notifications of valid His bundle capture.

[0036] Figure 2 This is a conceptual diagram of a leadless intracardiac pacemaker 100 configured as a His bundle pacing device. The pacemaker 100 is shown positioned within a respirator (RA) for delivering ventricular pacing via the His bundle. The pacemaker 100 may include a distal tip electrode 102 extending distally 112 away from the pacemaker housing 105. The intracardiac pacemaker 100 is configured to be implanted in the RA of a patient's heart 8 to position the distal tip electrode 102 for delivering pacing pulses to the His bundle. For example, the distal tip electrode 102 may be inserted at the lower end of the atrial septum, below the AV node, and near the tricuspid annulus to position the tip electrode 102 within, along, or near the His bundle. The distal tip electrode 102 may be a helical electrode providing fixation to anchor the pacemaker 100 at the implantation site. In other examples, the pacemaker 100 may include a fixation member that includes one or more teeth, hooks, barbs, coils or other fixation members (one or more) that anchor the distal end of the pacemaker 100 to the implantation site.

[0037] A portion of the distal tip electrode 102 may be electrically insulated, such that only the most distal end of the tip electrode 102 (farthest from the distal end 112 of the housing) is exposed to provide targeted pacing at a tissue site including a portion of the His bundle. One or more housing-based electrodes 104 and 106 may be mounted on the surface of the pacemaker 100 housing, near or located on the proximal end 110 of the pacemaker 100. His bundle pacing can be achieved using the distal tip electrode 102 as the cathode electrode and either of the housing-based electrodes 104 and 106 as the return anode.

[0038] The cardiac electrical signals generated by the heart 8 can be sensed by the pacemaker 100 using sensing electrode pairs selected from electrodes 102, 104, and 106. For example, a near-field signal can be sensed using a distal tip electrode 112 and a proximal shell-based electrode 104. A second electrical signal, as a relative far-field signal, can be sensed using electrodes 104 and 106. One or both of the near-field and far-field cardiac electrical signals can be analyzed to determine His bundle capture and to distinguish between valid and invalid His bundle capture or capture loss according to the techniques disclosed herein.

[0039] Figure 3 This is a schematic diagram of a circuit system that can be encapsulated within an example His bundle pacing device configured to perform His bundle pacing and capture detection. For ease of illustration, Figure 3 The block diagram represents Figure 1 The IMD 14, but it should be understood that, due to Figure 3 The functionality of the various circuits and components shown for performing His bundle pacing and detecting and distinguishing between valid and invalid His bundle captures can be similarly applied in other types of capture and / or capture loss. Figure 2 The His bundle pacing device is implemented in an intracardiac pacemaker 100 and generally involves the ability to deliver His bundle pacing pulses, sense cardiac electrical signals, and detect His bundle capture according to the techniques disclosed herein.

[0040] The outer casing 15 is represented as Figure 3 Electrodes are used for sensing and delivering cardiac electrical stimulation pulses. The electronic circuitry system, enclosed within housing 15, includes software, firmware, and hardware that work together to monitor cardiac electrical signals, determine when pacing therapy is needed, and deliver pacing pulses to the patient's heart as needed, based on programmed pacing modes and pacing pulse control parameters. The electronic circuitry system includes control circuitry 80, memory 82, therapy delivery circuitry 84, sensing circuitry 86, telemetry circuitry 88, and power supply 98.

[0041] Power source 98 provides power to the circuitry of IMD 14 (including each of components 80, 82, 84, 86, and 88) as needed. Power source 98 may include one or more energy storage devices, such as one or more rechargeable or non-rechargeable batteries. The connection between power source 98 and each of the other components 80, 82, 84, 86, and 88 will be established from […]. Figure 3The overall block diagram is for understanding purposes, but is not shown for clarity. For example, power supply 98 may be connected to one or more charging circuits included in therapy delivery circuitry 84 to provide the power needed to charge a holding capacitor included in therapy delivery circuitry 84, which discharges at appropriate times under the control of control circuitry 80 for the delivery of pacing pulses. Power supply 98 may also be connected to components of sensing circuitry 86 (such as sensing amplifiers, analog-to-digital converters, switching circuitry systems, etc.), telemetry circuitry 88, and memory 82 to provide power to various circuits as needed.

[0042] Figure 3 The functional blocks shown represent the functionality included in a His bundle pacing device and may include any discrete and / or integrated electronic circuitry components that implement analog and / or digital circuitry capable of producing the functionality attributed herein to the His bundle pacing device. Individual components may include application-specific integrated circuits (ASICs), electronic circuitry, processors (shared, dedicated, or grouped) and memories, combinational logic circuitry, state machines, or other suitable components or combinations thereof that provide the described functionality, executing one or more software or firmware programs. Given the disclosure herein, providing software, hardware, and / or firmware to implement the described functionality in the context of any modern cardiac medical device is within the capabilities of those skilled in the art.

[0043] Control circuitry 80 may communicate, for example via a data bus, with therapy delivery circuitry 84 and sensing circuitry 86 to sense cardiac electrical signals and control the delivery of cardiac electrical stimulation therapy in response to sensed intrinsic cardiac events (e.g., P waves with atrial depolarization and R waves with ventricular depolarization, or their absence). Electrodes 20, 22, 24, 26, 28, 30, 32, 34 and housing 15 may be electrically connected to therapy delivery circuitry 84 for delivering electrical stimulation pulses to the patient's heart and / or sensing circuitry 86 for sensing cardiac electrical signals generated by the heart, including intrinsic signals generated by the heart in the absence of stimulation pulses and evoked response signals generated by the heart in response to delivered stimulation pulses.

[0044] The sensing circuit 86 may include two or more sensing channels for sensing cardiac electrical signals from two or more sensing electrode vectors. For example, electrodes 20 and 22 may be used to sense the RA signal, electrodes 28 and 30 may be used to sense the RV signal, and electrodes 32 and 34 may be used to sense the His signal. In other examples, such as... Figure 3 As shown, the near-field signal of the His bundle can be sensed by a sensing channel, such as near-field sensing channel 84, for example using electrodes 32 and 34 of His lead 18. The far-field signal can be sensed by a second sensing channel, such as far-field sensing channel 89.

[0045] As used herein, a "near-field" signal refers to a cardiac electrical signal received from a sensing electrode vector, which includes at least one electrode located in or near the His bundle or near the His pacing pulse delivery site, such that the near-field signal may also be referred to as a "His bundle near-field signal." The His bundle near-field signal may or may not include a His bundle evoked response, depending on whether the His bundle is captured. The His bundle near-field signal may include evoked response QRS waveform signals caused by effective His bundle capture and ineffective His bundle capture, which may conduct only along a portion of the bundle branching system. The His bundle near-field signal may also include evoked response QRS waveform signals caused by VM capture and His bundle capture loss.

[0046] As used herein, a "far-field" signal refers to a cardiac electrical signal received from a pair of electrodes comprising at least one electrode that is relatively farther from the His bundle than the electrode vector used to sense the near-field His bundle signal, and / or the inter-electrode distance between the two electrodes defining the far-field sensing electrode vector is greater than the inter-electrode distance between the two electrodes defining the near-field sensing electrode vector of the His bundle. The far-field signal is more representative of overall ventricular activation, while the near-field signal is more representative of local tissue activation at or near the pacing site. The far-field signal may include an evoked response QRS waveform signal associated with an effective His bundle capture (which may be an SHB capture or an NSHB capture) or an ineffective His bundle capture, such as causing conduction only along a portion of the bundle branch system during partial His bundle capture, during a VM capture in which the His bundle capture is lost, or during a capture in which the His bundle pacing pulse is completely lost. In the latter case, the QRS waveform signal sensed by the far-field sensing channel 89 or the near-field sensing channel 87 may be an intrinsic R wave or an evoked response to a ventricular pacing pulse delivered from the RV pacing electrodes 28 and 30.

[0047] When the His bundle is effectively captured, the far-field QRS width is expected to be narrower than when the His bundle is not effectively captured (and ventricular myocardial tissue or only a portion of the conduction system, e.g., only the right bundle branch is captured). Effective capture of the His bundle, causing conduction via the intrinsic ventricular conduction system including both the right and left bundle branches, generally promotes increased synchronicity of right and left ventricular electrical activation times. This increased synchronicity is associated with a narrower far-field QRS width. A relatively wide QRS width is associated with increased asynchrony or heterogeneity of right and left ventricular electrical activation times. A wider QRS width may occur when the His bundle is completely uncaptured or only partially captured, causing conduction only along a portion of the bundle branch conduction system or depolarization along a pathway different from the normal intrinsic ventricular conduction system.

[0048] In some examples, electrodes carried by RA lead 16 and IMD housing 15 (e.g., electrode 20 and housing 15 or electrode 22 and housing 15) can be used to sense far-field signals. In examples including RV lead 17, RV coil electrode 24 paired with housing 15, SVC coil electrode 26 paired with housing 15, or RV coil electrode 24 paired with SVC coil electrode 26 can be used to sense far-field signals. The His bundle capture detection method disclosed herein includes detecting His bundle capture and may include using a capture detection threshold established based on ventricular synchrony measures to distinguish between valid and invalid His bundle captures or lost His bundle captures, as described below.

[0049] Sensing circuit 86 may include a switching circuit system for selectively coupling a near-field sensing electrode pair from available electrodes to a near-field sensing channel 87 for sensing a near-field His bundle signal, and for selectively coupling a far-field sensing electrode pair to a far-field sensing channel 89 for sensing a far-field electrical signal relative to the site of delivery of His bundle pacing pulses. The far-field sensing electrode pair may exclude at least one or both of the electrodes used to deliver His bundle pacing pulses. The switching circuit system may include a switch array, a switch matrix, a multiplexer, or any other type of switching device suitable for selectively coupling components of sensing circuit 86 to selected electrodes.

