Source: http://www.google.com/patents/US20060129196?ie=ISO-8859-1&dq=7565338
Timestamp: 2014-07-30 02:22:13
Document Index: 2071248

Matched Legal Cases: ['art 901', 'art 901', 'art 901', 'art 901', 'art 901', 'art 901', 'art 1068']

Patent US20060129196 - Capture verification with intrinsic response discrimination - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign in<nobr>Advanced Patent Search</nobr>PatentsApproaches to automatically classifying a cardiac response to pacing involve discriminating between a captured response and non-capture with intrinsic activation. A capture detection system senses for morphological characteristics of a cardiac signal associated with the pacing pulse. The cardiac signal...http://www.google.com/patents/US20060129196?utm_source=gb-gplus-sharePatent US20060129196 - Capture verification with intrinsic response discriminationAdvanced Patent SearchPublication numberUS20060129196 A1Publication typeApplicationApplication numberUS 11/010,973Publication dateJun 15, 2006Filing dateDec 13, 2004Priority dateDec 13, 2004Also published asEP1830921A1, US7761162, WO2006065797A1Publication number010973, 11010973, US 2006/0129196 A1, US 2006/129196 A1, US 20060129196 A1, US 20060129196A1, US 2006129196 A1, US 2006129196A1, US-A1-20060129196, US-A1-2006129196, US2006/0129196A1, US2006/129196A1, US20060129196 A1, US20060129196A1, US2006129196 A1, US2006129196A1InventorsYanting Dong, Scott Meyer, Qingsheng ZhuOriginal AssigneeYanting Dong, Meyer Scott A, Qingsheng ZhuExport CitationBiBTeX, EndNote, RefManReferenced by (14), Classifications (4), Legal Events (2) External Links: USPTO, USPTO Assignment, EspacenetCapture verification with intrinsic response discriminationUS 20060129196 A1Abstract Approaches to automatically classifying a cardiac response to pacing involve discriminating between a captured response and non-capture with intrinsic activation. A capture detection system senses for morphological characteristics of a cardiac signal associated with the pacing pulse. The cardiac signal may be sensed using a defibrillation electrode during one or more time intervals following delivery of the pacing pulse. If a first characteristic of the cardiac signal achieves a threshold value, the system continues to sense the cardiac signal and detects a second characteristic. The cardiac pacing response is determined based on at least one of the first and the second cardiac signal characteristics. Images(14) Claims(34)
Where Average PK(new) is the updated average maximum peak value of a captured response signal, Average PK(old) is the previous average maximum peak value, PK is the maximum peak value of the current cardiac signal, and c is a constant. In one example, c=0.3. By way of example, the processes of the present invention may be used to enhance capture threshold testing to determine the optimal energy for pacing. Determination of the optimal pacing energy may be implemented, for example, by an automatic capture threshold testing procedure executed by an implantable cardiac rhythm management system. Additionally, automatic capture verification may be used to monitor pacing on a beat-by-beat basis. Automatic capture verification may be used to control back up pacing when a pace pulse delivered to the heart fails to evoke a captured response (CR). These and other applications may be enhanced by employment of the systems and methods of the present invention. Those skilled in the art will appreciate that reference to a capture threshold procedure indicates a method of determining the capture threshold in one of left atrium, right atrium, left ventricle, and right ventricle. In such a procedure, the pacemaker, automatically or upon command, initiates a search for the capture threshold of the selected heart chamber. The capture threshold comprises the lowest pacing energy that consistently captures the heart. In one example of an automatic capture threshold procedure, the pacemaker delivers a sequence of pacing pulses to the heart and detects the cardiac responses to the pace pulses. The energy of the pacing pulses may be decreased in discrete steps until a predetermined number of loss-of-capture events occur. A capture threshold test may be performed using cardiac response classification methods of the present invention. Other procedures for implementing capture threshold testing may be utilized. In one example, the pacing energy may be increased in discrete steps until capture is detected. In another example, the pacing energy may be adjusted according to a binomial search pattern, or other pattern. Automatic capture threshold determination is distinguishable from automatic capture detection, a procedure that may occur on a beat-by-beat basis during pacing. Automatic capture detection verifies that a