Source: https://patents.google.com/patent/US20040106960?oq=6181294
Timestamp: 2018-03-24 12:38:52
Document Index: 783214010

Matched Legal Cases: ['art 102', 'art 102', 'art 102', 'art 102', 'art 102', 'art 102', 'art 102']

US20040106960A1 US10307896 US30789602A US2004106960A1 US 20040106960 A1 US20040106960 A1 US 20040106960A1 US 10307896 US10307896 US 10307896 US 30789602 A US30789602 A US 30789602A US 2004106960 A1 US2004106960 A1 US 2004106960A1
US7123962B2 (en )
This application is related to co-pending, commonly assigned Siejko et al. U.S. patent application Ser. No. ______, entitled “METHOD AND APPARATUS FOR PHONOCARDIOGRAPHIC IMAGE ACQUISITION AND PRESENTATION,” filed on even date herewith, (Attorney Docket No. 279.456US1), which is hereby incorporated by reference.
[0013]FIG. 1 is a schematic illustration of an embodiment of portions of a cardiac rhythm management system and portions of an environment in which it is used.
[0014]FIG. 2 is a conceptual illustration of one embodiment of a phonocardiographic image constructed of an acoustic sensor signal.
[0015]FIG. 3 is a schematic/block diagram illustrating one embodiment of portions of the cardiac rhythm management system with an implanted acoustic sensor.
[0016]FIG. 4 is a schematic/block diagram illustrating one embodiment of portions of the cardiac rhythm management system with an external acoustic sensor.
[0017]FIG. 5 is a schematic/block diagram illustrating one embodiment of a signal processor of the cardiac rhythm management system.
[0018]FIG. 6 is a schematic/block diagram illustrating one embodiment of a therapy controller of the cardiac rhythm management system.
[0019]FIG. 7 is an illustration of portions of a visual presentation including an actual phonocardiographic image according to the embodiment of FIG. 2.
[0020]FIG. 8 is a flow chart illustrating one embodiment of a method for acquiring, presenting, and using the phonocardiographic image.
[0021]FIG. 9 is a flow chart illustrating one embodiment of a method for phonocardiographic image-based diagnosis.
[0022]FIG. 10 is a flow chart illustrating one embodiment of a method for phonocardiographic image-based therapy evaluation.
[0023]FIG. 11 is a flow chart illustrating one specific embodiment of a method for phonocardiographic image-based AVD optimization.
[0024]FIG. 12 is an illustration of one embodiment of a method for AVD optimization for maximum ventricular contractility.
[0025]FIG. 13 is a flow chart illustrating one embodiment of a method for phonocardiographic image-based AVD optimization for maximum ventricular contractility.
[0026]FIG. 14 is a flow chart illustrating one embodiment of another method for phonocardiographic image-based AVD optimization for maximum ventricular contractility.
[0029]FIG. 1 is a schematic illustration of an embodiment of portions of a cardiac rhythm management system 100 and portions of an environment in which it is used. In one embodiment, system 100 is a cardiac rhythm management system including, among other things, an implanted device 110 and an external programmer 140. Implanted device 110 is implanted within a patient's body 101 and coupled to the patient's heart 102 by a lead system 105. Examples of implanted device 110 include pacemakers, cardioverter/defibrillators, pacemaker/defibrillators, CRT devices, and drug delivery devices. Programmer 140 includes a user interface for system 100. Throughout this document, the “user” refers to a physician or other caregiver who examines and/or treats the patient with system 100. The user interface allows a user to interact with implanted device 110 through a telemetry link 170.
