ECG bands for patient screening and tuning for bradycardia therapy

Abstract

Multiple external electrodes are used to monitor cardiac electrical activity from the patient's tissues. One or more cardiac measurements of the patient are generated based on the monitored electrical activity. If the patient has right bundle branch block, the one or more cardiac measurements are used based on a first global synchrony measure to determine whether the patient is a candidate for a cardiac resynchronization therapy (CRT) device. If the patient does not have right bundle branch block, the one or more cardiac measurements are used based on a second global synchrony measure to determine whether the patient is a candidate for a cardiac resynchronization therapy (CRT) device.

Description

[0001] This disclosure relates to systems and methods for determining whether a patient is a candidate for cardiac resynchronization therapy (CRT) and whether bradycardia pacing therapy is effective.

[0002] Implantable medical devices (IMDs), such as implantable pacemakers, cardioverter-defibrillators, or pacemaker-cardioverter-defibrillators, deliver therapeutic electrical stimulation to the heart. IMDs can provide pacing to resolve bradycardia, or pacing or shock to terminate rapid arrhythmias such as tachycardia or fibrillation. In some cases, the medical device can sense the heart's inherent depolarization, detect arrhythmias based on (or the absence of) inherent depolarization, and, if an arrhythmia is detected based on inherent depolarization, control the delivery of electrical stimulation to the heart.

[0003] IMD can also offer cardiac resynchronization therapy (CRT), a form of pacing. CRT involves delivering pacing pulses to the left ventricle or both the left and right ventricles. The timing and location of the pacing pulses delivered to the ventricles can be selected to improve the coordination and efficiency of ventricular contractions.

[0004] In addition to the implantable medical device itself, the system used for implanting the medical device may also include a workstation or other equipment. In some cases, this additional equipment assists a physician or other technician in placing the intracardiac lead at a specific location on the heart. In some cases, the equipment provides the physician with information about the electrical activity of the heart and the location of the intracardiac lead. The equipment can perform functions similar to the medical device, including delivering electrical stimulation to the heart and sensing cardiac depolarization. In some cases, the equipment may include devices for obtaining an electrocardiogram (ECG) via electrodes on the patient's surface or skin. More specifically, the patient may have multiple electrodes on an ECG belt or vest around the patient's torso. After the belt or vest has been secured to the torso, the physician can perform a series of tests to assess the patient's cardiac response. The assessment process may include detecting a baseline rhythm in which no electrical stimulation is delivered to the cardiac tissue and another rhythm after electrical stimulation is delivered to the cardiac tissue.

[0005] ECG electrodes placed on a patient's body surface can be used for a variety of therapeutic purposes (e.g., cardiac resynchronization therapy), including optimizing lead placement, pacing parameters, etc., based on one or more metrics derived from signals captured by the ECG electrodes. For example, electrical heterogeneity information can come from the electrical activation time calculated from multiple electrodes on the body surface. Summary of the Invention

[0006] The exemplary systems and methods described herein can be configured to assist users (e.g., physicians) in deciding and / or configuring cardiac therapies (e.g., selecting which patients receive specific cardiac therapies, or configuring cardiac therapies to be performed on patients during and / or after implantation of a cardiac therapy device). The systems and methods can be described as non-invasive. For example, the systems and methods may not require implantable devices such as leads, probes, sensors, catheters, etc., to assess and configure cardiac treatment. Instead, the systems and methods can utilize non-invasive electrical measurements obtained using multiple external electrodes attached, for example, to the patient's skin around the torso.

[0007] One embodiment relates to a system for cardiac assessment, comprising an electrode device including multiple external electrodes to be placed near a patient's skin. A computing device including a processing circuitry system is operatively coupled to the electrode device. The computing device is configured to use the multiple external electrodes to monitor electrical activity from the patient's tissues. One or more cardiac measurements of the patient are generated based on the monitored electrical activity. If the patient has right bundle branch block, the one or more cardiac measurements are used based on a first global synchrony measure to determine whether the patient is a candidate for a cardiac resynchronization therapy (CRT) device. If the patient does not have right bundle branch block, the one or more cardiac measurements are used based on a second global synchrony measure to determine whether the patient is a candidate for a cardiac resynchronization therapy (CRT) device.

[0008] One implementation relates to a method for cardiac assessment, comprising: using multiple external electrodes to monitor electrical activity from a patient's tissues; generating one or more cardiac metrics for the patient based on the monitored electrical activity; if the patient has right bundle branch block, using the one or more cardiac metrics based on a first global synchrony metric to determine whether the patient is a candidate for a cardiac resynchronization therapy (CRT) device; if the patient does not have right bundle branch block, using the one or more cardiac metrics based on a second global synchrony metric to determine whether the patient is a candidate for a cardiac resynchronization therapy (CRT) device.

[0009] One embodiment relates to a system for cardiac assessment, comprising an electrode device including multiple external electrodes to be placed near the skin of a patient. A computing device including a processing circuitry system is operatively coupled to the electrode device. The computing device is configured to use the multiple external electrodes to monitor cardiac electrical activity from the patient's tissues during bradycardia pacing delivery to the patient's heart. Electrical heterogeneity information (EHI) is generated based on the cardiac electrical activity monitored during bradycardia pacing delivery to the patient's heart. The effectiveness of bradycardia pacing therapy is determined based on the generated EHI, wherein the EHI reflects the normalization of conduction in the patient population during bradycardia pacing.

[0010] One implementation relates to a method for cardiac assessment, comprising: using multiple external electrodes to monitor cardiac electrical activity from the patient's tissues during bradycardia pacing delivery to the patient's heart; generating electrical heterogeneity information (EHI) based on the monitored cardiac electrical activity during bradycardia pacing delivery to the patient's heart; and determining the effectiveness of bradycardia pacing therapy based on the generated EHI, wherein the EHI reflects the normalization of conduction in the patient population during bradycardia pacing.

[0011] Traditional ECG-based measures, such as QRS duration / morphology, have been used as guidelines for CRT, but are generally not very sensitive or specific. The result is for patients with Class II indications (those without a left bundle or with a narrower QRS in the left bundle).

[0012] ECG straps are multi-electrode body surface mapping systems that provide measurements of electrical asynchrony. Variations in electrical asynchrony from inherent to CRT / LV pacing have proven useful for titrating LV lead placement and optimizing device programming parameters (vector, timing, etc.). This article describes the use of ECG straps in bradycardia populations to provide feedback on pacing therapy selection (e.g., His bundle / LBB zone pacing versus conventional RV lead or a combination of both, different RV lead placements). Attached Figure Description

[0013] Figure 1 A diagram of an exemplary system including an electrode device, a display device, and a computing device.

[0014] Figures 2 to 3 A diagram of an exemplary external electrode device for measuring the surface potential of the torso.

[0015] Figures 4 to 5 An exemplary method for determining whether a patient is a candidate for a cardiac resynchronization device (CRT) is shown.

[0016] Figures 6 to 8 A graph showing the intrinsic SDAT versus intrinsic LVAT of 115 patients is presented.

[0017] Figures 9 to 10 An exemplary method for determining whether bradycardia pacing therapy is effective is shown.

[0018] Figure 11 This is a diagram of an illustrative system including an illustrative implantable medical device (IMD).

[0019] Figure 12A yes Figure 11 An illustrative diagram of the IMD.

[0020] Figure 12B It is placed in Figure 12A An enlarged view of the distal end of the electrical lead in the left ventricle.

[0021] Figure 13 This is a conceptual diagram of an illustrative cardiac therapy system that includes an intracardiac medical device implanted in the patient's heart and a separate medical device positioned outside the patient's heart.

[0022] Figure 14 yes Figure 13 An enlarged conceptual diagram of the anatomy of an intracardiac medical device and a patient's heart.

[0023] Figure 15 This is a conceptual diagram of a patient's heart in a standard 17-segment view of the left ventricle, showing various electrode implantation sites, intended for use with the illustrative systems and devices described herein.

[0024] Figure 16A This is a block diagram illustrating an IMD (Information Management Device).

[0025] Figure 16B This is another diagram illustrating IMD. Detailed Implementation

[0026] In the following detailed description of the illustrative embodiments, reference is made to the accompanying drawings, which form part of the embodiments and illustrate specific embodiments that can be practiced by way of illustration. It should be understood that other embodiments may be utilized and structural changes may be made without departing from (e.g., still falling within) the scope of this disclosure presented herein.

[0027] Reference Figures 1 to 1 2. Description of Illustrative Systems and Methods. It will be apparent to those skilled in the art that elements or processes of one embodiment can be used in combination with elements or processes of other embodiments, and possible embodiments of such systems, methods, and apparatuses using combinations of features set forth herein are not limited to those shown in the figures and / or the specific embodiments described herein. Furthermore, it will be appreciated that the embodiments described herein may include many elements that are not necessarily shown to scale. Still further, it will be appreciated that the timing of the processes and the size and shape of the various elements herein may be modified but still fall within the scope of this disclosure; however, certain timings, one or more shapes and / or sizes, or element types may be preferred over others.

[0028] Multiple external electrodes positioned on or around a patient's surface or skin can be used to measure or monitor multiple electrocardiogram (ECG) signals (e.g., trunk surface potential). ECG signals can be used to evaluate and configure cardiac therapies, such as those provided by implantable medical devices performing cardiac resynchronization therapy (CRT), for example. As described herein, ECG signals can be acquired or obtained non-invasively because, for example, implantable electrodes may not be used to measure ECG signals. Furthermore, ECG signals can be used to determine cardiac electrical activation time, which can be used to generate various metrics (e.g., electrical heterogeneity information) that can be used by a user (e.g., a physician) to optimize one or more settings or parameters of a cardiac therapy (e.g., pacing therapy) (such as CRT).

[0029] Various illustrative systems, methods, and graphical user interfaces can be configured to noninvasively assist users (e.g., physicians) in assessing cardiac health and / or configuring (e.g., optimizing) cardiac therapies using electrode devices, display devices, and computing devices, including external electrodes. Figure 1 An illustrative system 100 is described, comprising an electrode device 110, a computing device 140, and a remote computing device 160.

[0030] The electrode device 110 shown in the figure includes a plurality of electrodes incorporated or included within a bandage wrapped around the chest or torso of the patient 14. The electrode device 110 is operatively coupled to a computing device 140 (e.g., via a wired or wireless connection) to provide electrical signals from each of the electrodes to the computing device 140 for analysis, evaluation, etc. An illustrative electrode device is described in U.S. Patent No. 9,320,446, entitled “Bioelectric Sensor Device and Methods,” filed March 27, 2014, and published March 26, 2016, which is incorporated herein by reference in its entirety. Further reference will be made to… Figures 2 to 3 A more detailed description of the illustrative electrode device 110.

[0031] Although not described herein, the illustrative system 100 may further include an imaging device. The imaging device can be any type of imaging device configured to non-invasively image or provide an image of at least a portion of a patient. For example, in addition to non-invasive tools such as contrast solutions, the imaging device may provide an image of the patient without using any components or parts that may be located within the patient's body. It should be understood that the illustrative systems, methods, and interfaces described herein may further utilize the imaging device to provide non-invasive assistance to a user (e.g., a physician) to position or place one or more pacing electrodes near a patient's heart in conjunction with a cardiac therapy configuration.

[0032] For example, illustrative systems and methods can provide image-guided navigation for navigating leads, leadless electrodes, wireless electrodes, catheters, etc., within a patient, while also providing non-invasive cardiac therapy configurations, including determining effective or optimal pre-excitation intervals, such as the AV and VV intervals. Illustrative systems and methods using imaging devices and / or electrode devices can be described in U.S. Patent Application Publication No. 2014 / 0371832, issued to Ghosh, December 18, 2014; U.S. Patent Application Publication No. 2014 / 0371833, issued to Ghosh et al., December 18, 2014; U.S. Patent Application Publication No. 2014 / 0323892, issued to Ghosh et al., October 30, 2014; and U.S. Patent Application Publication No. 2014 / 0323882, issued to Ghosh et al., October 20, 2014, each of which is incorporated herein by reference in its entirety.

[0033] The imaging device can be configured to capture X-ray images and / or any other alternative imaging modality. For example, the imaging device can be configured to capture images or image data using isocentric fluoroscopy, biplane fluoroscopy, ultrasound, computed tomography (CT), multi-slice computed tomography (MSCT), magnetic resonance imaging (MRI), high-frequency ultrasound (HIFU), optical coherence tomography (OCT), intravascular ultrasound (IVUS), two-dimensional (2D) ultrasound, three-dimensional (3D) ultrasound, four-dimensional (4D) ultrasound, intraoperative CT, intraoperative MRI, etc. Furthermore, it should be understood that the imaging device can be configured to capture multiple consecutive images (e.g., sequentially) to provide video frame data. In other words, multiple images captured by the imaging device over time can provide video frames, or motion pictures, data. Exemplary systems employing ultrasound can be found in U.S. Patent Application Publication No. 2017 / 0303840, entitled “Non-invasive Assessment of Cardiac Resynchronization Therapy,” granted to Stadler et al., which is incorporated herein by reference in its entirety. Additionally, these images can be obtained and displayed in two, three, or four dimensions. In more advanced forms, four-dimensional surface rendering of the heart or other areas of the body can also be achieved by combining cardiac data or other soft tissue data from mapping or preoperative image data captured from MRI, CT, or echocardiographic modalities. Image datasets from mixed modalities, such as positron emission tomography (PET) combined with CT or single-photon emission computed tomography (SPECT) combined with CT, may also provide functional image data superimposed on anatomical data, for example, for navigating implantable devices to target locations within the heart or other areas of interest.

