38 results about "Surface electrocardiogram" patented technology

Analyzes surface electrocardiographic and intracardiac signals to identify and separate electrical activity corresponding to distinct but superimposed events in the heart. Assesses the spatial phase, temporal phase, rate, spectrum and reproducibility of each event to determine uniformity of activation in all spatial dimensions. Uses numerical indices derived from these analyses to diagnose arrhythmias. Uses these indices to determine the location of an arrhythmia circuit, and to direct the movement of an electrode catheter to this location for ablation or permanent catheter positioning. Subsequently, uses these indices to determine whether ablation has successfully eliminated the circuit. Uses variability in these indices from the surface electrocardiogram to indicate subtle beat-to-beat fluctuations which reflect the tendency towards atrial and ventricular arrhythmias.

The invention provides a disposable sensor patch for the non-invasive detection and indication of a heart condition during a medical emergency. The patch is placed on the chest area for sensing and analyzing a surface electrocardiogram (ECG). The heart condition is rapidly indicated via an indicator integrated in the patch. The disposable smart patch is inexpensive and simple to use by a layperson assisting or living with the person experiencing the medical crisis. The patch is activated automatically upon its removal from the package and placement on the chest. The detection and indication occurs rapidly and within 90 seconds of placement on the chest. In another embodiment of the invention, a vibration sensor element is incorporated for detecting cardiovascular vibrations and for ruling out pulseless electrical activity.

Reconstructing electrograms, whose experimental registration requires an invasive access, by computational way on unipolar ECGs recorded at 80 and more points of the chest surface. On the set of surface electrocardiograms for each discrete moment of the cardiocycle, values of the heart electric field potential at points of ECG-recording are determined, and a value of the electric field potential at each point of the chest surface is calculated by interpolation. Based on data of any visualization methodology, boundaries of chest and lungs surfaces and of the heart epicardial surface are determined. Further, a continuation of the electric field potential over the whole chest surface up to the heart epicardial surface with taking into account differences in electroconductivity of large anatomical structures of the chest is performed by computational way based on solution of the Cauchy problem for the Laplace equation in a piecewise-homogenous medium.

The reconstruction of a surface electrocardiogram based upon an endocardial electrogram. This method includes: (a) acquisition (10) of a plurality of endocardial electrogram signals (EGM) through a plurality of endocardial derivations defined based upon endocardial electrodes; (b) calculation (12), by combining the endocardial electrogram (EGM) signals acquired at step (a), of the corresponding endocardial vectogram (VGM); (c) angular resealing (14) of the orthonormated mark of the endocardial vectogram (VGM) with that of the surface vectocardiogram (VCG); (d) estimation (16), based upon the endocardial vectogram (VGM) calculated at step (b), of a reconstructed surface vectocardiogram (VCG_{reconstructed}); and (e) calculation (18) of the surface electrocardiogram (ECG) corresponding to said reconstructed surface vectocardiogram (VCG_{reconstructed}).

An active medical device using non-linear filtering for the reconstruction of a surface electrocardiogram (ECG) from an endocardial electrogram (EGM) is disclosed. The device for the reconstruction of the surface ECG comprises: a plurality of inputs, receiving a corresponding plurality of EGM signals from endocardial or epicardial electrogram (x₁[n], x₂[n]) each collected on a respective EGM derivation of a plurality of EGM derivations, and at least one output delivering a reconstructed surface ECG electrocardiogram signal (y[n]), related to an ECG derivation, and a non-linear digital filter (12′, 12′, 14) with a transfer function that determines the reconstructed ECG signal based on said plurality of input EGM signals. The non-linear digital filter includes a Volterra filter type (12, 12′, 12″) whose transfer function includes a linear term (h1) and at least one quadratic (h2) and/or cubic (h3) term(s).

The invention provides an automated detection method of QRS wave groups of electrocardiosignals according to a time-domain difference threshold theory. The method comprises the concrete steps: S1, pre-processing electrocardiosignals; S2, calculating first-order time-domain fixed-point difference threshold of electrocardiosignals; S3, calculating self-adaptive threshold value; S4, detecting R wavecrest value points by combining self-adaptive threshold value and differential signals; S5, carrying out an echo detecting test on detected R wave crest value points. The automated detection method ofQRS wave groups of electrocardiosignals can be used for instruments and equipment for automatic analysis and recognition of surface electrocardiograms. Therefore, sensitivity and accuracy of automatic detection of QRS wave groups of electrocardiosignals are improved. The algorithm operation efficiency is increased.

Techniques are provided for estimating optimal atrioventricular pacing delay values for use in pacing the ventricles based on features of an intracardiac electrogram (IEGM) signal. Briefly, atrioventricular pacing delay pacing values are set based upon the location of atrial repolarization events within the IEGM. In one example, the end of an atrial repolarization is identified, then the interval from the atrial depolarization to the end of the atrial repolarization is measured. The atrioventricular pacing delay is then set by subtracting an offset value from that interval so as to time delivery of V-pulses prior the end of atrial repolarization. In this manner, atrioventricular pacing delay values are set based only IEGM signals and hence can be set to optimal/preferred values by the device itself without requiring surface electrocardiogram (EKG) signals and Doppler echocardiography or other cardiac performance monitoring techniques.

