Abstract: Heart monitoring apparatus with sensing stage connectable to intracardiac electrode picking up electric potentials and adapted to process electric signals representing a time course of said potentials, a mechanical action detection stage adapted to generate a geometry signal having a time course reflecting heart chamber's geometry change, an evaluation unit connected to sensing stage and impedance measuring stage and adapted to determine a first and second fiducial point in the time course of said potentials and geometry signal, respectively, both fiducial points belonging to same heart cycle, and to determine a measured time delay between said fiducial points. Evaluation unit adapted to repeat said determined time delay to determine plurality of measured time delays and variance thereof or divergence of the statistical properties of cycle times based on said time course of said electric potentials versus cycle times based on said time course reflecting a change of a heart chamber's geometry.

Abstract: A heart stimulator provides for a more appropriate yet simple setting of the AV-delay. The heart stimulator comprises a stimulation pulse generator adapted to generate electric stimulation pulses and connected to a ventricular stimulation electrode for delivering electric stimulation pulses. A sensing stage connected to an electrode for picking up electric potentials inside a ventricle is adapted to sense an excitation or a contraction of a heart chamber. A memory is adapted to store parameters defining a Bezier function determining the relationship between AV-delay values and heart rate and a control unit connected to said memory, said sensing stage and to said stimulation pulse generator, is adapted to determine an actual AV-delay based on an actual intrinsic heart rate or an actual stimulation rate and a non-linear smoothing interpolation between said parameters stored in said memory.

Abstract: Heart stimulator that provides for timing a premature stimulation pulse for anti-tachycardia pacing outside the vulnerable phase of a ventricle, to terminate stable ventricular tachycardia while minimizing the risk of accelerating stable ventricular tachycardia into unstable ventricular tachycardia or ventricular fibrillation. RT interval is determined instead of QT interval. Conventional QT interval is defined to end at T wave offset, which is difficult to measure because inherent imprecision in identifying the end of T wave from surface ECG. For safe ATP, such problems may be avoided. Because the VP usually refers to the portion of the T wave near the peak and early downslope (FIG. 3), in order to avoid the VP, only need to determine the peak of T wave, then set an blanking window or safety margin (e.g., 20 ms before to 20 ms after the peak of T wave) during which ATP pulses should not be delivered.

Abstract: A device for classifying of supraventricular tachyarrhythmia (SVT) from ventricular tachyarrhythmia (VT) comprising means for providing a template signal and a test signal originated from an electrogram, the template signal and the test signal comprising samples, means for transforming at least the test signal resulting in a representation of the test signal where the sample values of the signal take integers, means for determining a correlation between the template signal and the test signal and means for classifying of SVT from ventricular VT based on the correlation.

Abstract: An implantable cardiac device, e.g., a pacemaker, defibrillator, cardioverter or biventricular pacing device, that can sense cardiac electrical signals and accurately classify the sensed events. The device provides a template signal and a test signal originated from an electrogram. The device further transforms at least the test signal into a representation of the test signal for example in numerical format where the sample values of the test signal take the form of integers. The device further determines a correlation between the template and test signals, and classifies the sense events based on the correlation. The electrogram may be an intracardiac electrogram (IEGM), atrial electrogram (AEGM), ventricular electrogram (VEGM), surface electrocardiogram (ECG) or subcutaneous electrogram.

Abstract: The invention is directed to a heart stimulator for left-ventricular pacing comprising a left ventricular stimulation pulse generator connected or connectable to a single electrode lead for left ventricular stimulation having one or more electrodes for delivery of stimulation pulses to left ventricular myocardial heart tissue, said stimulation pulse generator being adapted to generate and deliver stimulation pulses of switchable polarity. The heart stimulator further comprises a control unit connected to the stimulation pulse generator for controlling the stimulation pulse generator and to trigger generation and delivery of stimulation pulses having a polarity controlled by said control unit, wherein the control unit is adapted to control said left ventricular stimulation pulse generator so as to deliver at least a pair of suprathreshold stimulation pulses of opposite polarity.

Abstract: A medical device and a method is suggested for assessing the risk of R on T events. The device comprises a memory, input means for acquiring or receiving an electrogram signal and processing means. The processing means are adapted to detect R-wave and T-waves represented by said electrogram, establish a QT-RR regression model based detected R-waves and T-waves, estimate a vulnerable period, and store estimated vulnerable period data in said memory. Likewise, the method comprises the steps of to detecting R-wave and T-waves represented by an electrogram, establishing a QT-RR regression model based detected R-waves and T-waves, estimating a vulnerable period, and storing estimated vulnerable period data.