[0034] Systems and / or imaging devices that can be used in conjunction with the illustrative systems and methods described herein are described in the following U.S. Patent Application Publication No. 2005 / 0008210, issued January 13, 2005, to Evron et al.; U.S. Patent Application Publication No. 2006 / 0074285, issued April 6, 2006, to Zakh et al.; U.S. Patent No. 8,731,642, issued May 20, 2014, to Zakh et al.; U.S. Patent No. 8,861,830, issued October 14, 2014, to Brada et al.; U.S. Patent No. 6,980,675, issued December 27, 2005, to Evron et al.; and U.S. Patent No. 1,007 / 2008 / 2009 ... U.S. Patent No. 7,286,866 to Okerlund et al., issued on October 23, 2011; U.S. Patent No. 7,308,297 to Reddy et al., issued on December 11, 2011; U.S. Patent No. 7,308,299 to Burrell et al., issued on December 11, 2011; U.S. Patent No. 7,321,677 to Evron et al., issued on January 22, 2008; U.S. Patent No. 7,346,381 to Okerlund et al., issued on March 18, 2008; U.S. Patent No. 7,454,248 to Burrell et al., issued on November 18, 2008; and U.S. Patent No. 7,454,248 to Burrell et al., issued on March 3, 2009. U.S. Patent No. 7,499,743 to Vass et al., issued July 21, 2009; U.S. Patent No. 7,565,190 to Okerlund et al., issued September 8, 2009; U.S. Patent No. 7,587,074 to Zakh et al., issued September 8, 2009; U.S. Patent No. 7,599,730 to Hunter et al., issued October 6, 2009; U.S. Patent No. 7,613,500 to Vass et al., issued November 3, 2009; U.S. Patent No. 7,742,629 to Zakh et al., issued June 22, 2010; and U.S. Patent No. 7,742,629 to Okerlund et al., issued June 29, 2010. U.S. Patent No. 7,747,047; U.S. Patent No. 7,778,685, issued August 17, 2010, to Evron et al.; U.S. Patent No. 7,778,686, issued August 17, 2010, to Vass et al.; U.S. Patent No. 7,813,785, issued October 12, 2010, to Okerlund et al.; U.S. Patent No. 7,996,063, issued August 9, 2011, to Vass et al.; U.S. Patent No. 8,060,185, issued November 15, 2011, to Hunter et al.; and U.S. Patent No. 8,401, issued March 19, 2013, to Verard et al.Each of the items in 616 is incorporated into this paper in full by quotation.

[0035] The computing device 140 and the remote computing device 160 may each include display devices 130 and 170, respectively, which can be configured to display and analyze data, such as electrical signals (e.g., electrocardiogram data), electrical activation time, electrical heterogeneity information, etc. One of a plurality of cardiac cycles or heartbeats represented by electrical signals collected or monitored by the electrode device 110 can be analyzed and evaluated for one or more metrics, including activation time and electrical heterogeneity information, relating to the therapeutic nature of one or more parameters (such as pacing parameters, lead position, etc.) related to cardiac therapy. More specifically, for example, the QRS complex of a single cardiac cycle can be assessed against one or more measures, such as, for example, QRS onset, QRS deviation, QRS peak, electrical heterogeneity information (EHI), electrical activation time referenced to the earliest activation time, standard deviation of left ventricular or chest electrical activation time (LVED), standard deviation of activation time (SDAT), mean left ventricular or chest alternative electrical activation time (LVAT), QRS duration (e.g., the interval between QRS onset and QRS deviation), the difference between mean left alternative activation time and mean right alternative activation time, relative or absolute QRS morphology, the difference between the higher and lower percentiles of activation time (the higher percentile could be 90%, 80%, 75%, 70%, etc., and the lower percentile could be 10%, 15%, 20%, 25%, and 30%, etc.), central tendency (e.g., median or mode), dispersion (e.g., mean deviation, standard deviation, variance, interquartile range), and other statistical measures. Furthermore, each of the one or more measures can be location-specific. For example, some metrics can be calculated based on signals recorded or monitored from electrodes located around selected areas of the patient (such as, for example, the patient's left side, the patient's right side, etc.).

[0036] In at least one embodiment, one or both of the computing device 140 and the remote computing device 160 may be a server, a personal computer, a tablet computer, a mobile device, and a cellular phone. The computing device 140 may be configured to receive input from an input device 142 (e.g., a keyboard) and transmit output to a display device 130, and the remote computing device 160 may be configured to receive input from an input device 162 (e.g., a touchscreen) and transmit output to a display device 170. One or both of the computing device 140 and the remote computing device 160 may include data storage devices that allow access to processing programs or routines and / or one or more other types of data, such as for analyzing multiple electrical signals captured by the electrode device 110, for determining QRS initiation, QRS offset, median, mode, average, peak or maximum, valley or minimum, for determining electrical excitation time, and for driving a graphical user interface configured to non-invasively assist the user in configuring one or more pacing parameters or settings, such as, for example, pacing rate, ventricular pacing rate, AV interval, VV interval, pacing pulse width, pacing vector, multi-point pacing vector (e.g., left ventricular vector quadrupole lead), pacing voltage, pacing configuration (e.g., biventricular pacing, right ventricular pacing only, left ventricular pacing only, etc.), as well as arrhythmia detection and treatment, rate adaptive settings, and performance, etc.

[0037] Computing device 140 can be operatively connected to input device 142 and display device 130 to transmit data to and from each of the input devices 142 and 130, for example, and remote computing device 160 can be operatively connected to input device 162 and display device 170 to transmit data to and from each of the input devices 162 and 170, for example,. For example, computing device 140 and remote computing device 160 can be electrically connected to input devices 142, 162 and display devices 130, 170 using, for example, analog electrical connections, digital electrical connections, wireless connections, bus-based connections, network-based connections, Internet-based connections, etc. As further described herein, a user can provide input to input devices 142, 162 to view and / or select one or more configuration information related to cardiac therapy delivered by a cardiac therapy device, such as, for example, an implantable medical device.

[0038] Although input device 142 is a keyboard and input device 162 is a touchscreen as depicted, it should be understood that input devices 142, 162 may include any device capable of providing input to computing device 140 and computing device 160 to perform the functions, methods and / or logic described herein. For example, input devices 142, 162 may include a keyboard, mouse, trackball, touchscreen (e.g., capacitive touchscreen, resistive touchscreen, multi-touch touchscreen, etc.), etc. Similarly, display devices 130, 170 may include any device capable of displaying information to a user, such as graphical user interfaces 132, 172 including: electrode status information, graphical representations of electrical activation, multiple signals of external electrodes on one or more heartbeats, QRS complexes, selection areas for various cardiac therapy options, rankings of various cardiac therapy options, various pacing parameters, electrical heterogeneity information (EHI), text commands, graphical depictions of the anatomy 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, the display devices 130 and 170 may include liquid crystal displays, organic light-emitting diode screens, touch screens, cathode ray tube displays, etc.

[0039] The processing programs or routines stored and / or executed by the computing device 140 and the remote computing device 160 may include programs or routines for computational mathematics, matrix mathematics, decomposition algorithms, compression algorithms (e.g., data compression algorithms), calibration algorithms, image construction algorithms, signal processing algorithms (e.g., various filtering algorithms, Fourier transform, fast Fourier transform, etc.), normalization algorithms, comparison algorithms, vector mathematics, or any other processing used to implement one or more of the illustrative methods and / or processes described herein. Data stored and / or used by computing device 140 and remote computing device 160 may include, for example, electrical signal / waveform data (e.g., multiple QRS groups) from electrode device 110, electrical activation time from electrode device 110, heart sound / signal / waveform data from acoustic sensors, graphics (e.g., graphic elements, icons, buttons, windows, dialog boxes, drop-down menus, graphics areas, graphics regions, 3D graphics, etc.), graphical user interfaces, results of one or more processing procedures or routines adopted according to this disclosure (e.g., electrical signals, electrical heterogeneity information, etc.), or any other data used to perform one or more processes or methods described herein.

[0040] In one or more embodiments, the illustrative systems, methods, and interfaces may be implemented using one or more computer programs that execute on a programmable computer, such as a computer including, for example, processing power, data storage devices (e.g., volatile or non-volatile memory and / or storage elements), input devices, and output devices. The program code and / or logic described herein may be applied to input data to perform the functions described herein and generate desired output information. The output information may be applied as input to one or more other means and / or methods as described herein or to be applied in a known manner.

[0041] One or more programs for implementing the systems, methods, and / or interfaces described herein can be provided using any programmable language (e.g., high-level programs and / or object-oriented programming languages ​​suitable for communicating with computer systems). Any such program can be stored, for example, on any suitable means (e.g., storage media) that can be read by a general-purpose or special-purpose program running on a computer system (e.g., including a processing device) for configuring and operating the computer system when that suitable means is read to execute the programs described herein. In other words, at least in one embodiment, the illustrative systems, methods, and interfaces can be implemented using a computer-readable storage medium configured with computer programs, wherein such a storage medium causes a computer to operate in a specific and predefined manner to perform the functions described herein. Further, in at least one embodiment, the illustrative systems, methods, and / or interfaces can be described as being implemented by logic (e.g., object code) encoded in one or more non-transitory media, which includes code for execution and, when executed by a processor or processing circuitry, is operable to perform operations such as the methods, processes, and / or functions described herein.

[0042] Computing device 140 and remote computing device 160 can be, for example, any fixed or mobile computer system (e.g., controller, microcontroller, personal computer, microcomputer, tablet computer, etc.). The exact configuration of computing device 140 and remote computing device 160 is not limiting, and any device capable of providing suitable computing and control capabilities (e.g., signal analysis, mathematical functions such as median, mode, average, maximum value determination, minimum value determination, slope determination, minimum slope determination, maximum slope determination, graphics processing, etc.) can be used. As described herein, digital files can be any medium (e.g., volatile or non-volatile memory, CD-ROM, punched card, magnetically recordable magnetic tape, etc.) containing digital bits (e.g., encoded in binary or ternary) that can be read and / or written by computing device 140 and remote computing device 160 as described herein. Moreover, as described herein, a user-readable format file can be any representation of data (e.g., ASCII text, binary numbers, hexadecimal numbers, decimal numbers, graphics, etc.) that can be presented on any medium (e.g., paper, monitor, etc.) that is readable and / or understandable to the user.

[0043] In view of the foregoing, it will be apparent that the functions described in one or more embodiments according to this disclosure can be implemented in any manner as known to those skilled in the art. Thus, the computer language, computer system, or any other software / hardware intended for implementing the processes described herein should not be limited to the scope of the systems, processes, or programs described herein (e.g., the functions provided by such systems, processes, or programs).

[0044] The illustrative electrode device 110 can be configured to measure the surface potential of the patient 14's body and, more specifically, the surface potential of the patient 14's torso. For example... Figure 2 As shown, the illustrative electrode device 110 may include an assembly or array of external electrodes 112, a strip 113, and an interface / amplifier circuitry 116. The electrodes 112 may be attached to or coupled to the strip 113, and the strip 113 may be configured to wrap around the torso of the patient 14 such that the electrodes 112 surround the patient's heart. As further shown, the electrodes 112 may be positioned around the circumference of the patient 14, including posterior, lateral, posterolateral, anterolateral, and anterior positions of the patient 14's torso.

[0045] The illustrative electrode device 110 can be further configured to measure or monitor at least one or both sounds from the patient 14. For example... Figure 2As shown, the illustrative electrode device 110 may include an array or collection of acoustic sensors 120 attached to or coupled to the strip 113. The strip 113 may be configured to wrap around the torso of the patient 14 such that the acoustic sensors 120 surround the patient's heart. As further shown, the acoustic sensors 120 may be positioned around the circumference of the patient 14, including posterior, lateral, posterolateral, anterolateral, and anterior positions of the patient 14's torso.

[0046] Furthermore, electrode 112 and acoustic sensor 120 can be electrically connected to interface / amplifier circuit 116 via wired connection 118. Interface / amplifier circuit 116 can be configured to amplify signals from electrode 112 and acoustic sensor 120 and provide the signals to one or both of computing device 140 and remote computing device 160. Other illustrative systems may use a wireless connection (e.g., as a data channel) to transmit signals sensed by electrode 112 and acoustic sensor 120 to interface / amplifier circuit 116, and further to one or both of computing device 140 and remote computing device 160. In one or more embodiments, interface / amplifier circuit 116 can be electrically connected to computing device 140 using, for example, analog electrical connections, digital electrical connections, wireless connections, bus-based connections, network-based connections, Internet-based connections, etc.

