Left ventricular assist device adjustment and evaluation

Abstract

Systems and methods for evaluating and adjusting a left ventricular assist device (LVAD) are described herein. The systems and methods can monitor cardiac electrical activity using at least a plurality of external electrodes before and during LVAD therapy. Cardiac electrical activity and other information such as heart sound information can be used to determine and adjust one or more LVAD output parameters such as pump speed.

Description

[0001] This application claims the benefit of U.S. Patent Application No. 62 / 649,929, filed on March 29, 2018, which is incorporated herein by reference in its entirety.

[0002] The disclosure herein relates to systems and methods for use in adjusting and evaluating cardiac therapy provided by a left ventricular assist device (LVAD) using an extracorporeal electrode arrangement.

[0003] Heart assist systems provide additional cardiac output in patients suffering from inadequate cardiac output. One type of heart assist system is known as a left ventricular assist device (LVAD). An LVAD can be described as an auxiliary pouch designed to act as a booster pump to assist the heart of an individual suffering from chronic congestive heart failure. Chronic congestive heart failure can often be caused by a heart attack that reduces the pumping ability of the human heart. By boosting the capacity of such a weakened heart, individuals suffering from this condition can be allowed to live a relatively normal, productive life again.

[0004] Heart failure patients undergoing surgery may also be provided with an LVAD to acutely unload the ventricle to promote recovery. Approximately 20% to 30% of patients treated with an LVAD may develop right ventricular failure that is refractory to medical treatment. Right ventricular function may decline as a result of changes in right ventricular preload and afterload produced by abnormal pressure imbalances between the left and right ventricles and abnormal wall motion observed as septal displacement and asynchronous bulging of the free walls. Maintaining a greater degree of synchronization between right and left ventricular pressure development can prevent the demise of right ventricular function in the presence of an LVAD.

[0005] Further, an implantable medical device (IMD) (such as an implantable pacemaker, cardioverter, defibrillator, or pacemaker-cardioverter-defibrillator) provides therapeutic electrical stimulation to the heart. An IMD may provide pacing to address bradycardia, or provide pacing or shock to terminate a rapid arrhythmia, such as tachycardia or fibrillation. In some cases, a medical device may: sense intrinsic depolarization of the heart; detect an arrhythmia based on the intrinsic depolarization (or the absence thereof); and control the delivery of electrical stimulation to the heart if an arrhythmia is detected based on the intrinsic depolarization.

[0006] IMDs can also provide cardiac resynchronization therapy (CRT), which is a form of pacing. CRT involves the delivery of pacing to the left ventricle, or both the left ventricle and the right ventricle. The timing and location of the delivery of pacing pulses to the ventricle(s) can be selected to improve the coordination and efficiency of ventricular contraction.

[0007] In addition to the implantable medical device itself, the system for implanting the medical device may include a workbench or other equipment. In some cases, these other pieces of equipment assist the physician or other technician in placing the intracardiac lead at a specific location on or in 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. Summary of the invention

[0008] The exemplary systems, devices, methods, and interfaces described herein may be configured to assist a user (e.g., a physician) in evaluating a patient and / or evaluating cardiac therapy (e.g., cardiac therapy performed on a patient via a left ventricular heart assist device (LVAD) and / or an implantable cardiac therapy device). In one or more embodiments, the systems, methods, and interfaces may be described as non-invasive. For example, in some embodiments, the systems, methods, and interfaces may not require or include implantable devices (such as leads, probes, sensors, catheters, implanted electrodes, etc.) to monitor or acquire multiple cardiac signals from a patient's tissue for use in evaluating the patient and / or cardiac therapy provided by an LVAD and / or by an implantable cardiac therapy device. Alternatively, the systems, methods, and interfaces may use measurements (e.g., electrical measurements, physical measurements, etc.) obtained non-invasively using, for example, multiple external electrodes and / or electrodes attached to the patient's skin around the patient's torso.

[0009] An exemplary system may include an electrode arrangement including a plurality of extracorporeal electrodes to monitor cardiac electrical activity from patient tissue, and a computing device including a processing circuit system and coupled to the electrode arrangement. The computing device may be configured to: monitor cardiac electrical activity using the plurality of extracorporeal electrodes at least during delivery of cardiac therapy using a left ventricular assist device (LVAD), generate electrical heterogeneity information based on the monitored electrical activity, and determine an output parameter of the LVAD based on the generated electrical heterogeneity information.

[0010] The method may include: monitoring electrical activity from patient tissue using multiple electrodes at least during delivery of cardiac therapy using a left ventricular assist device (LVAD), generating electrical heterogeneity information based on the monitored electrical activity, and determining an output parameter of the LVAD based on the generated electrical heterogeneity information.

[0011] The exemplary systems, devices, and methods disclosed herein may be described as a general tool for titrating pacing parameters for maximizing cardiac electrical synchronization during cardiac resynchronization therapy (CRT). More specifically, the exemplary systems, devices, and methods may use multiple extracorporeal electrodes to measure and monitor overall cardiac activation patterns during use of cardiac therapy using a left ventricular assist device (LVAD) for use in, for example, LVAD therapy evaluation, follow-up / programming for titrating LVAD therapy (including pump speed and concomitants of pacing therapy). The exemplary systems, devices, and methods disclosed herein may be further described as providing an immediate, non-invasive means of titrating LVAD therapy for optimal patient outcomes.

[0012] In one or more embodiments, the exemplary systems, devices, and methods may be equipped with or include one or more additional sensors to assist in LVAD device and patient management. For example, an acoustic sensor array may be incorporated into an electrode assembly including a plurality of extracorporeal electrodes, and the acoustic signals may be used to infer mechanical activation of the heart (e.g., valve opening and closing) and to detect acoustic signatures corresponding to thrombus accumulation within the pump of the LVAD or other mechanical problems with the LVAD.

[0013] Further, in one or more embodiments, exemplary systems, apparatuses, and methods including, for example, signal amplifiers, electrode arrays, analysis processes, or algorithms may be described as being integrated with an LVAD controller or LVAD monitor of an LVAD system. The exemplary systems, apparatuses, and methods may further include or utilize algorithms for automatically titrating parameters for optimal response (e.g., minimal right ventricular (RV) dyssynchrony, shortest RV activation time, etc.) and minimal chance of a patient developing RV failure.

[0014] In one or more embodiments, the exemplary systems, apparatuses, and methods may be configured to titrate only the LVAD pump rate or to titrate both the LVAD pump rate and the pacing device pacing parameters (automatically or manually). Further, the exemplary systems, apparatuses, and methods may also include or have other skin sensors and integrated associated signal processing (such as acoustics) for providing input into the mechanical function of the heart (e.g., valve opening and closing) as well as diagnostics related to the pump function itself (e.g., "accumulation" of thrombus within the pump, etc.).

[0015] The above summary of the invention is not intended to describe every embodiment or every implementation of the present disclosure. A more complete understanding will become apparent and understandable by referring to the following detailed description obtained in conjunction with the accompanying drawings and the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1is a diagram of an exemplary system including an electrode apparatus, a left ventricular assist device (LVAD) apparatus, a display apparatus, and a computing apparatus.

[0017] Figure 2-3 is a diagram of an exemplary in vitro electrode arrangement for measuring electrical potential on the surface of the torso.

[0018] Figure 4 is a block diagram of an exemplary method for determining LVAD output parameters.

[0019] Figure 5 is a block diagram of an exemplary method for adjusting one or both of LVAD output parameters and pacing parameters.

[0020] Figure 6 is a block diagram of an exemplary method for adjusting an LVAD based on one or both of electrical heterogeneity information and heart sounds.

[0021] Figure 7 is a diagram of an exemplary system including an exemplary implantable medical device (IMD).

[0022] Figure 8 is an exemplary LVAD device and Figure 7 Figure 2 is a diagram of an exemplary system of an IMD.

[0023] Fig.9A yes Figure 7 FIG. 5 is a diagram of an exemplary IMD of FIG.

[0024] Fig. 9B yes Fig.9A Figure 2 is an enlarged view of the distal end of an electrical lead positioned in the left ventricle.

[0025] Fig. 10A is an exemplary IMD (e.g. Figure 7 -9 system) block diagram.

[0026] Fig. 10B is Figure 7 Another block diagram of an exemplary IMD (e.g., implantable pulse generator) circuitry and associated leads employed in the system of FIG. DETAILED DESCRIPTION

[0027] In the following detailed description of the illustrative embodiments, reference is made to the accompanying drawings, which form a part of the embodiments and in which are shown by way of illustration specific embodiments that can be practiced. It should be understood that other embodiments can be used and structural changes can be made without departing from (e.g., still falling within) the scope of the present disclosure presented herein.

[0028] Will refer to Figure 1-10 to describe exemplary systems and methods. It will be apparent to those skilled in the art that elements or processes from one embodiment may be used in combination with elements or processes of other embodiments, and possible embodiments of such methods and systems using the combination of features set forth herein are not limited to the specific embodiments shown in the drawings and / or described herein. Further, it will be appreciated that the embodiments described herein may include many elements that are not necessarily shown to scale. Further, it will be appreciated that the timing of the processes herein and the sizes and shapes of the various elements may be modified and still fall within the scope of the present disclosure, but certain timings, one or more shapes and / or sizes, or types of elements may be advantageous relative to other timings, shapes and / or sizes, and types of elements.

[0029] Multiple electrocardiogram (ECG) records or signals may be measured or monitored using multiple external electrodes positioned around the surface or skin of a patient. The ECG signals may be used to evaluate and configure cardiac therapy, such as, for example, cardiac therapy provided by an LVAD or CRT. As described herein, since, for example, implanted electrodes may not be used to measure the ECG signals, the ECG signals may be collected or acquired non-invasively. Further, the ECG signals may be used to determine cardiac electrical excitation times, which may be used to generate various metrics (e.g., electrical heterogeneity information) that may be used by a user (e.g., a physician) to optimize one or more settings or parameters of a pacing therapy (such as a CRT) or cardiac therapy provided by an LVAD.

[0030] Various exemplary systems and methods may be configured to non-invasively assist a user (e.g., a physician) in the assessment of cardiac health and / or configuration (e.g., optimization) of cardiac therapy using an electrode device including an extracorporeal electrode, a display device, and a computing device. Figure 1 An exemplary system 100 including an electrode device 110, a computing device 140, a LVAD device 151, and a remote computing device 160 is depicted in FIG.

[0031] An exemplary LVAD device 151 may be generally described as including an LVAD 150 operably coupled to a patient's heart to perform left ventricular assist cardiac therapy and an LVAD controller 152 operably coupled to the LVAD 150 to control and provide power to the LVAD 150. The LVAD 150 may be operably coupled to the LVAD controller 152 (e.g., via one or more wired electrical connections, wirelessly, etc.). As shown, the LVAD 150 is operably coupled or connected to the LVAD controller 152 using a wired connection or wire. Reference may be made herein to Figure 8An exemplary LVAD device 151 is further described. It should be understood that the LVAD device 151 may include lower output flows and partial heart assist systems may be used for a wider range of HF patients, including those with fewer symptoms and those with preserved ejection fraction (HFpEF) in which high cardiac filling pressures may cause HF symptoms. Implantation methods for these lower output pumps can be performed using minimally invasive techniques and may include various placements (such as left atrium to aortic circulatory support). For purposes of this disclosure, all such complete or partial heart assist systems, including those that treat HF ​​with preserved ejection fraction, will be referred to as LVADs.