[0050] Each of the near-field sensing channel 87 and the far-field sensing channel 89 may include an input filter for receiving cardiac electrical signals from the corresponding sensing electrode pair, a preamplifier, an analog-to-digital converter, and a bandpass filter for generating a multi-bit digital EGM signal for detecting His bundle capture and distinguishing at least valid and invalid His bundle captures (including complete loss of His bundle capture), and for distinguishing SHB, NSHB, and VM captures and / or other types of valid and invalid captures, such as right bundle branch capture, left bundle branch capture, and fusion. The characteristics of the near-field and far-field EGM signals may be determined by the control circuitry 80, and in some examples, each sensing channel 87 and 89 may include a rectifier to generate a rectified signal, which the control circuitry 80 may use to determine signal characteristics for identifying His bundle capture. As described below, the QRS waveform following the His bundle pacing pulse can be used to detect valid and invalid His bundle captures. The QRS waveform following the capture of the His bundle and / or the His bundle pacing pulse of the ventricular myocardium may also be referred to herein as the “evoked response signal” and includes the evoked response R wave that can be sensed by the sensing circuit 86.

[0051] Sensing circuit 86 may include cardiac event detection circuitry, which may include one or more sensing amplifiers, filters, rectifiers, threshold detectors, comparators, analog-to-digital converters (ADCs), timers, or other analog or digital components for detecting cardiac electrical events. For example, an atrial event detector may be included in sensing circuit 86 for detecting an intrinsic P wave accompanying intrinsic atrial depolarization using one or both of electrodes 20 and 22 carried by RA lead 16. A ventricular event detector may be included in sensing circuit 86 for detecting an intrinsic R wave 17 accompanying intrinsic ventricular depolarization using electrodes 32 and 34 carried by His lead 18 and / or electrodes 24, 26, 28, and / or 30 carried by RV lead. Cardiac event sensing thresholds, such as P-wave sensing thresholds or R-wave sensing thresholds, can be automatically adjusted by sensing circuit 86 under the control of control circuit 80 based on timing intervals and sensing thresholds determined by control circuit 80, stored in memory 82, and / or controlled by hardware, firmware, and / or software of control circuit 80 and / or sensing circuit 86.

[0052] When detecting cardiac electrical events based on a crossing of a sensing threshold, sensing circuit 86 can generate a sensed event signal that is transmitted to control circuit 80. For example, an atrial event detector can generate a P-wave sensed event signal in response to a crossing of a P-wave sensing threshold. A ventricular event detector can generate an R-wave sensed event signal in response to a crossing of an R-wave sensing threshold. The sensed event signal is used by control circuit 80 to set an escape interval timer that controls the basic time interval used to schedule cardiac pacing pulses. Control circuit 80 may include various timers or counters for counting down AV pacing intervals, VV pacing intervals, AA pacing intervals, etc. The sensed event signal may trigger or suppress pacing pulses depending on a specific programmed pacing mode. For example, a P-wave sensed event signal received from sensing circuit 86 can cause control circuit 80 to suppress scheduled atrial pacing pulses and schedule His bundle pacing pulses at the programmed AV pacing interval. If the AV pacing interval expires before the control circuit 80 receives an R-wave sensing event signal from the sensing circuit 86, the control circuit 80 can control the therapy delivery circuit 84 to deliver a His pacing pulse with the AV pacing interval after the sensed P wave, thus providing atrial synchronic ventricular pacing that promotes increased ventricular synchrony. If an R-wave sensing event signal is received from the sensing circuit 86 before the AV pacing interval expires, the scheduled His pacing pulse can be disabled. The AV pacing interval controls the amount of time between an atrial event (pacing or sensing) and a His bundle pacing pulse to promote AV synchrony and induce ventricular capture via the His-Purkinje conduction system of the ventricles.

[0053] Therapy delivery circuit 84 may include a charging circuit system, one or more charge storage devices (such as one or more holding capacitors), an output capacitor, and a switching circuit system that controls when the holding capacitors (one or more) are charged and discharged across the output capacitor to deliver pacing pulses to selected pacing electrode vectors coupled to the therapy delivery circuit 84. Therapy delivery circuit 84 may include one or more pacing channels. In the example of IMD 14, therapy delivery circuit 84 may include an RA pacing channel, a His bundle pacing channel, and an RV pacing channel, each channel including a holding capacitor, one or more switches, and an output capacitor for generating pacing pulses delivered by the corresponding RA lead 16, RV lead 17, and His lead 18. It should be understood that in the case where IMD 14 is a single-chamber device configured to receive His lead 18, therapy delivery circuit 84 may include a single pacing channel. In the case where IMD 14 is a dual-chamber device configured to receive both RA lead 16 and His lead 18, therapy delivery circuit 84 may have an atrial pacing channel and a His pacing channel.

[0054] The therapy delivery circuit 84, based on a control signal received from the control circuit 80, will charge the capacitor to a programmed pacing voltage amplitude and discharge the capacitor to a programmed pacing pulse width. For example, the pacing timing circuit included in the control circuit 80 may include a programmable digital counter, set by the microprocessor of the control circuit 80, for controlling the basic pacing time interval associated with various single-chamber or multi-chamber pacing modes or anti-tachycardia pacing sequences. The microprocessor of the control circuit 80 may also set the amplitude, pulse width, polarity, or other characteristics of the cardiac pacing pulse based on programmed values ​​stored in memory 82.

[0055] Control circuit 80 is configured to perform His bundle capture monitoring by determining one or more characteristics of the QRS waveform of near-field and / or far-field cardiac electrical signals received from sensing circuit 86. The QRS characteristics determined after the His bundle pacing pulse are compared with an established His bundle capture detection threshold to distinguish between valid and invalid His bundle capture, as well as capture loss. If the QRS characteristics meet the capture detection threshold requirements, valid His bundle capture is detected. If not, invalid His bundle capture can be detected, which may include loss of His bundle capture or only partial capture by the His bundle conduction system. Control circuit 80 can control therapy delivery circuit 84 to adjust the pacing pulse output in response to the detection of capture loss or invalid His bundle capture, for example, by increasing the pacing pulse voltage amplitude and / or pulse width, to maintain valid His bundle capture and promote improved electrical synchrony between the right and left ventricles.

[0056] The appropriate capture detection threshold applied by control circuitry 80 to QRS waveform characteristics to detect effective His bundle capture can vary among patient, electrode position, sensing electrode vector (e.g., near or far field), His bundle pacing system, and other factors. In some cases, changes in the EGM signal generated by the His bundle pacing device due to effective His bundle capture may be difficult to distinguish from ineffective His bundle capture (particularly with the relative near field signal), which may not fully reflect the increase in overall electrical homogeneity or synchronicity of the right and left ventricles following an effective His bundle pacing pulse. The techniques disclosed herein are combined with... Figure 4 An external computing device is provided for identifying a valid His bundle capture with high determinism based on cardiac electrical signals received from surface electrodes. A His bundle pacing device, such as IMD 14, is notified that a valid His bundle capture has been identified by the computing device and is configured to establish a His bundle capture detection threshold in response to the notification. The His bundle capture detection threshold may be based on QRS waveform characteristics determined in response to notification of a confirmed valid His bundle capture.

[0057] Control parameters used by control circuitry 80 to sense cardiac events and control the delivery of pacing therapy can be programmed into memory 82 via telemetry circuitry 88. Telemetry circuitry 88 includes features for communicating with external device 50 using radio frequency communication or other communication protocols. Figure 1 The transceiver and antenna are used for communication. Under the control of the control circuit 80, the telemetry circuit 88 can receive downlink telemetry from the external device 50 and send uplink telemetry to the external device.

[0058] In some examples, telemetry circuit 88 is configured to perform bidirectional radio frequency communication with an external computing device, which is configured to identify His beam capture as described below. In some examples, telemetry circuit 88 is An enabling circuit configured to receive His bundle capture notification from an external device 50 or other external computing device, the external computing device being configured to identify a valid His bundle capture from surface cardiac electrical signals (e.g., electrocardiogram (ECG) signals). (As in combination) Figure 4-10 The IMD 14 or pacemaker 100 can respond to a His bundle capture notification received from an external computing device by establishing a His bundle capture detection threshold for His bundle capture monitoring.

[0059] Figure 4 This is a conceptual diagram of System 200, which is used to evaluate the use of His bundle pacing devices (such as...). Figure 1 The IMD14 shown is or Figure 2 The pacemaker 100 shown transmits electrical activation information of the patient's heart 8 during His bundle pacing. Although in Figure 4While the His bundle pacing device is not visible in the view, it should be understood that system 200 is used in conjunction with a His bundle pacing device configured to deliver His bundle pacing pulses to the heart 8. System 200 can be used in conjunction with the His bundle pacing device to establish a His bundle capture detection threshold, which is applied to the characteristics of the cardiac electrical signals received by the His bundle pacing device for monitoring and detecting effective His bundle capture.

[0060] System 200 includes an electrode device 210, an interface / amplifier circuitry system 216, and a computing device 240. The electrode device 210 includes a plurality of electrodes 212, which can be carried by a patient-attachable or wearable substrate 213, for example, a strap attached around the chest or torso of the patient 2. The electrode device 210 is operatively coupled to the computing device 240 via the interface / amplifier circuitry system 216 (e.g., via a wired electrical connection, wirelessly, etc.) to provide electrical signals from each of the electrodes 212 to the computing device 240 for analysis to identify His bundle trapping. The electrode device 210 may generally correspond to a bioelectric sensor device described in U.S. Patent No. 9,320,446 (Gillberg et al.) or a surface biopotential sensing device generally described in U.S. Patent No. 8,972,228 (Ghosh et al.).