[0047] Despite Figure 2In one example, electrode device 110 includes a strip 113; however, in other examples, any of a variety of mechanisms (e.g., tape or adhesive) may be used to assist in the spacing and placement of electrodes 112 and acoustic sensors 120. In some examples, strip 113 may include elastic band, tape strip, or cloth. Further, in some examples, strip 113 may be part of or integrated with a garment (e.g., a t-shirt). In other examples, electrodes 112 and acoustic sensors 120 may be placed separately on the torso of patient 14. Further, in other examples, one or both of electrodes 112 (e.g., arranged in an array) and acoustic sensors 120 (e.g., also arranged in an array) may be part of or located within a patch, vest, and / or other means of securing electrodes 112 and acoustic sensors 120 to the torso of patient 14. Still further, in other examples, one or both of electrodes 112 and acoustic sensors 120 may be part of or located within two material portions or two patches. One of the two patches may be located on the anterior side of the patient 14's torso (to monitor, for example, electrical signals representing the anterior side of the patient's heart, measure the electrical activation time of an alternative heart representing the anterior side of the patient's heart, monitor or measure sound in the anterior side of the patient, etc.), and the other patch may be located on the posterior side of the patient 14's torso (to monitor, for example, electrical signals representing the posterior side of the patient's heart, measure the electrical activation time of an alternative heart representing the posterior side of the patient's heart, monitor or measure sound in the posterior side of the patient, etc.). Furthermore, in other examples, one or both of the electrode 112 and the acoustic sensor 120 may be arranged in top and bottom rows extending from the anterior side of the patient 14, across the left side of the patient 14, to the posterior side of the patient 14. Furthermore, in other examples, one or both of the electrode 112 and the acoustic sensor 120 may be arranged in a curve around the axillary region, and the electrode / sensor density on the right chest may be lower than the density in other remaining areas.

[0048] Electrodes 112 can be configured to surround the heart of patient 14 and record or monitor electrical signals associated with cardiac depolarization and repolarization after the signal has propagated through the torso of patient 14. Each electrode in 112 can be used in a monopolar configuration to sense the torso surface potential reflecting cardiac signals. Interface / amplifier circuitry 116 can also be coupled to a return electrode or an unrelated electrode (not shown) that can be used in combination with each electrode 112 for monopolar sensing.

[0049] In some examples, there may be approximately 12 to approximately 50 electrodes 112 spatially distributed around the patient's torso and approximately 12 to approximately 50 acoustic sensors 120. Other configurations may have more or fewer electrodes 112 and more or fewer acoustic sensors 120. It should be understood that the electrodes 112 and acoustic sensors 120 may not be arranged or may be distributed in an array that extends all the way around or completely around the patient 14. Instead, the electrodes 112 and acoustic sensors 120 may be arranged in an array that extends only around a portion or partially around the patient 14. For example, the electrodes 112 and acoustic sensors 120 may be distributed on the front, back, and left sides of the patient, with fewer or no electrodes and acoustic sensors near the right side (including the posterior and anterior regions of the patient's right side).

[0050] The computing device 140 can record and analyze the torso surface potential signal sensed by the electrode 112 and the sound signal sensed by the acoustic sensor 120, which is amplified / modulated by the interface / amplifier circuitry 116. The computing device 140 can be configured to analyze the electrical signals from the electrode 112 to provide electrocardiogram (ECG) signals, information, or data from the patient's heart, as will be further described herein. The computing device 140 can also be configured to analyze the electrical signals from the acoustic sensor 120 to provide sound signals, information, or data from the patient's body and / or implanted devices (such as left ventricular assist devices).

[0051] Additionally, computing device 140 and telecomputing device 160 can be configured to provide graphical user interfaces 132, 172 that depict various information related to electrode device 110 and data collected or sensed using electrode device 110. For example, graphical user interfaces 132, 172 can depict ECG data including QRS complexes obtained using electrode device 110 and acoustic data including sound waves obtained using acoustic sensor 120, as well as other related information. The illustrative system and method can noninvasively use the electrical information collected using electrode device 110 and the acoustic information collected using acoustic sensor 120 to assess a patient's cardiac health and to evaluate and configure cardiac therapies delivered to the patient.

[0052] Furthermore, the electrode device 110 may further include, for example, reference electrodes and / or drive electrodes positioned around the lower torso of the patient 14, which may be further used by the system 100. For example, the electrode device 110 may include three reference electrodes, and signals from the three reference electrodes may be combined to provide a reference signal. Further, the electrode device 110 may use three tail-end reference electrodes (e.g., instead of the standard reference used in the Wilson Central Terminal) to obtain a “true” monopolar signal with less noise by averaging the three tail-end positioned reference signals.

[0053] Figure 3 Another illustrative electrode device 110 is shown, comprising multiple electrodes 112 and multiple acoustic sensors 120. The electrodes are configured to surround the heart of a patient 14 and record or monitor electrical signals associated with the depolarization and repolarization of the heart after the signal has propagated through the torso of the patient 14. The acoustic sensors are configured to surround the heart of the patient 14 and record or monitor sound signals associated with the heart after the signal has propagated through the torso of the patient 14. The electrode device 110 may include a vest 114 to which the multiple electrodes 112 and multiple acoustic sensors 120 may be attached, or the electrodes 112 and acoustic sensors 120 may be coupled to the vest. In at least one embodiment, the multiple electrodes 112 or an array of the electrodes may be used to collect electrical information, such as alternative electrical activation time. Similar to... Figure 2 Electrode equipment 110, Figure 3 The electrode device 110 may include an interface / amplifier circuitry 116 electrically connected via a wired connection 118 to each of the electrodes 112 and the acoustic sensor 120 and configured to transmit signals from the electrodes 112 and the acoustic sensor 120 to the computing device 140. As shown, the electrodes 112 and the acoustic sensor 120 may be distributed on the torso of the patient 14, including, for example, posterior, lateral, posterolateral, anterolateral, and anterior positions of the patient 14's torso.

[0054] Vest 114 may be formed of fabric, with electrodes 112 and acoustic sensors 120 attached to the fabric. Vest 114 may be configured to maintain the positioning and spacing of electrodes 112 and acoustic sensors 120 on the torso of patient 14. Further, vest 114 may be marked to aid in determining the position of electrodes 112 and acoustic sensors 120 on the surface of the torso of patient 14. In some examples, approximately 25 to approximately 256 electrodes 112 and approximately 25 to approximately 256 acoustic sensors 120 may be distributed around the torso of patient 14, but other configurations may have more or fewer electrodes 112 and more or fewer acoustic sensors 120.

[0055] The illustrative systems and methods can be used to provide noninvasive assistance to users in the assessment of a patient's cardiac health and / or in the assessment and configuration of cardiac treatments currently being delivered to the patient (e.g., via implantable medical devices for pacing therapy, via LVAD, etc.). Furthermore, it should be understood that computing device 140 and remote computing device 160 can be operatively coupled to each other in a variety of different ways to perform or execute the functions described herein. For example, in the depicted embodiments, computing device 140 can be operatively wirelessly coupled to remote computing device 160, as depicted by a wireless signal line emanating therebetween. Alternatively, in contrast to a wireless connection, one or more of computing device 140 and remote computing device 160 can be operatively coupled via a single or wired electrical connection.

[0056] According to the embodiments described herein, the illustrative system 100, which may be referred to as an ECG band system, can be used with cardiac therapy systems and devices (e.g., CRT pacing devices) to calculate various metrics related to a patient's cardiac health (e.g., standard deviation of activation time (SDAT)) across one or more cardiac cycles (or heartbeats) and specifically based on activation time or other data collected during each QRS event of a cardiac cycle (heartbeat). According to various embodiments, the illustrative system 100 can be used to calculate or generate electrical heterogeneity information, such as, for example, the SDAT of the cardiac cycle during CRT delivery (e.g., the SDAT for the cardiac cycle during CRT pacing delivery). For example, the illustrative system 100 can be used to calculate electrical heterogeneity information of the cardiac cycle during biventricular and / or left ventricular pacing. Further, the embodiments described herein can be used to assess a patient's cardiac health and / or non-CRT pacing. If the electrical heterogeneity information is inaccurate, the output of the illustrative system 100 may be misleading, which could potentially affect lead placement (e.g., implantable leads not placed in the optimal position) and / or optimal device programming. For example, if SDAT is inaccurate, it can be artificially low, which may cause clinicians to not reposition the currently positioned lead, but instead reposition the lead to obtain a better response.

[0057] The implementation scheme described in this article can be used to assess whether a patient will benefit from a cardiac rhythm therapy (CRT) device. Figure 4 An exemplary method 400 for determining whether a patient is a candidate for a CRT device, according to an embodiment described herein, is illustrated. Multiple external electrodes are used to monitor electrical activity from the patient's tissues 410. The multiple electrodes may be external surface electrodes configured in a belt or vest, similar to those described herein. Figures 1 to 3As described. Each electrode may be positioned or set around the patient's torso to monitor electrical activity (e.g., acquire torso potential) from multiple different locations around the patient's torso. Each of the different locations where the electrodes are located may correspond to electrical activation of a different part or region of cardiac tissue of the patient's heart. Depending on the configuration, the multiple external electrodes include multiple left external electrodes positioned on the left side of the patient's torso.

[0058] One or more cardiac metrics 420 for the patient are generated based on the monitored electrical activity. Depending on the configuration, one or more metrics include the standard deviation of activation time (SDAT) and the mean of left ventricular activation time (LVAT) based on electrical activity recorded from multiple external electrodes across the entire set. In some cases, other discrete metrics based on cardiac electrical activity monitored using multiple left external electrodes (e.g., standard deviation, range, interquartile range) may be used.

[0059] If the patient has right bundle branch block, one or more cardiac metrics are used based on a first global asynchronous metric to determine whether the patient is a candidate for a CRT device 430.

[0060] If the patient does not have right bundle branch block, one or more cardiac metrics are used based on a second global asynchronous metric to determine whether the patient is a candidate for a CRT device 440.

[0061] Figure 5 The diagram illustrates a more detailed method 500 for determining whether a patient is a candidate for cardiac resynchronization therapy (CRT). Inherent ECG band measurements 510 are performed. These measurements may include, for example, SDAT and LVAT.

[0062] Determine whether a patient is classified as having right bundle branch block 520. For example, this can be determined by a physician in a separate procedure. In some cases, the system can determine whether a patient has right bundle branch block as part of the same process as determining whether a patient is a candidate for a CRT device.

[0063] If a patient is determined to have right bundle branch block 520, a first global desynchronization measure 530 is determined. The first global desynchronization measure can be the sum of the scores of LFAT and SDAT. If the first global desynchronization measure is greater than a predetermined threshold, the patient can be determined to be a candidate for a CRT device. Depending on the configuration, the SDAT score is (5 SDAT) / 3, such as Figure 5 As shown. The predetermined threshold can range from approximately 30ms to approximately 80ms. In some cases, the predetermined threshold is approximately 50ms.

[0064] If it is determined that the patient is not classified as having right bundle branch block 520, a second global desynchronization measure 540 is determined. The second global desynchronization measure may include determining whether SDAT is greater than a first predetermined threshold and whether LVAT is greater than a second predetermined threshold. The first predetermined threshold may be in the range of approximately 15 ms to approximately 30 ms. In some cases, the first predetermined threshold is approximately 25 ms. The second predetermined threshold may be in the range of approximately 25 ms to approximately 40 ms. In some cases, the second predetermined threshold is approximately 35 ms. Depending on various configurations, the second global desynchronization measure includes determining whether SDAT divided by QRSd is greater than a third predetermined threshold and whether LVAT divided by QRSd is greater than a fourth predetermined threshold. The third predetermined threshold may be in the range of approximately 0.05 to approximately 0.25. In some cases, the third predetermined threshold is approximately 0.15. The fourth predetermined threshold may be in the range of approximately 0.10 ms to approximately 0.30. In some cases, the fourth predetermined threshold is approximately 0.20.

[0065] Figure 6 A graph showing intrinsic SDAT versus intrinsic LVAT for 115 patients is presented. Data points are color-coded as bright 630 or dark 640 based on the ability to resynchronize or desynchronize during CRT pacing (based on at least a 10% reduction in SDAT). Box 620 indicates patients with intrinsic SDAT <25ms and intrinsic LVAT <35ms (normal SDAT / LVAT levels). Approximately 45% of patients within this intrinsic SDAT / LVAT level have no electrical resynchronization, while a larger percentage (approximately 90%) of patients outside the box have electrical resynchronization. This implies a higher likelihood of resynchronization in patients with intrinsic SDAT or intrinsic LVAT higher than normal levels.

[0066] Figure 7 and Figure 8 The intrinsic SDAT / LVAT distributions are shown separately for patients with right bundle branch block (RBBB) and those with baseline QRS <150 ms. Patients above the linear dashed line (65°) are more likely to be resynchronized based on at least a 10% reduction in SDAT from intrinsic to CRT pacing. A linear combination of intrinsic SDAT and LVAT above a specific threshold (e.g., LVAT +5 / 3) is also considered. A baseline dyssynchrony measure of SDAT > 50 ms will be used as a screening measure for RBBB patients who are likely to be resynchronized by CRT. This measure exceeds the threshold even if the patient has a relatively low intrinsic LFAT but a high SDAT, and / or even if the patient has a relatively low SDAT but a high intrinsic LFAT, thus contributing to enhanced left ventricular dyssynchrony, leaving room for correction by CRT.

[0067] ECG bands are configured to provide measurements of electrical asynchrony. Variations in electrical asynchrony from inherent to CRT and / or LV pacing have proven useful for, for example, titrating LV lead placement and optimizing device programming parameters (e.g., vectoring and / or timing) in bradycardia pacing. The use of ECG bands in determining effective pacing therapy in the bradycardia population is described. This article describes His bundle and / or LBB zone pacing compared to conventional RV leads or a combination of both, and / or different RV lead placements.