[0032] The electrode device 110 shown includes a plurality of electrodes that are incorporated into, or included in, a band that is wrapped around the chest or torso of the patient 14. The electrode device 110 is operably coupled to a computing device 140 (e.g., via one or wired electrical connections, wirelessly, etc.) to provide electrical signals from each of the electrodes to the computing device 140 for analysis, evaluation, etc. An exemplary electrode device may be described in U.S. Patent No. 9,320,446, filed on March 27, 2014 and issued on March 26, 2016, entitled “Bioelectric Sensor Device and Methods.” Further, the exemplary electrode device 110 will be referred to in Figure 2-3 is described in more detail.

[0033] Although not described herein, the exemplary system 100 may further include an imaging device. The imaging device may be any type of imaging device configured to image at least a portion of the patient or provide an image of at least a portion of the patient in a non-invasive manner. For example, the imaging device may not use any components or portions that can be positioned within the patient to provide an image of the patient, other than non-invasive tools such as contrast agents. It should be understood that the exemplary systems and methods described herein may further use an imaging device to provide non-invasive assistance to a user (e.g., a physician) to position or place the LVAD 150 (or one or more portions thereof) or one or more pacing electrodes near the patient's heart in conjunction with configuring a cardiac therapy.

[0034] For example, exemplary systems and methods can provide image-guided navigation that can be used to navigate one or more portions of the LVAD 150, leads (including electrodes, leadless electrodes, wireless electrodes, catheters, etc.) within a patient's body, while also providing non-invasive cardiac treatment configuration, including determining effective or optimal LVAD parameters, AV intervals, etc. Exemplary systems and methods using imaging devices and / or electrode devices may be described in U.S. Patent Application Publication No. 2014 / 0371832 to Ghosh, published on December 18, 2014, U.S. Patent Application Publication No. 2014 / 0371833 to Ghosh et al., published on December 18, 2014, U.S. Patent Application Publication No. 2014 / 0323892 to Ghosh et al., published on October 30, 2014, and U.S. Patent Application Publication No. 2014 / 0323882 to Ghosh et al., published on October 20, 2014, each of which is incorporated herein by reference in its entirety.

[0035] Exemplary imaging devices may be configured to capture X-ray images and / or any other alternative imaging modalities. For example, the imaging device may be configured to capture images or image data using concentric 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. Further, it should be understood that the imaging device may be configured to (e.g., continuously) capture multiple continuous images to provide video frame data. That is, multiple images taken over time using an imaging device may provide video frames, or dynamic movies, data. Additionally, images may also be obtained and displayed in two dimensions, three dimensions, or four dimensions. In more advanced forms, four-dimensional surface rendering of the heart or other regions of the body can also be achieved by combining cardiac data or other soft tissue data from images or from preoperative image data captured by MRI, CT or echocardiography modalities. Image data sets from hybrid modalities (such as positron emission tomography (PET) combined with CT, or single photon emission computed tomography (SPECT) combined with CT) can also provide functional image data superimposed on anatomical data, for example, to be used to navigate an implantable device to a target location in the heart or other region of interest.

[0036] Systems and / or imaging devices that may be used in conjunction with the exemplary systems and methods described herein are described in: U.S. Patent Application Publication No. 2005 / 0008210, published on January 13, 2005, to Evron et al.; U.S. Patent Application Publication No. 2006 / 0074285, published on April 6, 2006, to Zarkh et al.; U.S. Patent No. 8,731,642, issued on May 20, 2014, to Zarkh et al.; U.S. Patent No. 8,861,830, issued on October 14, 2014, to Brada et al.; U.S. Patent No. 6,949,676, issued on December 27, 2005, to Evron et al. No. 980,675 to Okerlund et al., issued October 23, 2007; No. 7,286,866 to Okerlund et al., issued December 11, 2011; No. 7,308,297 to Reddy et al., issued December 11, 2011; No. 7,308,299 to Burrell et al., issued December 11, 2011; No. 7,321,677 to Evron et al., issued January 22, 2008; No. 7,346,381 to Okerlund et al., issued March 18, 2008; No. 7,346,381 to Burrell et al., issued November 18, 2008; No. 7,454,248 to Vass et al., issued March 3, 2009; No. 7,499,743 to Vass et al., issued March 3, 2009; No. 7,565,190 to Okerlund et al., issued July 21, 2009; No. 7,587,074 to Zarkh et al., issued September 8, 2009; No. 7,599,730 to Hunter et al., issued October 6, 2009; No. 7,613,500 to Vass et al., issued November 3, 2009; No. 7,742,674 to Zarkh et al., issued June 22, 2010; No. 29; U.S. Patent No. 7,747,047 issued on June 29, 2010 to Okerlund et al.; U.S. Patent No. 7,778,685 issued on August 17, 2010 to Evron et al.; U.S. Patent No. 7,778,686 issued on August 17, 2010 to Vass et al.; U.S. Patent No. 7,813,785 issued on October 12, 2010 to Okerlund et al.; U.S. Patent No. 7,996,063 issued on August 9, 2011 to Vass et al.; U.S. Patent No. 8,060,185 issued on November 15, 2011 to Hunter et al.;Verard et al., U.S. Patent No. 8,401,616, issued March 19, 2013, each of which is incorporated herein by reference in its entirety. ;

[0037] The computing device 140 and the remote computing device 160 may each include a display device 130, 160, which may be configured to display and analyze data, such as, for example, electrical signals (e.g., electrocardiogram data), electrical activation times, electrical heterogeneity information, etc. For example, one cardiac cycle out of a plurality of cardiac cycles or a plurality of heartbeats, or a heartbeat, represented by electrical signals collected or monitored by the electrode device 110 may be analyzed and evaluated to obtain one or more metrics, including activation times and electrical heterogeneity information, which may be related to therapeutic properties regarding one or more parameters of cardiac therapy, such as, for example, LVAD pump speed, LVAD pump power / current (e.g., current delivered to the pump to affect pump speed and / or other pump parameters), LVAD pump throughput, other LVAD operating parameters, pacing parameters, lead position, etc. More specifically, for example, the QRS complex of a single cardiac cycle can be evaluated for one or more metrics, such as, for example, QRS onset, QRS offset, QRS peak, electrical heterogeneity information, electrical activation time, left ventricular or thoracic electrical activation time standard deviation (LVED), standard deviation of activation time (SDAT), mean left ventricular or thoracic alternative electrical activation time (LVAT) (referenced as earliest activation time), QRS duration (e.g., the interval between QRS onset and QRS offset), mean left alternative activation time, and The difference between the mean right surrogate excitation times, the relative or absolute QRS morphology, the difference between the upper and lower percentiles of the excitation times (the upper percentiles can be 90%, 80%, 75%, 70%, etc., and the lower percentiles can be 10%, 15%, 20%, 25% and 30%, etc.), other statistical measures of central tendency (e.g., median or mode), dispersion (e.g., mean difference, standard deviation, variance, interquartile range, range) applied to all excitation times or left surrogate excitation times or right surrogate excitation times, etc.

[0038] In at least one embodiment, one or both of computing device 140 and remote computing device 160 may be a server, a personal computer, or a tablet computer. Computing device 140 may be configured to receive input from input device 142 (e.g., a keyboard) and transmit output to display device 130, and remote computing device 160 may be configured to receive input from input device 162 (e.g., a touch screen) and transmit output to display device 170. Both computing device 140 and remote computing device 160 may include a data store that allows access to processing programs or routines and / or one or more other types of data, for example, for analyzing a plurality of electrical signals captured by electrode device 110, for determining QRS onset, QRS offset, median, mode, mean, peak or maximum, valley or minimum, for determining electrical activation time, for driving a device configured to non-invasively assist a user in configuring one or more LVAD operating parameters or settings (e.g., LVAD pump speed, LVAD pump throughput, LVAD pump power, LVAD pump current, pump inflow gimbal angle, control of pump suction, etc.). , automatic algorithmic response to events such as changes in patient activity level and physiological parameter inputs, enabling / disabling periodic pump speed adjustment features such as Lavare cycles), driving a graphical user interface configured to non-invasively assist a 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-site pacing vector (e.g., left ventricular vector four-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 adaptation settings and performance, etc.

[0039] The computing device 140 may be operably coupled to the input device 142 and the display device 130, for example, to transmit data to and from each of the input device 142 and the display device 130, and the remote computing device 160 may be operably coupled to the input device 162 and the display device 170, for example, to transmit data to and from each of the input device 162 and the display device 170. For example, the computing device 140 and the remote computing device 160 may be electrically coupled to the input devices 142, 162 and the 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 may provide input to the input devices 142, 162 to view and / or select one or more configuration information related to cardiac therapy delivered by one or both of the LVAD device 151 and the implantable medical device.

[0040] Although the input device 142 is depicted as a keyboard and the input device 162 is a touch screen, it should be understood that the input device 142 may include any device capable of providing input to the computing device 140 in order to perform the functions, methods, and / or logic described herein. For example, the input device 142, 162 may include a keyboard, a mouse, a trackball, a touch screen (e.g., a capacitive touch screen, a resistive touch screen, a multi-point touch screen, etc.), etc. Similarly, the display device 130, 170 may include any device capable of displaying information to a user, such as a graphical user interface 132, 172 including one or more heartbeats, QRS complexes, LVAD operating parameters, LVAD operating metrics, pacing parameters, electrical heterogeneity information, text instructions, graphical depictions of electrical activation information, graphical depictions of the anatomy of a human heart, an image or graphical depiction of a patient's heart, a graphical depiction of the location of one or more electrodes, a graphical depiction of a human torso, an image or graphical depiction of a patient's torso, a graphical depiction or actual image of implanted electrodes and / or leads, etc. Furthermore, the display devices 130 and 170 may include a liquid crystal display, an organic light emitting diode screen, a touch screen, a cathode ray tube display, or the like.

[0041] 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 the following: 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 transforms, fast Fourier transforms, etc.), normalization algorithms, comparison algorithms, vector mathematics, or any other processing required to implement one or more of the exemplary methods and / or processes described herein. The data stored and / or used by the computing device 140 and the remote computing device 160 may include, for example, electrical signal / waveform data from the electrode device 110 (e.g., multiple QRS complexes), electrical activation time from the electrode device 110, heart sounds / signals / waveform data from the acoustic sensor 120, graphics (e.g., graphical elements, icons, buttons, windows, dialog boxes, drop-down menus, graphic areas, graphic regions, 3D graphics, etc.), graphical user interfaces, results from one or more processing programs or routines adopted in accordance with the disclosure of this document (e.g., electrical signals, electrical heterogeneity information, etc.), or any other data that may be required to perform one and / or more processes or methods described herein.

[0042] In one or more embodiments, exemplary systems and methods may be implemented using one or more computer programs executed on a programmable computer, such as a computer including, for example, processing power, data storage (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 in order to perform the functions described herein and generate desired output information. The output information may be applied as input to one or more other devices and / or methods as described herein or as will be applied in a known manner.

[0043] Any programmable language can be used to provide one or more programs for implementing the systems, devices, methods, and / or interfaces described herein, such as high-level procedural programming languages ​​and / or object-oriented programming languages ​​suitable for communicating with computer systems. Any such program can be, for example, stored on any suitable device (e.g., storage medium) readable by a general-purpose program or a special-purpose program, which runs on a computer system (e.g., including a processing device) for configuring and operating the computer system when reading suitable devices to execute the programs described herein. In other words, at least in one embodiment, an exemplary system and method interface can be implemented using a computer-readable storage medium configured with a computer program, wherein the storage medium so configured enables the computer to operate in a specific and predefined manner to perform the functions described herein. Further, in at least one embodiment, the exemplary system, device, method, and interface can be described as being implemented by logic (e.g., object code) encoded in one or more non-transient media, which include codes for executing and operable to perform operations such as methods, processes, and / or functions described herein when executed by a processor.