[0033]FIG. 2 is a conceptual illustration of one embodiment of the phonocardiographic image. The phonocardiographic image simultaneously presents multiple cardiac cycles each including representations or indications of electrical and mechanical events of heart 102 that occur during the cycle. In one embodiment, the electrical events include intrinsic depolarizations sensed from, and pacing pulses delivered to, heart 102. These electrical events are referred to as cardiac events. In one embodiment, the mechanical events of heart 102 are indicated by heart sounds. In one embodiment, as illustrated in FIG. 2, the phonocardiographic image includes a horizontal axis indicating time and a vertical axis indicating cardiac cycles. The cardiac events and heart sounds during each cardiac cycle is presented at the same vertical level. In one embodiment, the phonocardiographic image includes a stack of signal segments each represent at least one cardiac cycle including cardiac events and heart sounds detected during that cardiac cycle. In another embodiment, the phonocardiographic image includes stacked signal segments each represent at least a portion of a cardiac cycle including selected cardiac events and heart sounds detected during that cardiac cycle. In one embodiment, as illustrated in FIG. 2 by way of example, but not by way of limitation, the phonocardiographic image includes a stack of signal segments each include one complete cardiac cycle between two cardiac events A, and includes representations or indications of detected cardiac events A and V and heart sounds S1, S2, and S3. Cardiac event A represents an atrial event that is either an intrinsic depolarization sensed from an atrium or a pacing pulse delivery to the atrium. Cardiac event V represents a ventricular event that is either an intrinsic depolarization sensed from a ventricle or a pacing pulse delivery to the ventricle. Heart sound S1 represents the “first heart sound,” which is known to be indicative of, among other things, mitral valve closure, tricuspid valve closure, and aortic valve opening. Heart sound S2 represents the “second heart sound,” which is known to be indicative of, among other things, aortic valve closure and pulmonary valve closure. Heart sound S3 represents the “third heart sound,” which is known to be indicative of certain pathological conditions including heart failure. In other embodiments, the phonocardiographic image include representations and/or indications of one or more of other cardiac events and heart sounds such as the “fourth heart sound” and various components of the first, second, and third heart sounds.
[0036]FIG. 3 is a schematic/block diagram illustrating one embodiment of portions of cardiac rhythm management system 100 with an implanted acoustic sensor 335. System 100 provides for acquisition of at least a cardiac signal and an acoustic sensor signal indicating the cardiac events and heart sounds represented or indicated in the phonocardiographic image. In one embodiment, system 100 includes an implanted portion and an external portion. The implanted portion resides within body 101 and includes implanted device 110 and lead system 105 providing for electrical connection between implanted device 110 and heart 102. The external portion includes programmer 140 and wand 175 connected to programmer 140. Telemetry link 170 provides for bi-directional communications between implanted device 110 and programmer 140.
[0044]FIG. 4 is a schematic/block diagram illustrating one embodiment of portions of the cardiac rhythm management system 100 with an external acoustic sensor. System 100 in this embodiment differs from system 100 in the embodiment of FIG. 3 in that the acoustic sensor is externally placed onto body 101. In this embodiment, system 100 includes external acoustic sensor 130 that is attached onto body 101. The location on body 101 where external acoustic sensor 130 is placed onto depends on the mechanical events of interest. For example, when external acoustic sensor 130 is used to detect the first heart sound indicative of mitral valve closure, the sensor is attached onto body 101 over heart 102 near its mitral valve. External acoustic sensor 130 is connected to an external sensor circuit 431, which processes the acoustic sensor signal for being received by signal processor 350. In one embodiment, external sensor circuit 431 digitizes the acoustic sensor signal to produce the acoustic sensor signal samples that are converted to image pixels for presentation on display 341. In another embodiment, signal processor 350 digitizes the acoustic sensor signal. In one embodiment, as illustrated in FIG. 4, external sensor circuit 431 is part of programmer 140. In an alternative embodiment, external sensor circuit 431 is connected to programmer 140 and functions as an interface between external acoustic sensor 130 and programmer 140.
[0046]FIG. 5 is a schematic/block diagram illustrating one embodiment of signal processor 350. Among other functions, signal processor 350 produces the phonocardiographic image. In one embodiment, signal processor 350 includes, among other functional components, an acoustic sensor signal input 557, a cardiac signal input 558, and an image formation module 551. In one embodiment, acoustic sensor signal input 557 receives the acoustic sensor signal sensed by implanted acoustic sensor 335 and transmitted to programmer 140 via telemetry link 170. In an alternative embodiment, acoustic sensor signal input 557 receives the acoustic sensor signal sensed by external acoustic sensor 130 and transmitted to programmer 140 via wired electrical connections. In one embodiment, cardiac signal input 558 receives the one or more cardiac signals sensed by sensing circuit 321 and transmitted to programmer 140 via telemetry link 170. The cardiac signals each include indications of intrinsic depolarizations and therapy deliveries. In another embodiment, cardiac signal input 558 receives the event markers representative of the intrinsic depolarizations and therapy deliveries.
