Abstract: A medical implant has a stimulation pulse generator and an evoked response detector that senses an IEGM signal in an evoked response detection time window following delivery of a stimulation pulse, in order to distinguish capture from loss of capture based on a parameter, from among a number of parameters, of the IEGM signal. A setting unit sets a minimum tolerable difference between the value of the selected parameter obtained as a result of capture and obtained as a result of loss of capture, respectively. The selected parameter that is used to distinguish capture from loss of capture can be the parameter for which the minimum tolerable difference is obtained with the shortest evoked response detection time window, or the parameter for which a calculated difference, between the value of the parameter resulting from capture and the value of the parameter resulting from loss of capture, has a maximum difference from the minimum tolerable difference.

Abstract: An apparatus for detecting cardiac events in electrograms has a feature extraction unit that derives features of the cardiac events for discriminating among different types of cardiac events. A clustering unit groups cardiac events with similar features into respective clusters defined by predetermined cluster features. The feature extraction unit determines a feature vector describing waveform characteristics of cardiac events in the electrogram by a wavelet transform. The clustering unit determines the distance between the feature vector and corresponding cluster feature vectors in order to assign the cardiac event in question to that cluster which results in a minimum distance, providing that the minimum distance is less than a predetermined threshold value. A heart stimulator provided with such a cardiac event detecting apparatus detects the occurrence of an arrhythmia and appropriately controls a pulse stimulator to treat the arrhythmia.

Abstract: In a cardiac assist device and method, a microphone is placed in contact with the epicardium of the heart of a patient, and heart and lung sounds are simultaneously detected at the placement location of the microphone. The heart and lung sounds are automatically analyzed to set an appropriate cardiac therapy for the patient.

Abstract: A biventricular cardiac stimulation device has a pulse generator for delivering stimulation pulses at least to the ventricles of a patient's heart. An evoked response detector has independent first and second ventricular sensing channels for ventricular evoked response detection in the ventricles. The pulse generator is controlled to deliver stimulation pulses to the second ventricle with a VV time delay after delivery of a stimulation pulse to the first-stimulated ventricle, the VV time delay being shorter than an evoked response detection time window that follows delivery of the stimulation pulse to the first-stimulated ventricle. An evoked response detector closes the evoked response detection window, or discards detections therein, in response to the emission of a stimulation pulse to the second-stimulated ventricle during the evoked response detection time window of the first-stimulated ventricle.

Abstract: In a cardiac stimulation method, device and system, a capture verification condition is determined. For this purpose, a number of pacing pulses are delivered to a heart chamber and signals are sensed within a time window following each pacing pulse. The sensed signals are stored and categorized as representing capture or non-capture. Using the stored signals, a weight vector is determined, that assigns different weights for different parts of each sensed signal within the time window. The weight vector is used for calculating a weighted area within the time window. The capture verification condition is determined by identifying whether the weighted area, calculated with the weight vector, of a sensed signal within the time window is above or below a predetermined value.

Abstract: An implantable bi-ventricular heart stimulating device and system, suitable for treating congestive heart failure, have a control circuit with first and second pacing circuits and first and second sensing circuits. The device operates with time cycles corresponding to normal heart cycles. The control circuit determines: (a) whether a signal typical of an evoked response to a pacing pulse delivered by the first pacing circuit is sensed within a first time interval and (b) whether a signal typical for an R-wave transferred from the second ventricle, or from some other part of the heart, to the first ventricle is detected within a first time window. The operation of the device depends on whether the conditions (a) and (b) are fulfilled.

Abstract: In an implantable heart stimulating device, system and method, electrical stimulation pulses are delivered to first and second ventricles of a heart with a variable time interval therebetween, and signals are sensed at two different positions in the heart, from which an impedance value is derived. A minimum value and a maximum value of the impedance value are determined during a heart cycle, and a relationship between the minimum and maximum values also is determined. The time interval is varied and the relationship is monitored over a number of heart cycles. The time interval is set so that the relationship satisfies a predetermined requirement.

Abstract: An implantable medical apparatus for detecting diastolic heart failure, DHF, has a DHF determining device for determining at least one DHF parameter for detecting a DHF state of the heart of a patient. The DHF includes circuitry for determining, as the DHF parameter, the time duration of a predetermined phase of diastole. A pacemaker has such an apparatus and a control unit that optimizes pacing therapy and pacemaker settings depending on the determined time duration. A corresponding method of detecting diastolic heart failure, DHF, includes determining at least one DHF parameter for detecting a DHF state of the heart of a patient. As the DHF parameter, the time duration of a predetermined phase of diastole is determined.

Abstract: An implantable cardiac stimulation device has an atrial detector that detects atrial events of a patient's heart, and a memory in which sequences of IEGM signals are stored, having a predetermined length, and an analyzing unit that analyzes the sequences to determine if the stored sequences contain atrial events having a lower amplitude than the current sensitivity setting of the atrial detector. A control unit is connected to the atrial detector to adjust the sensitivity setting thereof to a threshold that is determined based on the aforementioned analysis of the IEGM signals.

Abstract: An implantable cardiac system has a master pacing unit and a remote satellite pacing unit. The master pacing unit is electrically coupled to a right side of a patient's heart via a lead assembly. The satellite pacing unit is a leadless device mounted on the left side of the patient's heart and is wirelessly controlled by the master pacing unit. The satellite pacing unit is affixed to the heart by one or more mounting members. The base of the satellite unit case has a gel-like material which facilitates adhesion of the pacing unit to the heart tissue. The gel-like material promotes tissue growth to hold the pacing unit in place on the heart. The gel-like material may be composed of polyvinlpyrrolidone and may contain a steroid, such as dimethyl sulfoxide (DMSO), or dexamethazone sodium phosphate.