[0044] Computing apparatus 140 and remote computing device 160 may be, for example, any fixed or mobile computer system (eg, controller, microcontroller, personal computer, minicomputer, tablet computer, etc.). The exact configuration of the computing apparatus 140 and the remote computing device 160 is not limited, and essentially any device that can provide suitable computing capabilities as well as 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, a digital file can be any medium (e.g., volatile or non-volatile memory, CD-ROM, punch cards, magnetic tape, etc.) containing digital bytes (e.g., encoded in binary, ternary, etc.) that is readable and / or writable by the computing apparatus 140 and the remote computing device 160 described herein. Similarly, as described herein, a file in a user-readable format can be any data representation (e.g., ASCII text, binary numbers, hexadecimal numbers, decimal numbers, diagrams, etc.) that can be presented on any medium (e.g., paper, display, etc.) that is readable and / or understandable by a user.

[0045] In view of the foregoing, it will be apparent that the functionality as described in one or more embodiments according to the present disclosure may be implemented in any manner as will be known to those skilled in the art. Thus, the computer language, computer system, or any other software / hardware used to implement the processes described herein should not be limited to the scope of the systems, processes, or programs described herein (e.g., the functionality provided by such systems, processes, or programs).

[0046] The exemplary electrode arrangement 110 may be configured to measure body surface potentials of the patient 14, and more specifically, torso surface potentials of the patient 14. Figure 2 As shown, an exemplary electrode device 110 may include a set of electrodes 112 or an array of electrodes 112, a strap 113, and an interface / amplifier circuit system 116. The electrodes 112 may be attached or coupled to the strap 113 and the strap 113 may be configured to wrap around the torso of the patient 14 so that the electrodes 112 surround the patient's heart. As further shown, the electrodes 112 may be positioned around the periphery of the patient 14, including posterior locations, lateral locations, posterolateral locations, anterolateral locations, and anterior locations of the torso of the patient 14.

[0047] The exemplary electrode arrangement 110 may be further configured to measure or monitor sounds from at least one or both of the patient 14 and one or more devices located within or operably coupled to the patient 14, such as the LVAD 150. Figure 2As shown, the exemplary electrode device 110 can include a set of acoustic sensors 120 or an array of acoustic sensors 120, which are attached to or coupled to a strap 113. The strap 113 can be configured to wrap around the torso of the patient 14 so that the acoustic sensors 120 surround the patient's heart. As further shown, the acoustic sensors 120 can be positioned around the periphery of the patient 14, including posterior positions, lateral positions, posterolateral positions, anterolateral positions, and anterior positions of the torso of the patient 14.

[0048] Further, the electrodes 112 and the acoustic sensor 120 may be electrically connected to the interface / amplifier circuitry 116 via a wired connection 118. The interface / amplifier circuitry 116 may be configured to amplify signals from the electrodes 112 and the acoustic sensor 120 and provide the signals to one or both of the computing device 140 and the remote computing device 160. Other exemplary systems may use a wireless connection to transmit the signals sensed by the electrodes 112 to the interface / amplifier circuitry 116, and in turn (e.g., as multi-channel data) to one or both of the computing device 140 and the remote computing device 160. In one or more embodiments, the interface / amplifier circuitry 116 may be electrically coupled to the computing device 140 using, for example, an analog electrical connection, a digital electrical connection, a wireless connection, a bus-based connection, a network-based connection, an Internet-based connection, etc.

[0049] Despite Figure 2In the example of the electrode device 110 includes a strap 113, but in other examples, any of a variety of mechanisms (e.g., tape or adhesive) can be used to assist in the spacing and placement of the electrodes 112 and the acoustic sensor 120. In some examples, the strap 113 may include an elastic band, a tape strip, or a cloth. Further, in some examples, the strap 113 can be part of or integrated with a piece of clothing such as, for example, a t-shirt. In other examples, the electrodes 112 and the acoustic sensor 120 can be placed separately on the torso of the patient 14. Further, in other examples, the electrodes 112 (e.g., arranged in an array) and the acoustic sensor 120 (e.g., also arranged in an array) can be part of or positioned within a patch, a vest, and / or other means of fastening the electrodes 112 and the acoustic sensor 120 to the torso of the patient 14. Still further, in other examples, the electrodes 112 and acoustic sensors 120 may be part of, or positioned within, two material portions or two “patches.” One of the two portions or patches may be positioned on the front side of the torso of patient 14 (e.g., to monitor electrical signals representing the front side of the patient's heart, measure alternative cardiac electrical activation times representing the front side of the patient's heart, monitor or measure sounds on the front side of the patient, etc.), and the other portion or patch may be positioned on the back side of the torso of patient 14 (e.g., to monitor electrical signals representing the back side of the patient's heart, measure alternative cardiac electrical activation times representing the back side of the patient's heart, monitor or measure sounds on the back side of the patient, etc.). And still further, in other examples, the electrodes 112 and acoustic sensors 120 may be arranged in a top column and a bottom column extending from the front side of patient 14 across the left side of patient 14 to the front side of patient 14. Still further, in other examples, the electrodes 112 and acoustic sensors 120 may be arranged in a curve around the axillary region and may have an electrode / sensor density that is more sparse on the right chest than other remaining areas.

[0050] The electrodes 112 may be configured to surround the heart of the patient 14 and record or monitor electrical signals associated with the depolarization and repolarization of the heart after they have propagated through the torso of the patient 14. Each of the electrodes 112 may be used in a unipolar configuration to sense torso surface potentials that reflect cardiac signals. The interface / amplifier circuitry 116 may also be coupled to a return electrode or neutral electrode (not shown) that may be used in combination with each electrode 112 for unipolar sensing.

[0051] In some examples, there may be about 12 to about 50 electrodes 112 and about 12 to about 50 acoustic sensors 120 spatially distributed around the patient's torso. 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 distributed in an array that extends completely around or completely around the patient 14. Alternatively, the electrodes 112 and acoustic sensors 120 may be arranged in an array that extends only around a portion of the patient 14 or partially around the patient 14. For example, the electrodes 112 and acoustic sensors 120 may be distributed on the front, back, and left side of the patient, with fewer or no electrodes and acoustic sensors near the right side (including the back and front areas of the right side).

[0052] Computing device 140 may record and analyze the torso surface potential signals sensed by electrodes 112 and acoustic sensor 120 and amplified / conditioned by interface / amplifier circuit 116. Computing device 140 may be configured to analyze the electrical signals from electrodes 112 to provide electrocardiogram (ECG) signals, information, or data from the patient's heart, as further described herein. Computing device 140 may be configured to analyze the electrical signals from acoustic sensor 120 to provide sound signals, information, or data from the patient's body and / or a device implanted in the patient's body (such as LVAD 150), as further described herein.

[0053] In addition, computing device 140 and remote computing device 160 may be configured to provide graphical user interfaces 132, 172 that depict an ECG including a QRS complex acquired using electrode device 110 and depict acoustic waves acquired using acoustic sensor 120, as well as other information related thereto. Exemplary systems and methods may non-invasively use electrical information collected using electrode device 110 and acoustic information collected using acoustic sensor 120 to assess a patient's cardiac health and to assess and configure cardiac therapy delivered to the patient, as well as to assess the mechanical function of an implanted device such as LVAD 150.

[0054] Further, the electrode device 110 may further include reference electrodes and / or drive electrodes, which are positioned, for example, around the lower torso of the patient 14 and may be further used by the system 100. For example, the electrode device 110 may include three reference electrodes, and the signals from the three reference electrodes may be combined to provide a reference signal. Further, the electrode device 110 may use three caudal 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 caudal positioned reference signals.

[0055] Figure 3 Another exemplary electrode device 110 is shown that includes a plurality of electrodes 112 configured to surround the heart of a patient 14 and record or monitor electrical signals associated with depolarization and repolarization of the heart after they have propagated through the torso of the patient 14, and a plurality of acoustic sensors 120 configured to surround the heart of the patient 14 and record or monitor acoustic signals associated with the heart and / or an implanted device, such as an LVAD 150, after they have propagated through the torso of the patient 14. The electrode device 110 may include a vest 114 to which the plurality of electrodes 112 and the plurality of acoustic sensors 120 may be attached, or to which the electrodes 112 and the acoustic sensors 120 may be coupled. In at least one embodiment, the plurality of electrodes 112 or an array of electrodes 112 may be used to collect electrical information, such as, for example, surrogate electrical activation times. Figure 2 Similar to the electrode device 110, Figure 3 The electrode device 110 may include an interface / amplifier circuit system 116 that is electrically coupled to each of the electrodes 112 and the acoustic sensor 120 via a wired connection 118 and is configured to transmit signals from the electrodes 112 and the acoustic sensor 120 to a 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 locations, lateral locations, posterolateral locations, anterolateral locations, and anterior locations of the torso of the patient 14.

[0056] The vest 114 may be formed of a braided fabric to which the electrodes 112 and the acoustic sensors 120 are attached. The vest 114 may be configured to maintain the location and spacing of the electrodes 112 and the acoustic sensors 120 on the torso of the patient 14. Further, the vest 114 may be marked to assist in locating the electrodes 112 and the acoustic sensors 120 on the surface of the torso of the patient 14. In some examples, there may be about 25 to about 256 electrodes 112 and about 25 to about 256 acoustic sensors 120 distributed around the torso of the patient 14, although other configurations may have more or fewer electrodes 112 and more or fewer acoustic sensors 120.

[0057] Exemplary systems and methods may be used to provide non-invasive assistance to a user in assessing a patient's cardiac health and / or assessing and configuring a cardiac therapy currently being delivered to a patient (e.g., via an LVAD, via an implantable medical device, etc.). For example, exemplary systems and methods may be used to assist a user in configuring and / or adjusting one or more cardiac therapy settings for left ventricular assist cardiac therapy delivered to a patient via an LVAD 150. Further, for example, exemplary systems and methods may provide for optimization of AV intervals or delays for pacing therapy (e.g., left univentricular pacing therapy). Still further, for example, exemplary systems and methods may be used to assist a user in configuring and / or adjusting one or more cardiac therapy settings for both LVAD-delivered cardiac therapy and pacing therapy using, for example, an implantable medical device.

[0058] Further, it should be understood that computing device 140, remote computing device 160, and LVAD controller 152 may be operably coupled to each other in a number of different ways in order to perform or implement the functionality described herein. For example, in the depicted embodiment, computing device 140 may be wirelessly operably coupled to remote computing device 160 and LVAD controller 152, as depicted by wireless signal lines emitted therebetween. Further, for example, in the depicted embodiment, remote computing device 160 may be wirelessly operably coupled to computing device 140 and LVAD controller 152, as depicted by wireless signal lines emitted therebetween. Further, for example, as opposed to wireless connections, one or more of computing device 140, remote computing device 160, and LVAD controller 152 may be operably coupled via one or more wired electrical connections.

[0059] Figure 4 The use of, for example, Figure 1-3 and Figure 7-1 0. As shown, method 200 includes using a plurality of external electrodes (such as, for example, those described herein with reference to Figure 1-3The electrode device 110 described above monitors the patient's electrical activity 202. The electrical activity 202 can be monitored for multiple cardiac cycles or heartbeats. Further, the electrical activity 202 can be monitored for a selected time period (such as, for example, five seconds). The electrical activity 202 can be monitored by multiple electrodes in the absence of LVAD therapy or during LVAD therapy.