[0068] In some cases, bradycardia pacing can be performed using atrial-ventricular (VfA) pacing. VfA pacing can be described as providing synchronized homogeneous activation of the heart's ventricles. As an example, patients with atrial-ventricular (AV) block or prolonged AV timing that may lead to heart failure and whose QRS is otherwise intact (e.g., normal) can benefit from VfA pacing therapy. Additionally, as an example, VfA pacing can provide beneficial activation in heart failure patients with inherent ventricular conduction disorders. Furthermore, proper placement of the VfA pacing device can provide optimal ventricular activation in such patients. Moreover, in heart failure patients with left bundle branch block (LBBB), left ventricular (LV) resynchronization can be found in VfA pacing, which allows for easier access to the left ventricular endocardium without exposing the leadless device or causing endocardial blood pooling. Simultaneously, in this example, this can facilitate engagement of portions of the conduction system to potentially correct the LBBB and effectively resynchronize the patient.

[0069] Figure 9 An exemplary method 900 for determining the effectiveness of bradycardia pacing therapy is illustrated. Multiple external electrodes are used to monitor electrical activity from the patient's tissues 910. Depending on various configurations, the multiple external electrodes include multiple left external electrodes positioned on the left side of the patient's torso.

[0070] Electrical heterogeneity information (EHI) is generated based on cardiac electrical activity monitored during bradycardia pacing delivery to the patient's heart. EHI can be generated based on one or more metrics, including SDAT, LVAT, LV dispersion measure based on the standard deviation of activation time of the left-sided electrode reflecting left ventricular activation, and RV dispersion measure based on the standard deviation of activation time of the right-sided electrode reflecting right ventricular activation. Depending on various configurations, metrics may include, for example, QRS duration, timing peaks on lead V6, and / or morphological changes on precordial leads V1 and V2.

[0071] The effectiveness of bradycardia pacing therapy is determined based on the generated EHI.930. Depending on the configuration, determining the effectiveness of bradycardia pacing therapy includes determining whether bradycardia pacing reflects the normalization of conduction in the patient population during bradycardia pacing. In some cases, the patient population shares at least one similar characteristic with the patient. For example, at least one characteristic may include age, sex, height, and weight.

[0072] Figure 10 Another method for determining the effectiveness of bradycardia pacing therapy is shown. A bradycardia lead 810 is implanted. Examples include His area, LBB area, atrium-to-ventricle, and / or septal vein leads.

[0073] Determine one or more ECG band measurements 820. ECG band measurements may include one or both of SDAT, LVAT, and EHI. Determine whether one or more of the determined measurements reflect normalization during conduction pacing 830. If the measurement is determined to reflect normalization 830, the process ends 840.

[0074] If it is determined that the metric does not reflect normalization during conduction pacing 830, then determine whether different options are available 850. One option may include changing the lead position. Different options may include changing the lead position and / or changing one or more of the pacing parameters. Pacing parameters may include one or more of AV delay, pulse width, amplitude, voltage, and / or burst length.

[0075] The position of the RV lead and / or pacing timing can be changed to minimize asynchrony during RV pacing. For example, the position of the RV lead can be moved between the RVOT, RV apex, and RV midsegment.

[0076] When using His bundle pacing or LBB bundle pacing, lead positions and / or AV / VV delays can be modified to minimize asynchrony. For example, a spare RV lead can be used in His bundle pacing, and the position of the spare RV lead can be optimized to minimize asynchrony.

[0077] Lead placement and / or timing for dual-bundle pacing can also be determined to minimize asynchrony. Two bundle leads can be positioned proximally in the His bundle and the other more distally in the left bundle. Dual-bundle pacing can be performed using a single multipolar lead. For example, a single multipolar lead can be used in patients with left bundle branch block (LBBB), such as those with prolonged PR, where inherent right bundle fusion is not possible.

[0078] For leads located in septal veins, lead location and / or pacing timing can be used. This can be used to provide feedback on the engagement of the conduction system from the pacing from the location within the septal performator branch of the great cardiac vein.

[0079] The implementation scheme described herein can be used to optimize the timing of intraventricular septal pacing. This can include both the RV and LV septal intervals.

[0080] If different options are determined to be available, the lead position and / or pacing parameters are changed. After changing the lead position and / or pacing parameters, the procedure continues to measure ECG band measurements 820.

[0081] If it is determined that different options are unavailable, one or more spare leads are implanted 870. The final pacing configuration and parameters 880 are set based on the lowest SDAT. The absolute value of SDAT can be determined during various pacing configurations, timings, and other parameters (e.g., pacing from two leads with different AV timings, VV timings, outputs, etc.), and a set of parameters and pacing configurations that produce the lowest absolute value of SDAT can be selected for final programming.

[0082] Various implementation schemes may include pacing at different locations. For example, locations may include the conduction system and / or the interval. Conduction system pacing leads and / or conventional pacing leads (e.g., RV leads) with different AV / VV timings and other pacing parameters may be used. The pacing location and / or parameters may be selected based on which produces the lowest electrical synchrony. In some cases, the pacing location and / or parameters may be selected to produce a metric representing a normal level of that particular metric's value, thereby indicating the 'normalization' of pacing activation.

[0083] Illustrative cardiac therapy systems and devices can be referenced in this article. Figures 11 to 13 To describe further, the Figures 11 to 13 This article can be used to target Figures 1 to 10 Describe the descriptive systems, interfaces, methods, and processes.

[0084] Figure 11 The illustration is provided to illustrate a conceptual diagram of a therapeutic system 10, which can be used to deliver pacing therapy to a patient 14. The patient 14 may be, but is not necessarily, a person. The therapeutic system 10 may include an implantable medical device 16 (IMD) that can be coupled to leads 18, 20, 22. The IMD 16 may be, for example, an implantable pacemaker, cardioverter-defibrillator, and / or a defibrillator, which delivers or provides electrical signals (e.g., pacing, etc.) to the heart 12 of the patient 14 via electrodes coupled to one or more of leads 18, 20, 22 and / or senses electrical signals from the patient's heart.

[0085] Leads 18, 20, and 22 extend into the heart 12 of the patient 14 to sense the electrical activity of the heart 12 and / or deliver electrical stimulation to the heart 12. Figure 11 In the example shown, the right ventricle (RV) lead 18 extends through one or more veins (not shown), the superior vena cava (not shown), and the right atrium 26, and enters the right ventricle 28. The left ventricle (LV) coronary sinus lead 20 extends through one or more veins, the vena cava, and the right atrium 26, and enters the coronary sinus 30 to reach the region of the free wall of the left ventricle 32 adjacent to the heart 12. The right atrium (RA) lead 22 extends through one or more veins and the vena cava, and enters the right atrium 26 of the heart 12.

[0086] The IMD 16 can sense electrical signals, such as those associated with depolarization and repolarization of the heart 12, via electrodes coupled to at least one of leads 18, 20, and 22. In some examples, the IMD 16 delivers pacing therapy (e.g., pacing pulses) to the heart 12 based on the electrical signals sensed within the heart 12. The IMD 16 can be operable to adjust one or more parameters associated with the pacing therapy, such as, for example, AV delay and other various timing, pulse width, amplitude, voltage, burst length, etc. Furthermore, the IMD 16 can be operable to deliver pacing therapy using various electrode configurations, which can be monopolar, bipolar, quadrupole, or other multipolar configurations. For example, a multipolar lead system can include several electrodes that can be used to deliver pacing therapy. Thus, a multipolar lead system can provide or supply multiple electrical vectors for pacing from it. The pacing vector may include at least one cathode and at least one anode, the at least one cathode being at least one electrode located on at least one lead, and the at least one anode being at least one electrode located on at least one lead (e.g., the same lead or different leads) and / or on the housing or casing of the IMD. While improvements in cardiac function as a result of pacing therapy may depend primarily on the cathode, electrical parameters such as impedance, pacing threshold voltage, current consumption, and lifespan may be more dependent on the pacing vector, which includes both the cathode and anode. The IMD 16 may also provide defibrillation therapy and / or cardioversion therapy via electrodes located on at least one of leads 18, 20, 22. Further, the IMD 16 may detect arrhythmias of heart 12, such as fibrillation of ventricles 28, 32, and provide defibrillation therapy to heart 12 in the form of electrical pulses. In some examples, the IMD 16 may be programmed to deliver a therapeutic process, such as pulses with increasing energy levels, until the fibrillation of heart 12 ceases.

[0087] Figures 12A to 12B To explain in more detail Figure 11A conceptual diagram of the IMD 16 and leads 18, 20, 22 of the therapy system 10. Leads 18, 20, 22 can be electrically connected via connector block 34 to a therapy delivery module (e.g., for delivering pacing therapy), a sensing module (e.g., for sensing one or more signals from one or more electrodes), and / or any other module of the IMD 16. In some examples, the proximal ends of leads 18, 20, 22 may include electrical contacts electrically connected to corresponding electrical contacts within connector block 34 of the IMD 16. Additionally, in some examples, leads 18, 20, 22 can be mechanically connected to connector block 34 by means of a retaining screw, connecting pin, or other suitable mechanical coupling mechanism.

[0088] Each of leads 18, 20, and 22 includes an elongated insulated lead body capable of carrying multiple conductors (e.g., concentric coil conductors, straight conductors, etc.) separated from each other by insulation (e.g., a tubular insulating sheath). In the example shown, bipolar electrodes 40 and 42 are located near the distal end of lead 18. Additionally, bipolar electrodes 44, 45, 46, and 47 are located near the distal end of lead 20, and bipolar electrodes 48 and 50 are located near the distal end of lead 22.

[0089] Electrodes 40, 44, 45, 46, 47, and 48 may be in the form of ring electrodes, and electrodes 42 and 50 may be in the form of extendable spiral-tipped electrodes retractably mounted within insulated electrode heads 52, 54, and 56, respectively. Each of electrodes 40, 42, 44, 45, 46, 47, 48, and 50 may be electrically connected to a corresponding conductor (e.g., a coil conductor and / or a straight conductor) within the lead body of its associated leads 18, 20, and 22, and thereby connected to a corresponding electrical contact at the proximal end of the leads 18, 20, and 22.

[0090] In addition, the surface area of ​​electrodes 44, 45, 46, and 47 can be approximately 5.3 mm². 2 up to approximately 5.8mm 2 Electrodes 44, 45, 46, and 47 may also be referred to as LV1, LV2, LV3, and LV4, respectively. The LV electrodes on lead 20 (i.e., left ventricular electrode 1 (LV1) 44, left ventricular electrode 2 (LV2) 45, left ventricular electrode 3 (LV3) 46, and left ventricular electrode 4 (LV4) 47, etc.) can be spaced apart at variable distances. For example, electrode 44 may be spaced from electrode 45 by, for example, approximately 21 millimeters (mm), electrodes 45 and 46 may be spaced apart by, for example, approximately 1.3 mm to approximately 1.5 mm, and electrodes 46 and 47 may be spaced apart by, for example, approximately 20 mm to approximately 21 mm.

[0091] Electrodes 40, 42, 44, 45, 46, 47, 48, and 50 can be further used to sense electrical signals (e.g., morphological waveforms within an electrogram (EGM)) accompanying depolarization and repolarization of the heart 12. The electrical signals are conducted to the IMD 16 via corresponding leads 18, 20, and 22. In some examples, the IMD 16 can also deliver pacing pulses via electrodes 40, 42, 44, 45, 46, 47, 48, and 50 to induce depolarization of the cardiac tissue of the patient's heart 12. Figure 12A In some of the examples shown, the IMD 16 includes one or more housing electrodes (such as housing electrode 58) that may be integrally formed with or otherwise coupled to the outer surface of the housing 60 of the IMD 16 (e.g., a hermetically sealed housing). Any of electrodes 40, 42, 44, 45, 46, 47, 48, and 50 may be combined with housing electrode 58 for unipolar sensing or pacing. It will be understood by those skilled in the art that other electrodes may also be selected to define or be used for pacing and sensing vectors. Furthermore, any of electrodes 40, 42, 44, 45, 46, 47, 48, 50, and 58 may be used to sense electrical activity during pacing therapy when not being used for delivering pacing therapy.

[0092] For reference Figure 12A In further detail, the housing 60 may encapsulate a therapy delivery module, which may include a stimulation generator for generating cardiac pacing pulses and defibrillation or cardioversion shocks, and a sensing module for monitoring electrical signals of the patient's heart (e.g., the patient's heart rhythm). Leads 18, 20, and 22 may also include elongated electrodes 62, 64, and 66, which may be in the form of coils. The IMD 16 may deliver defibrillation shocks to the heart 12 via any combination of the elongated electrodes 62, 64, and 66 and the housing electrode 58. Electrodes 58, 62, 64, and 66 may also be used to deliver cardiac cardioversion pulses to the heart 12. Furthermore, electrodes 62, 64, and 66 may be made of any suitable conductive material, such as, but not limited to, platinum, platinum alloys, and / or other materials known to be suitable for use in implantable defibrillation electrodes. Since electrodes 62, 64, and 66 are not typically configured for pacing therapy, any one of electrodes 62, 64, and 66 can be used to sense electrical activity and can be used in combination with any one of electrodes 40, 42, 44, 45, 46, 47, 48, 50, and 58. In at least one embodiment, the RV elongated electrode 62 can be used to sense the electrical activity of a patient's heart during delivery of pacing therapy (e.g., in combination with the housing electrode 58 or a defibrillator electrode-to-housing electrode vector).

