Abstract: Thousands of patients prone to irregular and sometimes life threatening heart rhythms have miniature heart-monitoring devices, such as defibrillators and cardioverters, implanted in their chests. These devices detect abnormal heart rhythms and automatically apply electrical therapy to restore normal heart function. Significant parts of these devices include the microprocessor and stored instructions, or algorithms, that govern how the devices interpret and react to electrical signals indicative of normal or abnormal heart rhythms. These algorithms generally use the time intervals between successive heart beats, or cardiac events, as a key factor in therapy decisions. To ensure accuracy of interval measurements, the inventor devised new methods for processing heart electrical signals, some of which ensure accurate interval measurements without unduly delaying therapy decisions or consuming significant battery power.

Abstract: A system and method for providing pacing pulses after a cardioversion/defibrillation shock, where the pacing pulses have a pacing rate at an initial value. The pacing rate is decreased from the initial value until at least one intrinsic cardiac contraction is detected. In one embodiment, the pacing rate is decreased by a set amount after pacing a set number of cardiac cycles. Providing the set number of pacing pulses and decreasing the pacing rate by the set amount is then repeated until at least one intrinsic cardiac contraction is detected. An intrinsic cardiac rate is then determined from the at least one intrinsic cardiac contraction. The pacing rate is then increased and maintained to be above (i.e., greater than) the intrinsic cardiac rate.

Abstract: Miniature heart-monitoring devices, such as defibrillators and cardioverters, are implanted in humans to detect and correct abnormal heart rhythms Microprocessors and stored instructions, or algorithms, within these devices govern how they interpret and react to abnormal heart rhythms. Algorithms that are too simple lead to unnecessary shocking of the heart, while those that are too complex consume considerable battery power. Accordingly, the inventor devised a relatively simple yet accurate algorithm for determining appropriate therapy options. One version of the algorithm computes three statistics—a range statistic, a minimum interval statistic, and a dispersion index—from a set of depolarization intervals. A scalar interval dispersion assessment,based on the three statistics, is then compared to a threshold to identify a rhythm as a flutter or fibrillation.

Abstract: An implantable heart-monitoring device designed to distinguish two differing heart rhythms. The device comprises electrodes, a template, and first, second and third electronic mechanisms. The first electronic mechanism converts electrical representations of heartbeats from the electrodes into digital data and performs calculations including at least a partial discrete wavelet transform upon the digital data to generate a subset of discrete wavelet transform components including components for distinguishing the two differing heart rhythms and also demonstrated to be relatively low in variability from one patient to another. The template contains a corresponding subset of discrete wavelet transform components captured from at least one individual whose heart was beating in accordance with one of the two differing heart rhythms. The second electronic mechanism correlates the subset of transform components against the template components and provides a correlation value.

Abstract: An ablation catheter stores a platelet inhibitor substance within a plurality of pockets or recesses of its shaft. The substance is adapted to elute upon contact with biological fluid. In the pocket configuration, the platelet inhibitor substance is in a capsule positioned within the pocket. In the recess configuration, the platelet inhibitor substance is in a hydrogel or silicone-based porous/semi-porous matrix positioned within the recess. Elution of the platelet inhibitor substance prevents or at least substantially minimizes the adhesion of blood platelets on the catheter surface during ablation. In another configuration, the catheter includes an internal lumen network having apertures terminating at the surface of the shaft. The lumen communicates with a source of platelet inhibitor fluid that is forced through the lumen by a variable pump.

Abstract: An apparatus for delivering energy to a biological site includes a catheter having an ablation electrode and a plurality of backplates distributed at various locations proximal the biological site. The backplates are coupled to a switching device for selecting which backplate to utilize as a return electrode to complete the circuit with the ablation electrode in order to obtain deeper, larger lesions for a given amount of energy. The backplate selection is made by determining which return electrode most closely places the biological site between the ablation electrode and the backplate. Backplate selection may be made automatically based on impedance measurements or conduction time measurements. Alternatively, the backplate selection can be made manually.

Abstract: Methods, systems and computer program products for selecting a shock profile for a defibrillator based on patient discomfort to a plurality of different defibrillating shocks include delivering a first defibrillating shock having an associated first shock profile to a patient, and measuring the associated physical displacement of a selected region in the patient. A second defibrillating shock having an associated second shock profile is delivered to the patient, and the associated physical displacement of the selected region in measured. One of the first or second shock profiles is selected based on which shock profile has the lesser amount of measured physical displacement.