[0060] The method 200 may further include generating electrical heterogeneity information 204 based on the monitored electrical activity 202. The electrical heterogeneity information may be generated using a measure of electrical heterogeneity. The measure of electrical heterogeneity information may include a measure of right ventricular activation time (RVAT) of an electrode on the right side of the patient's torso. The measure of RVAT may be determined based on electrodes on both the front surface and the rear surface. Further, RVAT may be an average, median, or other statistical composite value of electrical signals from a right electrode group on the right side of the patient's torso (e.g., the patient's right torso), or an average, median, or other statistical composite value calculated based on electrical signals from a right electrode group on the right side of the patient's torso (e.g., the patient's right torso). Moreover, the measure of electrical heterogeneity information may include septal electrical heterogeneity information indicating septal dyssynchrony, which is generated using electrical activity monitored by a central extracorporeal electrode group located near the patient's sternum or spine among a plurality of extracorporeal electrodes. More specifically, diaphragm dyssynchrony can be determined by looking at a subset of electrodes near the sternum and spine, and diaphragm timing relative to right-side activation (or left-side activation) can help titrate LVAD pump speed to avoid aspiration, right ventricular failure, etc.

[0061] Further, the measure of electrical heterogeneity may include a measure of the standard deviation of activation times (SDAT) of electrodes on the left side of the patient's torso and / or a measure of the mean left ventricular activation time (LVAT) of electrodes on the left side of the patient's torso. The measure of LVAT may be determined based on electrodes on both the anterior and posterior surfaces. The measure of electrical heterogeneity may include a measure of the mean total activation time (mTAT) obtained from multiple electrode signals from both sides of the patient's torso, or it may include other measures that reflect the range or dispersion of activation times on multiple electrodes located on the right side of the patient's torso or on the left side of the patient's torso, or on a combination of both the right and left sides of the patient's torso (e.g., standard deviation, interquartile range, difference between the latest activation time and the earliest activation time).

[0062] Additionally, the diaphragm repolarization index can also be used for titration (chance of obtaining good diastole or homogeneity) and further can be used to minimize RV activation time (measured by activation time from the right chest electrode). Further, it can be described that the systems and methods described herein can be used to monitor right or left ventricular remodeling by, for example, measuring right and left ventricular activation times and patterns.

[0063] As described herein, electrical activity may be monitored 202 via a plurality of electrodes in the absence of LVAD therapy or during LVAD therapy. If electrical activity is monitored 202 in the absence of LVAD therapy, electrical heterogeneity information generated 204 thereof may represent a baseline cardiac health value. If electrical activity is monitored 202 during LVAD therapy, electrical heterogeneity information generated 204 thereof may represent a cardiac health value during delivery of LVAD therapy at one or more LVAD output parameters, which may be configurable or adjustable using the exemplary systems, devices, apparatuses, and methods described herein.

[0064] The exemplary method 200 may further include determining an LVAD output parameter 206 based on the generated electrical heterogeneity information 204. For example, to determine the LVAD output parameter 206, the diaphragm center electrical heterogeneity information may be compared to other electrical heterogeneity information generated from a set of external electrodes on the right or left side of the patient's sternum or spine. Specifically, if the diaphragm center electrical heterogeneity information indicates that electrical activation of the ventricle results in mechanical pulsatile activity that is displaced by the LVAD flow rate when the diaphragm center electrical heterogeneity information is compared to other electrical heterogeneity information from a set of external electrodes on the right or left side of the patient's sternum or spine, then the LVAD output parameter (such as, for example, pump speed, RPM adaptive algorithm, or parameters for controlling cyclic speed regulation) may be reduced or customized.

[0065] Further, for example, determining LVAD output parameters 206 may include comparing present or currently generated electrical heterogeneity information 204 to previously generated electrical heterogeneity information 204 in the absence of LVAD therapy or using previous one or more LVAD output parameters. In this way, if the generated electrical heterogeneity information 204 indicates an improvement in electrical and / or mechanical heart function of the patient's heart, the exemplary method 200 may determine that the present one or more LVAD output parameters 206 are more effective than the absence of LVAD therapy or the previous one or more LVAD output parameters.

[0066] In this way, one or more LVAD output parameters 210 may be titrated or adjusted based on the generated electrical heterogeneity information 204 until an optimal LVAD output parameter is found. For example, after determining one or more LVAD output parameters 206, the exemplary method 200 may adjust the LVAD based on or using the determined one or more LVAD output parameters 210 (e.g., a user may do so manually or the system may automatically perform the adjustment), and then the method 200 may loop to again monitor electrical activity 202 during delivery of LVAD therapy, generate electrical heterogeneity information 204 based on the monitored electrical activity, and determine the LVAD output parameter based thereon. In other words, the exemplary method 200 may "try" multiple different LVAD output parameters until it is determined which of the multiple different LVAD output parameters are appropriate, acceptable, and / or optimal based on the generated electrical heterogeneity information. In one or more embodiments, it may be described that the method 200 provides feedback regarding rate control to avoid right ventricular dyssynchrony or other factors that may lead to right ventricular failure (right ventricle to left ventricle dyssynchrony).

[0067] As described herein, LVAD output parameters may include at least one of the following: LVAD pump speed, LVAD pump throughput, LVAD pump power, LVAD pump current, LVAD pump voltage, pump inflow gimbal angle, automatic algorithmic response to events such as pump suction, changes in patient activity level, and physiological parameter inputs, enabling / disabling periodic pump speed adjustment features such as Lavari cycles, etc. In at least one embodiment, method 200 may be described as adjusting the LVAD pump speed based on feedback of electrical heterogeneity information generated based on the electrical activity of the patient monitored using multiple external electrodes. Electrical activity may be monitored during multiple different LVAD pump speeds, and electrical heterogeneity information may be generated for each set of electrical activity monitored during multiple different LVAD pump speeds. Thus, electrical heterogeneity information may be associated with each of the multiple different LVAD pump speeds. The LVAD pump speed associated with the optimal or acceptable electrical heterogeneity information, or the LVAD pump speed with the optimal or acceptable electrical heterogeneity information, may be determined as the LVAD pump speed to be used with the patient. In one embodiment, the LVAD pump speed with the best electrical heterogeneity information (eg, lowest amount of asynchrony, lowest amount of right ventricular dyssynchrony, etc.) may be selected.

[0068] Further, other factors may also distinguish one LVAD output parameter from another LVAD output parameter (such as, for example, a setting used to promote native heart recovery), such as a flow rate selected to preserve native function or a periodic reduction adjustment to the RPM that is used to transfer more cardiac work to the native heart and to test recovery that may allow or enable withdrawal of support to the LVAD. In other words, while one LVAD output parameter may provide the best or optimal electrical heterogeneity information, a different LVAD output parameter may be determined or selected because the electrical information may support appropriate settings to encourage and accelerate native heart recovery, which may result in cessation of LVAD support and pump withdrawal without producing an acute lack of support.

[0069] Additionally, each time an LVAD output parameter is determined 206, the determined LVAD output parameter may be displayed 208 on a graphical user interface of a computing device or apparatus, such as a graphical user interface of a computer system or apparatus. Figure 1-3 Those shown and depicted. The user can see the determined LVAD output parameters and can then manually adjust the LVAD using the LVAD controller according to the determined LVAD output parameters. In other embodiments, the LVAD output parameters can be automatically adjusted using the systems and methods described herein. In other words, for "one-button" rate titration, feedback to the LVAD can be automatic.

[0070] Use of an LVAD can affect the volume of one or more heart chambers and can also affect the stretching of heart tissue. Further, conduction of heart tissue can be further affected by volume changes and stretching of heart tissue. Still further, activation patterns can also be affected by changes in heart shape, not just asynchrony. Thus, an LVAD can affect pacing therapy that can also be delivered to or applied to a patient.

[0071] The LVAD may also be used in conjunction with cardiac pacing therapy, and thus, the LVAD and cardiac pacing therapy may be adjusted or titrated simultaneously to provide acceptable or optimal cardiac therapy to the patient. Figure 5 The use of, for example, Figure 1-3 and Figure 7-1 0. As shown, the exemplary method 250 may include, for example, using the system and device described herein to adjust one or both of the LVAD output parameters and the pacing parameters. Figure 1 and Figure 8 LVAD device 151 is described to provide LVAD therapy 252, and for example, using references herein Figure 7-10 to provide pacing therapy 254. LVAD therapy 252 may include a plurality of different output parameters that may be adjustable by the exemplary systems described herein and / or a user using the exemplary systems. Similarly, pacing therapy 254 may include a plurality of different pacing parameters that may be adjustable by the exemplary systems described herein and / or a user using the exemplary systems. The plurality of different pacing parameters may include AV interval, VV interval, pacing pulse width, pacing vector, multi-point pacing vector, pacing voltage, pacing configuration (e.g., biventricular pacing, left ventricle only pacing, right ventricle only pacing), pacing rate, pacing rate response parameters, and the like.

[0072] Similar to method 200, exemplary method 250 may include using a plurality of extracorporeal electrodes (such as, for example, those described herein with reference to Figure 1-3 The method 250 may include monitoring the electrical activity 256 of the patient using the electrode device 110 described above. The electrical activity 256 may be monitored for multiple cardiac cycles or heartbeats. Further, the electrical activity 256 may be monitored for a selected time period (such as, for example, five seconds). The electrical activity 256 may be monitored in the absence of LVAD therapy, in the absence of cardiac pacing therapy, in the absence of both LVAD therapy and cardiac pacing therapy, during LVAD therapy, during cardiac pacing therapy, and during both LVAD therapy and cardiac pacing therapy. Moreover, similar to the method 200, the method 250 may further include generating electrical heterogeneity information 258 based on the monitored electrical activity 256. The generated electrical heterogeneity information 258 may then be used to adjust one or both of the LVAD output parameters of the provided LVAD therapy 252 and the cardiac pacing therapy parameters of the provided cardiac pacing therapy 254.

[0073] For example, the exemplary method 250 may try one of a plurality of different combinations of LVAD output parameters and cardiac pacing parameters, and may generate electrical heterogeneity information 258 based on the electrical activity monitored during use of the “tried” combination of LVAD output parameters and cardiac pacing parameters. The generated electrical heterogeneity information may be compared to baseline electrical heterogeneity information or electrical heterogeneity information generated during use of different combinations of LVAD output parameters and cardiac pacing parameters to determine whether the present or current combination of LVAD output parameters and cardiac pacing parameters results in acceptable or optimal therapy for the patient.

[0074] More specifically, for example, the speed of the LVAD pump can be configured to a plurality of different pump speeds, and for each pump speed, the right ventricular preexcitation of the cardiac pacing therapy can be adjusted to a plurality of different right ventricular preexcitations. More specifically, right ventricular (RV) preexcitation can be compared to left ventricular timing to minimize diaphragm motion, and right ventricular (RV) preexcitation can be adjusted by the timing of the AV or VV interval. In another embodiment, one or more device settings (which include a combination of the different device parameters previously described) can be adjusted to provide optimally synchronized (e.g., most synchronized) right ventricular activation (e.g., measured by the lowest RVAT or other measure of right-sided electrical heterogeneity) without impeding LVAD operation (e.g., not causing pumping at an operating LVAD speed). Thus, the LVAD and / or RV preexcitation can be programmed to optimize the contribution of the right ventricle. Electrical heterogeneity information can be generated for each different combination of LVAD pump speed and right ventricular preexcitation, so that the LVAD pump speed and right ventricular preexcitation that results in acceptable (e.g., optimal) electrical heterogeneity information can be determined. The determined LVAD pump speed and right ventricular preexcitation can then be displayed, for example, on a graphical user interface so that a practitioner can see the results, and / or automatically used to program the LVAD and cardiac pacing device. Further, for example, LVAD response algorithms (such as, for example, pumping response or rate adaptation), periodic speed adjustments, and / or operating mode features (such as Lavari cycles) can be employed to test for acute effects on electrical activation patterns that may occur during ambulatory operation.

