Source: http://www.google.es/patents/US20020016550
Timestamp: 2017-10-21 10:51:16
Document Index: 470241843

Matched Legal Cases: ['art 115', 'art 115', 'art 115', 'art 115', 'art 115', 'art 115', 'art 115', 'art 115']

Patente US20020016550 - Cardiac rhythm management system with arrhythmia prediction and prevention - Google Patentes
A cardiac rhythm management system predicts when an arrhythmia will occur and in one embodiment invokes a therapy to prevent or reduce the consequences of the arrhythmia. A cardiac arrhythmia trigger/marker is detected from a patient, and based on the trigger/marker, the system estimates a probability...http://www.google.es/patents/US20020016550?utm_source=gb-gplus-sharePatente US20020016550 - Cardiac rhythm management system with arrhythmia prediction and prevention
Número de publicación US20020016550 A1
Número de solicitud US 09/850,537
También publicado como DE60012951D1, DE60012951T2, EP1218060A1, EP1218060B1, US6272377, US6400982, US7050846, US20010020136, WO2001024876A1
Número de publicación 09850537, 850537, US 2002/0016550 A1, US 2002/016550 A1, US 20020016550 A1, US 20020016550A1, US 2002016550 A1, US 2002016550A1, US-A1-20020016550, US-A1-2002016550, US2002/0016550A1, US2002/016550A1, US20020016550 A1, US20020016550A1, US2002016550 A1, US2002016550A1
Citas de patentes (64), Citada por (113), Clasificaciones (6), Eventos legales (2)
US 20020016550 A1
[0037]FIG. 1 is a schematic drawing illustrating generally, by way of example, but not by way of limitation, one embodiment of portions of a cardiac rhythm management system 100 and an environment in which it is used. In FIG. 1, system 100 includes an implantable cardiac rhythm management device 105, also referred to as an electronics unit, which is coupled by an intravascular endocardial lead 110, or other lead, to a heart 115 of patient 120. System 100 also includes an external programmer 125 providing wireless communication with device 105 using a telemetry device 130. In one embodiment, external programmer 125 includes a visual or other display for providing information to a user regarding operation of implanted device 105. Catheter lead 110 includes a proximal end 135, which is coupled to device 105, and a distal end 140, which is coupled to one or more portions of heart 115.
[0038]FIG. 2 is a schematic drawing illustrating generally, by way of example, but not by way of limitation, one embodiment of device 105 coupled by leads 110A-C to heart 115, which includes a right atrium 200A, a left atrium 200B, a right ventricle 205A, a left ventricle 205B, and a coronary sinus 220 extending from right atrium 200A. In this embodiment, atrial lead 110A includes electrodes (electrical contacts) disposed in, around, or near an atrium 200 of heart 115, such as ring electrode 225 and tip electrode 230, for sensing signals and/or delivering pacing therapy to the atrium 200. Lead 110A optionally also includes additional electrodes, such as for delivering atrial and/or ventricular cardioversion/defibrillation and/or pacing therapy to heart 115.
[0041]FIG. 3 is a schematic diagram illustrating generally, by way of example, but not by way of limitation, one embodiment of portions of device 105, which is coupled to heart 115 and/or other portions of the patient's body. FIG. 3 illustrates one conceptualization of various modules, which are implemented either in hardware or as one or more sequences of steps carried out on a microprocessor or other controller. Such modules are illustrated separately for conceptual clarity; it is understood that the various modules of FIG. 3 need not be separately embodied, but may be combined and/or otherwise implemented, such as in software/firmware. In FIG. 3, device 105 includes, among other things, a power source 300, such as a battery. A communication module 305 includes a telemetry or other circuit by which implantable device 105 communicates with external programmer 125. A sensing module 310 senses intrinsic heart activity signals from one or more electrodes associated with heart 115. In one embodiment, sensing module 310 also senses other electrophysiological signals. A therapy module 315 provides therapy for treatment of present arrhythmias and prevention of future arrhythmias. In one embodiment, such therapy is provided at electrodes associated with heart 115 or portions of the nervous system such as, for example but without limitation, to sense other electrophysiological signals such as activity from sympathetic or parasympathetic members of the autonomic nervous system, or to sense blood temperature or blood flow. In various embodiments such therapy includes, among other things, pacing pulses, anti-tachyarrhythmia pacing (ATP), defibrillation shocks, etc.