[0049]FIG. 6 is a schematic/block diagram illustrating one embodiment of therapy controller 360. Therapy controller 360 allows the user to, for example, select a therapy, start the therapy, stop the therapy, and adjust parameters associated with the therapy. In one embodiment, therapy controller 360 converts user commands and selections received by user input module 342 to codes recognizable by implanted device 110, and sends the codes to implanted device 110 through telemetry link 170. In one embodiment, therapy controller 360 includes, among other functional components, a therapy protocol synthesizer 661 and an automatic therapy protocol execution module 667. In one embodiment, a therapy protocol includes therapy descriptions including a sequence of therapy parameter sets defining a sequence of therapies to be evaluated with a patient. In one embodiment, the therapy protocol defines a time period or a number of heart beats over which each of the therapies is to be delivered. In one embodiment, the therapy protocol includes therapy descriptions defining a sequence of therapies of the same type but each including at least one parameter whose value differs from that of the other therapies. In one embodiment, the therapy protocol includes therapy descriptions defining a sequence of alternating therapies and non-therapies. In other words, a “resting” or “washing” period is provided between therapy deliveries, such that the effects of each therapy can be isolated for analysis. The purpose for executing such a therapy protocol includes identifying a therapy type and/or a therapy parameter or parameter set associated with a desirable therapeutic result. In one embodiment, the therapeutic result is observed from the phonographic image discussed above with reference to FIG. 2.
[0053]FIG. 7 is an illustration of portions of a visual presentation including an actual phonocardiographic image 780 according to the embodiment of FIG. 2. In one embodiment, the visual presentation is displayed on display 341. Phonocardiographic image 780 is shown in FIG. 7, by way of example, but not by way of limitation, an implementation of the concepts discussed above with reference to FIG. 2. It is formed based on cardiac events and an accelerometer signal recorded during a pacing protocol execution. The pacing protocol is designed to test the effect of atrial tracking mode pacing (VDD mode pacing with multiple ventricular sites) with five different AVDs, AVD1-AVD5, on the hemodynamic performance of a patient suffering congestive heart failure but having a normal sinus node. The pacing protocol includes a sequence of alternating pacing and non-pacing periods, with AVD1-AVD5 calculated based on an intrinsic AVI measured from the patient and included in the pacing periods in a randomized order. The sequence is repeated for a predetermined number of times for statistical significance of the results, with the order of AVD1-AVD5 randomized separately for each repetition.
[0057]FIG. 8 is a flow chart illustrating one embodiment of a method for acquiring, presenting, and using the phonocardiographic image. At 800, a phonocardiograph session is started. In one embodiment, the user starts the phonocardiograph session by entering a command to programmer 140 through user input module 342. At 810, acoustic sensor signal input 557 receives an acoustic sensor signal indicative of mechanical events of heart 102. In one embodiment, the acoustic sensor signal is an accelerometer signal indicative of heart sounds. In an alternative embodiment, the acoustic sensor signal is a microphone signal indicative of heart sounds. At 812, cardiac signal input 558 receives a cardiac signal. In one embodiment, the cardiac signal is an intracardiac electrogram indicative of intrinsic cardiac depolarizations and therapy deliveries. In an alternative embodiment, the cardiac signal is a surface ECG. In another alternative embodiment, the cardiac signal includes event markers representative of intrinsic cardiac depolarizations and therapy deliveries. At 814, user input module 342 receives user instruction defining a presentation of the phonocardiographic image. The user instruction includes one or more types of the cardiac events or heart sounds used for segmenting and aligning the acoustic sensor signal segments, arrangement of the acoustic sensor signal segments for presentation, and other presentation format instructions. At 820, signal processor 350 associates the acoustic sensor signal and the cardiac signal by aligning the two signals to a common timing reference. In one embodiment, the acoustic sensor signal and the cardiac signal are received simultaneously. That is, steps 810 and 812 are performed simultaneously. Signal processor 350 aligns the acoustic sensor signal and the cardiac signal by aligning points or portions of the two signals that are recorded at the same time. At 830, signal segmenting module 552 partitions the received acoustic sensor signal into acoustic