Abstract: An apparatus and method for delivering electrical shock therapy in order to treat atrial tachyarrhythmias such as fibrillation is disclosed. In accordance with the method, atrial defibrillation shocks are delivered synchronously with an R wave if the current R-R interval meets one or more safety criteria so as to be considered shockable. A shockable R-R interval may be defined as one that exceeds the previous QT interval by a specified therapy margin. In one embodiment, the previous QT interval is estimated based upon the measured preceding R-R interval.

Abstract: Thousands of patients prone to irregular and sometimes life threatening heart rhythms have miniature heart-monitoring devices, such as defibrillators and cardioverters, implanted in their chests. These devices detect onset of abnormal heart rhythms and automatically apply one or more shocks to their hearts. When properly sized and timed, the shocks restore normal heart function without human intervention. A critical part of these devices is the monitoring circuitry, which includes a microprocessor and stored instructions, or algorithms, that govern how the devices interpret and react to electrical signals indicative of abnormal heart rhythms. Often, the algorithms are too simple or too complex. Algorithms that are too simple lead to unnecessary shocking of the heart, while those that are too complex consume considerable battery power. Accordingly, the inventor devised a relatively simple and accurate algorithm for determining appropriate therapy options.

Abstract: Information indicative of the flow rate of fluid through a biological organ is provided to a processor. Using this information the processor assesses whether the fluid-flow rate is high or low and controls a generator such that the generator provides energy to an electrode positioned within the organ to effect tissue ablation. Energy of a first level is provided during periods of high fluid-flow and energy of a second level, less than the first level, during periods of low fluid-flow. The flow rate information may be provided by an electrocardiograph (ECG) device or a flow sensor. A temperature sensor provides temperature signals to the processor indicative of the electrode temperature. The processor further controls the generator based on the electrode temperature to maintain the temperature at or near a target temperature and below a maximum threshold temperature.

Abstract: An ablation catheter stores a platelet inhibitor substance within a plurality of pockets or recesses of its shaft. The substance is adapted to elute upon contact with biological fluid. In the pocket configuration, the platelet inhibitor substance is in a capsule positioned within the pocket. In the recess configuration, the platelet inhibitor substance is in a hydrogel or silicone-based porous/semi-porous matrix positioned within the recess. Elution of the platelet inhibitor substance prevents or at least substantially minimizes the adhesion of blood platelets on the catheter surface during ablation. In another configuration, the catheter includes an internal lumen network having apertures terminating at the surface of the shaft. The lumen communicates with a source of platelet inhibitor fluid that is forced through the lumen by a variable pump.

Abstract: Thousands of patients prone to irregular and sometimes life threatening heart rhythms have miniature heart-monitoring devices, such as defibrillators and cardioverters, implanted in their chests. These devices detect abnormal heart rhythms and automatically apply electrical therapy to restore normal heart function. Significant parts of these devices include the microprocessor and stored instructions, or algorithms, that govern how the devices interpret and react to electrical signals indicative of normal or abnormal heart rhythms. These algorithms generally use the time intervals between successive heart beats, or cardiac events, as a key factor in therapy decisions. To ensure accuracy of interval measurements, the inventor devised new methods for processing heart electrical signals, some of which ensure accurate interval measurements without unduly delaying therapy decisions or consuming significant battery power.

Abstract: An apparatus and method for delivering electrical shock therapy in order to treat atrial tachyarrhythmias such as fibrillation is disclosed. In accordance with the method, atrial defibrillation shocks are delivered synchronously with an R wave if the current R-R interval meets one or more safety criteria so as to be considered shockable. A shockable R-R interval may be defined as one that exceeds the previous QT interval by a specified therapy margin. In one embodiment, the previous QT interval is estimated based upon the measured preceding R-R interval.

Abstract: An apparatus for delivering energy to a biological site includes a catheter having an ablation electrode and a plurality of backplates distributed at various locations proximal the biological site. The backplates are coupled to a switching device for selecting which backplate to utilize as a return electrode to complete the circuit with the ablation electrode in order to obtain deeper, larger lesions for a given amount of energy. The backplate selection is made by determining which return electrode most closely places the biological site between the ablation electrode and the backplate. Backplate selection may be made automatically based on impedance measurements or conduction time measurements. Alternatively, the backplate selection can be made manually.