delivered pace pulse results in a captured response. When a captured response is not detected following a pace pulse, the pacemaker may deliver a back up safety pace to ensure consistent pacing. The back up pace may be delivered, for example, about 70-80 ms after the initial pace pulse. The pacemaker may adjust the pacing energy if a pacing pulse does not capture the heart. If a predetermined number of pacing pulses delivered during normal pacing do not produce a captured response, the pacemaker may initiate a capture threshold test to determine the capture threshold. Automatic capture detection and back up pacing may be implemented using the cardiac response classification processes of the present invention. The embodiments of the present system are generally described herein as being implementable in an implantable cardiac defibrillator (ICD) that may operate in numerous pacing modes known in the art. Various types of single and multiple chamber implantable cardiac defibrillators are known in the art and may be used in connection with the cardiac response classification methods of the present invention. The methods of the present invention may be implemented in a variety of implantable or patient-external cardiac rhythm management devices, including single and multi-chamber pacemakers, defibrillators, cardioverters, rate adaptive pacemakers, bi-ventricular pacemakers, and cardiac resynchronizers, for example. Although the present system is described in conjunction with an implantable cardiac defibrillator having a microprocessor-based architecture, it will be understood that the implantable cardiac defibrillator (or other device) may be implemented in any logic-based integrated circuit architecture, if desired. Referring now to FIG. 9 of the drawings, there is shown a cardiac rhythm management system that may be used to implement cardiac response classification methods of the present invention. The cardiac rhythm management system in FIG. 9 includes an ICD 900 electrically and physically coupled to a lead system 902. The housing and/or header of the ICD 900 may incorporate one or more electrodes 1008, 1009 used to provide electrical stimulation energy to the heart and to sense cardiac electrical activity. The ICD 900 may utilize all or a portion of the ICD housing as a can electrode 1009. The ICD 900 may include an indifferent electrode positioned, for example, on the header or the housing of the ICD 900. If the ICD 900 includes both a can electrode 1009 and an indifferent electrode 1008, the electrodes 1008, 1009 typically are electrically isolated from each other. The lead system 902 is used to detect cardiac electrical signals produced by the heart 901 and to provide electrical energy to the heart 901 under certain predetermined conditions to treat cardiac arrhythmias. The lead system 902 may include one or more electrodes used for pacing, sensing, and/or defibrillation. In the embodiment shown in FIG. 9, the lead system 902 includes an intracardiac right ventricular (RV) lead system 904, an intracardiac right atrial (RA) lead system 905, an intracardiac left ventricular (LV) lead system 906, and an epicardiac left atrial (LA) lead system 908. The lead system 902 of FIG. 9 illustrates one embodiment that may be used in connection with the cardiac response classification methodologies described herein. Other leads and/or electrodes may additionally or alternatively be used. The lead system 902 may include intracardiac leads 904, 905, 906 implanted in a human body with portions of the intracardiac leads 904, 905, 906 inserted into a heart 901. The intracardiac leads 904, 905, 906 include various electrodes positionable within the heart for sensing electrical activity of the heart and for delivering electrical stimulation energy to the heart, for example, pacing pulses and/or defibrillation shocks to treat various arrhythmias of the heart. As illustrated in FIG. 9, the lead system 902 may include one or more epicardial leads 908 having electrodes, e.g., epicardial electrodes, positioned at locations outside the heart for sensing and pacing one or more heart chambers. The right ventricular lead system 904 illustrated in FIG. 9 includes a superior vena cava (SVC)-coil 916, a right ventricular (RV)-coil 914, an RV-ring electrode 911, and an RV-tip electrode 912. The right ventricular lead system 904 extends through the right atrium 920 and into the right ventricle 919. In particular, the RV-tip electrode 912, RV-ring electrode 911, and RV-coil electrode 914 are positioned at appropriate locations within the right ventricle 919 for sensing and delivering electrical stimulation pulses to the heart. The SVC-coil 916 is positioned at an appropriate location within the right atrium chamber 920 of the heart 901 or a major vein