[0093] Figures 11 to 13The illustrated configuration of the therapeutic system 10 shown is merely an example. In other examples, the therapeutic system may include epicardial leads and / or patch electrodes instead. Figure 11 The description refers to the transvenous access lines 18, 20, and 22, or as a counterpart to... Figure 11 The illustrated transvenous leads 18, 20, and 22 are supplementary. Furthermore, in other examples, the therapy system 10 may be implemented in the absence of transvenous leads (e.g., leadless / wireless pacing systems) or with leads implanted (e.g., transvenous implantation or method of use) into the left chamber of the heart (e.g., [missing information]). Figure 11 As shown, the IMD 16 is implanted in / around the cardiac septum as a supplement to or alternative to a transvenous lead placed in the right chamber of the heart. Further, in one or more embodiments, it is not necessary to implant the IMD 16 within the patient 14. For example, the IMD 16 can be used for various cardiac therapies via a percutaneous lead extending through the skin of the patient 14 to multiple locations within or outside the heart 12. In one or more embodiments, the system 10 can utilize wireless pacing (e.g., energy transfer to one or more intracardiac pacing components via ultrasound, inductive coupling, RF, etc.) and sensing cardiac activation using electrodes on the housing / shell and / or subcutaneous leads.

[0094] In other examples of therapeutic systems that provide electrical stimulation to the heart 12, such systems may include any suitable number of leads coupled to the IMD 16, and each lead may extend to any location within or near the heart 12. For example, as... Figures 11 to 13 As shown, other examples of therapeutic systems may include three positioned transvenous leads. Further still, other therapeutic systems may include a single lead extending from IMD 16 into the right atrium 26 or the right ventricle 28, or two leads extending into one of the corresponding right atrium 26 and right ventricle 28.

[0095] Depending on the configuration, VfA pacing can be used. Further illustrative systems, methods, and procedures for optimizing cardiac pacing therapy can be described in U.S. Patent Application Serial No. 15 / 934,517, entitled “Evaluation of Ventricle from Atrium Pacing Therapy,” filed March 23, 2019, and in U.S. Provisional Patent Application Serial No. 62 / 725763, entitled “Adaptive VFA Cardiac Therapy,” filed August 31, 2018, each of which is incorporated herein by reference in its entirety.

[0096] Figure 13 The text describes an illustrative VfA cardiac therapy system that can be configured to, for example, be described in this article. Figures 1 to 10 The described systems and methods are used together. Although it should be understood that this disclosure can utilize one or both of leadless and leaded implantable medical devices, Figure 13 The illustrative cardiac therapy system includes a leadless intracardiac medical device 10, which can be configured for single-chamber or dual-chamber therapy and implanted in a patient's heart 8. In some embodiments, device 200 can be configured for single-chamber pacing and can be switched, for example, between single-chamber pacing and multi-chamber pacing (e.g., dual-chamber or triple-chamber pacing). As used herein, "intracardiac" means a device configured to be completely implanted within a patient's heart, for example, to provide cardiac therapy. Device 200 is shown as implanted in a target implantation region 4 in the right atrium (RA) of a patient's heart 8. Device 200 may include one or more fixation members 20 anchoring the distal end of device 200 against the atrial endocardium in the target implantation region 4. The target implantation region 4 may be located between the His bundle 5 and the coronary sinus 3 and may be adjacent to or immediately adjacent to the tricuspid valve 6. Device 200 can be described as an atrial-ventricular device because it can perform one or both of the following when generally placed in the right atrium: sensing electrical activity from one or both ventricles (e.g., the right ventricle, the left ventricle, or both ventricles, as appropriate) and providing therapy thereto. Specifically, device 200 may include a tissue-piercing electrode that can be implanted from the Koch's triangle region of the right atrium through the right atrial endocardium and central fibrous body into the base and / or septal region of the left ventricular myocardium of the patient's heart.

[0097] Device 200 can be described as a leadless implantable medical device. As used herein, "leadless" means a device without leads extending from the patient's heart 8. Further, although a leadless device may have leads, the leads do not extend from outside the patient's heart to inside the heart or from inside the patient's heart to outside the heart. Some leadless devices can be introduced through a vein, but once implanted, the device has no or may not include any transvenous leads and can be configured to deliver cardiac therapy without the use of any transvenous leads. Further, specifically, the leadless VfA device does not use leads to operatively connect to electrodes in the ventricles when the device housing is positioned in the atrium. Additionally, leadless electrodes can be coupled to the housing of the medical device without the use of leads between the electrodes and the housing.

[0098] Device 200 may include a dart electrode assembly 12 defining or having a straight axis extending from a distal region of device 200. The dart electrode assembly 220 may be placed or at least configured to pass through the atrial myocardium and central fibrous tissue and enter into the ventricular myocardium 240 or along the interventricular septum without completely penetrating the ventricular endocardium or epicardial surface. The dart electrode assembly 220 may carry or include electrodes at the distal region of the axis, such that the electrodes can be positioned within the ventricular myocardium for sensing ventricular signals and delivering ventricular pacing pulses (e.g., depolarizing the left and / or right ventricles to induce contraction of the left and / or right ventricles). In some examples, the electrodes at the distal region of the axis are cathode electrodes provided for use in a bipolar electrode pair for pacing and sensing. While the implantation region 4 shown allows one or more electrodes of the dart electrode assembly 220 to be positioned in the ventricular myocardium, it should be recognized that devices having the aspects disclosed herein can be implanted at other locations where appropriate for use in multi-chamber pacing (e.g., dual-chamber or triple-chamber pacing), single-chamber pacing with multi-chamber sensing, single-chamber pacing and / or sensing, or other clinical therapies and applications.

[0099] It should be understood that although the device 200 is described herein as comprising a single dart electrode assembly, the device 200 may include more than one dart electrode assembly placed or configured to pass through the atrial myocardium and central fibrous body and into the ventricular myocardium 240 or along the interventricular septum without completely penetrating the ventricular endocardium or epicardial surface. Additionally, each dart electrode assembly may carry or include more than one electrode in a distal region of the axis or in other regions along the axis (e.g., a proximal region or a central region).

[0100] The cardiac therapy system may also include separate medical devices 250 (in Figure 13(Illustrated schematically) A separate medical device can be positioned outside (e.g., subcutaneously) the patient's heart 8 and can be operatively coupled to the patient's heart 8 to deliver cardiac therapy to it. In one example, the separate medical device 250 can be an extravascular ICD. In some embodiments, the extravascular ICD may include a defibrillation lead that includes or carries a defibrillation electrode. A therapy carrier may be present between the defibrillation electrode on the defibrillation lead and the housing electrode of the ICD. Further, one or more electrodes of the ICD can also be used to sense electrical signals in relation to the patient's heart 8. The ICD can be configured to deliver electrical shock therapy including one or more defibrillation or cardioversion shocks. For example, if an arrhythmia is sensed, the ICD can send pulses through the lead to shock the heart and restore its normal rhythm. In some examples, the ICD can deliver electrical shock therapy without placing the lead inside the heart or attaching the wire directly to the heart (subcutaneous ICD). Examples of vascular perivascular subcutaneous ICDs that can be used with System 2 described herein can be described in U.S. Patent No. 9,278,229 (Reinke et al.), published March 8, 2016, which is incorporated herein by reference in its entirety.

[0101] In the case of electrical shock therapy (e.g., defibrillation shock delivered by defibrillation electrodes via defibrillation leads), the standalone medical device 50 (e.g., an extravascular ICD) may include control circuitry that uses a therapy delivery circuit to generate a defibrillation shock with any of a variety of waveform characteristics, including leading-edge voltage, slope, delivered energy, pulse phase, etc. The therapy delivery circuitry may, for example, generate monophasic, biphasic, or multiphasic waveforms. Additionally, the therapy delivery circuitry may generate defibrillation waveforms with varying amounts of energy. For example, the therapy delivery circuitry may generate a defibrillation waveform that delivers a total energy of approximately 60-80 joules (J) for subcutaneous defibrillation.

[0102] The individual medical device 250 may also include sensing circuitry. The sensing circuitry may be configured to acquire electrical signals sensed by one or more combinations of electrodes and to process the acquired signals. Components of the sensing circuitry may include analog components, digital components, or combinations thereof. The sensing circuitry may include, for example, one or more sense amplifiers, filters, rectifiers, threshold detectors, analog-to-digital converters (ADCs), etc. The sensing circuitry may convert the sensed signals into digital form and provide the digital signals to control circuitry for processing and / or analysis. For example, the sensing circuitry may amplify the signal from the sensing electrodes and convert the amplified signal into a multi-bit digital signal via an ADC, and then provide the digital signal to control circuitry. In one or more embodiments, the sensing circuitry may also compare the processed signal with a threshold to detect the presence of atrial or ventricular depolarization (e.g., P wave or R wave) and indicate the presence of atrial depolarization (e.g., P wave) or ventricular depolarization (e.g., R wave) to control circuitry.

[0103] Device 200 and a separate medical device 250 can collaborate to provide cardiac therapy to a patient's heart 8. For example, device 200 and the separate medical device 250 can be used to detect tachycardia, monitor tachycardia, and / or provide tachycardia-related therapy. For example, device 200 can wirelessly communicate with the separate medical device 250 to trigger an electric shock therapy using the separate medical device 250. As used herein, "wireless" means an operational connection or link between device 200 and the separate medical device 250 that does not use a metallic conductor. In one example, wireless communication can use a unique, signaling, or triggering electrical pulse provided by device 200 that conducts through the patient's tissue and can be detected by the separate medical device 250. In another example, wireless communication can use a communication interface (e.g., an antenna) of device 200 to provide electromagnetic radiation that propagates through the patient's tissue and can be detected, for example, using a communication interface (e.g., an antenna) of the separate medical device 250.

[0104] Figure 14 yes Figure 13 An enlarged conceptual diagram of the anatomy of an intracardiac medical device 200 and a patient's heart 8. Specifically, the device 200 is configured to sense cardiac signals and / or deliver pacing therapy. The intracardiac device 200 may include a housing 30. The housing 30 may define internal components of the device 10 (such as those for bonding). Figure 10The generally described sensing circuitry, therapy delivery circuitry, control circuitry, memory, telemetry circuitry, other optional sensors, and power supply reside in a hermetically sealed internal cavity. The housing 65 may include a conductive material (e.g., formed therefrom or derived therefrom), such as, for example, titanium or titanium alloys, stainless steel, MP35N (a non-magnetic nickel-cobalt-chromium-molybdenum alloy), platinum alloys, or other biocompatible metals or metal alloys. In other examples, the housing 65 may include a non-conductive material (e.g., formed therefrom or derived therefrom), including ceramics, glass, sapphire, silicone, polyurethane, epoxy resins, acetyl copolymer plastics, polyetheretherketone (PEEK), liquid crystal polymers, or other biocompatible polymers.

[0105] In at least one embodiment, the housing 65 may be described as extending between the distal region 67 and the proximal region 69 and as defining a generally cylindrical shape, for example, to facilitate catheter delivery. In other embodiments, the housing 65 may be prismatic or any other shape to perform the functions and utilities described herein. The housing 65 may include, for example, a delivery tool interface member 71 defined or positioned at the proximal region 69 for engagement with a delivery tool during implantation of the device 200.

[0106] All or a portion of the housing 65 can function as a sensing and / or pacing electrode during cardiac therapy. In the example shown, the housing 65 includes a proximal housing-based electrode 73 external to a proximal portion of the housing 65 (e.g., closer to the proximal region 69 than the distal region 67). When the housing 65 is a conductive material (such as a titanium alloy or other examples listed above) (e.g., defining a conductive material, formed therefrom, etc.), portions of the housing 65 can be electrically insulated by a non-conductive material (such as a coating of parylene, polyurethane, silicone, epoxy, or other biocompatible polymers), thereby exposing one or more discrete regions of the conductive material to form or define the proximal housing-based electrode 73. When the housing 65 is a non-conductive material (such as a ceramic, glass, or polymeric material) (e.g., defining a non-conductive material, formed therefrom, etc.), a conductive coating or layer (such as titanium, platinum, stainless steel, or alloys thereof) can be applied to one or more discrete regions of the housing 65 to form or define the proximal housing-based electrode 73. In other examples, the proximal housing-based electrode 73 may be a component mounted or assembled onto the housing 65, such as a ring electrode. The proximal housing-based electrode 73 may be electrically connected to the internal circuitry of the device 200, for example, via a conductive housing 65 or, when the housing 65 is a non-conductive material, via an electrical conductor.

[0107] In the example shown, the proximal housing-based electrode 73 is positioned closer to the proximal housing region 69 than the distal housing region 67, and can therefore be referred to as the proximal housing-based electrode 73. However, in other examples, the proximal housing-based electrode 73 may be positioned at other locations along the housing 65, for example, further away from the location shown.

[0108] At the distal region 67, the device 200 may include a distal fixation and electrode assembly 36, which may include one or more fixation members 20 and one or more dart electrode assemblies 12 of equal or unequal length. In one such example as shown, a single dart electrode assembly 12 includes a shaft 63 extending distally away from the distal region 67 of the housing, and one or more electrode elements, such as a tip electrode 75, at or near the free distal region of the shaft 40. The tip electrode 75 may have a conical or hemispherical distal tip with a relatively narrow tip diameter (e.g., less than about 1 mm) for penetrating and piercing tissue layers without using a sharp or beveled tip or needle-like tip.

