144 results about "Arrhythmia detection" patented technology

A cardiac monitor is provided that monitors the condition of the heart of a cardiac patient and generates signals indicating one of several conditions, such as supraventricular tachycardia, ventricular tachycardia and ventricular fibrillation. In order to generate these signals, the ECG from the patient is analyzed to determine a cardiac interval and heart rate, as well as a waveform factor and a waveform factor irregularity. The waveform factor is derived from the average of the ECG amplitudes during a cardiac interval and the peak value of the ECG during the same interval. Preferably, a running average is calculated over several intervals. This waveform factor is then used to detect shockable ventricular arrhythmia. The waveform factor irregularity is indicative of the variability of the waveform factor and is used to differentiate between ventricular tachycardia and ventricular defibrillation.

A system and method for detecting and discriminating atrial arrhythmias based on mechanical signals of cardiac wall motion and electrical signals of cardiac depolarizations. A mechanical event rate determined from sensed mechanical events is used to corroborate an electrical event rate determined from sensed EGM or ECG signals to classify the heart rhythm. If the event rates are not correlated, other parameterized data from the mechanical signal and electrical signal are evaluated to detect evidence of an arrhythmia. If electrical and mechanical event data do not corroborate a common arrhythmia condition, electrical and mechanical sensing parameters may be adjusted.

An implantable medical device and associated method for automatically generating morphology templates during fast cardiac rhythms, confirming a provisional template as a confirmed template, and using the confirmed template to classify subsequent detected arrhythmias. A provisional SVT template may be created during a fast ventricular rate and activated as a confirmed SVT template upon verification that the fast rate was due to an SVT. The confirmed SVT template may be used to discriminate SVT from VT/VF.

A system and method for detecting and classifying cardiac arrhythmias based on cardiac pressure signals or the combination of cardiac electrical and cardiac pressure signals. A cardiac electrogram signal is sensed to derive a cardiac rate from which an arrhythmia detection is made when the cardiac rate meets arrhythmia detection criteria. An intracardiac pressure signal is sensed to derive an indicator of tachycardia based on an analysis of the pressure signal in either the time domain or frequency domain. The detected arrhythmia is classified as tachycardia or fibrillation based on the tachycardia indicator wherein the tachycardia indicator is compared to tachycardia detection criteria and the arrhythmia is classified as tachycardia if tachycardia detection criteria are met and the arrhythmia is classified as fibrillation if the tachycardia detection criteria are not met.

An external defibrillator includes a detector used to detect a life threatening condition of a patient, a controller operating the defibrillator automatically and a therapy delivery circuit that delivers appropriate therapy. Advantageously a parameter is derived from the cardiac signals sensed in the patient, the parameters being used to differentiate between shockable events such as ventricular tachyarrhythmia and other events such as SVT. The defibrillator is attached to a patient by an attendant and once it is attached, the defibrillator is adapted to monitor the patient and when a life threatening condition is detected, to apply therapy automatically, i.e., without any involvement by the patient or the attendant.

An implantable subcutaneous cardiac device includes at least two subcutaneous electrodes adapted for placement external to a heart beneath the skin of a patient. The device further includes an arrhythmia detector that detects a sustained tachyarrhythmia of the heart and a pulse generator that delivers anti-tachycardia pacing pulses to the subcutaneous electrodes in response to detection of a sustained tachyarrhythmia. The pacing pulses preferably have waveforms devoid of any exponential voltage decay and include rounded or substantially constant portions to minimize pain.

A method and device for detecting arrhythmias in a patient that includes electrodes positioned subcutaneously within the patient, a microprocessor, coupled to the electrodes, determining one of a sequence of the sensing of cardiac signals by the electrodes and a duration between the sensing of cardiac signals by the electrodes, and control circuitry delivering a therapy in response to one of the determined sequence and the determined duration.

A system comprising an implantable medical device (IMD) that includes a tachyarrhythmia detector, a baroreflex detector to obtain baroreflex information, and a processor in communication with the tachyarrhythmia detector and the baroreflex detector. The processor adjusts at least one of a tachyarrhythmia detection parameter of the IMD or a tachyarrhythmia therapy parameter of the IMD using the baroreflex information.

A system comprising an implantable medical device (IMD). The IMD includes an implantable sensor operable to produce an electrical signal representative of mechanical activity of a heart of a subject and a controller circuit coupled to the sensor. The IMD also includes a heart sound sensor interface circuit to produce a heart sound signal, a tachyarrhythmia detector, and a controller circuit. The controller circuit includes a hemodynamic stability assessment module configured to determine that at least one episode of ventricular tachyarrhythmia is detected in a subject and obtain a measurement of hemodynamic stability of the ventricular tachyarrhythmia from the heart sound signal.