[0061] The dispersion of electrical activation time in a patient's heart can be assessed to detect effective His bundle capture via pacing pulses delivered to the heart 8 by a His bundle pacing device (e.g., IMD 14 or pacemaker 100). The more heterogeneous or asynchronous the electrical activation time of the patient's ventricles, the less likely the His bundle pacing pulses are to effectively capture the His bundle. Electrical activation time indicating relatively homogeneous or synchronous ventricular electrical activation indicates effective His bundle capture. Electrode device 210 can be used to monitor or determine alternative electrical activation information or data for one or more regions of the patient's heart. Electrode device 210 can be configured to measure the body surface potential of patient 2, more specifically, torso-surface potential of patient 2, also referred to herein as the body surface cardiac electrical signal. Figure 4 As shown, the electrode device 210 may include a set or array of electrodes 212 disposed on a substrate 213 to be wrapped around the torso of the patient 2 such that the electrodes 212 surround the patient's heart 8. The electrodes 212 may be positioned around the patient 2, including posterior, lateral, posterolateral, anterolateral, and anterior positions of the patient 2's torso.

[0062] Electrode 212 may be electrically connected to interface / amplifier circuitry 216 via wired connection 218. Interface / amplifier circuitry 216 may be configured to filter and amplify electrical signals from electrode 212 and provide the amplified signals to computing device 240, for example, as a data channel. For example, interface / amplifier circuitry 216 may include an input filter and amplifier, an analog-to-digital converter, and an output amplifier for generating surface biopotentials or ECG signals from each of electrodes 212. In some examples, system 200 may include wireless communication for transmitting signals from interface / amplifier circuitry 216 to computing device 240. For example, interface / amplifier circuitry 216 may be electrically connected to computing device 240 via analog electrical connection, digital electrical connection, wireless connection, bus-based connection, network-based connection, Internet-based connection, etc.

[0063] Despite Figure 4 In some examples, electrode device 210 includes an electrode substrate 213 in the form of a strip or band that can be wrapped around the torso of patient 2. In other examples, any of a variety of substrates, such as tape, adhesive, vest, jacket, or other substrates, can be used to assist in the spacing, placement, and contact of electrodes 212 along the patient's torso surrounding the heart 8. In some examples, substrate 213 may include an elastic band, tape strip, or cloth. In other examples, electrodes 212 may be placed individually on the torso of patient 2, for example, using an adhesive pad as an electrode substrate. Furthermore, in other examples, electrodes 212 (e.g., arranged in an array) may be patches, vests, and / or other means of securing electrodes 212 to or positioning them within the torso of patient 2.

[0064] Figure 5 This is a conceptual diagram of an electrode device 210 according to another example. In this example, a plurality of spaced-apart electrodes 212 are carried by a substrate 214 configured as a vest, which is configured to distribute the electrodes 212 along the torso of the patient 2 and to keep the electrodes 212 in close proximity or direct contact with the patient's skin for sensing surface biopotential signals caused by the electrical activity of the patient's heart. As shown, the electrodes 212 may be distributed above the torso of the patient 2, including, for example, the anterior surface, lateral surface, posterolateral surface, anterolateral surface, and posterior surface of the torso of the patient 2.

[0065] The substrate 214 may be formed of fabric, to which the electrodes 212 are attached. The substrate 214 may be configured to maintain the position and spacing of the electrodes 212 on the torso of the patient 2, and may be marked to help determine the position of the electrodes 212 on the surface of the patient 2's torso. In one example, the substrate 214 includes 17 or more anterior electrodes that can be positioned close to the patient's anterior torso, and 39 or more posterior electrodes that can be positioned close to the patient's posterior torso. In some examples, although other configurations may have more or fewer electrodes 212, approximately 25 to approximately 256 electrodes carried by the substrate 214 may be distributed around the torso of the patient 2.

[0066] As described herein, electrode device 210 can be configured to measure electrical information (e.g., electrical signals) representing different regions of a patient's heart. For example, the activation time of different regions of the patient's heart can be approximated by the activation time determined based on a surface potential signal received from electrode 212, which is located near the body surface region corresponding to the different regions of the patient's heart.

[0067] General Reference Figure 4 and 5 The system 200 shown has electrodes 212 carried by a selected substrate configured to surround the heart 8 for recording or monitoring cardiac electrical signals accompanying cardiac depolarization and repolarization after a signal has propagated through the torso of the patient 2. Each of the electrodes 212 can be used in a unipolar configuration to sense a torso-surface potential reflecting cardiac signals. An interface / amplifier circuitry system 216 can also be coupled to a return electrode or an unrelated electrode (not shown) that can be used in combination with each electrode 212 used for unipolar sensing. In some examples, approximately 12 to approximately 50 electrodes 212 may be spatially distributed around the torso of the patient 2. Other configurations may have more or fewer electrodes 212. Figure 4 and Figure 5 The size, number, and arrangement of the electrodes 212 on the substrate 213 or 214 shown and relative to the heart 8 are intended to illustrate the concept of an electrode device that can be used in the system 200 without any intention to limit it.

[0068] The computing device 240 can record and analyze electrical signals (e.g., trunk-surface potential signals) sensed by the electrodes 212 and filtered and amplified by the interface / amplifier circuitry system 216. The computing device 240 can be configured to analyze signals from the electrodes 212 to provide anterior and posterior electrode signals and cardiac electrical activation times, such as actual or local electrical activation times representing one or more regions of the patient's heart. For example, an electrical signal received by an electrode located on the left anterior surface of the patient's trunk may represent the electrical signal of the left anterior left ventricular region of the patient's heart. An electrical signal received by an electrode located on the left lateral surface of the patient's trunk may represent the electrical signal of the left lateral left ventricular region of the patient's heart. An electrical signal received by an electrode located on the left posterolateral surface of the patient's trunk may represent the electrical signal of the posterolateral left ventricular region of the patient's heart. An electrical signal received by an electrode located on the posterior surface of the patient's trunk may represent the electrical signal of the posterior left ventricular region of the patient's heart, and so on.

[0069] Compared to pacing from other sites within or above the ventricles, His bundle pacing provides more synchronized and homogeneous electrical activation to the right and left ventricles of the heart because the depolarization caused by a His bundle pacing pulse that effectively captures the His bundle can be conducted through the ventricles' natural, intrinsic conduction system. Characterizing the spatial electrical activation of the ventricles using System 200 can be performed by the His bundle pacing device during His bundle pacing to determine with high certainty when the His bundle pacing pulse effectively captures the His bundle based on a reduction in ventricular asynchrony (sometimes referred to as "electrical heterogeneity"). This determination is used to inform the His bundle pacing device upon confirmation of effective His bundle capture, enabling the His bundle pacing device to establish His bundle capture detection thresholds for His bundle capture monitoring and to distinguish between effective and ineffective His bundle captures.

[0070] Under different pacing pulse output settings and / or in the absence of His bundle pacing, electrical activity monitored during His bundle pacing can be used to construct a surface isochronous map of ventricular activation. The monitored electrical activity and / or ventricular activation map can be used to generate electrical asynchrony data. Electrical asynchrony data may include measures that determine electrical asynchrony. A measure of electrical asynchrony, also referred to as a measure of “electrical heterogeneity,” is an indication of the temporal dispersion of electrical activation time in the ventricle. The measure of electrical asynchrony can be determined based on the QRS waveform of electrical signals received from electrodes 212, which are spatially distributed above the patient’s trunk and surrounding heart 8. For example, the electrical activation time in the ventricular region can be determined as the time interval from the start of the QRS waveform to a reference point of the QRS waveform. In some examples, the electrical activation time is the time from the start of the QRS waveform to the maximum slope of the QRS waveform. For example, the electrical activation time is determined as the time from the start of the QRS waveform to the maximum negative slope of the QRS waveform. (The following is in conjunction with...) Figure 7 Describe an example method for determining the electrical activation time.

[0071] The computing device 240 can be configured to determine a measure of electrical asynchrony by determining the electrical activation time based on each or a selected subset of the cardiac electrical signals received from the electrodes 212, and to determine the standard deviation (SDAT) of those electrical activation times. In some examples, a measure of left ventricular electrical asynchrony can be obtained by determining the mean and / or standard deviation of electrical signals received from electrodes on the left side of the patient's torso. For example, the mean of the left ventricular activation time (LVAT) can be determined. The measure of LVAT can be determined from electrodes on both the anterior and posterior surfaces along the left side of the patient 2. A measure of electrical asynchrony may include a measure of the mean right ventricular activation time (RVAT) from electrodes on the right side of the patient's torso. The measure of RVAT can be determined from electrodes on both the anterior and posterior surfaces along the right side of the patient 2. Measurements of electrical asynchrony may include the mean total activation time (MTAT) obtained from multiple electrode signals from the left and right sides of the patient's trunk (from the anterior and / or posterior surfaces of the patient 2), and / or may include other measures (standard deviation, interquartile range, difference between the latest and earliest activation times, as examples), which are related to or correspond to the range or dispersion of activation times sensed by multiple spaced electrodes (including posterior, anterior, and / or laterally positioned electrodes) located on the right side, left side, or a combination of the left and right sides of the patient's trunk.