sensor signal segments. In one embodiment, the acoustic sensor signal segments each represent at least one cardiac cycle including representations or indications of the cardiac events and heart sounds detected during that cardiac cycle. In another embodiment, the acoustic sensor signal segments each represent at least a portion of a cardiac cycle including selected representations or indications of the cardiac events and heart sounds detected during that cardiac cycle. In one embodiment, points of segmenting are determined based on the user instruction received at 814. In this embodiment, signal segmenting module 552 partitions the acoustic sensor signal based on the one or more types of the cardiac events and heart sounds. In one embodiment, points of segmenting are related to times associated with the event markers. At 840, signal alignment module 553 aligns all the acoustic sensor signal segments by the selected type of cardiac events or heart sounds. In one embodiment, this alignment facilitates observation of timing trends related to the heart sounds, especially time intervals between a selected type of the heart sounds and the selected type of cardiac events. In one embodiment, the selected type of cardiac events includes atrial contraction. In another embodiment, the selected type of cardiac events includes ventricular contraction. In one embodiment, signal alignment module 553 aligns all the acoustic sensor signal segments by pre-selected type of cardiac events or heart sounds. In another embodiment, signal alignment module 553 aligns all the acoustic sensor signal segments according to the user instruction received at 814. At 850, signal grouping module 554 sorts and groups the acoustic sensor signal segments. In one embodiment, signal grouping module 554 sorts and groups the acoustic sensor signal segments to present them in a pre-defined or default order. In another embodiment, signal grouping module 554 sorts and groups the acoustic sensor signal segments to arrange them according to the user instruction received at 814. In one embodiment, signal grouping module 554 sorts and groups the acoustic sensor signal segments to present them in an order related to values of a therapy parameter or a measured cardiac parameter such as AVD, pacing rate, heart rate, and cardiac cycle length interval measured at an atrium or ventricle. In a further embodiment, signal grouping module 554 averages the acoustic sensor signal segments associated with one or more common values of the therapy parameter or the measured cardiac parameter such as AVD, pacing rate, heart rate, and cardiac cycle length interval measured at an atrium or ventricle. At 860, display 341 presents the phonocardiographic image including the aligned and grouped acoustic sensor signal segments. At 870, the user observes the phonocardiographic image. In one embodiment the user observes from phonocardiographic image indications of at least one of events and time intervals such as mitral valve closure, aortic valve opening and closure, electromechanical activation delays, isovolumic contraction time, ejection period, and diastolic filling period.
[0061]FIG. 9 is a flow chart illustrating one embodiment of a method for phonocardiographic image-based diagnosis. One of the applications of the phonocardiographic image such as phonocardiographic image 780 is to provide a tool for diagnosis of cardiac conditions based on the acoustic sensor signal and the cardiac signal recorded from the patient, with or without delivering a cardiac therapy while recording the signals. In one embodiment, the phonocardiographic image-based diagnosis is performed on a patient suspected to have an abnormal cardiac condition. In another embodiment, the phonocardiographic image-based diagnosis is performed to a patient being a therapy candidate to determine whether a particular therapy is likely to improve the patient's cardiac conditions and hemodynamic performance. In yet another embodiment, the phonocardiographic image-based diagnosis is performed as a follow-up examination for a patient having been treated with a therapy. In one embodiment, the phonocardiographic image-based diagnosis provides a non-invasive way to examine a patient, with the cardiac signal and the acoustic sensor signal acquired through surface ECG electrodes and an external acoustic sensor. In another embodiment, the phonocardiographic image-based diagnosis provides a non-invasive way to examine a patient carrying an implanted device, with the cardiac signal and the acoustic sensor signal acquired by the implanted device and telemetered to an external device. In yet another embodiment, the phonocardiographic image-based diagnosis provides a non-invasive way to examine a patient carrying an implanted device, with the cardiac signal acquired by the implanted device and telemetered to an external device, and the acoustic sensor signal acquired by the external device through an acoustic sensor attached onto the patient.