leading to the right atrial chamber 920 of the heart 901. In one configuration, the RV-tip electrode 912 referenced to the can electrode 1009 may be used to implement unipolar pacing and/or sensing in the right ventricle 919. Bipolar pacing and/or sensing in the right ventricle may be implemented using the RV-tip 912 and RV-ring 911 electrodes. In yet another configuration, the RV-ring 911 electrode may optionally be omitted, and bipolar pacing and/or sensing may be accomplished using the RV-tip electrode 912 and the RV-coil 914, for example. The right ventricular lead system 904 may be configured as an integrated bipolar pace/shock lead. The RV-coil 914 and the SVC-coil 916 are defibrillation electrodes. The left ventricular lead 906 includes an LV distal electrode 913 and an LV proximal electrode 917 located at appropriate locations in or about the left ventricle 924 for pacing and/or sensing the left ventricle 924. The left ventricular lead 906 may be guided into the right atrium 920 of the heart via the superior vena cava. From the right atrium 920, the left ventricular lead 906 may be deployed into the coronary sinus ostium, the opening of the coronary sinus 950. The lead 906 may be guided through the coronary sinus 950 to a coronary vein of the left ventricle 924. This vein is used as an access pathway for leads to reach the surfaces of the left ventricle 924 which are not directly accessible from the right side of the heart. Lead placement for the left ventricular lead 906 may be achieved via subclavian vein access and a preformed guiding catheter for insertion of the LV electrodes 913, 917 adjacent to the left ventricle. Unipolar pacing and/or sensing in the left ventricle may be implemented, for example, using the LV distal electrode referenced to the can electrode 1009. The LV distal electrode 913 and the LV proximal electrode 917 may be used together as bipolar sense and/or pace electrodes for the left ventricle. The left ventricular lead 906 and the right ventricular lead 904, in conjunction with the ICD 900, may be used to provide cardiac resynchronization therapy such that the ventricles of the heart are paced substantially simultaneously, or in phased sequence, to provide enhanced cardiac pumping efficiency for patients suffering from heart failure. The right atrial lead 905 includes a RA-tip electrode 956 and an RA-ring electrode 954 positioned at appropriate locations in the right atrium 920 for sensing and pacing the right atrium 920. In one configuration, the RA-tip 956 referenced to the can electrode 1009, for example, may be used to provide unipolar pacing and/or sensing in the right atrium 920. In another configuration, the RA-tip electrode 956 and the RA-ring electrode 954 may be used to effect bipolar pacing and/or sensing. FIG. 9 illustrates one embodiment of a left atrial lead system 908. In this example, the left atrial lead 908 is implemented as an epicardiac lead with LA distal 918 and LA proximal 915 electrodes positioned at appropriate locations outside the heart 901 for sensing and pacing the left atrium 922. Unipolar pacing and/or sensing of the left atrium may be accomplished, for example, using the LA distal electrode 918 to the can 1009 pacing vector. The LA proximal 915 and LA distal 918 electrodes may be used together to implement bipolar pacing and/or sensing of the left atrium 922. Referring now to FIG. 10A, there is shown an embodiment of a cardiac defibrillator 1000 suitable for implementing a cardiac response classification methodology of the present invention. FIG. 10A shows a cardiac defibrillator divided into functional blocks. It is understood by those skilled in the art that there exist many possible configurations in which these functional blocks can be arranged. The example depicted in FIG. 10A is one possible functional arrangement. Other arrangements are also possible. For example, more, fewer or different functional blocks may be used to describe a cardiac defibrillator suitable for implementing the cardiac response classification methodology of the present invention. In addition, although the cardiac defibrillator 1000 depicted in FIG. 10A contemplates the use of a programmable microprocessor-based logic circuit, other circuit implementations may be utilized. The cardiac defibrillator 1000 depicted in FIG. 10A includes circuitry for receiving cardiac signals from a heart and delivering electrical stimulation energy to the heart in the form of pacing pulses or defibrillation shocks. In one embodiment, the circuitry of the cardiac defibrillator 1000 is encased and hermetically sealed in a housing 1001 suitable for implanting in a human body. Power to the cardiac defibrillator 1000 is supplied by an electrochemical battery 1080. A connector block (not shown) is attached