[0075] Heart sound information can also be used (such as, for example, using the Figure 1-3 The acoustic sensor 120 described above captures the LVAD output parameters. Figure 6 The use of, for example, Figure 1-3 and Figure 7-1 0 based on one or both of electrical heterogeneity information and heart sounds. Similar to method 250, exemplary method 270 may include, for example, using the referenced method herein. Figure 1 and Figure 8 LVAD device 151 is described to provide LVAD 272. Although not described in Figure 6 However, it should be understood that method 270 may also include, for example, using the reference Figure 7-1 0 to provide pacing therapy, and to adjust pacing therapy using the same or similar methods and processes as method 270. In addition, the LVAD cardiac therapy adjusted or titrated in method 270 can be adjusted or titrated based on one or both of the electrical heterogeneity information and the heart sound information together with or simultaneously with the cardiac pacing therapy.

[0076] Similar to method 200, exemplary method 270 may include using a plurality of extracorporeal electrodes (such as, for example, those described herein with reference to Figure 1-3 The method 270 may include monitoring electrical activity 274 of the patient using the electrode device 110 described above. The electrical activity 274 may be monitored for multiple cardiac cycles or heartbeats. Further, the electrical activity 274 may be monitored for a selected time period (such as, for example, five seconds). The electrical activity 274 may be monitored in the absence of LVAD therapy or during LVAD therapy. Moreover, similar to the method 200, the method 270 may further include generating electrical heterogeneity information 278 based on the monitored electrical activity 274. The generated electrical heterogeneity information 288 may then be used to adjust 280 an LVAD output parameter 280 of the LVAD therapy provided.

[0077] LVAD output parameters 280 may also be adjusted in view of or based on the heart sound information. For example, the exemplary method 270 may further include monitoring heart sounds 276 using an acoustic sensor. A number of different types of devices and systems may be used to monitor heart sounds. In at least one embodiment, for example, the present invention may be used to monitor heart sounds using an acoustic sensor. Figure 1-3 In other embodiments, the heart sounds may be monitored using an external acoustic sensor 120 described above. In other embodiments, one or more implanted devices or other sound monitoring devices that are not associated with the electrode device 110 (e.g., coupled to the electrode device 110, are part of the electrode device 110, etc.) may be used to monitor the heart sounds. In addition, in other embodiments, a sound capture device that is not in contact with the patient's tissue (e.g., not in contact with the patient's skin, not attached to, coupled to, or close to the heart tissue, etc.) may be used to measure or monitor the heart sounds.

[0078] Heart sound monitoring 276 may result in electrical signals representing heart sounds from a plurality of different locations around the patient. Such heart sounds may be used to determine one or both of LVAD output parameters and cardiac pacing parameters. Heart sounds may be used to determine mechanical heart function (e.g., force, timing, motion, etc.), such as, but not limited to: heart valve opening, heart valve closing, heart chamber contraction (e.g., during depolarization), heart valve relaxation (e.g., during repolarization), valvular regurgitation, progression of right or left heart failure, arrhythmias (e.g., atrial fibrillation or ventricular tachyarrhythmia / fibrillation), etc.

[0079] The exemplary method 270 may further include adjusting one or more LVAD output parameters 280 based on one or both of the generated electrical heterogeneity information 278 and the monitored heart sounds 276. For example, if the heart sounds indicate that the aortic valve is open and the electrical heterogeneity information indicates that the right ventricle is activated before the hemodynamic emptying of the left ventricle, the LVAD pump speed may be increased. Further, for example, if there is evidence of abnormal heart sounds that may indicate the progression of left or right heart failure, the LVAD pump speed may be changed. For example, a right ventricular third heart sound may indicate right ventricular dysfunction and the LVAD speed may be titrated lower and / or pacing parameters may be adjusted to reduce electrical heterogeneity.

[0080] In at least one embodiment, exemplary method 200 may include determining whether at least one heart valve is open or closed based on monitored heart sounds, and then adjusting an output parameter of the LVAD to allow at least some opening of the heart valve. More specifically, a feature of a second heart sound on the acoustic signal may be analyzed to detect a transition of the aortic valve from open to closed, and changes in the feature of the second heart sound may be monitored for various LVAD speeds to detect speeds at which the valve does not open. For example, a threshold for a programmable LVAD speed may be set to a maximum speed that still allows the aortic valve to open.

[0081] The exemplary method 270 may adjust the LVAD, and the method 270 may loop to again monitor electrical activity and heart sounds 274 , 276 during delivery of LVAD therapy, generate electrical heterogeneity information 278 based on the monitored electrical activity, and further determine and adjust LVAD output parameters 280 based thereon.

[0082] The exemplary systems, devices, and methods described herein can also be used to titrate or adjust medications that can be used with the LVAD and pacing therapy described herein. For example, certain medications can affect cardiac activation, and thus, the exemplary systems, devices, and methods can be used to titrate or adjust the LVAD, cardiac pacing therapy, and medications at the same or similar times for patients having, for example, heart failure with preserved ejection fraction, heart failure with reduced ejection fraction, etc.

[0083] Further, the exemplary systems, devices, and methods described herein may also be used to titrate or adjust left atrial versus right atrial pacing in patients with atrial dyssynchrony.

[0084] Moreover, the systems, devices and methods described herein can also be used to measure or monitor the patient's recovery, for example to assist in evaluating whether the LVAD can be removed from the patient. In other words, the exemplary systems, devices and methods can assist in determining whether the patient still requires LVAD cardiac therapy.

[0085] As described herein, the exemplary systems and methods described herein may be used with reference to implantation and configuration of an implantable medical device (IMD) and / or LVAD. Figure 7-1 The exemplary treatment system 10 described in FIG. 0 uses exemplary systems and methods.

[0086] Figure 7 is a conceptual diagram illustrating an exemplary therapy system 10 that may be used to deliver pacing therapy to a patient 14. The patient 14 may be, but is not necessarily, a human. The therapy system 10 may include an implantable medical device 16 (IMD) that may be coupled to leads 18, 20, 22. The IMD 16 may be, for example, an implantable pacemaker, cardioverter, and / or defibrillator that delivers or provides electrical signals to and / or measures or monitors electrical signals from the heart 12 of the patient 14 via electrodes coupled to one or more of the leads 18, 20, 22.

[0087] Leads 18, 20, 22 extend into heart 12 of patient 14 to sense electrical activity of heart 12 and / or deliver electrical stimulation to heart 12. Figure 7 In the example shown in , the right ventricular (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 ventricular (LV) coronary sinus lead 20 extends through one or more veins, the vena cava, the right atrium 26, and enters the coronary sinus 30 to reach the area adjacent to the free wall of the left ventricle 32 of the heart 12. The right atrial (RA) lead 22 extends through one or more veins and the vena cava, and enters the right atrium 26 of the heart 12. Although the system 10 includes the RV lead 18, it is understood that the exemplary systems and methods described herein may not utilize electrodes positioned on the RV lead 18 for sensing and / or pacing. Further, it is understood that the system 10 is only an example, and the exemplary systems and methods described herein may utilize systems that do not include the RV lead 18 (e.g., for sensing and / or pacing).

[0088] The IMD 16 may sense electrical signals associated with depolarization and repolarization of the heart 12, etc., via electrodes coupled to at least one of the leads 18, 20, 22. In some examples, the IMD 16 provides pacing therapy (e.g., pacing pulses) to the heart 12 based on the electrical signals sensed within the heart 12. The IMD 16 may be operable to adjust one or more parameters associated with the pacing therapy, such as, for example, AV delay and other various timings, pulse width, amplitude, voltage, pulse train length, etc. Further, the IMD 16 may be operable to deliver pacing therapy using various electrode configurations, which may be unipolar, bipolar, quadripolar, or further multipolar. For example, a multipolar lead may include several electrodes that can be used to deliver pacing therapy. Thus, a multipolar lead system may provide or supply multiple electrical vectors from which to pace. The pacing vector may include: at least one cathode, which may be at least one electrode positioned on at least one lead; and at least one anode, which may be at least one electrode positioned on at least one lead (e.g., the same lead or different leads) and / or on the housing or can of the IMD. Although the improvement in cardiac function due to pacing therapy may be primarily dependent on the cathode, electrical parameters such as impedance, pacing threshold voltage, current consumption, life span, etc. may be more dependent on the pacing vector including both the cathode and the anode. The IMD 16 may also provide defibrillation therapy and / or cardioversion therapy via electrodes located on at least one of the leads 18, 20, 22. Further, the IMD 16 may detect arrhythmias of the heart 12 (e.g., fibrillation of the ventricles 28, 32) and deliver defibrillation therapy to the heart 12 in the form of electrical pulses. In some examples, the IMD 16 may be programmed to deliver progressive therapy (e.g., pulses with increasing energy levels) until the fibrillation of the heart 12 ceases.

[0089] Figure 81 is a partial cross-sectional view of a patient's heart coupled to an IMD 16 via cardiac leads and additionally coupled to an exemplary LVAD 150. The LVAD 150 includes an inflow conduit 173 that is surgically implanted into the apical region of the LV so that the blood volume that normally fills the LV is at least partially unloaded to a central pumping chamber 176 of the LVAD 150. Upon actuation, the pumping chamber 176 ejects blood through an outflow conduit 174 that is coupled to the arterial system (typically to the ascending aorta or the descending aorta). The inflow conduit 173 and the outflow conduit 174 may include valves to control the direction of blood flow into and out of the LVAD 150. Actuation of the LVAD 150 may be pneumatic, hydraulic, electromagnetic, or by other means known in the art. An LVAD controller or control and power unit 152 may provide power for actuating the LVAD 150. Controller 152 may additionally be configured to control or execute actuation of LVAD 150 with respect to time, pressure, flow rate, or other operational factors. Controller (e.g., control and power unit) 152 may be integrated with LVAD 150 in a fully implantable system, or controller 152 may be located external to the patient's body with any necessary connections for actuating a percutaneous arrangement of LVAD 150.

[0090] In the embodiment shown in FIG9 , a pressure transducer 168 is positioned transmyocardially in the left ventricle. The pressure transducer 168 is carried by a lead 166 coupled to the IMD 16 via a connector. During placement of the LVAD, exposure of the LV may allow the opportunity to place a pressure sensor directly in the LV. Alternatively, the sensor may be positioned in a cardiac vein (as previously described) or other location for measuring the correlation of the LVP.

[0091] Figure 8 Other similarly labeled components in Figure 7 9-10. IMD 14 in this embodiment may be described as receiving EGM and RVP signals from lead 18 and receiving LVP signals from lead 166. RVP and LVP signals may be stored and processed in IMD 16 for use in detecting a measure of ventricular synchrony. IMD 16 and Figure 1 IMD 16, computing device 140, and remote computing device 160 may be in telemetric communication with LVAD controller 152 such that LVAD operating parameters may be adjusted based on commands received from IMD 16, computing device 140, and remote computing device 160. Further, LVAD controller 152 may receive pressure-related data transmitted from IMD 16, and may process such data to determine a measure of ventricular synchronization and adjust LVAD actuation timing based on the measure.

[0092] Figures 9A-9Bis shown in more detail Figure 7 1 and 10. Conceptual diagram of IMD 16 and leads 18, 20, 22 of therapy system 10 of FIG. Leads 18, 20, 22 may be electrically coupled 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 IMD 16 via connector block 34. In some examples, proximal ends of leads 18, 20, 22 may include electrical contacts that are electrically coupled to corresponding electrical contacts in connector block 34 of IMD 16. Additionally, in some examples, leads 18, 20, 22 may be mechanically coupled to connector block 34 by means of set screws, connecting pins, or another suitable mechanical coupling mechanism.

[0093] Each of leads 18, 20, 22 includes an elongated insulated lead body that can carry a plurality of conductors (e.g., concentrically coiled conductors, straight conductors, etc.) separated from one another by a separator (e.g., a tubular insulating sheath). In the example shown, bipolar electrodes 40, 42 are positioned near the distal end of lead 18. In addition, bipolar electrodes 44, 45, 46, 47 are positioned near the distal end of lead 20, and bipolar electrodes 48, 50 are positioned near the distal end of lead 22.