[0072] Assessing ventricular electrical dyssynchrony during His bundle pacing to establish a capture detection threshold via the His bundle pacing device may include determining at least one of SDAT, LVAT, RVAT, and MTAT. As an example, computing device 240 may detect a valid His bundle capture in response to an SDAT less than a selected SDAT threshold generated during His bundle pacing. As an example, the selected SDAT threshold may be less than or equal to 25 milliseconds (ms) or another selected threshold (which may be patient-specific) to distinguish between valid and invalid His bundle captures. When the patient has intact atrioventricular conduction, His bundle pacing may be stopped so that a baseline electrical dyssynchrony measure can be determined upon cessation of His bundle pacing. In this case, a His bundle capture can be identified as a decrease in SDAT compared to no His bundle pacing, such as a relative change in SDAT. If the patient has AV block and is therefore dependent on ventricular pacing, a measure of electrical dyssynchrony may be determined during RV pacing (when RV pacing electrodes are available, such as those with…). Figure 1 (IMD 14). For example, effective His bundle capture can be identified when the SDAT during His bundle pacing is lower than the SDAT determined during RV pacing.

[0073] In other examples, effective His bundle capture can be detected based on the LVAT being below a selected threshold during His bundle pacing. As an example, the selected threshold corresponding to the LVAT indicating effective His bundle capture may be less than or equal to 35 milliseconds. In at least one example, effective His bundle capture is identified in response to both the SDAT and LVAT generated during His bundle pacing being below the selected threshold. In yet another example, effective His bundle capture can be detected in response to the RVAT and / or MTAT generated during His bundle pacing therapy being below the selected threshold. In other examples, the His bundle pacing device is configured to deliver His bundle pacing pulses with multiple pacing pulse outputs (e.g., multiple pacing pulse amplitudes), and the computing device 240 identifies His bundle capture when the SDAT, LVAT, RVAT, and / or MTAT are at their minimum or relatively reduced values ​​compared to the same metrics obtained during His bundle pacing with different pacing pulse outputs.

[0074] Additionally, computing device 240 may be configured to generate a display or graphical user interface depicting data on the electrical activation time and / or electrical asynchrony obtained using electrode device 210. In various examples, computing device 240 may be a server, personal computer, or tablet computer, and may include user input device 242 and display device 230. Computing device 240 may be configured to receive input from input device 242 and transmit output to display device 230. Figure 4 In addition, computing device 240 may include data storage that allows access to processors or routines and / or one or more other types of data, such as for driving a graphical user interface (GUI) configured to non-intrusively identify His bundle captures.

[0075] Computing device 240 may be operatively coupled to input device 242 and display device 230 to, for example, transmit data to and from each of input device 242 and display device 230. For example, computing device 240 may be electrically coupled to each of input device 242 and display device 230 using analog electrical connections, digital electrical connections, wireless connections, bus-based connections, network-based connections, Internet-based connections, etc. As further described herein, a user may provide input to input device 242 to manipulate or modify one or more graphical depictions displayed on display device 230, and to view and / or select one or more pieces of information relating to electrically activated data.

[0076] Although input device 242 is a keyboard as depicted, it should be understood that input device 242 may include any device capable of providing input to computing device 240 to perform the functions, methods, and / or logic described herein. For example, input device 242 may include a mouse, trackball, touchscreen (e.g., capacitive touchscreen, resistive touchscreen, multi-touch touchscreen, etc.), etc. Similarly, display device 230 may include any device capable of displaying information to a user, such as graphical user interface 232, which includes cardiac electrical signal information, text commands, graphical or tabular depictions of electroactivation information, graphical depictions of the anatomical structure of the human heart, images or graphical depictions of a patient's heart, graphical depictions of the location of one or more electrodes, graphical depictions of the human torso, images or graphical depictions of a patient's torso, graphical depictions or actual images of implanted electrodes and / or leads, etc. Furthermore, display device 230 may include a liquid crystal display, an organic light-emitting diode screen, a touchscreen, a cathode ray tube display, etc.

[0077] Data stored and / or used by computing device 240 may include, for example, electrical signal / waveform data from electrode device 210, portions or parts of various signals received from electrode device 210, electrical activation times determined based on signals received from electrode device 210, graphics (e.g., graphic elements, icons, buttons, windows, dialog boxes, drop-down menus, graphic areas, graphic regions, 3D graphics, etc.), graphical user interfaces, results from one or more processing procedures or routines employed according to this disclosure (e.g., electrical asynchrony measurements and His bundle capture or non-capture determination), or any other data necessary for performing one or more processes or methods described herein.

[0078] The computing device 240 can be configured to generate a His bundle capture recognition notification in response to electrically activated data that meets the valid His bundle capture detection criteria. The notification can be generated on the display 230 of the computing device 240. The notification may include an audible notification in the form of a beep, tone, voice, or other sound. In some examples, the notification includes a wireless transmission signal indicating His bundle capture detection. The His bundle pacing device can be configured, for example, via… Or other wireless connections can be used to receive transmitted notifications directly from computing device 240. The His bundle pacing device can respond by establishing a His bundle capture detection threshold, as described below. Figure 8 As described.

[0079] Computing device 240 may be, for example, any fixed or mobile computer system (e.g., controller, microcontroller, personal computer, microcomputer, tablet computer, etc.) and can generally be described as including a processing circuitry system. The exact configuration of computing device 240 is not limiting, and substantially any means capable of providing suitable computing and control capabilities (e.g., graphics processing, etc.) may be used. Given the disclosure herein, providing software, hardware, and / or firmware to implement the described functionality in the context of any modern medical device system is within the capabilities of those skilled in the art. Therefore, computer languages, computer systems, or any other software / hardware that will be used to implement the processes described herein should not limit the scope of the systems, processes, or programs described herein (e.g., the functionality provided by such systems, processes, or programs). In some examples, functionality attributed to computing device 240 may be incorporated into… Figure 1 In the external device 50, a programmer for communicating with the His bundle pacing device to program pacing and sense control parameters and retrieve data from the His bundle pacing device can be configured to generate electrical asynchrony data based on signals received from the electrode device 210, detect valid His bundle capture from the electrical asynchrony data, and transmit a notification of His bundle capture to the His bundle pacing device.

[0080] Figure 6 This is a flowchart 250 illustrating an example method for identifying His bundle capture by computing device 240 during His bundle pacing. The method in flowchart 250 is performed by system 200 during His bundle pacing delivered by a His bundle pacing device (such as IMD 14 or pacemaker 100). In block 252, computing device 240 generates electrical asynchrony data. The electrical asynchrony data may include SDAT, LVAT, RVAT, MTAT, or other measures (one or more) of the temporal dispersion of ventricular electrical activation derived from cardiac electrical signals received from electrode device 210. Computing device 240 may generate the electrical asynchrony data before or simultaneously with suppressing His bundle pacing by the His bundle pacing device. By generating the electrical asynchrony data before or simultaneously with suppressing His bundle pacing, computing device 240 may generate baseline or His bundle non-capture electrical asynchrony data for comparative analysis with electrical asynchrony data generated during the delivery of His bundle pacing. In pacing-dependent patients, when His bundle pacing is suppressed to avoid ventricular arrest, RV pacing can be delivered, for example, using RV lead 17, while generating electrical asynchrony data corresponding to His bundle non-capture.

[0081] The computing device 240 can generate electrical asynchrony data in block 252 by determining the electrical activation time based on one or more QRS waveforms of each cardiac electrical signal (or a selected subset of cardiac electrical signals) received from the electrode device 210. Figure 7This is a conceptual diagram of a QRS waveform and a method for determining the electrical activation time, which can be executed by computing device 240. In this example, the illustrated QRS waveform 280 is depicted as a net negative waveform. In various examples, the QRS waveform may be a net negative or net positive composite wave and may have regions exceeding the baseline signal (positive region) and regions below the baseline signal (negative region). The electrical activation time 284 can be determined as the time point at which the maximum negative slope 283 of the QRS waveform 280 occurs. The electrical activation time 284 can be determined relative to the QRS start 282. In this example, the electrical activation time 284 can be determined as the time from the QRS start 282 (considering time 0 ms) to the steepest negative slope 283 of the QRS waveform 280. Therefore, computing device 240 may include a differentiator or algorithm for calculating the continuous difference between QRS waveform sampling points to identify the maximum negative slope of the QRS waveform 280, which in this example is earlier than the maximum peak 288 on the leading portion of the QRS waveform 280.

[0082] QRS initiation 282 can be determined by identifying the smallest sample point of the QRS waveform 280 before peak 288 but within QRS time window 290. In other examples, QRS initiation 282 can be determined by identifying the most recent sample point of the QRS waveform 280 that occurred before peak 288 and whose absolute value is equal to or less than a predetermined threshold 292. For example, threshold 292 can be set to 110% (or other selected percentage) of the smallest absolute value sample point of the QRS waveform 280 detected before peak 288 but within window 290. Window 290 can be defined as a predetermined time interval extending from the delivered pacing pulse or sensed cardiac event (e.g., a sensed P wave or a previously sensed R wave). Alternatively, window 290 can be defined relative to peak 288 or relative to a QRS sensing threshold.

[0083] In other examples, the QRS start 282 can be identified by generating a dispersed waveform from multiple QRS waveforms and detecting the start of the dispersed waveform, as generally disclosed in prior granted U.S. Patent Application Publication 2018 / 0263522 (Ghosh et al.). For example, a dispersed signal can be generated from multiple QRS waveforms as a signal representing the electrical dispersion of the QRS waveforms over time. In one example, the dispersed signal is generated by determining the standard deviation of the sampling points of the multiple QRS waveforms. The start of the dispersed signal can be determined as the start of the QRS waveform.

[0084] The time of the maximum slope 283 relative to the identified QRS initiation 282 can be stored as the electrical activation time of the heart position corresponding to the electrode position of the electrode device 210 from which the QRS waveform 280 is received. Although a single QRS waveform is like Figure 7As shown, the electrical activation time of a given electrode “channel” during His bundle pacing can be determined based on multiple QRS waveforms received from the given electrode or based on time-averaged, filtered, or dispersed waveforms generated from multiple QRS waveforms, as a representative QRS waveform of the cardiac electrical signal corresponding to the patient’s cardiac location or region.