to the housing 1001 of the cardiac defibrillator 1000 to allow for the physical and electrical attachment of the lead system conductors to the circuitry of the cardiac defibrillator 1000. The cardiac defibrillator 1000 may be a programmable microprocessor-based system, including a control system 1020 and a memory 1070. The memory 1070 may store parameters for various pacing, defibrillation, and sensing modes, along with other parameters. Further, the memory 1070 may store data indicative of cardiac signals received by other components of the cardiac defibrillator 1000. The memory 1070 may be used, for example, for storing historical EGM and therapy data. The historical data storage may include, for example, data obtained from long term patient monitoring used for trending or other diagnostic purposes. Historical data, as well as other information, may be transmitted to an external programmer unit 290 as needed or desired. The control system 1020 and memory 1070 may cooperate with other components of the cardiac defibrillator 1000 to control the operations of the cardiac defibrillator 1000. The control system depicted in FIG. 10A incorporates a cardiac response classification processor 1025 for classifying cardiac responses to pacing stimulation in accordance with various embodiments of the present invention. The control system 1020 may include additional functional components including a pacemaker control circuit 1022, an arrhythmia detector 1021, along with other components for controlling the operations of the cardiac defibrillator 1000. If an arrhythmia is detected by the arrhythmia detector 1021, the cardiac defibrillator 1000 may respond by delivering one or more of a variety of therapies to mitigate or terminate the arrhythmia. For example, the cardiac defibrillator may deliver anti-tachycardia pacing via one or more of the pacing circuits 1041-1044, or may delivery one or more high energy shocks to the heart via the defibrillator pulse generator 1050. Telemetry circuitry 1060 may be implemented to provide communications between the cardiac defibrillator 1000 and an external programmer unit 1090. In one embodiment, the telemetry circuitry 1060 and the programmer unit 1090 communicate using a wire loop antenna and a radio frequency telemetric link, as is known in the art, to receive and transmit signals and data between the programmer unit 1090 and the telemetry circuitry 1060. In this manner, programming commands and other information may be transferred to the control system 1020 of the cardiac defibrillator 1000 from the programmer unit 1090 during and after implant. In addition, stored cardiac data pertaining to capture threshold, capture detection and/or cardiac response classification, for example, along with other data, may be transferred to the programmer unit 1090 from the cardiac defibrillator 1000. In some embodiments, a sensor 1095 may be coupled to the control system 1020 of the defibrillator 1000. The sensor 1095 may comprise, for example, a transthoracic impedance sensor capable of sensing the patient's respiration, or an accelerometer configured to sense patient activity. The output from the sensor 1095 may be employed by the control system 1020 to adaptively control the pacing rate. Rate adaptive pacing is may be used to modify the pacing rate to accommodate changes in the patient's activity level and/or hemodynamic need. In the embodiment of the cardiac defibrillator 1000 illustrated in FIG. 10A, electrodes RA-tip 956, RA-ring 954, RV-tip 912, RV-ring 911, RV-coil 914, SVC-coil 916, LV distal electrode 913, LV proximal electrode 917, LA distal electrode 918, LA proximal electrode 915, indifferent electrode 1008, and can electrode 1009 may be coupled through a switch matrix 1010 to sensing circuits 1031-1037. A right atrial sensing circuit 1031 serves to detect and amplify electrical signals from the right atrium of the heart. Bipolar sensing in the right atrium may be implemented, for example, by sensing voltages developed between the RA-tip 956 and the RA-ring 954. Unipolar sensing may be implemented, for example, by sensing voltages developed between the RA-tip 956 and the can electrode 1009. Outputs from the right atrial sensing circuit are coupled to the control system 1020. A right ventricular sensing circuit 1032 serves to detect and amplify electrical signals from the right ventricle of the heart. The right ventricular sensing circuit 1032 may include, for example, a right ventricular rate channel 1033 and a right ventricular shock channel 1034. Right ventricular cardiac signals sensed through use of the RV-tip 912 electrode are right ventricular near-field signals and are denoted RV rate channel signals. A bipolar RV rate channel signal may be sensed as a voltage developed between the RV-tip 