[0109] The dart electrode assembly 220 can be configured to pierce one or more tissue layers to position the tip electrode 75 within a desired tissue layer (such as, for example, ventricular myocardium). Thus, the height 77 or length of the shaft 63 can correspond to the intended pacing site depth, and the shaft 63 can have relatively high compressive strength along its longitudinal axis to resist bending in the lateral or radial directions when pressed and inserted into the implantation region 4. If a second dart electrode assembly 220 is used, its length may not be equal to the intended pacing site depth and it can be configured to act as an independent electrode for delivering pacing energy to the tissue and / or sensing signals from the tissue. In one embodiment, a longitudinal axial force can be applied to the tip electrode 75, for example, by applying a longitudinal thrust to the proximal region 69 of the housing 65, to advance the dart electrode assembly 220 into the tissue within the target implantation region.

[0110] Shaft 63 can be described as longitudinally non-compressible and / or elastically deformable in the lateral or radial direction when subjected to lateral or radial forces, allowing for temporary bending, for example, with tissue movement, but returning to its normal straight position when the lateral force decreases. Therefore, the dart electrode assembly 220 including shaft 63 can be described as elastic. When shaft 63 is not exposed to any external force or is only exposed to a force along its longitudinal central axis, shaft 63 can maintain a pen-like straight position as shown.

[0111] In other words, the shaft 63 of the dart electrode assembly 220 can be a normally straight component and can be rigid. In other embodiments, the shaft 63 can be described as relatively rigid, but still possessing limited flexibility in the lateral direction. Further, the shaft 63 can be non-rigid to allow some lateral bending with heart movement. However, in a relaxed state, when not subjected to any external force, the shaft 63 can maintain a straight position as shown to space the tip electrode 75 from the distal region 67 of the housing by at least the height or length 77 of the shaft 63.

[0112] One or more fixation members 9 can be described as one or more “teeth” having a normally curved position. The teeth can be held in a distally extended position within the delivery tool. The distal tip of the teeth can penetrate cardiac tissue to a limited depth before being resiliently or elastically bent proximally back to the normally curved position (as shown) upon release from the delivery tool. Further, fixation member 20 can include one or more aspects described, for example, in U.S. Patent No. 9,675,579, issued June 13, 2017 (Grubac et al.) and U.S. Patent No. 9,119,959, issued September 1, 2015 (Rys et al.), each of which is incorporated herein by reference in its entirety.

[0113] In some examples, the distal fixation and electrode assembly 36 includes a distal housing-based electrode 79. When using the device 10 as a pacemaker for multi-chamber pacing (e.g., dual-chamber or triple-chamber pacing) and sensing, the tip electrode 75 can serve as a cathode electrode paired with the proximal housing-based electrode 73, which acts as a return anode electrode. Alternatively, the distal housing-based electrode 79 can serve as a return anode electrode paired with the tip electrode 75 for sensing ventricular signals and delivering ventricular pacing pulses. In other examples, the distal housing-based electrode 79 can be a cathode electrode for sensing atrial signals and delivering pacing pulses to the atrial myocardium in the target implantation region 4. When the distal housing-based electrode 79 acts as an atrial cathode electrode, the proximal housing-based electrode 73 can serve as a return anode paired with the tip electrode 75 for ventricular pacing and sensing, and can also serve as a return anode paired with the distal housing-based electrode 79 for atrial pacing and sensing.

[0114] As illustrated in the diagram, in some pacing applications, the target implantation region 4 is along the atrial endocardium 218, typically below the AV node 15 and His bundle 5. The dart electrode assembly 220 may at least partially define the height 77 or length of the shaft 63 to penetrate the atrial endocardium 218 in the target implantation region 4, through the central fibrous body 216, and into the ventricular myocardium 240 without penetrating the ventricular endocardial surface 17. When the height 77 or length of the dart electrode assembly 220 is fully advanced into the target implantation region 4, the tip electrode 75 may be positioned within the ventricular myocardium 240, and the distal shell-based electrode 79 may be positioned in close contact with or very close to the atrial endocardium 218. In various examples, the dart electrode assembly 220 may have a total combined height 77 or length of the tip electrode 75 and shaft 63 of about 3 mm to about 8 mm. The diameter of the shaft 63 may be less than about 2 mm and may be about 1 mm or less, or even about 0.6 mm or less.

[0115] Figure 15 This is a two-dimensional (2D) ventricular diagram 300 of a patient's heart (e.g., a top-down view), showing the left ventricle 320 and right ventricle 322 in a standard 17-segment view. Figure 300 defines or includes multiple regions 326 corresponding to different areas of the human heart. As shown, regions 326 are numbered 1-17 (e.g., corresponding to 17 segments of a standard 17-segment human heart model, corresponding to 17 segments of the left ventricle of the human heart, etc.). Regions 326 of Figure 300 may include the anterior basal region 1, the anterior basal septum region 2, the subbasal septum region 3, the subbasal region 4, the subbasal lateral region 5, the anterior basal lateral region 6, the mid-anterior region 7, the mid-anterior septum region 8, the mid-inferior septum region 9, the mid-inferior region 10, the mid-inferior lateral region 11, the mid-anterior lateral region 12, the anterior vertex region 13, the vertex septum region 14, the vertex lateral region 15, the vertex lateral region 216, and the apex region 17. The inferior and anterior septal regions of the right ventricle 322, as well as the right bundle branch (RBB) 25 and the left bundle branch (LBB) 27, are also shown.

[0116] In some embodiments, any tissue-piercing electrode of this disclosure can be implanted in the base and / or septal region of the left ventricular myocardium of a patient's heart. Specifically, the tissue-piercing electrode can be implanted through the right atrial endocardium and central fibrous body from the Koch's triangle region of the right atrium. Once implanted, the tissue-piercing electrode can be positioned at a target implantation area, such as the base and / or septal region of the left ventricular myocardium. Figures 7 to 8 Referring to Figure 300, the basal region includes one or more of the following: anterior basal region 1, anterior basal septal region 2, subbasal septal region 3, subbasal region 4, mid-anterior region 7, mid-anterior septal region 8, mid-inferior septal region 9, and mid-inferior region 10. Referring to Figure 300, the septal region includes one or more of the following: anterior basal septal region 2, anterior basal septal region 3, mid-anterior septal region 8, mid-inferior septal region 9, and apical septal region 14.

[0117] In some implementations, the tissue-piercing electrode can be positioned in the basal septum region of the left ventricular myocardium upon implantation. The basal septum region may include one or more of the following: anterior basal septum region 2, subbasal septum region 3, anterior mid-septum region 8, and inferior mid-septum region 9.

[0118] In some implementations, upon implantation, the tissue-piercing electrode can be positioned in the superior / posterior basal septum region of the left ventricular myocardium. The superior / posterior basal septum region of the left ventricular myocardium may include a portion of one or more of the subbasal septum region 3 and the mid-inferior septum region 9 (e.g., only the subbasal septum region, only the mid-inferior septum region, or both the subbasal septum region and the mid-inferior septum region). For example, the superior / posterior basal septum region may include region 324, generally illustrated as a dashed boundary. As shown, the dashed boundary indicates the approximate location of the superior / posterior basal septum region, and its shape or size may vary slightly depending on the specific application.

[0119] Figure 16A This is a functional block diagram illustrating one configuration of the IMD 16. As shown, the IMD 16 may include a control module 81, a therapy delivery module 84 (e.g., which may include a stimulation generator), a sensing module 86, and a power supply 90.

[0120] The control module or device 81 may include a processor 80, a memory 82, and a telemetry module or device 88. The memory 82 may include computer-readable instructions that, when executed, for example by the processor 80, cause the IMD 16 and / or control module 81 to perform various functions belonging to the IMD 16 and / or control module 81 described herein. Further, the memory 82 may include any volatile, non-volatile, magnetic, optical, and / or electrical media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), electrically erasable programmable ROM (EEPROM), flash memory, and / or any other digital media. An illustrative capture management module may be a left ventricular capture management (LVCM) module as described in U.S. Patent 7,684,863, entitled “LV Threshold Measurement and Capture Management,” published March 23, 2010, which is incorporated herein by reference in its entirety.

[0121] The processor 80 of the control module 81 may include any one or more of the following: a microprocessor, a controller, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), and / or equivalent discrete or integrated logic circuitry. In some examples, the processor 80 may include multiple components, such as any combination of one or more microprocessors, one or more controllers, one or more DSPs, one or more ASICs, and / or one or more FPGAs, as well as other discrete or integrated logic circuitry. The functionality of the processor 80 as defined herein may be embodied in software, firmware, hardware, or any combination thereof.

[0122] The control module 81 can control the therapy delivery module 84 to deliver therapy (e.g., electrical stimulation therapy such as pacing) to the heart 12 according to one or more selected therapy programs that can be stored in the memory 82. More specifically, the control module 81 (e.g., processor 80) can control various parameters of the electrical stimulation delivered by the therapy delivery module 84 (e.g., AV delay, VV delay, pacing pulses with amplitude, pulse width, frequency, or electrode polarity, etc.), which can be specified by one or more selected therapy programs (e.g., AV and / or VV delay adjustment programs, pacing therapy programs, pacing recovery programs, capture management programs, etc.). As shown, the therapy delivery module 84 is electrically connected to electrodes 40, 42, 44, 45, 46, 47, 48, 50, 58, 62, 64, 66, for example, via conductors of the respective leads 18, 20, 22 or, in the case of housing electrodes 58, via electrical conductors arranged within the housing 60 of the IMD 16. The therapy delivery module 84 can be configured to generate an electrical stimulation therapy, such as pacing therapy, using one or more of electrodes 40, 42, 44, 45, 46, 47, 48, 50, 58, 62, 64, 66 and deliver the electrical stimulation therapy to the heart 12.

[0123] For example, the therapy delivery module 84 can deliver pacing stimulation (e.g., pacing pulses) via ring electrodes 40, 44, 45, 46, 47, 48 and / or spiral tip electrodes 42, 50 of leads 18, 22. Further, for example, the therapy delivery module 84 can deliver a defibrillation shock to the heart 12 via at least two of electrodes 58, 62, 64, 66. In some examples, the therapy delivery module 84 can be configured to deliver pacing, cardioversion, or defibrillation stimulation in the form of electrical pulses. In other examples, the therapy delivery module 84 can be configured to deliver one or more of these types of stimulation in the form of other signals, such as sine waves, square waves, and / or other substantially continuous time signals.

[0124] The IMD 16 may further include a switching module 85, and the control module 81 (e.g., processor 80) may use the switching module 85 to select, for example via a data / address bus, which of the available electrodes are used for delivering therapy, such as pacing pulses for pacing therapy, or which of the available electrodes are used for sensing. The switching module 85 may include a switch array, switch matrix, multiplexer, or any other type of switching device suitable for selectively coupling the sensing module 86 and / or the therapy delivery module 84 to one or more selected electrodes. More specifically, the therapy delivery module 84 may include a plurality of pacing output circuits. Each of these plurality of pacing output circuits may, for example, be selectively coupled using the switching module 85 to one or more electrodes of electrodes 40, 42, 44, 45, 46, 47, 48, 50, 58, 62, 64, 66 (e.g., a pair of electrodes for delivering therapy to a bipolar or multipolar pacing vector). In other words, each electrode may be selectively coupled using the switching module 85 to one of the pacing output circuits of the therapy delivery module.

[0125] The sensing module 86 is connected (e.g., electrically connected) to a sensing device, which may include electrodes 40, 42, 44, 45, 46, 47, 48, 50, 58, 62, 64, 66 to monitor the electrical activity of the heart 12, such as electrocardiogram (ECG) / electrogram (EGM) signals. ECG / EGM signals can be used to measure or monitor activation time (e.g., ventricular activation time), heart rate (HR), heart rate variability (HRV), heart rate oscillation (HRT), deceleration / acceleration capacity, deceleration sequence morbidity, T wave alternation (TWA), P wave to P wave interval (also known as PP interval or AA interval), R wave to R wave interval (also known as RR interval or VV interval), P wave to QRS complex interval (also known as PR interval, AV interval or PQ interval), QRS complex morphology, ST segment (i.e., the segment connecting the QRS complex and the T wave), T wave changes, QT interval, electrical vectors, etc.

[0126] The switching module 85 can also be used with the sensing module 86 to select which of the available electrodes are used or enabled to, for example, sense the electrical activity of a patient's heart (e.g., using one or more electrical vectors of a patient's heart using any combination of electrodes 40, 42, 44, 45, 46, 47, 48, 50, 58, 62, 64, 66). Similarly, the switching module 85 can also be used with the sensing module 86 to select which of the available electrodes are not used (e.g., disabled) to, for example, sense the electrical activity of a patient's heart (e.g., using one or more electrical vectors of a patient's heart using any combination of electrodes 40, 42, 44, 45, 46, 47, 48, 50, 58, 62, 64, 66), etc. In some examples, the control module 81 can select the electrodes that act as sensing electrodes by providing signals, for example, via a data / address bus, through the switching module within the sensing module 86.