[0085] Figure 7 A method for determining the electrical activation time from at least one QRS waveform of a given electrode signal is described. The electrical activation time can be determined using alternating start, initial, or reference time points and subsequent electrical activation time points, which are defined as reference points of the QRS waveform during the QRS window and indicate the electrical depolarization time of the corresponding region of the heart. For example, the electrical activation time can be determined as the time from start 282 to the R-wave peak 288, to a predetermined percentage of the R-wave peak 288, etc.

[0086] Back Figure 6 In block 254, the His bundle pacing device delivers His bundle pacing according to programmed pacing output control parameters. In block 254, computing device 240 generates electrical asynchrony data during the delivery of His bundle pacing. In block 256, computing device 240 identifies when a valid His bundle capture occurs based on the electrical asynchrony data. In some examples, computing device 240 may compare one or more electrical asynchrony metrics to thresholds indicating acceptable electrical activation synchrony or homogeneity. For example, a valid His bundle capture can be detected if the SDAT is less than 25 milliseconds. Additionally or alternatively, as an example, criteria for detecting a valid His bundle capture may include an RVAT of less than 30 milliseconds, an LVAT of less than 30 milliseconds, and / or an MTAT of less than 50 milliseconds.

[0087] In some examples, computing device 240 may identify or detect a valid His bundle capture in response to detecting a relative change in one or more electrical asynchrony measures (e.g., SDAT, LVAT, RVAT, and MTAT) determined during His bundle pacing, compared to similar measures that are determined as baseline measures, for example, when His bundle pacing is not delivered (during the patient's intrinsic rhythm or during RV pacing). The threshold reduction for the electrical asynchrony measure that results in the detection of a valid His bundle capture may be 10%, 20%, 25%, 30%, or other predetermined percentage or threshold change. In yet another example, as electrical asynchrony data is being generated by computing device 240, His bundle pacing may be delivered by a His bundle pacing device in the form of multiple pacing pulse outputs (e.g., multiple pacing pulse voltage amplitudes). In block 256, computing device 240 may detect a valid His bundle capture based on one or more electrical asynchrony measures reaching a threshold or from a maximum reduction in the maximum value of a measure determined as the His bundle pacing output changes. Therefore, effective His bundle capture can be detected based on the relative decrease of SDAT, LVAT, RVAT and / or MTAT as the His bundle pacing pulse energy increases or decreases (or changes randomly).

[0088] In some examples, computing device 240 may be configured to identify different types of capture associated with His bundle pacing in box 256. For example, in some patients, incomplete capture of the His bundle may result in capture of either the right bundle branch (RBB) or the left bundle branch (LBB), but not both simultaneously. Computing device 240 may generate electrical asynchrony data by determining a right ventricular metric, such as RVAT, based on a QRS waveform received from electrode device 210 corresponding to cardiac electrical signals received along the patient's right side, and a left ventricular metric, such as LVAT, based on a QRS waveform received from electrode device 210 corresponding to cardiac electrical signals received along the patient's left side. Computing device 240 may compare the right and left ventricular metrics with corresponding right bundle branch capture thresholds and left bundle branch capture thresholds to identify invalid His bundle captures. For example, an invalid His bundle capture may be identified in response to at least one of the right or left ventricular metrics failing to meet the corresponding right or left bundle branch capture threshold. To illustrate, if RVAT is less than 30 milliseconds (or other selected threshold) but LVAT is greater than 30 milliseconds (or other selected threshold), a capture loss in both the RBB and LBB is identified, resulting in an invalid His bundle capture. The His bundle pacing device can respond to an invalid His bundle capture notification by increasing the pacing pulse output, which can result in an valid His bundle capture, conducted simultaneously along both the LBB and RBB.

[0089] In some cases, when the His bundle capture threshold is greater than the ventricular myocardial capture threshold, the His bundle pacing pulse may capture ventricular myocardial tissue (VM capture) without capturing the His bundle. Effective capture of the His bundle with a higher pacing pulse output results in effective His bundle capture, which may include capture of peripheral ventricular myocardium, i.e., non-selective His bundle capture. The computing device 240 may be configured to distinguish between effective and ineffective His bundle capture based on electrical asynchrony data (which may include only partial activation of the conduction system or only VM capture or complete loss of capture). In some cases, a relatively low His bundle pacing pulse that captures ventricular myocardium without capturing the His bundle may be delivered to establish baseline electrical asynchrony data during the period of His bundle non-capture. The computing device 240 may generate electrical asynchrony data as the His bundle pacing pulse output increases until effective His bundle capture is achieved, such that the computing device 240 can identify effective His bundle capture based on a comparison with the electrical asynchrony data generated during VM capture. In other examples, as the pacing pulse output decreases from an initial high level, the computing device 240 can distinguish between valid and invalid His bundle captures until a partial capture of the His bundle or only VM capture is identified, and then decrease further until a complete loss of capture is identified.

[0090] When computing device 240 determines in block 256 that electrical asynchrony data meets the valid His bundle capture criterion based on a comparative analysis of one or more electrical asynchrony metrics with predefined thresholds or the relative changes of one or more metrics, computing device 240 may generate a His bundle capture indication in block 258. The His bundle capture indication may include a notification generated on display 230 or the GUI of computing device 240, which generates an audible signal to transmit a wireless or wired signal to external device 50. Figure 1 This can be transmitted to the His bundle pacemaker or the wireless signal can be transmitted directly to the His bundle pacemaker, as an example. When an indication of His bundle capture is generated as a notification on the GUI of display 230 or computing device 240, the user can transmit the signal via wireless communication (e.g., The signal can be transmitted directly from the computing device 240 to the His bundle pacing device, or via another external device 50. Figure 1 The user can enter a command to transmit a notification to the His bundle pacemaker. In other examples, when the computing device 240 effectively detects His bundle capture, the computing device 240 transmits a His bundle capture notification to the His bundle pacemaker without user intervention.

[0091] In some examples, pacing output control parameters can be changed by the His bundle pacing device during His bundle pacing. For example, a predetermined number of pacing pulses can be delivered at each of a plurality of pacing pulse voltage amplitudes, such as 5 to 20 or more pulses delivered at each of two or more pacing pulse voltage amplitudes delivered in increments or decrements of 0.25V, 0.5V, 1.0V, or other selected voltage increments or decrements. The computing device 240 can detect a valid His bundle capture at block 256 based on electrical asynchrony data generated during His bundle pacing at different pacing pulse voltage amplitudes (and / or pulse widths). The computing device 240 generates a capture indication at block 258 in response to identifying a valid His bundle capture. In some examples, the computing device 240 can identify when a His bundle capture loss or invalid His bundle capture is detected and generate an invalid His bundle capture indication at block 258. In this way, the His bundle pacing device can receive notification or acknowledgment of both valid and invalid His bundle captures.

[0092] When computing device 240 is configured to distinguish between different types of His bundle captures, such as an invalid His bundle capture causing RBB or LBB capture but not both, or NSHB versus SHB capture, computing device 240 can generate different notifications to indicate the type of capture detected. In this way, when an invalid His bundle capture notification is generated, the His bundle pacing device can respond to the notification by increasing the pacing output to attempt to fully capture the His bundle and await confirmation from computing device 240 that a valid His bundle capture has been identified. In some examples, computing device 240 can generate a notification when an NSHB capture is identified and an SHB capture is identified as a change in His bundle pacing output.

[0093] By generating an indication of His bundle capture in box 258, computing device 240 provides a notification that can be transmitted directly or indirectly to the His bundle pacemaker via another device for the His bundle pacemaker to establish a His bundle capture detection threshold. Therefore, the His bundle pacemaker can establish a His bundle capture detection threshold by determining cardiac electrical signal characteristics in response to receiving the notification generated by computing device 240, while computing device 240 confirms that a valid His bundle capture is occurring. Cardiac electrical signal characteristics during periods of invalid His bundle capture (including His bundle capture loss) can also be determined by the His bundle pacemaker to allow the His bundle pacemaker to select a His bundle capture detection threshold that reliably distinguishes between valid His bundle captures and invalid capture types that can occur during His bundle pacing. The His bundle capture threshold can be determined by the control circuitry 80 of the His bundle pacemaker (…). Figure 3A QRS characteristic threshold is established to distinguish between different types of valid His bundle captures (e.g., SHB and NSHB captures) and different types of invalid His bundle captures (e.g., VM, RBB, or LBB captures only). In some examples, the His bundle pacing device control circuit 80 establishes a QRS characteristic threshold to distinguish between SHB and NSHB captures. In some cases, SHB captures may be required, while in others NSHB captures may be expected, which may depend at least in part on which has a higher capture threshold (and therefore a higher power requirement for generating the pacing pulse). Therefore, the computing device 240 can be configured to distinguish between SHB and NSHB captures and generate notifications about the type of valid His bundle capture detected. The His bundle pacing device has the improved ability to tailor the His bundle capture detection threshold for a given patient and a specific type of required valid His bundle capture (e.g., SHB or NSHB capture).

[0094] Figure 8 This is a flowchart 300 illustrating an example method for establishing a capture detection threshold, performed collaboratively by system 200 and a His bundle pacemaker. In block 302, control circuitry 80 of the His bundle pacemaker (e.g., IMD 14 or pacemaker 100) determines baseline QRS characteristics based on cardiac electrical signals received from sensing circuitry 86. One or more baseline QRS characteristics may be determined based on near-field signals received from near-field sensing channel 87, far-field signals received from far-field sensing channel 89, or both. The near-field and far-field signals are generated by the His bundle pacemaker sensing circuitry, for example, as described above. Figure 3 The sensing circuit 86 is described below. Figure 9 Examples of near-field and far-field signals that can be generated by the cardiac electrical signal sensing circuitry of a His bundle pacemaker are described.