912 and the RV-ring. Alternatively, bipolar sensing in the right ventricle may be implemented using the RV-tip electrode 912 and the RV-coil 914. Unipolar rate channel sensing in the right ventricle may be implemented, for example, by sensing voltages developed between the RV-tip 912 and the can electrode 1009. Right ventricular cardiac signals sensed through use of the defibrillation electrodes 914, 916 are far-field signals, also referred to as RV morphology or RV shock channel signals. More particularly, a right ventricular shock channel signal may be detected as a voltage developed between the RV-coil 914 and the SVC-coil 916. A right ventricular shock channel signal may also be detected as a voltage developed between the RV-coil 914 and the can electrode 1009. In another configuration the can electrode 1009 and the SVC-coil electrode 916 may be electrically shorted and a RV shock channel signal may be detected as the voltage developed between the RV-coil 914 and the can electrode 1009/SVC-coil 916 combination. Outputs from the right ventricular sensing circuit 1032 are coupled to the control system 1020. Left atrial cardiac signals may be sensed through the use of one or more left atrial electrodes 915, 918, which may be configured as epicardial electrodes. A left atrial sensing circuit 1035 serves to detect and amplify electrical signals from the left atrium of the heart. Bipolar sensing and/or pacing in the left atrium may be implemented, for example, using the LA distal electrode 918 and the LA proximal electrode 915. Unipolar sensing and/or pacing of the left atrium may be accomplished, for example, using the LA distal electrode 118 to can vector 1009 or the LA proximal electrode 915 to can vector 1009. A left ventricular sensing circuit 1036 serves to detect and amplify electrical signals from the left ventricle of the heart. Bipolar sensing in the left ventricle may be implemented, for example, by sensing voltages developed between the LV distal electrode 913 and the LV proximal electrode 917. Unipolar sensing may be implemented, for example, by sensing voltages developed between the LV distal electrode 913 or the LV proximal electrode 917 to the can electrode 1009. Optionally, an LV coil electrode (not shown) may be inserted into the patient's cardiac vasculature, e.g., the coronary sinus, adjacent the left heart. Signals detected using combinations of the LV electrodes, 913, 917, LV coil electrode (not shown), and/or can electrodes 1009 may be sensed and amplified by the left ventricular sensing circuitry 1036. The output of the left ventricular sensing circuit 1036 is coupled to the control system 1020. The outputs of the switching matrix 1010 may be operated to couple selected combinations of electrodes 911, 912, 913, 914, 915, 916, 917, 918, 956, 954, 1008, 1009 to an evoked response sensing circuit 1037. The evoked response sensing circuit 1037 serves to sense and amplify voltages developed using various combinations of electrodes for cardiac response classification in accordance with embodiments of the invention. Various combinations of pacing and sensing electrodes may be utilized in connection with pacing and sensing the cardiac signal following the pace pulse to classify the cardiac response to the pacing pulse. In embodiments described herein, the RV-tip 912 to RV-coil 914 sensing vector, the RV-ring 911 to RV-coil 914 sensing vector, the LV distal electrode 913 to LV coil electrode sensing vector, the LV proximal electrode 917 to LV coil electrode sensing vector, the RA-tip 956 to SVC-coil 916 sensing vector, the RA-ring 954 to SVC-coil 916 sensing vector, the LA distal electrode 918 to LA coil electrode sensing vector (not shown), or the LA proximal electrode 915 to LA coil electrode sensing vector, is used for discriminating non-capture, capture, and non-captured intrinsic beats. Sensing the cardiac signal following a pacing pulse using the same electrode combination for both pacing and sensing may yield a sensed cardiac signal including a pacing artifact component associated with residual post pace polarization at the electrode-tissue interface. The pacing artifact component may be superimposed on a smaller signal indicative of the cardiac response to the pacing pulse, i.e., the evoked response. The pacing output circuitry may include a coupling capacitor to block DC components from the heart and to condition the pacing stimulus pulse. A relatively large coupling capacitor may cause a larger pacing artifact that decays exponentially over a relatively long period of time. The presence of a large pacing artifact signal may complicate the classification of the cardiac response to pacing. Various embodiments of the invention are directed to methods involving detection of a cardiac signal following