[0094] Electrodes 40, 44, 45, 46, 47, 48 may take the form of ring electrodes, and electrodes 42, 50 may take the form of extendable spiral tip electrodes telescopically mounted within insulating electrode heads 52, 54, 56, respectively. Each of electrodes 40, 42, 44, 45, 46, 47, 48, 50 may be electrically coupled to a respective one of the conductors (e.g., wound and / or straight) within the lead body of its associated lead 18, 20, 22, and thereby coupled to a respective one of the electrical contacts on the proximal end of the lead 18, 20, 22.

[0095] In addition, electrodes 44, 45, 46 and 47 may have a width of about 5.3 mm. 2 To approximately 5.8mm 2 Electrode surface area. 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, left ventricular 4 (LV4) 47, etc.) may be spaced apart at variable distances. For example, electrode 44 may be spaced apart from electrode 45, for example, by about 21 millimeters (mm), electrodes 45 and 46 may be spaced apart from each other, for example, by a distance of about 1.3 mm to about 1.5 mm, and electrodes 46 and 47 may be spaced apart from each other, for example, by a distance of 20 mm to about 21 mm.

[0096] Electrodes 40, 42, 44, 45, 46, 47, 48, 50 may further be used to sense electrical signals (e.g., morphological waveforms within an electrogram (EGM)) associated with depolarization and repolarization of heart 12. The sensed electrical signals may be used to adjust one or more pacing parameters, such as, for example, AV interval, VV interval, etc., to provide optimal and / or effective cardiac function. These electrical signals are conducted to IMD 16 via corresponding leads 18, 20, 22. In some examples, IMD 16 may also deliver pacing pulses via electrodes 40, 42, 44, 45, 46, 47, 48, 50 to cause depolarization of cardiac tissue of the patient's heart 12. In some examples, as Fig.9A As shown in , IMD 16 includes one or more housing electrodes, such as housing electrode 58, which may be integrally formed with or otherwise coupled to an outer surface of a housing 60 (e.g., a hermetically sealed housing) of IMD 16. Any of electrodes 40, 42, 44, 45, 46, 47, 48, 50 may be used for unipolar sensing or pacing in combination with housing electrode 58. In other words, any of electrodes 40, 42, 44, 45, 46, 47, 48, 50, 58 may be used in combination to form a sensing vector, for example, a sensing vector that may be used to evaluate and / or analyze the effectiveness of pacing therapy. Those skilled in the art will appreciate that other electrodes may also be selected to define or be used for pacing and sensing vectors. Further, when not being used to deliver pacing therapy, any of electrodes 40, 42, 44, 45, 46, 47, 48, 50, 58 may be used to sense electrical activity during pacing therapy.

[0097] As reference Fig.9AAs described in further detail, housing 60 may enclose a therapy delivery module that may include a stimulation generator for generating cardiac pacing pulses and defibrillation or cardioversion shocks, and a sensing module for monitoring electrical signals of a patient's heart (e.g., the patient's heart rhythm). Leads 18, 20, 22 may also include elongated electrodes 62, 64, 66, respectively, which may take the form of coils. IMD 16 may deliver defibrillation shocks to heart 12 via any combination of elongated electrodes 62, 64, 66 and housing electrodes 58. Electrodes 58, 62, 64, 66 may also be used to deliver cardioversion pulses to heart 12. Further, electrodes 62, 64, 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 useful for implantable defibrillation electrodes. Because electrodes 62, 64, 66 are generally not configured to deliver pacing therapy, any of electrodes 62, 64, 66 may be used to sense electrical activity (e.g., for determining electrode effectiveness, for analyzing pacing therapy effectiveness, etc.) and may be used in combination with any of electrodes 40, 42, 44, 45, 46, 47, 48, 50, 58. In at least one embodiment, RV elongated electrode 62 may be used to sense electrical activity of the patient's heart during delivery of pacing therapy (e.g., in combination with housing electrode 58, or in combination with a defibrillation electrode to housing electrode vector).

[0098] Figure 7-1 The exemplary configurations of the treatment system 10 shown in FIG. 0 are only a few examples. In other examples, alternative Fig.9A The transvenous leads 18, 20, 22 shown or other than Fig.9A In addition to the transvenous leads 18, 20, 22 shown, the therapy system may include epicardial leads and / or patch electrodes. Additionally, in other examples, the therapy system 10 may be implanted in / around the cardiac space without using a transvenous lead (e.g., a leadless / or wireless pacing system), or with a lead implanted (e.g., implanted transvenously or using an approach) into the left chamber of the heart (in addition to, for example, Fig.9A In addition to or in place of a transvenous line placed into the right chamber of the heart as shown Fig.9A14, 17 and 18. In one or more embodiments, the system 10 may employ wireless pacing (e.g., using energy transmission to a pacing component(s) within the heart via ultrasound, inductive coupling, RF, etc.) and sensing cardiac activation using electrodes on the can / housing and / or on subcutaneous leads.

[0099] In other examples of treatment systems that provide electrical stimulation therapy to heart 12, such treatment systems may include any appropriate number of leads coupled to IMD 16, and each of the leads may extend to any location within or near heart 12. For example, other examples of treatment systems may include fewer than or more than three transvenous leads. In at least one embodiment, a treatment system that provides pacing or electrical stimulation therapy to heart 12 may provide left univentricular pacing therapy only by using or including sensing or pacing electrodes positioned in the left ventricle. In these left univentricular pacing systems, at least one pacing and / or sensing electrode may be positioned in the left ventricle of the patient, and at least one pacing and / or sensing electrode may be positioned in one or both of the right atrium and the left atrium. Further still, other treatment 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 the right atrium 26 and the right ventricle 28, respectively.

[0100] Fig. 10A is a functional block diagram of one exemplary configuration of IMD 16. As shown, IMD 16 may include a control module 81, a therapy delivery module 84 (eg, which may include a stimulation generator), a sensing module 86, and a power source 90.

[0101] Control module 81 may include processor 80, memory 82, and telemetry module 88. Memory 82 may include computer-readable instructions that, when executed, for example, by processor 80, cause IMD 16 and / or control module 81 to perform various functions described herein and attributed to IMD 16 and / or control module 81. Further, memory 82 may include any volatile, nonvolatile, magnetic, optical, and / or electrical media, such as random access memory (RAM), read-only memory (ROM), nonvolatile RAM (NVRAM), electrically erasable programmable ROM (EEPROM), flash memory, and / or any other digital media. An exemplary capture management module may be a left ventricular capture management (LVCM) module described in U.S. Pat. No. 7,684,863, issued Mar. 23, 2010, entitled “LV THRESHOLD MEASUREMENT AND CAPTURE MANAGEMENT,” which is incorporated herein by reference in its entirety.

[0102] 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 an equivalent discrete or integrated logic circuit system. In some examples, the processor 80 may include multiple components, such as any combination of the following: one or more microprocessors, one or more controllers, one or more DSPs, one or more ASICs, and / or one or more FPGAs, and other discrete or integrated logic circuit systems. The functions attributed to the processor 80 herein may be embodied as software, firmware, hardware, or any combination thereof.

[0103] Control module 81 may control therapy delivery module 84 to deliver therapy (e.g., electrical stimulation therapy such as pacing) to heart 12 according to one or more selected therapy programs that may be stored in memory 82. In addition, in particular, control module 81 (e.g., processor 80) may control various parameters of the electrical stimulation delivered by therapy delivery module 84 (e.g., AV delay, VV delay, pacing pulses having amplitude, pulse width, frequency, or electrode polarity, etc.), which may be specified by one or more selected therapy programs (e.g., AV and / or VV delay adjustment program, pacing therapy program, pacing recovery program, capture management program, etc.). As shown, therapy delivery module 84 is electrically coupled to electrodes 40, 42, 44, 45, 46, 47, 48, 50, 58, 62, 64, 66, for example, via conductors of respective leads 18, 20, 22 or, in the case of housing electrode 58, via electrical conductors disposed within housing 60 of IMD 16. Therapy delivery module 84 may be configured to generate and deliver electrical stimulation therapy, such as pacing therapy, to heart 12 using one or more of electrodes 40 , 42 , 44 , 45 , 46 , 47 , 48 , 50 , 58 , 62 , 64 , 66 .

[0104] For example, therapy delivery module 84 may deliver pacing stimulation (e.g., pacing pulses) via ring electrodes 40, 44, 45, 46, 47, 48 coupled to leads 18, 20, 22 and / or via helical tip electrodes 42, 50 of leads 18, 22. Further, for example, therapy delivery module 84 may deliver a defibrillation shock to heart 12 via at least two of electrodes 58, 62, 64, 66. In some examples, therapy delivery module 84 may be configured to deliver pacing, cardioversion, or defibrillation stimulation in the form of electrical pulses. In other examples, therapy delivery module 84 may be configured to deliver one or more of these types of stimulation in the form of other signals (e.g., sine waves, square waves, and / or other substantially continuous time signals).

[0105] The IMD 16 may further include a switch module 85, and the control module 81 (e.g., the processor 80) may use the switch module 85 to select, for example, via a data / address bus, which of the available electrodes are used to deliver therapy (such as pacing pulses for pacing therapy), or which of the available electrodes are used for sensing. The switch module 85 may include a switch array, a switch matrix, a multiplexer, or any other type of switch 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. The switch module 85 may be used, for example, to selectively couple each of the plurality of pacing output circuits to one or more of the electrodes 40, 42, 44, 45, 46, 47, 48, 50, 58, 62, 64, 66 (e.g., a pair of electrodes that deliver therapy using a bipolar or multipolar pacing vector). That is, the switch module 85 may be used to selectively couple each electrode to one of the pacing output circuits of the therapy delivery module.

[0106] The sensing module 86 is coupled (e.g., electrically coupled) to a sensing device, which, as well as additional sensing devices, may include electrodes 40, 42, 44, 45, 46, 47, 48, 50, 58, 62, 64, 66 for monitoring electrical activity of the heart 12, such as electrocardiogram (ECG) / electrogram (EGM) signals, etc. ECG / EGM signals can be used to measure or monitor activation time (e.g., ventricular activation time, etc.), heart rate (HR), heart rate variability (HRV), heart rate oscillations (HRT), deceleration / acceleration ability, deceleration sequence incidence, T wave alternans (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 T wave), T wave changes, QT interval, electrical vector, etc.

[0107] The switch module 85 can also be used with the sensing module 86 to select which of the available electrodes to use or enable, for example, to sense electrical activity of the patient's heart (e.g., using any combination of electrodes 40, 42, 44, 45, 46, 47, 48, 50, 58, 62, 64, 66 to sense one or more electrical vectors of the patient's heart). Similarly, the switch module 85 can also be used with the sensing module 86 to select which of the available electrodes to not use (e.g., disable) to, for example, sense electrical activity of the patient's heart (e.g., using any combination of electrodes 40, 42, 44, 45, 46, 47, 48, 50, 58, 62, 64, 66 to sense one or more electrical vectors of the patient's heart), etc. In some examples, the control module 81 can select the electrodes to be used as sensing electrodes via the switch module within the sensing module 86 (e.g., by providing a signal via a data / address bus).

[0108] In some examples, the sensing module 86 includes a channel including an amplifier having a relatively wider passband than an R-wave or P-wave amplifier. The signal from the selected sensing electrode can be provided to a multiplexer and then converted by an analog-to-digital converter into a multi-bit digital signal for storage in the memory 82, for example, as an electrogram (EGM). In some examples, the storage of such an EGM in the memory 82 can be under the control of a direct memory access circuit.

