Abstract: A method for detecting an ectopic signal in an electrocardiogram is disclosed. This method comprises the following steps: detecting consecutive R-R intervals in an electrocardiogram; calculating an average R-R interval for a determinable number of latest R-R intervals; recognizing a signal as ectopic signal if the signal belongs to at least one of two consecutive R-R intervals, wherein i) a first of the two consecutive R-R intervals is significantly shorter than the average R-R interval; and ii) a second of the two consecutive R-R intervals is significantly longer than the average R-R interval, wherein the second R-R interval occurs later than the first R-R interval; wherein the first and the second of the two consecutive R-R intervals are discarded from calculating the average R-R interval, if the signal is recognized as ectopic signal.

Abstract: An implantable medical device includes an electronic processing device configured for processing a physiological signal, a memory, and a communication device for communicating with an external device. The processing device includes a coding module for coding the physiological signal to obtain an output signal for transmission by the communication device to the external device. The coding module is configured to encode the physiological signal using at least one fixed Huffman code table stored in the memory to obtain the output signal.

Abstract: An implantable medical device comprises a sensor device for obtaining a signal indicative of cardiac activity within a patient, and a processor device configured to process said signal obtained using the sensor device. The processor device is configured to detect a peak indicative of a cardiac event in said signal by comparing said signal to a sense threshold. The processor device in addition is configured to adaptively control said sense threshold such that the sense threshold in at least one time period assumes a value which is constant over said at least one time period, wherein the sense threshold is reduced after lapse of said at least one time period.

Abstract: An implantable medical device includes an electronic processing device configured for processing a physiological signal, a memory, and a communication device for communicating with an external device. The processing device includes a coding module for coding the physiological signal to obtain an output signal for transmission by the communication device to the external device. The coding module is configured to encode the physiological signal using at least one fixed Huffman code table stored in the memory to obtain the output signal.

Abstract: A method for arrhythmia detection within a heart signal of a patient, wherein the method is executed by a processor and comprises steps of: providing an input signal which refers to the heart signal of the patient, wherein the input signal comprises cardiac events and noise events, wherein the cardiac events are related to cardiac activity of interest of the heart of the patient, and wherein the noise events are not related to cardiac activity of interest of the heart; determining the cardiac events from the input signal in an arrhythmia detection window; evaluating the arrhythmia detection window by taking into account at least one of: (i) at least one noise event occurring before a start of the arrhythmia detection window, or (ii) at least one noise event occurring after an end of the arrhythmia detection window. Also, a device for arrhythmia detection is provided.

Abstract: ECG data is analyzed by detecting points in the ECG data which represent ventricular activity; measuring time intervals between each two consecutive points in the ECG data which represent ventricular activity; and then within a set of such time intervals, evaluating the time intervals by computing at least one comparative dimension for at least one time interval subset. The time interval subset includes at least two time intervals, and the comparative dimension represents variations between the interval lengths between the time intervals of the time interval subset.

Abstract: ECG data is analyzed by detecting points in the ECG data which represent ventricular activity; measuring time intervals between each two consecutive points in the ECG data which represent ventricular activity; and then within a set of such time intervals, evaluating the time intervals by computing at least one comparative dimension for at least one time interval subset. The time interval subset includes at least two time intervals, and the comparative dimension represents variations between the interval lengths between the time intervals of the time interval subset.

Abstract: A cardiac device and method thereof for detecting atrial fibrillation within a mean heart signal of a body, wherein the cardiac device includes at least two sensing electrodes. The method includes providing an input heart signal, detecting sense events (VS) and noise events (VN), and generating further noise events (VN) each at a predetermined time interval after a noise event (VN) has been detected and when the noise event (VN) continues. The method includes incrementing a noise counter for each noise event (VN) and each further noise event (VN), and terminating the detection of atrial fibrillation when the noise counter reaches a predetermined limit.

Abstract: A method of enhancing the signal-to-noise ratio (SNR) of measured electrocardiogram (ECG) signals is provided. The method includes the steps of providing at least three cardiac input signals derived from the measured ECG signals S1 and forming a first estimate U1 S2 from each of at least three pairs of input signals. Moreover, the method includes the steps of forming a second estimate U2 S3 from each of at least three input signals; comparing S4 the polarity and the amplitude of a first and second estimate U1, U2 to at least one threshold T; generating S5 a composite signal X, wherein the polarity and the amplitude of the composite signal X depend on the result of the comparison; and using S6 the generated composite signal X to produce an output signal with enhanced signal-to-noise ratio (SNR). Furthermore, a corresponding cardiac device is also provided.