pacing and canceling the pacing artifact from the detected signal. Classification of the cardiac response to pacing is implemented using the pacing artifact cancelled signal. Cancellation of the pacing artifact in cardiac response classification is particularly important when the same or similar electrode combinations are used both for delivering pacing pulses and for sensing the cardiac signals following the delivery of the pacing pulses. Cancellation of the pacing artifact may also be used when a first electrode combination is used for pacing the heart chamber and a different electrode combination is used to sense the subsequent cardiac response. Cancellation of pacing artifacts, aspects of which may be utilized in the capture detection approaches of embodiments described herein, are discussed in commonly owned U.S. patent application Ser. No. 10/335,534, filed on Dec. 31, 2002, which is incorporated herein by reference. The pacemaker control circuit 1022, in combination with pacing circuitry for the left atrium, right atrium, left ventricle, and right ventricle 1041, 1042, 1043, 1044, may be implemented to selectively generate and deliver pacing pulses to the heart using various electrode combinations. The pacing electrode combinations may be used to effect bipolar or unipolar pacing of the heart chambers as described above. As described above, bipolar or unipolar pacing pulses may be delivered to a heart chamber using one of the pacing vectors as described above. The cardiac signal following the pacing pulse may be sensed using the same vector or a different vector than that used for delivery of the pacing pulse. In a preferred embodiment, a pacing pulse is delivered to the right ventricle using the RV-tip to RV-ring vector. The cardiac signal following and associated with the pacing pulse is sensed using the RV-tip to RV-coil sensing vector. In this scenario, with a suitable blanking period, the pacing artifact has dissipated substantially from the sensed cardiac signal leaving sufficient signal to determine the cardiac response to the pacing pulse. Alternatively, the pacing artifact cancellation techniques described in commonly owned U.S. patent application Ser. No. 10/335,534 may be utilized to reduce the effect of the pacing artifact. The cardiac response classification processor 1025 includes circuitry for determining the cardiac response to the pacing pulse. In a preferred embodiment, sensing in the right ventricle is accomplished using the RV-tip 912 and RV-coil 914 electrodes. The cardiac response classification processor 1025 is primarily responsible for implementing the cardiac response classification methodologies described above. Using the above-described processes, the cardiac response classification processor 1025 may classify the cardiac response to pacing as one of a non-captured response, a captured response and a non-captured response and an intrinsic beat as previously described. Cardiac response classification may be accomplished, for example, using multiple classification intervals defined following delivery of the pacing pulse as described in greater detail herein. FIGS. 10B and 10C illustrate more detailed examples of pacing and sensing circuitry, respectively, that may be used for cardiac pace/sense channels of a pacemaker in accordance with embodiments of the invention. In example embodiments of the invention, the pacing circuit of FIG. 10B includes a power supply or battery 1061, a first switch 1062, a second switch 1064, a pacing charge storage capacitor 1063, coupling capacitor 1065, and a pacer capacitor charging circuit 1069 all of which are cooperatively operable under the direction of a controller of known suitable construction. The power supply or battery 1061 is preferably the battery provided to power the pacemaker and may comprise any number of commercially available batteries suitable for pacing applications. The switches 1062, 1064 may be implemented using any number of conventionally available switches. The pacing capacitor charging circuit 1069 includes circuitry to regulate the voltage across the pacing charge storage capacitor 1063. The pacing charge storage capacitor 1063 may also comprise any number of conventional storage capacitors that can be used to develop a sufficient pacing charge for stimulating the heart. The primary function of the coupling capacitor 1065 is to block any DC signal from reaching the heart during pacing and additionally to attenuate the polarization voltage or �afterpotential� that results from pacing. The coupling capacitor 1065 may have a capacitance, for example, in the range of about 2 microfarads to about 22 microfarads. Energy stored in the pacing charge storage capacitor 1063 may be delivered to the heart 1068 using various combinations of