The method for acquiring, presenting, and using the phonocardiographic image as discussed above with reference to FIG. 8 is incorporated into the method for the phonocardiographic image-based diagnosis. At 900, the user selects a type of cardiac events based on which the acoustic sensor signal is to be segmented and the acoustic sensor signal segments are to be aligned. In one embodiment, the user selects the type of cardiac events. In another embodiment, the user selects a type of diagnosis or a particular heart sound or a particular time interval to be observed, and signal processor 350 selects the cardiac event based on the user's selection. At 905, the user selects an order for arranging the acoustic sensor signal segmnents for presentation. In one embodiment, the user selects a timing interval and/or therapy parameter associated with each acoustic sensor signal segment. This timing interval and/or therapy parameter then determines the location of each acoustic sensor signal segment in the stack of the acoustic sensor signal segments of the phonocardiographic image. In another embodiment, the user selects a type of diagnosis or a particular heart sound or a particular time interval to be observed, and signal processor 350 sorts, groups, and arranges the acoustic sensor signal segments according to a predetermined default arrangement. In one embodiment, the selections made by the user at 900 and 905 are received by user input module 342 at 814.
[0065]FIG. 10 is a flow chart illustrating one embodiment of a method for phonocardiographic image-based therapy evaluation. One of the applications of the phonocardiographic image such as phonocardiographic image 780 is to provide means for determining a suitable therapy treating a cardiac condition. In one embodiment, the phonocardiographic image provides for an overall visual presentation of results of a therapy evaluation. In one embodiment, as illustrated in FIG. 10, the therapy evaluation provides for indications of whether a therapy is effective and an approximately optimal therapy parameter.
[0072]FIG. 11 is a flow chart illustrating one embodiment of a method for phonocardiographic image-based AVD optimization. This embodiment provides for an example of the method for phonocardiographic image-based therapy evaluation discussed above with reference to FIG. 10. Other applications includes, by way of example, but not by way of limitation, determination or optimization of pacing site or sites, pacing mode, and other pacing interval or delay parameters.
[0079]FIG. 12 is an illustration of one embodiment of a method for AVD optimization for maximum ventricular contractility. One strategy optimizing hemodynamic performance with CRT is to maximize ventricular contractility. One measure of ventricular contractility is the maximum rate of ventricular pressure increase, dP/dtmax, during isovolumic contraction. Direct measurement of dP/dt requires intraventracular catheterization with a pressure transducer. On the other hand, it has been observed that the timing of certain heart sounds correlates to the strength of heart contraction. Thus, heart sound timing is capable of being a surrogate measure of relative dP/dt changes that does not require an intraventricular pressure sensor. It is believed that ventricular contractility is maximized when the onset of S1 due to pacing coincides with the intrinsic S1 to achieve the best fusion of paced and intrinsic activations.
[0080]FIG. 12 illustrates an acoustic sensor signal segment 1292A and another acoustic sensor signal segment 1292B each indicative of S1. Cardiac events A (sensed or paced atrial events) and V (sensed or paced ventricular events) are marked on both acoustic sensor signal segments. Acoustic sensor signal segment 1292A is associated with ventricular pacing at a relatively short AVD, AVDS, and including S1 S due to the pacing at AVDS. The A-S1 interval, TA-S1,S, indicates the S1 timing associated with pacing. Acoustic sensor signal segment 1292B is associated with an intrinsic ventricular contraction or ventricular pacing at a relatively long AVD, AVDL, and including S1 L, which is the intrinsic S1. The A-S1 interval, TA-S1,L, indicates the intrinsic S1 timing not affected by pacing. To achieve an approximately maximum ventricular contractility, a ventricular pacing pulse is delivered to cause approximately simultaneous paced and intrinsic activations. The approximately optimal AVD is an AVD at with the ventricular pacing minimally shortens the intrinsic A-S1 interval.
