Composite electrode

摘要

An implantable assembly for defibrillation and monitoring and/or regulating the beat of a heart. The defibrillation electrode is flexible and preferably made of braided carbon fiber and conductive metallic wire. It provides a low polarization, low capacitance and low impedance electrical interface with body fluid and/or excitable tissue. The conductivity of the defibrillation electrode is increased over electrodes made only of carbon fiber by the presence of the conductive metallic wire in the preferred embodiment, or by a thin exterior coating of titanium and silver in another embodiment. This electrode delivers energy more efficiently to body tissue than conventional defibrillation electrodes, resulting in lower energy needed to achieve defibrillation, which allows batteries powering the defibrillator to last longer. The fibers together provide an effective surface area for the electrical interface which is considerably larger than the apparent actual surface area of the electrode as determined from the linear dimensions of the electrode. This lows the electrode to be smaller than conventional defibrillation electrodes. The preferred configuration of the defibrillation electrode is tubular, which can be used with at least one additional device, such as a second electrode for pacing or sensing the heartbeat, to be mounted on the distal end of the defibrillator electrode. Lead(s) connected to the additional device(s) pass through the defibrillator electrode and run inside the lead connected to the defibrillator electrode.