cardiac electrodes 1066, 1067, as described above. FIG. 10C illustrates a block diagram of circuit 1099 that may be used to sense cardiac signals following the delivery of a pacing stimulation and classify the cardiac response to the pacing stimulation according to embodiments of the invention. A switch matrix 1084 is used to couple the cardiac electrodes 1071, 1072 in various combinations discussed above to the sensing portion 1070 of the cardiac response classification circuit 1095. The sensing portion 1070 includes filtering and blanking circuitry 1075, 1077, sense amplifier 1085, band pass filter 1081, and analog to digital converter 1082. The analog to digital converter 1082 is coupled to a cardiac response classification processor 1083. A control system, e.g., the control system 1020 depicted in FIG. 10A, is operatively coupled to components of the cardiac response classification circuit 1025 and controls the operation of the cardiac response classification circuit 1025, including the filtering and blanking circuits 1075, 1077. Following a blanking period of sufficient duration following delivery of the pacing stimulation, the blanking circuitry 1075, 1077 operates to allow detection of a cardiac signal responsive to the pacing stimulation. The cardiac signal is filtered, amplified, and converted from analog to digital form. The digitized signal is communicated to the cardiac response classification processor 1025 which operates to classify cardiac responses to pacing according to the methodologies presented in embodiments of the invention described herein. Various modifications and additions can be made to the preferred embodiments discussed hereinabove without departing from the scope of the present invention. Accordingly, the scope of the present invention should not be limited by the particular embodiments described above, but should be defined only by the claims set forth below and equivalents thereof. Referenced byCiting PatentFiling datePublication dateApplicantTitleUS7499751 *Apr 28, 2005Mar 3, 2009Cardiac Pacemakers, Inc.Cardiac signal template generation using waveform clusteringUS7574260Apr 28, 2005Aug 11, 2009Cardiac Pacemakers, Inc.Adaptive windowing for cardiac waveform discriminationUS7711424Feb 14, 2008May 4, 2010Cardiac Pacemakers, Inc.Selection of cardiac signal features detected in multiple classification intervals for cardiac pacing response classificationUS7794404Nov 13, 2006Sep 14, 2010Pacesetter, IncSystem and method for estimating cardiac pressure using parameters derived from impedance signals detected by an implantable medical deviceUS7925349Mar 12, 2007Apr 12, 2011Pacesetter, Inc.Tissue characterization using intracardiac impedances with an implantable lead systemUS7945326Mar 12, 2007May 17, 2011Pacesetter, Inc.Tissue characterization using intracardiac impedances with an implantable lead systemUS7979113May 5, 2009Jul 12, 2011Cardiac Pacemakers, Inc.Multi channel approach to capture verificationUS8010196Mar 12, 2007Aug 30, 2011Pacesetter, Inc.Tissue characterization using intracardiac impedances with an implantable lead systemUS8065005Mar 12, 2007Nov 22, 2011Pacesetter, Inc.Tissue characterization using intracardiac impedances with an implantable lead systemUS8116870Jun 23, 2008Feb 14, 2012Cardiac Pacemakers, Inc.Capture detection for multi-chamber pacingUS8145296Aug 10, 2009Mar 27, 2012Cardiac Pacemakers, Inc.Adaptive windowing for cardiac waveform discriminationUS8306623May 31, 2011Nov 6, 2012Pacesetter, Inc.Tissue characterization using intracardiac impedances with an implantable lead systemUS8600497 *Nov 9, 2006Dec 3, 2013Pacesetter, Inc.Systems and methods to monitor and treat heart failure conditionsUS8712519Nov 9, 2006Apr 29, 2014Pacesetter, Inc.Closed-loop adaptive adjustment of pacing therapy based on cardiogenic impedance signals detected by an implantable medical device* Cited by examinerClassifications U.S. Classification607/28International ClassificationA61N1/365Cooperative ClassificationA61N1/3712European ClassificationA61N1/37D2Legal EventsDateCodeEventDescriptionDec 27, 2013FPAYFee paymentYear of fee payment: 4Feb 15, 2005ASAssignmentOwner name: CARDIAC PACEMAKERS, INC., MINNESOTAFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:DONG, YANTING;MEYER, SCOTT A.;ZHU, QINGSHENG;REEL/FRAME:015720/0401;SIGNING DATES FROM 20041129 TO 20041202Owner name: CARDIAC PACEMAKERS, INC.,MINNESOTAFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:DONG, YANTING;MEYER, SCOTT A.;ZHU, QINGSHENG;SIGNED BETWEEN 20041129 AND 20041202;REEL/FRAME:15720/401Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:DONG, YANTING;MEYER, SCOTT A.;ZHU, QINGSHENG;SIGNING DATES FROM 20041129 TO 20041202;REEL/FRAME:015720/0401RotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services©2012 Google