Abstract: Heart stimulator that stimulates at least a heart's right atrium and ventricle in an atrium asynchronous stimulation mode with an overdrive stimulation rate. Interposes one resynchronization cycle after a sensed atrial event to regain AV synchrony during otherwise asynchronous stimulation mode. Allows for pacing mode that can pace the atrium with an overdrive stimulation rate in dual-chamber asynchronous mode while maintaining the AV synchrony and is called DDI(R)+. In DDI(R)+, pacemaker performs an atrial asynchronous (V synchronous) pacing mode such as DDI or DDI(R). The overdrive stimulation rate (OSR) is either a fixed rate (programmed by the external device) that is thought to be above the underlying intrinsic atrial rate, or is dynamically adjusted according to the measured atrial cycle length to be slightly above intrinsic atrial rate. The overdrive stimulation rate may be based on an intrinsic atrial rate or on hemodynamic need. DDI(R)+ timing may be ventricle-based.

Abstract: A heart stimulator provides a reliable automatic capture threshold search feature. A stimulation pulse generator is connected to at least a ventricular stimulation electrode for delivering electric stimulation pulses to at least the ventricle of the heart. The stimulation pulses generated have a strength depending on a control signal. A sensing stage is connected to an electrode for picking up electric potentials inside at least said ventricle of a heart and a control unit connected to the sensing stage and to the stimulation pulse generator determines points of time for scheduling stimulation pulses, to trigger the stimulation pulse generator so as to deliver a stimulation pulse when scheduled and to put out control signals for controlling the strength of the stimulation pulse. The control unit is further adapted to perform a capture analysis which may take into account extraordinary events.

Abstract: An implantable cardiac stimulator (10), configured to switch mode of operation between at least one right ventricular stimulation mode in which no control signals triggering left ventricular stimulation pulses are delivered to the left ventricular stimulation unit and a biventricular stimulation mode in alternation. Switching takes place as a function of duration of prevailing QRS signal interval, such that the cardiac stimulator switches to biventricular stimulation mode when comparison of the duration of a prevailing QRS signal interval with a first comparison value reveals the duration of the prevailing QRS signal interval is longer than a first reference value represented by the first comparison value and switches to right ventricular stimulation mode when comparison of the duration of a prevailing QRS signal interval with a second comparison value reveals the duration of the prevailing QRS signal interval is shorter than a second reference value represented by the second comparison value.

Abstract: Heart stimulating system for stimulating at least a ventricle of a heart including: stimulation pulse generator adapted to generate stimulation pulses and connected to a ventricular stimulation electrode for delivering stimulation pulses, atrial sensing stage connected to an electrode for picking up potentials inside an atrium and adapted to sense an excitation or contraction of atrial myocardium, ventricular sensing stage connected to an electrode for picking up potentials inside a ventricle and adapted to sense an excitation or contraction of ventricular myocardium, memory for AV-delay values, a control unit adapted to trigger said stimulation pulse generator to generate ventricular stimulation pulses timed based on AV-delay values stored in said memory and to acquire atrioventricular interval samples, and atrioventricular interval timing analyzing unit for receiving atrioventricular interval samples from said control unit and adapted to generate at least one histogram based on said atrioventricular interva

Abstract: Implantable medical device with an impedance determination unit with constant current/voltage source having current feed terminals connected to electrodes for intracorporal placement which generates measuring current pulses having constant current/voltage, for causing a current through a body via intracorporally placed electrodes, a measuring unit for measuring voltage/current strength of voltage/current fed through body, an impedance value determination unit connected to the current/voltage source and adapted to determine an impedance value for each measuring current pulse, and an impedance measuring control and evaluation unit connected to the impedance determination unit which controls the unit and evaluates a sequence of consecutive impedance values, the impedance determination unit further adapted to determine at least intrathoracic and intracardiac impedance values for same period of time, the intrathoracic values sampled with a lower sampling rate than the intracardiac values.

Abstract: A medical device having a sensor for sampling a biological signal, the biological signal representing a signal waveform and forming a waveform vector composed of the biological signal samples, and a memory for storing a least two threshold vectors composed of boundary samples representing at least two boundaries related to the biological signal defining subspaces for the biological signal samples. One threshold vector is an upper threshold vector composed of upper boundary samples and the other threshold vector is a lower threshold vector composed of lower boundary samples. An evaluation unit connected to the sensor determines a similarity index (ASCI) by comparing each of the biological signal samples of the waveform vector to corresponding boundary samples of the threshold vectors, thus determining to which subspace each biological signal sample belongs to and creating a trichotomized signal vector, and calculating the signed correlation product of two trichotomized signal vectors.