The present invention relates to an active medical device that uses non-linear filtering for reconstructing a surface electrocardiogram from an endocardial electrogram. At least one endocardial EGM electrogram signal is collected from of samples collected from at least one endocardial or epicardial derivation (71′, 72′, 73′), and at least one of a reconstructed surface electrocardiogram (ECG) signal through the processing of collected EGM samples by a transfer function (TF) of a neural network (60′). The neural network (60′) is a time-delay-type network that simultaneously processes said at least one endocardial EGM electrogram signal, formed by a first sequence of collected samples, and at least one delayed version of this EGM signal, formed by a second sequence of collected samples distinct from the first sequence collected samples. The neural network (60′) provides said reconstructed ECG signal from the EGM signal and its delayed version.

The reconstruction of a surface electrocardiogram based upon an endocardial electrogram. This method includes: (a) acquisition (10) of a plurality of endocardial electrogram signals (EGM) through a plurality of endocardial derivations defined based upon endocardial electrodes; (b) calculation (12), by combining the endocardial electrogram (EGM) signals acquired at step (a), of the corresponding endocardial vectogram (VGM); (c) angular resealing (14) of the orthonormated mark of the endocardial vectogram (VGM) with that of the surface vectocardiogram (VCG); (d) estimation (16), based upon the endocardial vectogram (VGM) calculated at step (b), of a reconstructed surface vectocardiogram (VCG_{reconstructed}), and (e) calculation (18) of the surface electrocardiogram (ECG) corresponding to said reconstructed surface vectocardiogram (VCG_{reconstructed}).

A surface electrocardiogram (EKG) is emulated using signals detected by internal leads of an implanted device. In one example, emulation is performed using a technique that concatenates portions of signals sensed using different electrodes, such as by combining far-field ventricular signals sensed in the atria with far-field atrial signals sensed in the ventricles. In another example, emulation is performed using a technique that selectively amplifies or attenuates portions of a single signal, such as by attenuating near-field portions of an atrial unipolar signal relative to far-field portions of the same signal. The surface EKG emulation may be performed by the implanted device itself or by an external programmer based on cardiac signals transmitted thereto. A transtelephonic monitoring network is also described, wherein the emulated surface EKG (or raw data used to emulate the EKG) is relayed from an implanted device to a remote monitor, typically installed in a physician's office.

Provided is a non-invasive system for estimating an atrial signal, including a plurality of sensors to sense a surface electrocardiogram signal, a reference atrial signal generation unit to generate an estimated ventricular signal with respect to a R wave in an electrocardiogram signal from one sensor among the plurality of sensors, and to generate a reference atrial signal by subtracting the estimated ventricular signal from the electrocardiogram signal from the one sensor, and an atrial signal estimation unit to generate an estimated atrial signal by applying a constrained independent component analysis algorithm based on the reference atrial signal to the received surface electrocardiogram signal, and to estimate one of the estimated atrial signals as an actual atrial signal, and a method using the same.

The invention discloses an optional technology of an invasive temporary cardiac on-demand pace-making sensing source. According to the optional technology of the invasive temporary cardiac on-demand pace-making sensing source, a self-developed temporary cardiac on-demand pacemaker is connected and combined with a monitor in a matched manner; a combined pace-making and monitoring integrated instrument provides a more reliable pacing-sensing technology; the pacemaker collects intracardiac electrocardiogram signals through a pace-making electrode; the intracardiac electrocardiogram signals are transmitted to the monitor through using a communication module; intubation medical staff observe an intracardiac electrocardiogram through the monitor, and accurately judges a location where the electrode is located based on a synchronous surface electrocardiogram; after the pace-making electrode is led to a proper position, the pacemaker carries out on-demand pace-making on ventricles; as for the problem of difficulty in fixing a pace-making position in the clinical temporary cardiac pace-making VVI technology, the integrated pace-making and monitoring integrated technology can greatly improve the understanding of the medical staff on pace-making states greatly; and as for the problem of difficult processing caused by a situation that a clinical temporary cardiac on-demand pace-making sensing source is unreliable, surface electrocardiogram R waves from the monitor are provided and are adopted as a stable ventricular pace-making source.

Methadone is a frequently employed agent for the treatment of drug addiction and the treatment of pain. Methadone prolongs the cardiac action potential, which on the surface electrocardiogram is represented by QT prolongation. This QT prolongation is known to increase the risk for the development of cardiac arrhythmias, especially the form of ventricular tachycardia known as Torsade de Pointes. For this reason, the FDA has inserted a “black box” warning for potential life threatening arrhythmias. The invention described in this application is the surprising finding that the R-isomer of methadone causes less inhibition of the potassium channel, IKr and thus would have less of a chance of causing life threatening arrhythmias. What is claimed is a method of chirally separating methadone with one isomer having less QT prolongation and more analgesic action that would make a superior pharmacologic agent than the racemate R,S methadone.