[0095] The baseline QRS waveform characteristics determined by the His bundle pacing device at block 302 may include the QRS width and / or QRS area determined based on near-field and / or far-field signals received from sensing circuitry 86. In other examples, the QRS waveform characteristics determined at block 302 may include QRS polarity, QRS time delay, and / or QRS waveform template representing the overall shape or morphology of the QRS waveform within a specific time window. At block 302, a combination of two or more characteristics may be determined from near-field signals, far-field signals, or both near-field and far-field signals to establish baseline QRS waveform characteristics representing the uncaptured His bundle. In some examples, the baseline QRS waveform characteristics may be determined by control circuitry 80 when His bundle pacing is suppressed by control circuitry 80 or during RV-only pacing delivered by therapy delivery circuitry 84.

[0096] In block 304, the His bundle pacing device delivers His bundle pacing. Control circuitry 80 controls therapy delivery circuitry 84 to deliver His bundle pacing pulses according to programmed, default, or recently used pacing output control parameters. In some examples, the His bundle pacing pulse is delivered with a predetermined starting pulse output (e.g., pulse voltage amplitude for a given pacing pulse width) that is expected to capture the His bundle. In other examples, the pacing pulse output may be set to an initial low value, such as a low pacing pulse voltage amplitude that is not expected to capture the His bundle, or an initial high value, such as a high pacing pulse voltage amplitude that is expected to capture the His bundle.

[0097] In block 306, the His bundle pacing device waits for His bundle capture notification while generating and delivering His bundle pacing pulses. Telemetry circuitry 88 may receive a wireless communication signal directly from computing device 240 or from another external device 40, indicating that computing device 240 has identified (detected) a valid His bundle capture based on analysis of one or more electrical asynchrony metrics. If no His bundle capture notification is received within a predicted time period (e.g., 30 seconds, one minute, two minutes, or other selected time period), or if an invalid His bundle capture notification is received in block 306, control circuitry 80 may adjust the pacing pulse output in block 308. In some examples, the pacing pulse voltage amplitude is increased. In other examples, the pacing pulse width is increased. In still other examples, when an additional His bundle pacing electrode vector is available, the selection of at least one electrode for delivering the His bundle pacing pulse can be changed, for example, by switching the circuitry included in therapy delivery circuitry 84.

[0098] In block 304, His bundle pacing is delivered by therapy delivery circuit 84 with adjusted pacing output settings, and in block 306, control circuit 80 waits for His bundle capture notification. The process of adjusting pacing output control parameters, delivering His bundle pacing using the adjusted control parameters, and waiting for His bundle capture notification from the His bundle pacing device can be repeated multiple times until a valid His bundle capture is confirmed by computing device 240, and a notification is generated and received by the His bundle pacing device.

[0099] Upon receiving a His bundle capture notification, control circuitry 80 determines one or more characteristics of the cardiac electrical signal during confirmed effective His bundle pacing at the pacing output control parameters associated with the receipt of the His bundle capture notification. For example, QRS width, QRS area, QRS time delay to the immediately preceding His bundle pacing pulse, QRS polarity, QRS waveform template, and / or other QRS characteristics may be determined at block 310. In some examples, control circuitry 80 compares the determined characteristics to baseline characteristics at block 312 to verify a detectable change or difference between the QRS characteristics determined during His bundle capture and the same QRS characteristics determined during non-His bundle capture periods. If the QRS characteristics are determined to be substantially unchanged (e.g., within a threshold difference or percentage such as 10% or less), different QRS waveform characteristics may be determined at block 310 for monitoring effective His bundle capture.

[0100] In block 314, control circuitry 80 uses the QRS waveform characteristics determined during effective His bundle capture to set a His bundle capture detection threshold. For example, if the QRS width is determined by control circuitry 80 in block 310, control circuitry 80 of the His bundle pacemaker can set the capture detection threshold to the determined QRS width associated with His bundle capture detection plus a small offset, such as 5%, 10%, or 20% of the QRS width, or a fixed offset of 5 milliseconds, or other predetermined value, to allow for some variation in the QRS width that may occur during effective His bundle capture. When the baseline QRS characteristic value is determined during His bundle non-capture, the capture detection threshold established in block 314 can be set to a value between the value determined in block 310 and the baseline value determined in block 302, for example, at the midpoint between the values ​​or at different parts of the difference.

[0101] When computing device 240 is configured to generate notifications corresponding to different types of valid His bundle captures (e.g., SHB and NSHB captures), the His bundle pacemaker can determine one or more QRS features corresponding to each His bundle capture type notification, and establish thresholds for detecting and distinguishing His bundle capture types in block 314. Criteria for detecting different types of valid (e.g., SHB and NSHB captures) and invalid His bundle captures (e.g., RBB capture, LBB capture, VM-only capture) can be established by control circuitry 80 in block 314, each unique set of criteria relating to one or more capture detection thresholds established based on one or more corresponding QRS features determined from the sensed near-field and / or far-field cardiac electrical signals from the His bundle pacemaker.

[0102] Figure 9Figure 400 shows cardiac electrical signals that can be generated by a His bundle pacemaker. The cardiac electrical signals include evoked response QRS waveforms representing SHB capture (left column), NSHB capture (right column), and VM capture (middle column). In each example, the far-field cardiac electrical signal 402 and the corresponding His bundle near-field signal 412 are shown as being time-aligned with the corresponding His bundle pacing pulses 410, 415, or 417.

[0103] In the left column, the His bundle pacing pulse 410 causing SHB capture generates a His bundle near-field evoked response QRS waveform 414 that occurs after a time delay 420. During effective His bundle capture, the His bundle near-field QRS waveform 414 is positively polar and relatively narrow in some patients. The far-field evoked response QRS waveform 404 is also considered relatively narrow, positively polar, and occurs after the time delay. The time delay 420 from the effective His bundle pacing pulse 410 until the QRS waveform 414 is due to the time required for depolarization along the His-Purkinje conduction system.

[0104] In the middle column, the far-field evoked response QRS waveform 406 and the corresponding near-field evoked response QRS waveform 416 are shown after an ineffective His bundle pacing pulse 415 that captures only ventricular myocardial tissue without capturing the His bundle. Since there is no conduction along the His-Purkinje conduction system after the ineffective His bundle pacing pulse 415, the near-field QRS waveform 416 appears after a time delay 422, which is relatively shorter than the time delay 420 of the QRS waveform 414, during effective SHB capture. The near-field evoked response QRS waveform 416 during VM capture is relatively wide and has negative polarity. The wide QRS waveform width is evidence of increased electrical asynchrony during ineffective His bundle capture.

[0105] The far-field QRS waveform 408 and the near-field QRS waveform 418 during NSHB capture are shown in the right column. In the near-field His signal 412, the QRS waveform 416 (middle column) during invalid His capture (VM capture) and the QRS waveform 418 (right column) during effective His capture are substantially similar. Both signals 416 and 418 appear earlier than their respective His pacing pulses 415 and 417, both are negative in polarity, and both have a relatively wider QRS waveform width than the SHB QRS waveform 414. Therefore, effective His pacing leading to SHB capture can be actively detected from the near-field His signal 412, for example, based on the longer time delay 420 up to QRS waveform 414, positive polarity (at least in some patients), a relatively narrow QRS waveform width, a relatively small QRS waveform area, or any combination thereof. The similarity in timing and morphology between the His bundle near-field evoked response signal 418 during a valid NSHB capture and the near-field evoked response signal 416 during an invalid VM capture may make it difficult to distinguish these two types of captures from the His bundle near-field signal in some patients, especially when the far-field signal 402 is unavailable in the His bundle pacemaker. Therefore, when a notification confirming a valid His bundle capture is received from the computer device 240, the His bundle pacemaker's control circuitry 80 can establish a His bundle capture detection threshold based on QRS waveform characteristics, which can improve the performance of the His bundle pacemaker in detecting valid His bundle captures, even if valid His bundle captures include captures of nearby ventricular myocardial tissue.

[0106] exist Figure 9 In the example, the far-field evoked QRS waveform 408 during a valid NSHB capture is narrower than the far-field QRS waveform 406 during a invalid VM capture. When the far-field signal 402 is available in the His bundle pacemaker, establishing the His bundle capture detection threshold may include establishing the threshold based on characteristics of the far-field signal (e.g., based on the width, area, and / or QRS waveform morphology of the far-field evoked response signal). The His bundle capture detection threshold established by the control circuit 80 based on the far-field QRS waveform can increase the reliability of the His bundle pacemaker in detecting valid His bundle capture and can be used alone or in combination with a capture detection threshold based on the near-field QRS waveform. The threshold for QRS width, the threshold for QRS area, or the waveform template for His bundle capture detection can be determined by the His bundle pacemaker in conjunction with the computing device 240. Figure 4 The electrical asynchrony data and His bundle capture notification generated by the far-field signal 402 and / or near-field signal 412 can be used to establish or determine the His bundle capture detection threshold for a given characteristic applied to His bundle capture monitoring.

[0107] Figure 10 This is a flowchart 500 illustrating an example method for monitoring and maintaining effective His bundle capture using an established His bundle capture detection threshold by a His bundle pacing device. In some examples, the procedures of flowchart 500 may be executed when each His bundle pacing pulse is delivered by the His bundle pacing device. Confirming effective His bundle capture with each pacing pulse enables the His bundle pacing device to track the overall effectiveness of His bundle pacing, for example, by determining the percentage of His bundle pacing pulses in which His bundle capture is detected out of all delivered His bundle pacing pulses. In other examples, the procedures of flowchart 500 may be executed once daily, once hourly, once per minute, or at other frequencies or according to a predetermined capture monitoring schedule. In some examples, the procedures of flowchart 500 are executed when a triggering event occurs, such as detecting a change in lead impedance or other changes that may be correlated with or indicate a change in the His bundle pacing capture threshold.