[0127] In some examples, the sensing module 86 includes a channel comprising an amplifier having a relatively wider passband than an R-wave or P-wave amplifier. Signals from selected sensing electrodes can be supplied to a multiplexer and subsequently converted by an analog-to-digital converter into multi-bit digital signals for storage in memory 82, for example, as an electrogram (EGM). In some examples, such storage of an EGM in memory 82 can be under the control of direct memory access circuitry.

[0128] In some examples, control module 81 can operate as an interrupt-driven device and can respond to interrupts from the pacemaker timing and control module, where the interruption may correspond to the occurrence of sensed P and R waves and the generation of cardiac pacing pulses. Any necessary mathematical calculations can be performed by processor 80, and any updates to values ​​or intervals controlled by the pacemaker timing and control module may occur after such interruptions. A portion of memory 82 can be configured as a plurality of recirculation buffers capable of holding one or more series of measurement intervals that can be analyzed by, for example, processor 80 in response to the occurrence of pacing or sensing interruptions to determine whether the patient's heart 12 is currently exhibiting atrial or ventricular tachyarrhythmias.

[0129] The telemetry module 88 of the control module 81 may include any suitable hardware, firmware, software, or any combination thereof for communicating with another device, such as a programmer. For example, under the control of the processor 80, the telemetry module 88 may receive downlink telemetry from the programmer and send uplink telemetry to the programmer via an antenna (which may be internal and / or external). The processor 80 may, for example, provide data to be transmitted uplink to the programmer and control signals for the telemetry circuitry within the telemetry module 88 via an address / data bus. In some examples, the telemetry module 88 may provide the received data to the processor 80 via a multiplexer.

[0130] The various components of the IMD 16 are further connected to a power source 90, which may include a rechargeable or non-rechargeable battery. A non-rechargeable battery may be selected to last for several years, while a rechargeable battery may be inductively charged from an external device, for example, on a daily or weekly basis.

[0131] Figure 16B Another embodiment of the functional block diagram of IMD 16 depicts bipolar RA leads 22, bipolar RV leads 18, and bipolar LV CS leads 20 without LA CS pacing / sensing electrodes and connected to an implantable pulse generator (IPG) circuit 31, which has programmable modes and biventricular DDD / R type parameters known in the pacing field. Furthermore, sensor signal processing circuitry 91 is indirectly connected to timing circuitry 43 and via data and control bus to microcomputer circuitry system 33. IPG circuitry 31 is shown in the functional block diagram, which is generally divided into microcomputer circuitry 33 and pacing circuitry 21. Pacing circuitry 21 includes digital controller / timer circuitry 43, output amplifier circuitry 51, sensing amplifier circuitry 55, RF telemetry transceiver 41, activity sensor circuitry 35, and many other circuits and components described below.

[0132] When battery 29 provides power, crystal oscillator circuit 89 provides a basic timing clock to pacing circuit 21. Power-on reset circuit 87 responds to the initial connection of the circuit with the battery to define initial operating conditions, and similarly resets the operating state of the device in response to the detection of a low battery condition. Reference mode circuit 37 generates a stable voltage reference and current for the analog circuitry within pacing circuit 21. Analog-to-digital converter (ADC) and multiplexer circuit 39 digitizes the analog signals and voltages to provide, for example, real-time telemetry of cardiac signals from sensing amplifier 55 for uplink transmission via RF transmitter and receiver circuit 41. Voltage reference and bias circuit 37, ADC and multiplexer 39, power-on reset circuit 87, and crystal oscillator circuit 89 may correspond to any of those used in illustrative implantable cardiac pacemakers.

[0133] If the IPG is programmed into a rate-response mode, signals output from one or more physiological sensors are used as rate control parameters (RCPs) to derive the physiological escape interval. For example, the escape interval is adjusted proportionally to the patient activity level generated in the patient activity sensor (PAS) circuit 35 within the illustrated IPG circuit 31. The patient activity sensor 27 is coupled to the IPG housing and may take the form of a piezoelectric crystal transducer. The output signal of the patient activity sensor 27 can be processed and used as the RCP. The sensor 27 generates an electrical signal in response to sensed body activity, which is processed by the activity circuit 35 and provided to the digital controller / timer circuit 43. The active circuit 35 and associated sensor 27 can correspond to the circuit systems disclosed in U.S. Patent 5,052,388, entitled "METHOD AND APPARATUSFOR IMPLEMENTING ACTIVITY SENSING IN A PULSE GENERATOR," issued October 1, 1991, and U.S. Patent 4,428,378, entitled "Rate Adaptive Pacer," issued January 31, 1984, each of which is incorporated herein by reference in its entirety. Similarly, the illustrative systems, apparatus, and methods described herein can be practiced in conjunction with alternative types of sensors, such as oxygenation sensors, pressure sensors, pH sensors, and respiration sensors, to provide rate-responsive pacing capability. Alternatively, the QT time can be used as a rate indication parameter, in which case no additional sensor is required. Similarly, the illustrative embodiments described herein can also be practiced in non-rate-responsive pacemakers.

[0134] Data transmission to and from the external programmer is achieved via telemetry antenna 57 and an associated RF transceiver 41, which demodulates both received downlink telemetry and transmits uplink telemetry. Uplink telemetry capabilities may include the ability to transmit stored digital information, such as operating modes and parameters, EGM histograms and other events, as well as real-time EGM of atrial and / or ventricular electrical activity and marker channel pulses indicating the occurrence of sensed and paced depolarization in the atria and ventricles.

[0135] The microcomputer 33 contains a microprocessor 80 and an associated system clock, as well as on-processor RAM chips 82A and ROM chips 82B. Additionally, the microcomputer circuitry 33 includes a separate RAM / ROM chip 82C to provide additional memory capacity. The microprocessor 80 typically operates in a low-power mode and is interrupt-driven. The microprocessor 80 is awakened in response to defined interrupt events, which may include A-TRIG, RV-TRIG, and LV-TRIG signals generated by timers in the digital timer / controller circuitry 43, and A-EVENT, RV-EVENT, and LV-EVENT signals generated by the sense amplifier circuitry 55, etc. The specific values ​​of the timeout intervals and delays by the digital controller / timer circuitry 43 are controlled by the microcomputer circuitry 33 via the data and control bus from programmed parameter values ​​and operating modes. Furthermore, if programmed to operate as a rate-responsive pacemaker, timing interrupts, such as every cycle or every two seconds, may be provided to allow the microprocessor to analyze active sensor data and update the basic AA, VA, or VV escape intervals (if applicable). In addition, the microprocessor 80 can also be used to define variable, operable AV delay intervals, VV delay intervals, and the energy delivered to each ventricle and / or atrium.

[0136] In one embodiment, microprocessor 80 is a custom microprocessor adapted to fetch and execute instructions stored in RAM / ROM unit 82 in a conventional manner. However, other embodiments are contemplated that may be suitable for practicing this disclosure. For example, off-the-shelf, commercially available microprocessors or microcontrollers or custom-designed, dedicated hardwired logic or state machine type circuitry can perform the functions of microprocessor 80.

[0137] The digital controller / timer circuit 43 operates under the general control of the microcomputer 33 to control timing and other functions within the pacing circuit 21, and includes a set of timing and associated logic circuits, some of which are depicted in relation to this disclosure. The depicted timing circuits include a URI / LRI timer 83A, a VV delay timer 83B, an intrinsic interval timer 83C for timing the elapsed V-EVENT to V-EVENT interval or V-EVENT to A-EVENT interval or VV conduction interval, an escape interval timer 83D for timing the AA, VA, and / or VV pacing escape interval, an AV delay interval timer 83E for timing the A-LVp delay (or A-RVp delay) from a previous A-EVENT or A-TRIG, a postventricular timer 83F for timing the postventricular time period, and a date / time clock 83G.

[0138] The AV delay interval timer 83E is loaded with an appropriate delay interval (e.g., A-RVp delay or A-LVp) for a ventricular chamber to time out from a previous A-PACE or A-EVENT. The interval timer 83E triggers pacing stimulus delivery and can be based on one or more previous cardiac cycles (or on a dataset derived empirically for a given patient).

[0139] The post-event timer 83F causes the post-ventricular time period following RV-EVENT, LV-EVENT, RV-TRIG, or LV-TRIG, and the post-atrial time period following A-EVENT or A-TRIG, to time out. The duration of the post-event time period can also be selected as a programmable parameter stored in the microcomputer 33. The post-ventricular time period includes PVARP, post-atrial ventricular blanking period (PAVBP), ventricular blanking period (VBP), post-ventricular atrial blanking period (PVARP), and ventricular refractory period (VRP), but other time periods can be appropriately defined, at least in part, according to the operating circuitry employed in the pacemaker. The post-atrial time period includes the atrial refractory period (ARP) and atrial blanking period (ABP). During the atrial refractory period, A-EVENT is ignored for the purpose of resetting any AV delays, and during the atrial blanking period, atrial sensing is disabled. It should be noted that the onset of the post-atrial time interval and AV delay may begin substantially simultaneously with the start or end of each A-EVENT or A-TRIG, or in the latter case, at the end of an A-PACE that can follow an A-TRIG. Similarly, the onset of the post-ventricular time interval and VA escape interval may begin substantially simultaneously with the start or end of a V-EVENT or V-TRIG, or in the latter case, at the end of a V-PACE that can follow a V-TRIG. The microprocessor 80 also optionally calculates the AV delay, VV delay, post-ventricular time interval, and post-atrial time interval, which vary with sensor-based escape intervals and / or intrinsic atrial and / or ventricular rates established in response to one or more RCPs.

[0140] Output amplifier circuit 51 contains an RA pacing pulse generator (and an LA pacing pulse generator, if LA pacing is provided), an RV pacing pulse generator, an LV pacing pulse generator, and / or any other pulse generator configured to provide atrial and ventricular pacing. To trigger the generation of an RV-PACE or LV-PACE pulse, digital controller / timer circuit 43 generates an RV-TRIG signal when the A-RVp delay (in the case of RV pre-excitation) provided by AV delay interval timer 83E (or VV delay timer 83B) times out, or generates an LV-TRIG signal when the A-LVp delay (in the case of LV pre-excitation) times out. Similarly, digital controller / timer circuit 43 generates an RA-TRIG signal (or an LA-TRIG signal, if provided) that triggers the output of an RA-PACE pulse at the end of a VA escape interval timed by escape interval timer 83D.

[0141] Output amplifier circuit 51 includes a switching circuit for connecting selected pacing electrode pairs from the lead conductors and IND-CAN electrodes 20 to the RA pacing pulse generator (and LA pacing pulse generator, if provided), RV pacing pulse generator, and LV pacing pulse generator. Pacing / sensing electrode pair selection and control circuit 53 selects the lead conductors and associated pacing electrode pairs for connection to the atrial and ventricular output amplifiers within output amplifier circuit 51 for RA, LA, RV, and LV pacing.

[0142] Sensing amplifier circuit 55 contains sensing amplifiers for atrial and ventricular pacing and sensing. High-impedance P-wave and R-wave sensing amplifiers can be used to amplify the voltage difference signal generated across the sensing electrode pair due to the passage of the cardiac depolarization wavefront. The high-impedance sensing amplifier uses high gain to amplify low-amplitude signals and relies on passband filtering, time-domain filtering, and amplitude threshold comparison to distinguish the P-wave or R-wave from background electrical noise. Digital controller / timer circuit 43 controls the sensitivity settings of atrial and ventricular sensing amplifier 55.

[0143] During the blanking period before, during, and after the delivery of a pacing pulse to any of the pacing electrodes in the pacing system, the sensing amplifier can be decoupled from the sensing electrode to avoid saturation of the sensing amplifier. Sensing amplifier circuit 55 includes a blanking circuit for decoupling selected lead conductor pairs and IND-CAN electrode 20 from the inputs of the RA sensing amplifier (and LA sensing amplifier, if provided), RV sensing amplifier, and LV sensing amplifier during ABP, PVABP, and VBP. Sensing amplifier circuit 55 also includes a switching circuit for connecting selected sensing electrode lead conductors and IND-CAN electrode 20 to the RA sensing amplifier (and LA sensing amplifier, if provided), RV sensing amplifier, and LV sensing amplifier. Similarly, sensing electrode selection and control circuit 53 selects the conductors and associated sensing electrode pairs to be coupled to the atrial and ventricular sensing amplifiers within output amplifier circuit 51 and sensing amplifier circuit 55 for RA, LA, RV, and LV sensing along desired unipolar and bipolar sensing vectors.

[0144] Right atrial depolarization or a P wave in the RA-SENSE signal sensed by the RA sensing amplifier results in an RA-EVENT signal being transmitted to the digital controller / timer circuit 43. Similarly, left atrial depolarization or a P wave in the LA-SENSE signal sensed by the LA sensing amplifier (if provided) results in an LA-EVENT signal being transmitted to the digital controller / timer circuit 43. Ventricular depolarization or an R wave in the RV-SENSE signal sensed by the ventricular sensing amplifier results in an RV-EVENT signal being transmitted to the digital controller / timer circuit 43. Similarly, ventricular depolarization or an R wave in the LV-SENSE signal sensed by the ventricular sensing amplifier results in an LV-EVENT signal being transmitted to the digital controller / timer circuit 43. The RV-EVENT, LV-EVENT, RA-EVENT, and LA-SENSE signals may be refractory or responsive and may be inadvertently triggered by electrical noise signals or abnormally conducted depolarization waves instead of genuine R or P waves.