Abstract: A heart stimulator is adapted to adapt an atrioventricular delay interval or an interventricular delay interval or both during night time by adding a delay interval to a respective daytime interval, and the device statistics for day and night are calculated, stored, and can be displayed separately.

Abstract: A system for heart monitoring comprises an IEGM input for an intracardiac electrocardiogram (IEGM) that is connected to an active filtering stage that is adapted to transform an incoming IEGM into an output ECG signal. The active filtering stage is connected to a filter characterization stage that is adapted to process a recorded, patient specific IEGM template and a corresponding SECG template and to adapt the filter characteristics of said active filtering stage such that the filter characteristics best characterize the input-output relationship between the IEGM template and the corresponding SECG template. As a consequence, the active filtering stage is adapted to transform an incoming IEGM such that the output ECG signal closely resembles a morphology of a corresponding SECG.

Abstract: An implantable medical device has an atrial fibrillation detector adapted to detect an atrial fibrillation. A telemetry unit is adapted to transmit an AF message to an external receiver. A control unit is connected to the atrial fibrillation detector and said telemetry unit and is adapted to only indicate an atrial fibrillation detected by the atrial fibrillation detector that lasts longer than a predetermined waiting time period of at least several hours. Additionally the implantable medical device has an atrial shock generator which is connected or connectable to an atrial defibrillation electrode and adapted to generate and deliver an atrial cardioversion pulse when triggered and the control unit is connected to the atrial shock generator.

Abstract: A heart stimulator provides a reliable automatic capture threshold search feature. A stimulation pulse generator is connected to at least a ventricular stimulation electrode for delivering electric stimulation pulses to at least the ventricle of the heart. The stimulation pulses generated have a strength depending on a control signal. A sensing stage is connected to an electrode for picking up electric potentials inside at least said ventricle of a heart and a control unit connected to the sensing stage and to the stimulation pulse generator determines points of time for scheduling stimulation pulses, to trigger the stimulation pulse generator so as to deliver a stimulation pulse when scheduled and to put out control signals for controlling the strength of the stimulation pulse. The control unit is further adapted to perform a capture analysis which may take into account extraordinary events.

Abstract: A heart stimulator provides for a more appropriate yet simple setting of the AV-delay. The heart stimulator comprises a stimulation pulse generator adapted to generate electric stimulation pulses and connected to a ventricular stimulation electrode for delivering electric stimulation pulses. A sensing stage connected to an electrode for picking up electric potentials inside a ventricle is adapted to sense an excitation or a contraction of a heart chamber. A memory is adapted to store parameters defining a Bezier function determining the relationship between AV-delay values and heart rate and a control unit connected to said memory, said sensing stage and to said stimulation pulse generator, is adapted to determine an actual AV-delay based on an actual intrinsic heart rate or an actual stimulation rate and a non-linear smoothing interpolation between said parameters stored in said memory.

Abstract: A heart stimulator for stimulating a chamber of a heart by way of electrical stimulation pulses, said pacemaker comprises a sensing stage connected or being connectable to an electrode lead comprising an electrode for picking up electric potentials inside a heart chamber, said sensing stage being adapted to sense an excitation of a heart chamber by way of picked up electric potentials, a stimulation pulse generator adapted to generate electric stimulation pulses and being connected or being connectable to an electrode lead comprising a stimulation electrode for delivering electric stimulation pulses to said chamber of a heart, and a control unit being connected to said sensing stage and to said stimulation pulse generator and being adapted to trigger stimulation pulses to be generated by the stimulation pulse generator and to be delivered via said electrode lead, said stimulation pulses being triggered with a controlled stimulation rate controlled by the control unit.

Abstract: Heart stimulator that provides for timing a premature stimulation pulse for anti-tachycardia pacing outside the vulnerable phase of a ventricle, to terminate stable ventricular tachycardia while minimizing the risk of accelerating stable ventricular tachycardia into unstable ventricular tachycardia or ventricular fibrillation. RT interval is determined instead of QT interval. Conventional QT interval is defined to end at T wave offset, which is difficult to measure because inherent imprecision in identifying the end of T wave from surface ECG. For safe ATP, such problems may be avoided. Because the VP usually refers to the portion of the T wave near the peak and early downslope (FIG. 3), in order to avoid the VP, only need to determine the peak of T wave, then set an blanking window or safety margin (e.g., 20 ms before to 20 ms after the peak of T wave) during which ATP pulses should not be delivered.