[0081]FIG. 13 is a flow chart illustrating one embodiment of a method for phonocardiographic image-based AVD optimization for maximum ventricular contractility. At 1300, an acoustic sensor signal indicative of S1 is recorded. A cardiac signal indicative of cardiac events A (sensed or paced atrial events) and V (sensed or paced ventricular events) is also recorded. Ventricular pacing pulses at a plurality of AVDs are delivered while the acoustic sensor signal and cardiac signal are recorded at 1310. In one embodiment, the pacing pulses are delivered by executing a pacing protocol that is discussed above with reference to FIG. 11. At 1320, an S1 timing trend is determined as a curve indicating the beginning of S1 relative to cardiac event A. In one embodiment, the acoustic sensor signal is presented as the phonocardiographic image, which includes acoustic sensor signal segments aligned by cardiac event A, and the S1 timing trend is observed from the phonocardiographic image. At 1330, a turning point (“knee”) is detected from the S1 timing trend. The knee represents a point at which the A-S1 interval begins to shorten as a result of pacing. In one embodiment, the S1 timing trend is a curve indicating the beginning of heart sound S1 on the stacked acoustic sensor signal segments of the phonocardiographic image. In one embodiment, heart sound detector 555 detects the leading edge of the first heart sounds and presents it on display 341. In a further embodiment, the user observes the detected leading edge of the first heart sounds to confirm its accuracy before locating the turning point. At 1340, an approximately optimal AVD is determined as the longest AVD, among the tested plurality of AVDs, at the knee. In other words, the approximately optimal AVD is the longest AVD associated with a visibly shortened A-S1 interval.
[0082]FIG. 14 is a flow chart illustrating one embodiment of another method for phonocardiographic image-based AVD optimization for maximum ventricular contractility. At 1400, an acoustic sensor signal indicative of S1 sounds is recorded. A cardiac signal indicative of atrial and ventricular electrical events is also recorded. Ventricular pacing pulses are delivered while the acoustic sensor signal and cardiac signal are recorded at 1410. The acoustic sensor signal includes indications of S1 associated with paced ventricular activation and S1 associated with intrinsic ventricular activation. S1 associated with the paced ventricular activations are observed at AVDs that are sufficient short such that the ventricular pacing visibly shortens the A-S1 interval. S1 associated with the intrinsic ventricular activations are observed when ventricular pacing is not delivered or at AVDs that are sufficiently long such that the ventricular pacing does not visibly shortens the A-S1 interval. In one embodiment, the pacing pulses are delivered by executing a pacing protocol that is discussed above with reference to FIG. 11. At 1420, an S1 associated with a paced ventricular activation, S1 S, is detected. At 1430, a short A-S1 interval, TA-S1,S, is measured between a cardiac event A and S1 S, where S1 S is adjacently subsequent to cardiac event A. At 1440, an S1 associated with an intrinsic ventricular activation, S1 L, is detected. At 1450, a long A-S1 interval, TA-S1,L, is measured between a cardiac event A and S1 L, where S1 L is adjacently subsequent to cardiac event A. In one embodiment, steps 1420-1450 are performed based on a display of acoustic sensor signal such as the phonocardiographic image. In one specific embodiment, S1 S is one of the S1 sounds observed to be associated with the shortest A-S1 interval, typically seen with the shortest AVD, and S1 L is one of the S1 sounds observed to be associated with the longest A-S1 interval, typically seen with AVI (non-paced cardiac cycles) as well as the longest AVD. In one embodiment, the user measures the A-S1 intervals on the phonocardiographic image with the electronic caliper of user input module 342. In another embodiment, signal processor 350 measures the A-S1 intervals automatically. In one embodiment, each A-S1 interval is measured between the cardiac event A and the beginning of heart sound S1. In one specific embodiment, cardiac event A is represented by an atrial event marker. At 1460, the approximately optimal AVD is determined by using a formula:
In a specific embodiment combining methods illustrated in FIG. 7 (phonocardiographic image 780), FIG. 11 (pacing protocol with AVD1-AVD5), FIG.13, and FIG. 14, S1 S is detected at AVD1, and S1 L is detected at AVD5. The user measures A-S1 intervals associated with AVD1 and AVD5. The approximately optimal AVD is determined as:
US20040106960A1 true true US20040106960A1 (en) 2004-06-03
US7123962B2 (en) 2006-10-17 grant