[0108] In box 502, His bundle pacing is delivered according to the programmed pacing therapy protocol and His bundle pacing control parameters. In some examples, the procedure of flowchart 500 may be performed as part of a pacing capture threshold test, wherein the His bundle pacing pulse delivered in box 502 is one of a sequence of delivered variable pacing amplitude pulses (or variable pulse widths) to determine the minimum pulse amplitude (or minimum pulse width) that results in effective His bundle capture.

[0109] In box 504, after the therapy delivery circuit 84 delivers the His bundle pacing pulse, the cardiac electrical signal characteristics, specifically the QRS waveform characteristics, are determined by the control circuit 80 based on the cardiac electrical signal received from the sensing circuit 86, such as in conjunction with... Figure 8 The control circuit 80 has established capture detection thresholds for the sensing circuit. In some examples, when multiple capture detection thresholds are established, multiple QRS waveform features can be determined by the control circuit 80. In block 506, the control circuit 80 compares the determined cardiac electrical signal features (one or more) with the corresponding previously established capture detection thresholds (one or more). If the comparison (one or more) between the determined QRS waveform features (one or more) and the established capture detection thresholds (one or more) satisfies the His bundle capture detection criterion, the control circuit 80 detects His bundle capture in block 508.

[0110] When a valid His bundle capture is not detected in the control circuit 80 at block 508, for example, if the capture detection threshold is not met based on one or more defined QRS characteristics, the control circuit 80 may signal the therapy delivery circuit 84 at block 510 to adjust the pacing pulse output, for example, by increasing the pacing pulse amplitude and / or pulse width. The next His bundle pacing pulse may be delivered at block 502 according to the increased pulse output (or other adjustments to the His bundle pacing control parameters, such as the pacing electrode vector), and the process of detecting capture using the previously established capture detection threshold is repeated.

[0111] When His bundle capture monitoring includes maintaining the percentage of effective His bundle pacing pulses by control circuitry 80, the percentage of detected capture pacing pulses can be updated in block 512 after effective His capture (or ineffective His capture) is determined in block 508. The percentage updated by control circuitry 80 in block 512 can be determined as the percentage of all delivered His bundle pacing pulses of His pacing therapy delivered by therapy delivery circuitry 84, which causes effective His bundle capture detection by control circuitry 80 from therapy initiation or within a predetermined time interval (e.g., within a 24-hour interval or within a week, as an example). If the process of flowchart 500 is performed by the His bundle pacing device as part of a capture threshold test, the pacing pulse voltage amplitude and / or pulse width corresponding to effective capture detection (“Yes” branch) or ineffective capture detection (“No” branch) in block 508 can be stored in memory 82 in block 512 so that control circuitry 80 can determine the minimum pacing output at which effective His bundle capture is detected based on the His bundle capture threshold.

[0112] After updating the data related to His capture monitoring in memory 82 at block 512, control circuit 80 continues the process of flowchart 500 by returning to block 502 to control the delivery of the next His bundle pacing pulse (via therapy delivery circuit 84), which can be delivered with adjusted His bundle pacing output control parameters. In this way, the His bundle pacing device is configured to maintain or promote effective His bundle capture by determining whether effective His bundle capture has occurred based on established His bundle capture detection thresholds (one or more) and adjusting the His bundle pacing control parameters in response to the absence of effective His bundle capture, in order to restore effective His bundle capture.

[0113] Some of the techniques disclosed herein are described by the following illustrative embodiments.

[0114] Example 1. A medical device system comprising:

[0115] An electrode device comprising a plurality of external electrodes configured to monitor a plurality of surface electrical signals of a patient; and

[0116] A computing device, comprising a processing circuitry system coupled to an electrode device, and configured to:

[0117] During the delivery of His bundle pacing pulses, cardiac electrical synchrony data are generated based on surface electrical signals received from multiple external electrodes.

[0118] Effective His bundle capture is identified using His bundle pacing pulses based on electrical asynchrony data, where effective His bundle capture includes captures of both the left and right branches of the His bundle; and

[0119] An instruction to generate a His bundle capture is generated in response to the identification of a valid His bundle capture.

[0120] Example 2. The system according to Example 1 further includes a His bundle pacing device, the His bundle pacing device comprising:

[0121] A sensing circuit configured to sense cardiac electrical signals;

[0122] Therapeutic delivery circuitry, configured to deliver His bundle pacing pulses; and

[0123] The control circuit, which is connected to the sensing circuit and the therapy delivery circuit, is configured as follows:

[0124] Receive communication signals corresponding to the His beam capture indication generated by the computing device;

[0125] In response to receiving a communication signal, the characteristics of the cardiac electrical signal are determined; and

[0126] The capture detection threshold is established based on the characteristics of the determined cardiac electrical signals.

[0127] Example 3. The system according to Example 2, wherein the control circuit is further configured to control the therapy delivery circuit to maintain effective His bundle capture in such a way as:

[0128] Determine the characteristics of the cardiac electrical signal received from the sensing circuit after the His bundle pacing pulse delivered by the therapy delivery circuit;

[0129] The features are compared with the established capture detection threshold; and

[0130] In response to a characteristic that does not meet the established capture detection threshold, the pacing control parameters used by the therapy delivery circuit are adjusted to deliver His bundle pacing pulses.

[0131] Example 4. A system according to any one of Examples 2 to 3, wherein the computing device is configured to generate a notification by transmitting a wireless signal.

[0132] The His bundle pacing device includes telemetry circuitry configured to receive wireless signals directly from a computing device.

[0133] Example 5. A system according to any one of Examples 2 to 4, wherein the control circuit is configured to determine the characteristics of the cardiac electrical signal by determining at least one of the following:

[0134] The QRS width, QRS area, QRS polarity, QRS morphology, and QRS time delay from the His bundle pacing pulse.

[0135] Example 6. A system according to any one of Examples 1 to 5, wherein the computing device is further configured as follows:

[0136] Generate baseline electrical synchrony data in the absence of His bundle pacing pulses; and

[0137] His bundle capture is identified by comparing the electrical asynchrony data generated during the delivery of the His bundle pacing pulse with baseline electrical asynchrony data.

[0138] Example 7. The system according to Example 6, wherein baseline electrical asynchrony data is generated during the delivery of pacing pulses that capture the ventricular myocardium without capturing the His bundle.

[0139] Example 8. A system according to any one of Examples 1 to 7, wherein the computing device is configured as follows:

[0140] Electrical asynchrony data is generated in the following manner:

[0141] The electrical activation time is determined based on multiple QRS waveforms received from the electrode device, and

[0142] Determine a measure of electrical activation time; and

[0143] Effective His bundle capture is identified by comparing a measure of electrical activation time with a threshold.

[0144] Example 9. A system according to any one of Examples 1 to 8, wherein the computing device is further configured as follows:

[0145] Electrical asynchrony data is generated in the following manner:

[0146] The right ventricular metric for electrical activation time is determined based on a first plurality of QRS waveforms corresponding to the surface electrical signals received along the patient's right side from the electrode device.

[0147] The left ventricular metric for electrical activation time is determined based on a second set of QRS waveforms of surface electrical signals received from external electrodes of the electrode device along the patient's left side; and

[0148] Valid His bundle captures can be identified using the following methods:

[0149] Compare right ventricular and left ventricular measurements with the corresponding right bundle branch capture thresholds and left bundle branch capture thresholds; and

[0150] A valid His bundle capture is identified in response to both the right ventricular and left ventricular measurements satisfying the corresponding right bundle branch capture threshold and left bundle branch capture threshold.

[0151] Example 10. A system according to any one of Examples 1 to 9, wherein the computer device is further configured to:

[0152] Based on the analysis of the generated electrical asynchrony data, at least two different types of His bundle capture were distinguished from selective His bundle capture, non-selective His bundle capture, ventricular myocardial capture only, right bundle branch capture, and left bundle branch capture; and

[0153] Generate notifications corresponding to the types of His bundle captures that distinguish them.

[0154] Example 11. A system according to any one of Examples 1 to 10, wherein the electrode device includes an electrode array coupled to a substrate configured to surround the patient's torso.

[0155] Example 12. A method performed by a medical device system, comprising:

[0156] Receives surface electrical signals from an electrode device containing multiple external electrodes via a computing device;

[0157] Electrical asynchrony data is generated by a computing device based on surface electrical signals received from multiple external electrodes during the delivery of His bundle pacing pulses;

[0158] Effective His bundle capture is identified by a computing device based on electrical asynchrony data, wherein effective His bundle capture includes capture of both the left and right branches of the His bundle; and

[0159] In response to the identification of a valid His bundle capture, the computing device generates an indication of His bundle capture.

[0160] Example 13. The method according to Example 12 further includes:

[0161] Therapeutic delivery circuitry of the His bundle pacing device delivers His bundle pacing pulses;

[0162] The sensing circuit of the His bundle pacemaker senses cardiac electrical signals;

[0163] The telemetry circuit of the His bundle pacing device receives a communication signal corresponding to the His bundle capture indication generated by the computing device;

[0164] The characteristics of the sensed cardiac electrical signal are determined by the control circuitry of the His bundle pacemaker in response to the received communication signal; and

[0165] A capture detection threshold is established based on the defined characteristics of the sensed cardiac electrical signals.

[0166] Example 14. The method according to Example 13 further includes maintaining His bundle trapping by:

[0167] Determine the characteristics of the cardiac electrical signal received from the sensing circuit after the His bundle pacing pulse delivered by the therapy delivery circuit;

[0168] The features are compared with the established capture detection threshold; and

[0169] In response to a characteristic that does not meet the established capture detection threshold, the pacing control parameters used by the therapy delivery circuit are adjusted to deliver His bundle pacing pulses.