[0046]FIG. 4A is a block diagram illustrating generally, by way of example, but not by way of limitation, one conceptual embodiment of portions of trigger/marker module 345. In this embodiment, trigger/marker module 345 includes beat classification module 400, detection processing module 405, and a trigger/marker data bank such as trigger/marker list 410. Trigger/marker module 345 recurrently examines signals from sensing module 310 and/or sensing module 320 and detects the presence, timing, and (if appropriate) magnitude of triggers/markers. These detections, timings, and magnitudes are output to detection processing module 405 either for each heartbeat, or corresponding to a time period encompassing multiple heartbeats.
[0060]FIG. 5 is a timing diagram illustrating generally, by way of example, but not by way of limitation, a heart rate variability trigger/marker, D1, which is updated using a 5 minute observation period. In this example, D1=1 during time periods 500 when heart rate variability is below its detection threshold and D1=0 during other time periods 505 when heart rate variability is above its detection threshold. FIG. 5 also depicts a “long-short sequence” trigger, D2, which is updated at 2 minute intervals. In this example, D2=1 during time periods 510 when the long-short sequence has been detected in the preceding 2 minute observation period, and D2=0 at other times. In this way, particular trigger/marker detection values are updated independently of other trigger/marker detection values in the set of trigger/marker detection values, D, as sufficient data for making the particular trigger/marker detection becomes available.
[0067]FIG. 6 is a block diagram illustrating generally, by way of example, but not by way of limitation, one conceptual embodiment of portions of arrhythmia prediction module 350. In one embodiment, arrhythmia prediction module 350 includes an arrhythmia probability calculation module 600, a conditional probability data bank such as a list of conditional probabilities 605, trigger/marker use data bank such as trigger/marker use list 610. In a further embodiment, arrhythmia prediction module 350 also includes an adaptive processing module 615. In one embodiment, conditional probability list 605 and trigger/marker use list 610 each have members corresponding to the members of trigger/marker list 410, as explained below.
For example, consider the Ith trigger/marker of trigger/marker list 410. In one embodiment, the detection value D1 is either one or zero depending on the respective presence or absence of this trigger/marker during the basic time period equal to T. Further, consider that the rate of arrhythmias R1 associated with this trigger/marker is zero when the trigger/marker is absent and that the rate R1 has a nonzero value when the trigger/marker is present. The contribution of the Ith trigger/marker to the arrhythmia probability is D1 (1−e−RT), or simply D1×C1 where CP1 is the conditional probability for the arrhythmia given that D1 is present. The total probability for an arrhythmia, P, which includes the contributions from all trigger/markers, is computed as P=D1CP1+D2×CP2+D3×CP3+. . . +DN×CPN, for the case where there is a detection value and a conditional probability for each member of the trigger/marker list 410.
A statistical test determines whether the observed occurrences of #D+A+, #D+A−, #D−A+, and #D−A− are different from those that would be expected if the trigger/marker did not have predictive power. One example such test computes the following sum: Sum =  [ #  D +  A + - #  A + × #  D + / #  BTP ] 2 #  A + × #  D + ÷ #  BTP +  [ #  D +  A - - #  A - × #  D + / #  BTP ] 2 #  A - × #  D + ≡ #  BTP +  [ #  D -  A + - #  A + × #  D - / #  BTP ] 2 #  A + × #  D - / #  BTP +  [ #  D -  A - - #  A - × #  D - / #  BTP ] 2 #  A - × #  D - ≡ #  BTP
For patient-specific adaptive processing, the ratios (R+ P=# D+A+÷#D+) and (R− P=# D−A+÷# D−) from the population database (hence the P subscripts) are used to compute the following sum: Sum =  [ #  D +  A + - R p + × #  D + ] 2 R p + × #  D + +  [ #  D +  A - - ( 1 - R p + ) × #  D + ] 2 ( 1 - R p + ) · #  D + +  [ #  D -  A + - R p - × #  D - ] 2 R p - × #  D - +  [ #  D -  A - - ( 1 - R p - ) × #  D - ] 2 ( 1 - R p - ) × #  D -
If the initial value for CP1 is also correct for the particular patient, then after observing # D1 + BTP's with trigger/marker I, one would expect (# D1 +×CP1) cases where an arrhythmia was found. More or fewer arrhythmias may result from chance alone. The standard deviation for the number of expected arrhythmias is {# D1 +×CP1 (1−CP1)}½. A 95% confidence interval would include about 1.96 times this standard deviation above and below the expected values. Thus, if the initially entered values for CP1 were also valid for this particular patient, then there exists a 95% confidence that the number of arrhythmias observed after # D1 + occurrences of trigger/markerIis between [# D1 +×CP1−1.96 {# D1 +×CP1×(1−CP1)}½] and [# D1 +×CP1+1.96 {# D1 +×CP1×(1−CP1)}½]. Expressed as percentages of # D1 + this yields the following confidence interval for the conditional probability: [CP1−1.96×{CP1×(1−CP1)/# D1 +}½] and [CP1 +1.96×{CP1×(1−CP1)/# D1 +}½].