[0145] The techniques described in this disclosure (including those attributable to IMD 16, computing device 140, and / or various constituent components) can be implemented, at least in part, in the form of hardware, software, firmware, or any combination thereof. For example, aspects of the techniques can be implemented within one or more processors embodied as programmers, stimulators, image processing devices, or other devices, including one or more microprocessors, DSPs, ASICs, FPGAs, or any other equivalent integrated or discrete logic circuits, and any combination of such components. The terms “module,” “processor,” or “processing circuit” can generally refer to any of the aforementioned logic circuits individually or in combination with other logic circuits, or any circuit in any other equivalent circuit.

[0146] Such hardware, software, and / or firmware may be implemented within the same device or in separate devices to support the various operations and functions described in this disclosure. Furthermore, any described unit, module, or component may be implemented together or individually as discrete but interoperable logical devices. Describing different features as modules or units is intended to highlight different functional aspects and does not necessarily imply that such modules or units must be implemented by separate hardware or software components. Rather, the functionality associated with one or more modules or units may be performed by separate hardware or software components, or integrated into common or separate hardware or software components.

[0147] When implemented in software, the functionality attributable to the systems, apparatus, and techniques described in this disclosure can be embodied in instructions on a computer-readable medium such as RAM, ROM, NVRAM, EEPROM, flash memory, magnetic data storage medium, optical data storage medium, etc. These instructions can be executed by processing circuitry and / or one or more processors to support one or more aspects of the functionality described in this disclosure.

[0148] Exemplary implementation plan

[0149] Implementation Scheme 1. A system for cardiac assessment, the system comprising:

[0150] Electrode device, the electrode device comprising a plurality of external electrodes to be placed near the patient's skin; and

[0151] A computing device, including processing circuitry, operatively coupled to the electrode device and configured to:

[0152] The plurality of external electrodes are used to monitor electrocardiographic activity from the patient's tissues;

[0153] One or more cardiac measurements of the patient are generated based on the monitored electrical activity;

[0154] If the patient has right bundle branch block, the one or more cardiac metrics are used based on a first global asynchrony metric to determine whether the patient is a candidate for a ventricular resynchronization therapy (CRT) device; and

[0155] If the patient does not have right bundle branch block, the one or more cardiac metrics are used based on a second global asynchrony metric to determine whether the patient is a candidate for cardiac resynchronization therapy (CRT) devices.

[0156] Implementation Scheme 2. The system according to Implementation Scheme 1, wherein the plurality of external electrodes includes a plurality of left external electrodes positioned to the left side of the patient’s torso, wherein the one or more metrics include the standard deviation of activation time (SDAT) and the mean of left ventricular activation time (LVAT) based on the cardiac electrical activity monitored using the plurality of left external electrodes.

[0157] Implementation Scheme 3. The system according to Implementation Scheme 2, wherein the first global asynchrony metric is the sum of the scores of the LLAT and the SDAT, wherein determining whether the patient is a candidate for a CRT device includes: determining that the patient is a candidate for a CRT device if the first global asynchrony metric is greater than a predetermined threshold.

[0158] Implementation Scheme 4. The system according to Implementation Scheme 3, wherein the score of SDAT is (5 SDAT) / 3.

[0159] Implementation Scheme 5. The system according to Implementation Scheme 3, wherein the predetermined threshold is in the range of about 30 ms to about 80 ms.

[0160] Implementation Scheme 6. The system according to Implementation Scheme 3, wherein the predetermined threshold is approximately 50 ms.

[0161] Implementation Scheme 7. The system according to Implementation Scheme 2, wherein the second global asynchronous metric includes:

[0162] Determine whether the SDAT is greater than a first predetermined threshold; and

[0163] Determine whether the LVAT is greater than a second predetermined threshold.

[0164] Implementation Scheme 8. The system according to Implementation Scheme 7, wherein the first predetermined threshold is in the range of about 15ms to about 30ms, and the second predetermined threshold is in the range of about 25ms to about 40ms.

[0165] Implementation Scheme 9. The system according to Implementation Scheme 7, wherein the first predetermined threshold is approximately 25 ms and the second predetermined threshold is approximately 35 ms.

[0166] Implementation Scheme 10. The system according to Implementation Scheme 3, wherein the second global asynchronous metric includes:

[0167] Determine whether the SDAT divided by QRSd is greater than a third predetermined threshold; and

[0168] Determine whether the LVAT divided by the QRSd is greater than a fourth predetermined threshold.

[0169] Implementation Scheme 11. The system according to Implementation Scheme 10, wherein the third predetermined threshold is in the range of about 0.05 to about 0.25, and the fourth predetermined threshold is in the range of about 0.10 to about 0.30.

[0170] Implementation Scheme 12. The system according to any one of Implementation Schemes 10 to 11, wherein the third predetermined threshold is about 0.15 and the fourth predetermined threshold is about 0.20.

[0171] Implementation Scheme 13. A method for cardiac assessment, the method comprising:

[0172] Multiple external electrodes are used to monitor cardiac electrical activity from the patient's tissues;

[0173] One or more cardiac measurements of the patient are generated based on the monitored electrical activity;

[0174] If the patient has right bundle branch block, the one or more cardiac metrics are used based on a first global asynchrony metric to determine whether the patient is a candidate for a ventricular resynchronization therapy (CRT) device; and

[0175] If the patient does not have right bundle branch block, the one or more cardiac metrics are used to determine whether the patient is a candidate for a CRT device based on a second global asynchronous metric.

[0176] Implementation Scheme 14. The method according to Implementation Scheme 13, wherein the plurality of external electrodes includes a plurality of left external electrodes positioned to the left side of the patient’s torso, wherein one or more metrics include the standard deviation of activation time (SDAT) and the mean of left ventricular activation time (LVAT) based on cardiac electrical activity monitored using the plurality of left external electrodes.

[0177] Implementation Scheme 15. The method according to Implementation Scheme 14, wherein the first global asynchrony metric is the sum of the scores of the LLAT and the SDAT, wherein determining whether the patient is a candidate for a CRT device includes: determining that the patient is a candidate for a CRT device if the first global asynchrony metric is greater than a predetermined threshold.

[0178] Implementation Scheme 16. The method according to Implementation Scheme 15, wherein the score of SDAT is (5 SDAT) / 3.

[0179] Implementation Scheme 17. The method according to Implementation Scheme 14, wherein the second global asynchronous metric includes:

[0180] Determine whether the SDAT is greater than a first predetermined threshold; and

[0181] Determine whether the LVAT is greater than a second predetermined threshold.

[0182] Implementation Scheme 18. The method according to Implementation Scheme 15, wherein the second global asynchronous metric comprises:

[0183] Determine whether the SDAT divided by QRSd is greater than a third predetermined threshold; and

[0184] Determine whether the LVAT divided by the QRSd is greater than a fourth predetermined threshold.

[0185] Implementation Scheme 19. A system for cardiac assessment, the system comprising:

[0186] Electrode device, the electrode device comprising a plurality of external electrodes to be placed near the patient's skin; and

[0187] A computing device, including processing circuitry, operatively coupled to the electrode device and configured to:

[0188] The plurality of external electrodes are used to monitor the electrical activity of the patient’s tissues during the delivery of bradycardia pacing to the patient’s heart;

[0189] Electrical heterogeneity information (EHI) is generated based on the monitored cardiac activity during bradycardia pacing delivered to the patient's heart; and

[0190] The effectiveness of bradycardia pacing therapy is determined based on the generated EHI, wherein the EHI reflects the normalization of conduction in the patient population during bradycardia pacing.

[0191] Implementation Scheme 20. The system according to Implementation Scheme 19, wherein if the metric does not reflect normalization, it is determined whether additional options for pacing are available.

[0192] Implementation Scheme 21. The system according to Implementation Scheme 20, wherein the additional options include changing one or more lead positions and changing one or more of one or more pacing parameters.

[0193] Implementation Scheme 22. The system according to Implementation Scheme 21, wherein the pacing parameters include AV delay, pulse width, amplitude, voltage, and burst length.

[0194] Implementation Scheme 23. The system according to Implementation Scheme 20, wherein if it is determined that an additional option is unavailable, it is recommended to implant at least one spare lead.

[0195] Implementation Scheme 24. The system according to Implementation Scheme 23, wherein after implantation of the one or more spare leads, the computing device is configured to set the final pacing parameters based on the lowest measurement activation time standard deviation (SDAT).

[0196] Implementation Scheme 25. The system according to any of Implementation Schemes 19 to 24, wherein the EHI is based on one or more metrics, including the activation time standard deviation (SDAT) metric, the left ventricular activation time metric, the LV dispersion metric based on the activation time standard deviation of the electrodes on the left side of the body reflecting left ventricular activation, and the RV dispersion metric based on the activation time standard deviation of the electrodes on the right side of the body reflecting right ventricular activation time.

[0197] Implementation Scheme 26. The system according to any one of Implementation Schemes 19 to 25, wherein the patient group has at least one similar characteristic to the patient.

[0198] Implementation Scheme 27. The system according to Implementation Scheme 26, wherein the at least one similar feature includes age, sex, height, and weight.

[0199] Implementation Scheme 28. A method for cardiac assessment, the method comprising:

[0200] Multiple external electrodes are used to monitor the electrical activity of the patient’s tissues during the delivery of bradycardia pacing to the patient’s heart;

[0201] Electrical heterogeneity information (EHI) is generated based on the cardiac electrical activity monitored during bradycardia pacing delivery to the patient's heart; and

[0202] The effectiveness of bradycardia pacing therapy is determined based on the generated EHI, wherein the EHI reflects the normalization of conduction in the patient population during bradycardia pacing.

[0203] Implementation Scheme 29. The method according to Implementation Scheme 28, wherein if the metric does not reflect normalization, it is determined whether additional options for pacing are available.

[0204] Implementation Scheme 30. The method according to Implementation Scheme 29, wherein the additional options include changing one or more lead positions and changing one or more of one or more pacing parameters.

[0205] Implementation Scheme 31. The method according to Implementation Scheme 30, wherein the pacing parameters include AV delay, pulse width, amplitude, voltage, and burst length.

[0206] Implementation Scheme 32. The method described in any of Implementation Schemes 28-31, wherein if it is determined that other options are not available, it is recommended to implant at least one spare lead.

[0207] Implementation Scheme 33. The method according to Implementation Scheme 32, wherein after implantation of the one or more spare leads, the computing device is configured to set the final pacing parameters based on the lowest measurement activation time standard deviation (SDAT).

Claims

1. A system for cardiac assessment, the system comprising: An electrode device comprising a plurality of external electrodes to be placed near the patient’s skin; as well as A computing device, including processing circuitry, operatively coupled to the electrode device and configured to: The plurality of external electrodes are used to monitor electrocardiographic activity from the patient's tissues; One or more cardiac measurements of the patient are generated based on the monitored electrocardiographic activity; If the patient has right bundle branch block, the one or more cardiac metrics are used based on a first global asynchrony metric to determine whether the patient is a candidate for a ventricular resynchronization therapy (CRT) device. as well as If the patient does not have right bundle branch block, the one or more cardiac metrics are used to determine whether the patient is a candidate for a cardiac resynchronization therapy (CRT) device based on a second global asynchronous metric, wherein the second global asynchronous metric is different from the first global asynchronous metric.

2. The system of claim 1, wherein the plurality of external electrodes comprises a plurality of left external electrodes positioned to the left side of the patient’s torso, wherein the one or more cardiac measurements comprise the standard deviation of activation time (SDAT) and the mean of left ventricular activation time (LVAT) based on the cardiac electrical activity monitored using the plurality of left external electrodes.

3. The system of claim 2, wherein the first global asynchrony metric is the sum of the scores of the LVAT and the SDAT, wherein determining whether the patient is a candidate for a CRT device includes: If the first global asynchrony metric is greater than a predetermined threshold, the patient is determined to be a candidate for a CRT device.

4. The system according to claim 3, wherein the score of SDAT is (5) SDAT) / 3.

5. The system according to any one of claims 3 to 4, wherein the predetermined threshold is in the range of 30 ms to 80 ms.

6. The system according to any one of claims 3 to 4, wherein the predetermined threshold is 50 ms.

7. The system according to any one of claims 2 to 4, wherein the second global desynchronization metric comprises: Determine whether the SDAT is greater than a first predetermined threshold; as well as Determine whether the average left ventricular activation time (LVAT) is greater than a second predetermined threshold.

8. The system of claim 7, wherein the first predetermined threshold is in the range of 15ms to 30ms, and the second predetermined threshold is in the range of 25ms to 40ms.

9. The system according to claim 7, wherein the first predetermined threshold is 25ms and the second predetermined threshold is 35ms.

10. The system according to any one of claims 2 to 4, wherein the second global desynchronization metric comprises: Determine whether the SDAT divided by the QRS duration QRSd is greater than a third predetermined threshold; as well as Determine whether the average left ventricular activation time (LVAT) divided by the QRSd is greater than a fourth predetermined threshold.

11. The system of claim 10, wherein the third predetermined threshold is in the range of 0.05 to 0.25, and the fourth predetermined threshold is in the range of 0.10 to 0.

30.

12. The system of claim 10, wherein the third predetermined threshold is 0.15 and the fourth predetermined threshold is 0.20.

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