Abstract: A biventricular cardiac stimulation device has a pulse generator for delivering stimulation pulses at least to the ventricles of a patient's heart. An evoked response detector has independent first and second ventricular sensing channels for ventricular evoked response detection in the ventricles. The pulse generator is controlled to deliver stimulation pulses to the second ventricle with a VV time delay after delivery of a stimulation pulse to the first-stimulated ventricle, the VV time delay being shorter than an evoked response detection time window that follows delivery of the stimulation pulse to the first-stimulated ventricle. An evoked response detector closes the evoked response detection window, or discards detections therein, in response to the emission of a stimulation pulse to the second-stimulated ventricle during the evoked response detection time window of the first-stimulated ventricle.

Abstract: In an implantable heart stimulating device, system and method, a control circuit has first and second circuits for sensing and pacing. The first circuit can be connected to a first electrode member suited to be positioned in or at a first ventricle of the heart. The second circuit can be connected to a second electrode member suited to be positioned in or at a second ventricle of the heart. The control circuit is able to detect whether signals sensed by the second circuit are likely to be far field signals. The control circuit performs this detection by at least determining whether, during a predetermined time (length, more signals are sensed by the second circuit than by the first circuit.

Abstract: An implantable bi-ventricular heart stimulating device and system operate, within a time cycle, to deliver pacing pulses with both a first and a second pacing circuit with a first time delay between these pacing pulses. The device employs a criterion with which a signal typical for a premature ventricular contraction is detected. The device also operates with a second time delay and/or with a third time delay, and, if a predefined pacing rule is fulfilled, to deliver a pacing pulse with the second time delay or said third time delay. The risk for arrhythmia in connection with a PVC is reduced.

Abstract: A heart stimulator for electric stimulation of a patient's heart has an impedance measuring unit that measures the impedance between at least two measurement electrodes implanted in a patient such that volume changes of at least one of the chambers of the left heart result in changes in the measured impedance. An analyzer analyzes the measured impedance for the control of the stimulation of the heart. A calculation unit calculates an average impedance morphology curve during a time interval of several cardiac cycles. The analyzer analyzes the average impedance morphology curve for use for the control of the stimulation to optimize the patient hemodynamics.

Abstract: A congestive heart failure monitor has an impedance measuring unit that measures the impedance between at least two electrodes implanted in a patient, to use a detected change of the measured impedance as an indication of a change in the left atrium volume. Any analyzing unit analyzes the measured impedance and detects insipient congestive heart failure dependent on a quotient of a maximum value of the measured impedance and a minimum value of the measured impedance during a cardiac cycle.

Abstract: A multi-chamber pacing system has a pulse generator for successively delivering pacing pulses to chambers of a patient's heart. Evoked response detectors having blanking intervals following the delivery of pacing pulses include sensing elements for sensing IEGM-signals from each of the heart chambers and an integrating unit that integrates the IEGM-signal within evoked response detection time windows after delivery of pacing pulses for detecting evoked response. The evoked response detection time window for a heart chamber contain at least one blanking interval resulting from delivery of a pacing pulse to another chamber and each of the sensed IEGM signals having a generally known morphology. An integral reconstructing unit reconstructs the time integral of the IEGM signal from one of the heart chambers in the blanking interval following delivery of a pacing pulse to another heart chamber.

Abstract: An implantable bi-ventricular heart stimulating device (10) has a control circuit with first and second sensing circuits for respectively sensing in the two ventricles and first and second stimulation circuits for respectively stimulating the two ventricles. The control circuit determines whether a signal, sensed by said second sensing circuit, occurs essentially simultaneously with a signal sensed by the first sensing circuit. Furthermore, the control circuit determines whether a further signal is sensed by said second sensing circuit within a predetermined time interval which follows after the signal sensed by the second sensing circuit but within the same time cycle as that signal. If this occurs, the control circuit determines whether the sensed signals represent actual cardiac events, or are likely the result of far field detection.

Abstract: An implantable medical apparatus for detecting diastolic heart failure, DHF, has a DHF determining device for determining at least one blood pressure parameter for detecting a DHF state of the heart of a patient. The DHF determining device includes a pressure measuring unit for measuring pulse pressure in a cardiac cycle for a predetermined workload situation of the patient as the blood pressure parameter, and a comparator compares the measured pulse pressure with a predetermined reference value. A pacemaker includes such an apparatus and a control unit that optimizes pacing therapy depending on the result of the comparison of the measured pulse pressures with the predetermined reference values.

Abstract: A multi-chamber pacing system has a pulse generator for successively delivering pacing pulses to chambers of a patient's heart, and IEGM signal detectors, having blanking intervals following the delivery of pacing pulses, including sensing circuits for sensing IEGM-signals from each of the heart chambers. Each of said sensed IEGM signals has a generally known morphology. A signal-reconstructing unit reconstructs the IEGM signal from one of the heart chambers in the blanking interval following delivery of a pacing pulse to another heart chamber.

Abstract: An implantable bi-ventricular heart stimulating device has a control circuit that within a time cycle, delivers pacing pulses with both first and second pacing circuits with a time gap between a pacing pulse delivered by these pacing circuits. The time gap can be such that a pacing pulse delivered by the second pacing circuits falls substantially within a first time interval in which an evoked response can be expected to a pacing pulse delivered by the first pacing circuit. The control circuit performs a temporary modification of the operation of the device such that during at least one time cycle no pacing pulse is delivered by the second pacing circuit during the first time interval.