[0109] In some examples, the control module 81 may operate as an interrupt driven device and may respond to interrupts from the pacemaker timing and control module, wherein the interrupts may correspond to the occurrence of sensed P and R waves and the generation of cardiac pacing pulses. Any necessary mathematical calculations may be performed by the processor 80, and any updates to values ​​or intervals controlled by the pacemaker timing and control module may occur following such interrupts. A portion of the memory 82 may be configured as a plurality of recirculating buffers capable of retaining one or more series of measured intervals (e.g., intrinsic AV conduction times) that may be analyzed by, for example, the processor 80 in response to the occurrence of a pacing or sensing interruption to determine whether the patient's heart 12 is currently exhibiting an atrial or ventricular tachyarrhythmia.

[0110] The pacing timing and control module may include a programmable counter that controls the basal time intervals associated with DDD, VVI, DVI, VDD, AAI, DDI, DDDR, VVIR, DVIR, VDDR, AAIR, DDIR, and other modes of single-chamber pacing and dual-chamber pacing. In the aforementioned pacing modes, "D" may indicate dual chamber, "V" may indicate ventricle, "I" may indicate disabled pacing (e.g., no pacing), and "A" may indicate atrium. The first letter in the pacing mode may indicate the chamber being paced, the second letter may indicate the chamber in which the electrical signal is sensed, and the third letter may indicate the chamber in which the response to the sensing is provided.

[0111] Telemetry module 88 of 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 processor 80, telemetry module 88 may receive downlink telemetry from a programmer and send uplink telemetry to the programmer via an antenna (which may be an internal and / or external antenna). Processor 80 may provide data to be transmitted to the programmer via an uplink and control signals for telemetry circuitry within telemetry module 88, for example, via an address / data bus. In some examples, telemetry module 88 may provide the received data to processor 80 via a multiplexer.

[0112] The various components of IMD 16 are further coupled to a power source 90, which may include rechargeable and non-rechargeable batteries. Non-rechargeable batteries may be selected to last for several years, while rechargeable batteries may be inductively charged from an external device, for example, daily or weekly.

[0113] Fig. 10B is another embodiment of a functional block diagram of IMD 16 . Fig. 10B A bipolar RA lead 22, a bipolar RV lead 18, and a bipolar LV CS lead 20 are depicted without LA CS pacing / sensing electrodes and coupled to an implantable pulse generator (IPG) circuit 31 having programmable modes and parameters of a biventricular DDD / R type as is well known in the art of pacing. In turn, a sensor signal processing circuit 91 is indirectly coupled to a timing circuit 43 and to a microcomputer circuit system 33 via a data and control bus. The IPG circuit 31 is shown in a functional block diagram generally divided into a microcomputer circuit 33 and a pacing circuit 21. The pacing circuit 21 includes a digital controller / timer circuit 43, an output amplifier circuit 51, a sense amplifier circuit 55, an RF telemetry transceiver 41, an activity sensor circuit 35, and a number of other circuits and components described below.

[0114] Crystal oscillator circuit 89 provides a basic timing clock for pacing circuit 21, while battery 29 provides power. Power-on reset circuit 87 responds to initial connection of the circuit to the battery for defining initial operating conditions, and similarly responds to detecting a low battery condition to reset the operating state of the device. Reference mode circuit 37 generates a stable voltage reference and current for analog circuits within pacing circuit 21. Analog-to-digital converter (ADC) and multiplexer circuit 39 digitize analog signals and voltages to provide real-time telemetry of cardiac signals, such as from sense 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 an exemplary implantable cardiac pacemaker.

[0115] If the IPG is programmed for rate responsive mode, the signals output by one or more physiological sensors are used as a rate control parameter (RCP) to derive the physiological escape interval. For example, the escape interval is adjusted in proportion to the patient's activity level generated in the patient activity sensor (PAS) circuit 35 in the depicted, exemplary IPG circuit 31. The patient activity sensor 27 is coupled to the IPG housing and can 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 electrical signals in response to the sensed physical activity, which are processed by the activity circuit 35 and provided to the digital controller / timer circuit 43. The activity circuit 35 and associated sensor 27 may correspond to the circuit systems disclosed in U.S. Pat. No. 5,052,388, issued on Oct. 1, 1991, entitled “METHOD AND APPARATUS FORIMPLEMENTING ACTIVITY SENSING IN A PULSE GENERATOR,” and U.S. Pat. No. 4,428,378, issued on Jan. 31, 1984, and entitled “RATE ADAPTIVE PACER,” each of which is incorporated herein by reference in its entirety. Similarly, the exemplary systems, apparatus, and methods described herein may be practiced in conjunction with alternative types of sensors, such as oxygenation sensors, pressure sensors, pH sensors, and respiration sensors, for providing rate-responsive pacing functionality. Alternatively, the QT time may be used as a rate-indicating parameter, in which case no additional sensor is required. Similarly, the exemplary embodiments described herein may also be practiced in a non-rate-responsive pacemaker.

[0116] Data transmission to and from an external programmer is accomplished through telemetry antenna 57 and associated RF transceiver 41 for both demodulating received downlink telemetry and for transmitting uplink telemetry. The uplink telemetry capability may include the ability to transmit stored digital information (e.g., operating modes and parameters, EGM histograms and other events, and real-time EGMs of atrial and / or ventricular electrical activity and marker channel pulses indicating the occurrence of sensed and paced depolarizations in the atria and ventricles).

[0117] The microcomputer 33 includes a microprocessor 80 and an associated system clock, and includes on-processor RAM and ROM chips 82A and 82B, respectively. In addition, the microcomputer circuit 33 includes a separate RAM / ROM chip 82C to provide additional memory capacity. The microprocessor 80 is usually operated in a reduced power consumption mode and is interrupt driven. The microprocessor 80 is awakened in response to a defined interrupt event, which may include an A-trigger (TIRG) signal, an RV-trigger signal, a LV-trigger signal generated by a timer in the digital timer / controller circuit 43, and an A-event signal, an RV-event signal, and a LV-event signal generated by the sense amplifier circuit 55, etc. The specific value of the interval and delay of the countdown (timeout) performed by the digital controller / timer circuit 43 is controlled by the microcomputer circuit 33 through the data and control bus according to the parameter values ​​and operating modes programmed into the microcomputer circuit 33. In addition, if programmed to operate as a rate-responsive pacemaker, a timed interrupt may be provided, for example, every cycle or every two seconds, to allow the microprocessor to analyze the activity sensor data and update the basic AA, VA, or VV escape intervals, as applicable. In addition, the microprocessor 80 may also be used to define variable, actionable AV delay intervals and / or VV intervals, as well as the energy delivered to the ventricles and / or atria.

[0118] 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, it is contemplated that other implementations may be suitable for practicing the present invention. For example, an off-the-shelf commercially available microprocessor or microcontroller, or a custom dedicated hard-wired logic or state machine type circuit may perform the functions of microprocessor 80.

[0119] The digital controller / timer circuit 43 operates under the overall control of the microcomputer 33 to control timing and other functions within the pacing circuit 321 and includes a set of timing circuits and associated logic circuits, certain of which are depicted that are relevant to the present invention. The depicted timing circuits include a URI / LRI timer 83A, a VV delay timer 83B, an intrinsic interval timer 83C for timing past V-event to V-event intervals or V-event to A-event intervals or VV conduction intervals, an escape interval timer 83D for timing AA, VA and / or VV pacing escape intervals, an AV delay interval timer 83E for timing the A-LVp delay (or A-RVp delay) from a preceding A-event or A-trigger, a post-ventricular timer 83F for timing post-ventricular time periods, and a date / time clock 83G.

[0120] The AV delay interval timer 83E is loaded with the appropriate delay interval for one ventricular chamber (e.g., A-RVp delay or A-LVp delay) to count down from a preceding A-pacing or A-event. The interval timer 83E triggers pacing stimulus delivery and may be based on one or more previous cardiac cycles (or from an empirically derived data set for a given patient).

[0121] The post-event timer 83F counts down the post-ventricular time period after an RV-event or LV-event or RV-trigger or LV-trigger, and the post-atrial time period after an A-event or A-trigger. The duration of the post-event time period may also be selected as a programmable parameter stored in the microcomputer 33. The post-ventricular time period includes the PVARP, the post-atrial ventricular blanking period (PAVBP), the ventricular blanking period (VBP), the post-ventricular atrial blanking period (PVARP), and the ventricular refractory period (VRP), although other time periods may also be appropriately defined based at least in part on the operating circuitry employed in the pacing engine. The post-atrial time period includes the atrial refractory period (ARP) (during which the A-event is ignored for the purpose of resetting any AV delay) and the atrial blanking period (ABP) (during which atrial sensing is disabled). It should be noted that the start of the post-atrial time period and AV delay may begin substantially simultaneously with the start or end of each A-event or A-trigger, or in the case of an A-trigger, at the end of an A-pacing that may follow an A-trigger. Similarly, the start of the post-ventricular time period and VA escape interval may begin substantially simultaneously with the start or end of a V-event or V-trigger, or in the case of a V-trigger, at the end of a V-pacing that may follow a V-trigger. The microprocessor 80 also optionally calculates AV delay, VV delay, post-ventricular time period, and post-atrial time period as a function of sensor-based escape intervals established in response to RCP(s), intrinsic AV conduction time, intrinsic heart rate, and / or any other parameter or metric.

[0122] The output amplifier circuit 51 includes an RA pacing pulse generator (and a 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 RV-pacing or LV-pacing pulses, the digital controller / timer circuit 43 generates an RV-trigger signal upon timeout of the A-RVp delay (in the case of RV preexcitation) or generates an LV-trigger upon timeout of the A-LVp delay (in the case of LV preexcitation), the timeout of the A-RVp delay and the timeout of the A-LVp delay being provided by the AV delay interval timer 83E (or the VV delay timer 83B). Similarly, at the end of the VA escape interval timed by the escape interval timer 83D, the digital controller / timer circuit 43 generates an RA-trigger signal that triggers the output of an RA-pacing pulse (or an LA-trigger signal that triggers the output of an LA-pacing pulse, if provided).

[0123] The output amplifier circuit 51 includes switching circuitry for coupling selected pacing electrode pairs from between the lead conductors and the IND-CAN electrode 20 to the RA pacing pulse generator (and LA pacing pulse generator, if provided), RV pacing pulse generator, and LV pacing pulse generator. The pacing / sense electrode pair selection and control circuit 53 selects the lead conductors and associated pacing electrode pairs to be coupled to the atrial and ventricular output amplifiers within the output amplifier circuit 51 for accomplishing RA, LA, RV, and LV pacing.

[0124] The sense amplifier circuit 55 contains sense amplifiers for atrial and ventricular pacing and sensing. High impedance P-wave and R-wave sense amplifiers can be used to amplify the differential pressure signal generated across the sensing electrode pair by the passage of the cardiac depolarization wavefront. The high impedance sense amplifier uses high gain to amplify low amplitude signals and relies on passband filters, time domain filtering, and amplitude threshold comparison to distinguish the P wave or R wave from background electrical noise. The digital controller / timer circuit 43 controls the sensitivity setting of the atrial and ventricular sense amplifiers 55.

[0125] The sense amplifier is typically decoupled from the sense electrode during blanking periods before, during, and after delivery of a pacing pulse to any of the pacing electrodes of the pacing system to avoid saturation of the sense amplifier. The sense amplifier circuit 55 includes a blanking circuit for decoupling the selected lead conductor pairs and the IND-can electrode 20 from the inputs of the RA sense amplifier (and the LA sense amplifier if provided), the RV sense amplifier, and the LV sense amplifier during ABP, PVABP, and VBP. The sense amplifier circuit 55 also includes a switching circuit for coupling the selected sensing electrode lead conductors and the IND-can electrode 20 to the RA sense amplifier (and the LA sense amplifier if provided), the RV sense amplifier, and the LV sense amplifier. Similarly, the sense electrode selection and control circuit 53 selects conductors and associated sensing electrode pairs for coupling with the output amplifier circuit 51 and the atrial and ventricular sense amplifiers within the sense amplifier circuit 55 for accomplishing RA, LA, RV, and LV sensing along the desired unipolar and bipolar sensing vectors.