If the patient's true conditional probability equals CP,, then the ratio of BTP's with arrhythmias absent to those with arrhythmias present should equal (1−CP1)/CP1. For a conditional probability of 20%, for example, an average of 4 BTPs without arrhythmias are expected for each BTP with an arrhythmia. In this case, the conditional probability is decreased 4 times by a small amount (0.2× STEP) but increased 1 time by a large amount (0.8× STEP), yielding no net drift in the CP, over time. If the patient's actual conditional probability was significantly higher than CP1, then there would be a higher proportion of BTP's with an arrhythmia. As a result, CP1 would tend to increase until CP1 approached the correct value. Similarly, if the actual value was too low, CP1 would decrease until it approached the correct value. In one embodiment, the selection of STEP is small (0.05) such that these changes are stable over time.
This alternate embodiment also provides a different technique of trigger/marker detection. Instead of setting the detection value, D1, to either zero or one, the trigger/marker detection processing module 405 sets the detection value D1 to the number of times the Ith trigger/marker occurred during the BTP. The arrhythmia probability calculation is computed as P=D1×P1,D1+D2×CP2,D2+D3×CP3,D3+. . . +DN×CPN,DN, where CPI,K is the conditional probability when trigger/marker I is present K times during the BTP, and N is the number of triggers/markers.
[0102]FIG. 7 is a block diagram illustrating generally, by way of example, but not by way of limitation, one conceptual embodiment of portions of preventive therapy control module 355. In this embodiment, prediction scheduler 700 schedules predictions of future arrhythmias. Preventive therapy decision module 705 decides whether arrhythmia prevention therapy is warranted. Preventive therapy selection module 710 selects one or more appropriate prevention therapies. Prevention activation module 715 activates the selected arrhythmia prevention therapy. Preventive therapy control module 355 also includes a prevention therapy list 720, and a trigger/marker vs. preventive therapy translation matrix 725 that relates the prevention therapies of preventive therapy list 720 to the triggers/markers used by arrhythmia prediction module 350 in predicting future arrhythmias. The various submodules in therapy control module 355 are illustrated as such for conceptual purposes only; alternatively, these submodules may be understood as being incorporated in arrhythmia prediction module 350 or elsewhere.
[0111]FIG. 8 is a diagram illustrating generally, by way of example, but not by way of limitation, one embodiment of a translation matrix 725. In this embodiment, rows of translation matrix 725 correspond to the members of trigger/marker list 410. Columns of translation matrix 725 correspond to the members of preventive therapy list 720. In one embodiment, the cells in translation matrix 725 are set to either “Use,” “Do Not Use,” or “Don't Care.” A “Use” entry indicates that the corresponding preventive therapy is expected to provide a beneficial effect to reduce the risk of the arrhythmia when the associated trigger/marker is present. A “Do Not Use” entry indicates that the corresponding preventive therapy is expected to result in a detrimental effect that may increase the risk of arrhythmia when the associated trigger/marker is present. The “Don't Care,” entry indicates that the corresponding preventive therapy is expected to neither increase or decrease the risk of arrhythmia when the associated trigger/marker is present.
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Clasificación cooperativa G06F19/3431, A61N1/3622