[0170] Example 15. The method according to any one of Examples 13 to 14 further comprises:

[0171] Notifications are generated by transmitting wireless signals from a computing device; and

[0172] The His bundle pacing device receives wireless signals directly from the computing device.

[0173] Example 16. The method according to any one of Examples 13-15, wherein determining the characteristics of the cardiac electrical signal comprises determining at least one of the following:

[0174] The QRS width, QRS area, QRS polarity, QRS morphology, and QRS time delay from the His bundle pacing pulse.

[0175] Example 17. The method according to any one of Examples 12 to 16 further comprises:

[0176] In the absence of His bundle pacing pulses, baseline electrical asynchrony data are generated by a computing device; and

[0177] His bundle capture is identified by comparing the electrical asynchrony data generated during the delivery of the His bundle pacing pulse with baseline electrical asynchrony data.

[0178] Example 18. The method according to Example 17 further includes generating baseline electrical asynchrony data during the delivery of pacing pulses that capture the ventricular myocardium without capturing the His bundle.

[0179] Example 19. The method according to any one of Examples 12 to 18 further comprises:

[0180] The generated electrical asynchrony data includes:

[0181] The electrical activation time is determined based on multiple QRS waveforms received from the electrode device, and

[0182] Determine a measure of electrical activation time; and

[0183] Identifying effective His bundle capture involves comparing a metric of electrical activation time with a threshold.

[0184] Example 20. The method according to any one of Examples 12 to 19, further comprising:

[0185] The generated electrical asynchrony data includes:

[0186] The right ventricular metric for electrical activation time is determined based on a first plurality of QRS waveforms corresponding to the surface electrical signals received along the patient's right side from the electrode device.

[0187] The left ventricular metric for electrical activation time is determined based on a second set of QRS waveforms of surface electrical signals received from external electrodes of the electrode device along the patient's left side; and

[0188] Identifying valid His bundle captures includes:

[0189] Compare right ventricular and left ventricular measurements with the corresponding right bundle branch capture thresholds and left bundle branch capture thresholds; and

[0190] A valid His bundle capture is identified in response to both the right ventricular and left ventricular measurements satisfying the corresponding right bundle branch capture threshold and left bundle branch capture threshold.

[0191] Example 21. The method according to any one of Examples 12 to 20, further comprising:

[0192] Based on the analysis of the generated electrical asynchrony data, at least two different types of His bundle capture were distinguished from selective His bundle capture, non-selective His bundle capture, ventricular myocardial capture only, right bundle branch capture, and left bundle branch capture; and

[0193] Generate notifications corresponding to the types of His bundle captures that distinguish them.

[0194] Example 22. The method according to any one of Examples 12 to 21, wherein receiving a body surface electrical signal from an electrode device comprises receiving a body surface electrical signal from an array of a plurality of external electrodes coupled to a substrate configured to surround the patient's torso.

[0195] Example 23. A non-transitory computer-readable storage medium comprising a set of instructions, which, when executed by a processor of a computing device of a medical device system, cause the computing device to:

[0196] Receives surface electrical signals from an electrode device containing multiple external electrodes;

[0197] During the delivery of His bundle pacing pulses, electrical asynchrony data is generated based on surface electrical signals received from multiple external electrodes.

[0198] Effective His bundle capture is identified based on electrical asynchrony data, where effective His bundle capture includes capture of both the left and right branches of the His bundle; and

[0199] An instruction to generate a His bundle capture is generated in response to the identification of a valid His bundle capture.

[0200] It should be understood that, depending on the example, certain actions or events of any method described herein may be performed in a different order, may be added, combined, or may be excluded entirely (e.g., not all described actions or events are necessary for the practice of the method). Furthermore, in some examples, actions or events may be performed simultaneously rather than sequentially, for example, through multithreaded processing, interrupt handling, or multiple processors. Additionally, although some aspects of this disclosure are described as being performed by a single circuit or unit for clarity, it should be understood that the techniques of this disclosure may be performed by a combination of circuitry or components associated with, for example, a medical device.

[0201] In one or more examples, the described functionality may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functionality may be stored on a computer-readable medium in the form of one or more instructions or code and may be executed by a hardware-based processing unit. A computer-readable medium may include a computer-readable storage medium, which corresponds to a tangible medium such as a data storage medium (e.g., RAM, ROM, EEPROM, flash memory, or any other medium that can be used to store the required program code in the form of instructions or data structures and is accessible by a computer).

[0202] The instructions can be executed by one or more processors, such as one or more digital signal processors (DSPs), general-purpose microprocessors, application-specific integrated circuits (ASICs), field-programmable arrays (FPGAs), or other equivalent integrated or discrete logic circuit systems. Therefore, as used herein, the term "processor" can refer to any of the foregoing structures or any other structure suitable for implementing the techniques described herein. Furthermore, the techniques can be implemented entirely within one or more circuit or logic elements.

[0203] Therefore, a medical device system has been presented in the foregoing description with reference to specific examples. It should be understood that the various aspects disclosed herein can be combined in different combinations than those shown in the accompanying drawings. It should be understood that various modifications may be made to the reference examples without departing from the scope of this disclosure and the appended claims.

Claims

1. A medical device system, comprising: an electrode apparatus comprising a plurality of external electrodes configured to monitor a plurality of body surface electrical signals of a patient; and a computing apparatus coupled to the electrode apparatus and comprising processing circuitry configured to: generate cardiac electrical dyssynchrony data from the body surface electrical signals received from the plurality of external electrodes during delivery of His-bundle pacing pulses; identifying effective His-bundle capture by the His-bundle pacing pulses based on the cardiac electrical dyssynchrony data, wherein the effective His-bundle capture includes capture of both the left and right bundle branches of the His-bundle; and generate an indication of His-bundle capture in response to identifying the effective His-bundle capture, wherein the cardiac electrical dyssynchrony data relates to electrical dyssynchrony of a right ventricle and a left ventricle, the medical device system further comprising a His-bundle pacing device, the His-bundle pacing device comprising: sensing circuitry configured to sense a cardiac electrical signal; therapy delivery circuitry configured to deliver the His-bundle pacing pulses; and control circuitry coupled to the sensing circuitry and the therapy delivery circuitry and configured to: receive a communication signal corresponding to the indication of His-bundle capture generated by the computing apparatus; determine a characteristic of the cardiac electrical signal in response to receiving the communication signal; and establish a capture detection threshold based on the determined characteristic of the cardiac electrical signal.

2. The medical device system of claim 1, wherein the control circuitry is further configured to control the therapy delivery circuitry to maintain effective His-bundle capture by: determining the characteristic of the cardiac electrical signal received from the sensing circuitry following a His-bundle pacing pulse delivered by the therapy delivery circuitry; comparing the characteristic to the established capture detection threshold; and adjusting a pacing control parameter used by the therapy delivery circuitry to deliver the His-bundle pacing pulses in response to the characteristic not satisfying the established capture detection threshold.

3. The medical device system of claim 1 or 2, wherein the computing apparatus is configured to generate a notification by transmitting a wireless signal, the His-bundle pacing device comprising telemetry circuitry configured to receive the wireless signal directly from the computing apparatus.

4. The medical device system of claim 1 or 2, wherein the control circuitry is configured to determine the characteristic of the cardiac electrical signal by determining at least one of: a QRS width, a QRS area, a QRS polarity, a QRS morphology, and a QRS time delay from a His-bundle pacing pulse.

5. The medical device system of claim 1 or 2, wherein the computing apparatus is further configured to: generate baseline electrical dyssynchrony data in the absence of His-bundle pacing pulses; and identify His-bundle capture by comparing the cardiac electrical dyssynchrony data generated during delivery of His-bundle pacing pulses to the baseline electrical dyssynchrony data.

6. The medical device system of claim 5, wherein the baseline electrical dyssynchrony data is generated during delivery of pacing pulses that capture ventricular myocardium without capturing the His-bundle.

7. The medical device system of claim 1 or 2, wherein the computing apparatus is configured to: generate electrical dyssynchrony data by: determining an electrical activation time from a plurality of QRS waveforms received from the electrode apparatus, and determining a measure of the electrical activation time; and identifying the effective His-bundle capture by comparing the measure of the electrical activation time to a threshold value.

8. The medical device system of claim 1 or 2, wherein the computing apparatus is further configured to: generate electrical dyssynchrony data by: determining a right ventricular measure of electrical activation time from a first plurality of QRS waveforms received from the electrode apparatus corresponding to body surface electrical signals received along the patient’s right side, and determining a left ventricular measure of electrical activation time from a second plurality of QRS waveforms of the body surface electrical signals received from the external electrodes of the electrode device along the left side of the patient; and identify an effective His-bundle capture by: comparing the right ventricular measure and the left ventricular measure to respective right bundle branch capture threshold values and left bundle branch capture threshold values; and identifying an effective His-bundle capture in response to both the right ventricular measure satisfying the respective right bundle branch capture threshold value and the left ventricular measure satisfying the left bundle branch capture threshold value.

9. The medical device system of claim 1 or 2, wherein the computing apparatus is further configured to: differentiate at least two different types of His-bundle capture from selective His-bundle capture, non-selective His-bundle capture, ventricular myocardium only capture, right bundle branch capture, and left bundle branch capture based on analysis of the generated electrical dyssynchrony data; and generate a notification corresponding to the differentiated type of His-bundle capture.

10. The medical device system of claim 1 or 2, wherein the electrode apparatus includes an electrode array coupled to a substrate configured to encircle a torso of the patient.

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