[0126] A right atrial depolarization or P wave in the RA-sense signal sensed by the RA sense amplifier results in an RA-event signal that is transmitted to the digital controller / timer circuit 43. Similarly, a left atrial depolarization or P wave in the LA-sense signal sensed by the LA sense amplifier (if provided) results in an LA-event signal that is transmitted to the digital controller / timer circuit 43. A ventricular depolarization or R wave in the RV-sense signal sensed by the ventricular sense amplifier results in an RV-event signal that is transmitted to the digital controller / timer circuit 43. Similarly, a ventricular depolarization or R wave in the LV-sense signal sensed by the ventricular sense amplifier results in an LV-event signal that is transmitted to the digital controller / timer circuit 43. The RV-event signal, the LV-event signal, as well as the RA-event signal, the LA-sense signal may be refractory or non-refractory, and may be inadvertently triggered by an electrical noise signal or an abnormally conducted depolarization wave, rather than a true R-wave or P-wave.

[0127] The techniques described in the present disclosure (including techniques attributed to IMD 16, computing device 140, remote computing device 160, and / or various component parts) may be implemented at least in part in hardware, software, firmware, or any combination thereof. For example, aspects of these techniques may be implemented within one or more processing circuit systems and / or one or more processors, wherein the one or more processing circuit systems and / or one or more processors include one or more microprocessors, DSPs, ASICs, FPGAs, or any other equivalent integrated or discrete logic circuit systems, as well as any combination of such components embodied in a programmer (such as a physician programmer or patient programmer, stimulator, image processing device, or other device). The terms "module," "processor," or "processing circuit system" may generally refer to any of the foregoing logic circuit systems, either independently or in combination with other logic circuit systems, or any other equivalent circuit systems.

[0128] Such hardware, software and / or firmware may be implemented in the same device or in separate devices to support the various operations and functions described in the present disclosure. In addition, any of the described units, modules or components may be implemented together, or may be implemented separately as discrete but interoperable logical devices. Depicting different features as modules or units is intended to emphasize different functional aspects, and does not necessarily imply that such modules or units must be implemented by separate hardware or software components. Instead, the functions associated with one or more modules or units may be performed by separate hardware or software components, or may be integrated in common or separate hardware or software components.

[0129] When implemented in software, the functionality attributed to the systems, devices, and techniques described in this disclosure may be embodied as instructions on a computer-readable medium (such as RAM, ROM, NVRAM, EEPROM, flash memory, magnetic data storage media, optical data storage media, etc.). These instructions may be executed by one or more processors to support one or more aspects of the functionality described in this disclosure.

[0130] Illustrative Embodiments

[0131] Embodiment 1: A system comprising:

[0132] an electrode assembly comprising a plurality of extracorporeal electrodes for monitoring cardiac electrical activity from tissue of a patient; and

[0133] a computing device comprising processing circuitry and coupled to the electrode device, and configured to:

[0134] monitoring cardiac electrical activity using a plurality of external electrodes at least during delivery of cardiac therapy using a left ventricular assist device (LVAD);

[0135] generating electrical heterogeneity information based on the monitored electrical activity; and

[0136] An output parameter of the LVAD is determined based on the generated electrical heterogeneity information.

[0137] Embodiment 2: A method comprising:

[0138] monitoring electrical activity from patient tissue using a plurality of external electrodes at least during delivery of cardiac therapy using a left ventricular assist device (LVAD);

[0139] generating electrical heterogeneity information based on the monitored electrical activity; and

[0140] An output parameter of the LVAD is determined based on the generated electrical heterogeneity information.

[0141] Embodiment 3: The system or method of any of Embodiments 1-2, wherein the plurality of extracorporeal electrodes comprises body surface electrodes positioned in an array and configured to be located proximate to the skin of the patient's torso.

[0142] Example 4: A system or method as described in any of Examples 1-3, wherein the system further includes a display, wherein the display includes a graphical user interface, and the graphical user interface is configured to assist a user in assessing a patient's cardiac health, wherein the computing device is further configured to display electrical heterogeneity information and determined output parameters of the LVAD on the graphical user interface.

[0143] Embodiment 5: The system or method of any one of embodiments 1-4, wherein the computing device is further configured to perform or the method further comprises: adjusting the LVAD according to the determined output parameter.

[0144] Example 6: A system or method as described in any of Examples 1-5, wherein the electrical heterogeneity information includes right ventricular electrical heterogeneity information indicating right ventricular asynchrony, and the right ventricular electrical heterogeneity information is generated using electrical activity monitored by a right extracorporeal electrode group positioned near the patient's right torso among a plurality of extracorporeal electrodes.

[0145] Example 7: The system or method of Example 6, wherein the electrical heterogeneity information includes an average value of right ventricular electrical activation time monitored by the right extracorporeal electrode group.

[0146] Example 8: A system or method as described in any of Examples 1-7, wherein the electrical heterogeneity information includes diaphragm electrical heterogeneity information indicating diaphragm asynchrony, and the diaphragm electrical heterogeneity information is generated using electrical activity monitored by a central extracorporeal electrode group positioned near the patient's sternum or spine among a plurality of extracorporeal electrodes.

[0147] Example 9: The system or method of Example 8, wherein determining the output parameters of the LVAD based on the generated electrical heterogeneity information includes: comparing the diaphragm center electrical heterogeneity information with other electrical heterogeneity information generated from a set of extracorporeal electrodes on the right or left side of the patient's sternum or spine.

[0148] Example 10: A system or method as described in any of Examples 1-9, wherein the computing device is further configured to execute or the method further includes: determining one or more cardiac pacing parameters to be used in cardiac pacing therapy in combination with an LVAD based on the generated electrical heterogeneity information.

[0149] Example 11: The system or method of Example 10, wherein the one or more pacing parameters include right ventricular pre-excitation.

[0150] Example 12: The system or method as described in any of Examples 1-11 further includes or provides an acoustic sensor, which includes at least one transducer to monitor the patient's heart sounds, wherein the computing device is further configured to execute or the method further includes: determining the output parameters of the LVAD based on the patient's heart sounds monitored during the delivery of cardiac therapy using the LVAD.

[0151] Embodiment 13: The system or method of Embodiment 12, wherein determining an output parameter of the LVAD based on heart sounds of the patient monitored during delivery of cardiac therapy using the LVAD comprises:

[0152] Determining whether a heart valve is open or closed based on monitored heart sounds; and

[0153] An output parameter of the LVAD is adjusted to allow at least some opening of the heart valve.

[0154] Example 14: The system or method as described in any of Examples 12-13 further includes a display or provides a display, wherein the display includes a graphical user interface configured to assist a user in assessing the patient's cardiac health, wherein the computing device is further configured to display cardiac sound information based on the patient's heart sounds monitored during the delivery of cardiac therapy using an LVAD.

[0155] The present disclosure has been provided with reference to illustrative embodiments, and the disclosure is not intended to be interpreted in a limiting sense. As previously stated, those skilled in the art will recognize that various other illustrative applications can use the techniques described herein to take advantage of the beneficial properties of the apparatus and methods described herein. Various modifications of the illustrative embodiments and additional embodiments of the present disclosure will be apparent when referring to this specification.

Claims

1. A system for adjusting and evaluating a left ventricular assist device, the system comprising: an electrode assembly comprising a plurality of extracorporeal electrodes for monitoring cardiac electrical activity from tissue of a patient; as well as a computing device comprising processing circuitry and coupled to the electrode device, and configured to: monitoring cardiac electrical activity using the plurality of extracorporeal electrodes at least during delivery of cardiac therapy using a left ventricular assist device (LVAD) including a pump; generating electrical heterogeneity information based on monitored cardiac electrical activity at least during delivery of cardiac therapy using the left ventricular assist device including a pump; as well as An output parameter of the left ventricular assist device including a pump is determined based on the generated electrical heterogeneity information.

2. A method for adjusting and evaluating a left ventricular assist device, comprising: monitoring electrical activity from tissue of a patient using a plurality of external electrodes at least during delivery of cardiac therapy using a left ventricular assist device (LVAD) including a pump; generating electrical heterogeneity information based on monitored cardiac electrical activity at least during delivery of cardiac therapy using the left ventricular assist device including a pump; as well as An output parameter of the left ventricular assist device including a pump is determined based on the generated electrical heterogeneity information.

3. The system or method according to any one of claims 1 to 2, characterized in that: The plurality of extracorporeal electrodes include body surface electrodes positioned in an array and configured to be located proximate to the skin of the patient's torso.

4. The system or method according to any one of claims 1 to 3, characterized in that: The computing device is further configured to perform or the method further includes: displaying the electrical heterogeneity information and the determined output parameter of the LVAD on a graphical user interface to assist a user in assessing a patient's cardiac health.

5. The system or method according to any one of claims 1 to 4, characterized in that: The computing device is further configured to perform or the method further includes: adjusting the LVAD according to the determined output parameter.

6. The system or method according to any one of claims 1 to 5, characterized in that: The electrical heterogeneity information includes right ventricular electrical heterogeneity information indicative of right ventricular asynchrony, the right ventricular electrical heterogeneity information being generated using electrical activity monitored by a right extracorporeal electrode set of the plurality of extracorporeal electrodes positioned proximate a right torso of the patient.

7. The system or method of claim 6, wherein: The electrical heterogeneity information includes the average value of the right ventricular electrical activation time monitored by the right extracorporeal electrode group.

8. The system or method according to any one of claims 1 to 7, characterized in that: The electrical heterogeneity information includes diaphragm electrical heterogeneity information indicative of diaphragm asynchrony, the diaphragm electrical heterogeneity information being generated using electrical activity monitored by a central set of extracorporeal electrodes of the plurality of extracorporeal electrodes positioned near a sternum or spine of the patient.

9. The system or method according to any one of claims 8, characterized in that Determining an output parameter of the LVAD based on the generated electrical heterogeneity information includes comparing the diaphragm center electrical heterogeneity information with other electrical heterogeneity information generated from a set of extracorporeal electrodes on the right or left side of the sternum or spine of the patient.

10. The system or method according to any one of claims 1 to 9, characterized in that: The computing device is further configured to perform or the method further includes determining one or more cardiac pacing parameters to be used in cardiac pacing therapy in conjunction with the LVAD based on the generated electrical heterogeneity information.

11. The system or method of claim 10, wherein: The one or more pacing parameters include right ventricular pre-excitation.

12. The system or method according to any one of claims 1 to 11, characterized in that: The computing device is further configured to perform or the method further comprises: monitoring heart sounds of the patient using an acoustic sensor during delivery of cardiac therapy using the LVAD; and The output parameter of the LVAD is determined based on heart sounds of the patient monitored during delivery of cardiac therapy using the LVAD.

13. The system or method of claim 12, wherein: Determining the output parameter of the LVAD based on the patient's heart sounds monitored during delivery of cardiac therapy using the LVAD includes: Determining whether a heart valve is open or closed based on monitored heart sounds; and The output parameter of the LVAD is adjusted to allow at least some opening of the heart valve.

14. The system or method according to any one of claims 12-13, characterized in that: The computing device is further configured to perform or the method further includes: displaying heart sound information on a graphical user interface based on the patient's heart sounds monitored during delivery of cardiac therapy using the LVAD to assist a user in assessing the patient's cardiac health.

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