A diatrophic, bio-physiological interface is self-contained with onboard intensification, filtering, and signal processing and is wirelessly enabled (idio-electrode), with multiple sensory system for bio-physiological measurements, described herein utilizes spatially resolved potential profiles from a cluster of mini electrodes to form constituent sets comprising mini sensorial electrodes. The sets of sub electrodes containing the clusters are jointly optimized to attain measurable gradient of some diagnostic value. The present invention provides a distinct lead-free single electrode that is rotationally invariant with onboard Digital Signal Processor for arrhythmia detection, source encoding, and passive and active wireless transmission. Additionally, in one aspect of the present invention the lead-free idio-electrode bio-physiological adapter allows for utmost clinical operational freedom and dramatically obviates the needs for leads of any length that invariably encumber the acquisition and performance of electrocardiogram recordings of any sort.

In an IMD, when tachyarrhythmia detection criterion are satisfied or a high intrinsic heart rate is detected, a peak amplitude detection circuit is enabled to detect the peak amplitude of the cardiac signal of interest, i.e., the P-wave in the case of atrial tachyarrhythmias and the R-wave in case of ventricular tachyarrhythmias. Peak amplitude data is accumulated for subsequent use in setting sensing thresholds and/or gain of a sense amplifier to reduce undersensing of lower amplitude cardiac signals during such tachyarrhythmias.

A cardiac rhythm sensor positioned on or close to the heart senses electrical or mechanical activity and transmits a cardiac rhythm signal wirelessly to a subcutaneous ICD. Arrhythmia detection and delivery of therapy are performed by the SubQ ICD based upon the cardiac rhythm signal received from the sensor.

A system including an implantable medical device (IMD). The IMD includes a ventricular contraction sensing circuit that provides a sensed ventricular contraction signal, a timer circuit that provides a ventricular time interval between ventricular contractions, and a controller circuit coupled to the timer circuit, the controller circuit determines the ventricular contraction rate using the ventricular time interval. The controller circuit further includes a tachyarrhythmia detection module that declares tachyarrhythmia, in response to detecting a sudden rate increase, without comparing a ventricular rate or time interval to a respective tachyarrhythmia detection rate or time interval threshold.

A subcutaneous cardiac stimulation system verifies accelerated arrhythmia detection before delivering accelerated arrhythmia therapy to the heart. The stimulation system includes a verification circuit that verifies detection of the accelerated arrhythmia with each of first and second sense channels utilizing first and second electrode configurations. The therapy circuit delivers the stimulation therapy to the heart if the accelerated arrhythmia detection is verified with each of the first and second electrode configurations. The system also compensates for transient rate changes during the detection of the accelerated arrhythmia.

Apparatus for detecting atrial arrhythmias in the treatment of disorders of the heartbeat rate in active implantable medical devices of the pacemaker, cardioverter, defribillator and/or multisite type. This device includes conventional systems, circuits and control algorithm for detecting spontaneous and stimulated ventricular events (R, V) and atrial events (P, A), indicating the delivery of a ventricular and/or atrial event, and inhibiting the detection of atrial events after detection of a ventricular event throughout a post-ventricular atrial absolute refractory period (PVAARP). Detecting atrial events includes protecting against the detection of atrial signals that do not correspond to an atrial event that has actually occurred, in particular protecting against atrial detection of far-field signals caused by a ventricular event. The protection operates by a dynamic adjustment of the sensitivity of detection by temporarily raising (t₁, t₂) a detection threshold (ΔS₁, ΔS₂) after detection of a ventricular event without detection of a preceding (spontaneous or stimulated) atrial event during the same cardiac cycle.

A system for heart performance characterization and abnormality detection detects peaks and at least one of, a valley and a baseline comprising a substantially zero voltage level, of received signal data representing oxygen content of blood in a patient vessel over multiple heart beat cycles. The signal processor determines signal parameters including at least one of, (a) a signal amplitude magnitude between a maximum peak and minimum valley, of the received signal data, (b) a signal amplitude magnitude between a maximum peak and a baseline, of the received signal data and (c) a signal amplitude magnitude between a second highest maximum peak and minimum valley, of the received signal data. The system compares a determined signal parameter or value derived from the determined signal parameter, with a threshold value and generates an alert message associated with the threshold, in response to the comparison.