Abstract: An apparatus and method for delivering electrical shock therapy in order to treat atrial tachyarrhythmias such as fibrillation is disclosed. In accordance with the method, atrial defibrillation shocks are delivered synchronously with an R wave if the current R-R interval meets one or more safety criteria so as to be considered shockable. A shockable R-R interval may be defined as one that exceeds the previous QT interval by a specified therapy margin. In one embodiment, the previous QT interval is estimated based upon the measured preceding R-R interval.

Abstract: Information indicative of the flow rate of fluid through a biological organ is provided to a processor. Using this information the processor assesses whether the fluid-flow rate is high or low and controls a generator such that the generator provides energy to an electrode positioned within the organ to effect tissue ablation. Energy of a first level is provided during periods of high fluid-flow and energy of a second level, less than the first level, during periods of low fluid-flow. The flow rate information may be provided by an electrocardiograph (ECG) device or a flow sensor. A temperature sensor provides temperature signals to the processor indicative of the electrode temperature. The processor further controls the generator based on the electrode temperature to maintain the temperature at or near a target temperature and below a maximum threshold temperature.

Abstract: Thousands of patients prone to irregular and sometimes life threatening heart rhythms have miniature heart-monitoring devices, such as defibrillators and cardioverters, implanted in their chests. These devices detect abnormal heart rhythms and automatically apply electrical therapy to restore normal heart function. Significant parts of these devices include the microprocessor and stored instructions, or algorithms, that govern how the devices interpret and react to electrical signals indicative of normal or abnormal heart rhythms. These algorithms generally use the time intervals between successive heart beats, or cardiac events, as a key factor in therapy decisions. To ensure accuracy of interval measurements, the inventor devised new methods for processing heart electrical signals, some of which ensure accurate interval measurements without unduly delaying therapy decisions or consuming significant battery power.

Abstract: Thousands of patients prone to irregular and sometimes life threatening heart rhythms have miniature heart-monitoring devices, such as defibrillators and cardioverters, implanted in their chests. These devices detect onset of abnormal heart rhythms and automatically apply one or more shocks to their hearts. When properly sized and timed, the shocks restore normal heart function without human intervention. A critical part of these devices is the monitoring circuitry, which includes a microprocessor and stored instructions, or algorithms, that govern how the devices interpret and react to electrical signals indicative of abnormal heart rhythms. Often, the algorithms are too simple or too complex. Algorithms that are too simple lead to unnecessary shocking of the heart, while those that are too complex consume considerable battery power. Accordingly, the inventor devised a relatively simple and accurate algorithm for determining appropriate therapy options.

Abstract: Thousands of patients prone to irregular and sometimes life threatening heart rhythms have miniature heart-monitoring devices, such as defibrillators and cardioverters, implanted in their chests. These devices detect onset of abnormal heart rhythms and automatically apply one or more shocks to their hearts. When properly sized and timed, the shocks restore normal heart function without human intervention. A critical part of these devices is the monitoring circuitry, which includes a microprocessor and stored instructions, or algorithms, that govern how the devices interpret and react to electrical signals indicative of abnormal heart rhythms. Often, the algorithms are too simple or too complex. Algorithms that are too simple lead to unnecessary shocking of the heart, while those that are too complex consume considerable battery power. Accordingly, the inventor devised a relatively simple and accurate algorithm for determining appropriate therapy options.

Abstract: A pattern recognition system for use in an implantable cardioverter defibrillator that is capable of responding correctively to abnormal activity of the heart efficiently and specifically. The system of the present invention first establishes a template standard defining a median or other statistical measure of central tendency representing the point above which or below which actual sample values would be remarkable. Against the median are compared sampled values within a window having a pre-programmed length. For each cycle, a comparison is made between the template median and every value sampled within this pre-programmed window. Each cycle is then individually diagnosed such that if a selected value is above a particular pre-established threshold or below a particular pre-established threshold it will be classified as abnormal. A plurality of specific cycles must be classified abnormal in order for a final diagnosis to be made that the individual is experiencing arrhythmia.