Abstract: A medical device has at least one electrode lead with at least one electrode pole that is configured to measure electrical potentials in human or animal tissue, and a measurement and control unit that is connected to the electrode lead. The measurement and control unit is configured to initiate measurements of the impedance via the electrode pole of the electrode lead. The measurements of the impedance have at least one individual measurement, an individual measurement occurring over a defined window of time.

Abstract: A device and method that detects a lead failure condition for a lead having at least one electrode in contact with body tissue, wherein the lead is connected to the device. The device includes a first filter that filters an electric signal sensed by the at least one electrode to a first filtered signal, and a lead failure detection unit that detects signal characteristics of the first filtered signal. The lead failure detection unit indicates a lead failure condition when the detected signal characteristics correspond to a step response of the first filter.

Abstract: A device and method that detects a lead failure condition for a lead having at least one electrode in contact with body tissue, wherein the lead is connected to the device. The device includes a first filter that filters an electric signal sensed by the at least one electrode to a first filtered signal, and a lead failure detection unit that detects signal characteristics of the first filtered signal. The lead failure detection unit indicates a lead failure condition when the detected signal characteristics correspond to a step response of the first filter.

Abstract: The invention relates to methods of differentiating between ventricular tachycardias (VTs) and supraventricular tachycardias (SVT) with the assistance of morphology detection, and signal processing devices implementing such methods.

Abstract: The invention relates to methods of differentiating between ventricular tachycardias (VTs) and supraventricular tachycardias (SVT) with the assistance of morphology detection, and signal processing devices implementing such methods.

Abstract: A cardiac pacing system and method incorporate DSP processing and software algorithms for collecting signal amplitude data and noise data, and organizing the data for automatic checking of signal channel gain and signal detection sensitivity. Unfiltered signals are used to obtain values representative of maximum amplitude, which values are stored in a gain histogram, from which determination of the percentage of clipped signals can be made. Gain is adjusted by limiting clipping to a predetermined range of allowed clipping, to optimize use of the DSP range. The signals, both P waves and R waves for a dual chamber system, are also processed by DSP and parameters representing maximum amplitudes are stored in amplitude histograms. At the same time, noise is analyzed for respective windows of time following each ventricular event, and noise amplitude data is stored in noise histograms.

Abstract: A method and system for ventricular fusion prevention is provided. It is determined whether an atrial sense occurred within a prior wait time and a scheduled ventricular pace is administered if no atrial sense occurred. If an atrial sense occurred and a ventricular sense follows within an additional wait time, the scheduled ventricular pace is canceled to avoid a fusion beat. If an atrial sense occurred and no ventricular sense follows within an additional wait time, the scheduled ventricular pace is administered. In another embodiment, the max AV interval is increased if too many scheduled ventricular paces are canceled to avoid fusion beats.

Abstract: A cardiac pacing system and method incorporate DSP processing and software algorithms for collecting signal amplitude data and noise data, and organizing the data for automatic checking of signal channel gain and signal detection sensitivity. Unfiltered signals are used to obtain values representative of maximum amplitude, which values are stored in a gain histogram, from which determination of the percentage of clipped signals can be made. Gain is adjusted by limiting clipping to a predetermined range of allowed clipping, to optimize use of the DSP range. The signals, both P waves and R waves for a dual chamber system, are also processed by DSP and parameters representing maximum amplitudes are stored in amplitude histograms. At the same time, noise is analyzed for respective windows of time following each ventricular event, and noise amplitude data is stored in noise histograms.

Abstract: A method and system for ventricular fusion prevention is provided. It is determined whether an atrial sense occurred within a prior wait time and a scheduled ventricular pace is administered if no atrial sense occurred. If an atrial sense occurred and a ventricular sense follows within an additional wait time, the scheduled ventricular pace is canceled to avoid a fusion beat. If an atrial sense occurred and no ventricular sense follows within an additional wait time, the scheduled ventricular pace is administered. In another embodiment, the max AV interval is increased if too many scheduled ventricular paces are canceled to avoid fusion beats.

Abstract: There is provided an implantable cardiac pacing system or other cardiac monitoring system, having an enhanced capability of classifying intracardiac signals through a combination of DSP techniques and software algorithms. The implantable device has one or more DSP channels corresponding to different signals which are being monitored. Each DSP channel provides for amplification of the incoming signal; conversion from analog to digital form; digital filtering of the converted signals to provide filtered signals; operating on the filtered signals to provide slope signals; determining from the filtered and slope signals whenever an intracardiac event has been detected, e.g., R wave, P wave, etc.; and signal processing of the filtered and slope signals for a predetermined analysis interval after threshold crossing, for generating a plurality of signal parameters.