Abstract: A cardiac device and method thereof for detecting atrial fibrillation within a mean heart signal of a body, wherein the cardiac device includes at least two sensing electrodes. The method includes providing an input heart signal, detecting sense events (VS) and noise events (VN), and generating further noise events (VN) each at a predetermined time interval after a noise event (VN) has been detected and when the noise event (VN) continues. The method includes incrementing a noise counter for each noise event (VN) and each further noise event (VN), and terminating the detection of atrial fibrillation when the noise counter reaches a predetermined limit.

Abstract: A cardiac device and method for detecting QRS signals within a composite heart signal of a body including providing at least two input heart signals via at least two separate input channels, wherein each of the at least two input heart signals is recorded by pairs of sensing electrodes that have one electrode in common and provided coincidental in time. The cardiac device and method include generating estimated signals from the input heart signals, combining the input heart signals and the estimated signals to a combined input stream (SECG), and detecting the QRS signal by comparing the combined input stream (SECG) to an adaptive detection threshold (ATHR) which adapts throughout time.

Abstract: An implantable heart monitoring device including a sensing unit, a signal quality analysis unit, and an evaluation unit. The sensing unit is connected to at least one electrode that picks up electric potentials. The sensing unit processes electrical signals corresponding to the electric potentials, and generates sense signals including events corresponding to myocardial contractions. The signal quality analysis unit determines whether a noise condition (NC) and/or a low signal indication is present for an event and generates an indication signal. The evaluation unit evaluates the sense signals and the indication signals, treats a detected event as non-valid if a NC and/or low signal indication signal is present for that event, and uses only intervals defined by two consecutive events which do not have a NC and/or a low signal indication to determine a rate of events of the sense signal.

Abstract: A cardiac device and method for detecting QRS signals within a composite heart signal of a body including providing at least two input heart signals via at least two separate input channels, wherein each of the at least two input heart signals is recorded by pairs of sensing electrodes that have one electrode in common and provided coincidental in time. The cardiac device and method include generating estimated signals from the input heart signals, combining the input heart signals and the estimated signals to a combined input stream (SECG), and detecting the QRS signal by comparing the combined input stream (SECG) to an adaptive detection threshold (ATHR) which adapts throughout time.

Abstract: A method of enhancing the signal-to-noise ratio (SNR) of measured electrocardiogram (ECG) signals is provided. The method includes the steps of providing at least three cardiac input signals derived from the measured ECG signals S1 and forming a first estimate U1 S2 from each of at least three pairs of input signals. Moreover, the method includes the steps of forming a second estimate U2 S3 from each of at least three input signals; comparing S4 the polarity and the amplitude of a first and second estimate U1, U2 to at least one threshold T; generating S5 a composite signal X, wherein the polarity and the amplitude of the composite signal X depend on the result of the comparison; and using S6 the generated composite signal X to produce an output signal with enhanced signal-to-noise ratio (SNR). Furthermore, a corresponding cardiac device is also provided.

Abstract: Improving the signal-to-noise ratio of electrocardiogram (ECG) measurements facilitates cardiac beat detection in a human or animal patient. ECG signals measured either on the surface of the skin or subcutaneously from pairs of leads may be combined to calculate a differential signal. The measured signal may also be averaged to produce a second estimate. A point-by-point product of the differential signal and the averaged signal is generated if the sample pair has the same polarity. The product signals feature enhanced signal components and reduced noise components, thus improving the signal-to-noise ratio of the to respective input channels. Product signals are then subjected to peak detection through a conventional auto-sensing approach. Preliminary event detection results from the conditional product signals may then be aggregated, and final sense markers for ECG beat detection may be generated by means of a voting algorithm.

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: 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: 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: Method and apparatus that uses dual-chamber (RA-RV), three-chamber (BiA-RV, or RA-BiV), or four-chamber (BiA-BiV) implantable cardiac devices including pacemakers, defibrillators and cardioverters, which stimulate cardiac tissue electrically to control the patient's heart rhythm. The method and apparatus are further configured to create a far-field intra-atrial electrogram (AEGM) and a far-field intra-ventricular electrogram (VEGM) that are independently filtered, scaled, and then summed to form a composite far-field electrogram.

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.