| 摘要 |
An electrode for use in cardiac pacing has a substrate composed of a material conventionally employed for pacing electrodes, and a surface layer or film of iridium oxide overlying the substrate. For use as a stimulating cathodic electrode and a sensing electrode, the iridium oxide layer is arranged to be in cardiac tissue stimulating relationship when the electrode is in proper position with respect to the patient is heart. The electrode impresses electrical stimuli on the excitable myocardial tissue to provide pacing at very low stimulation thresholds. At the completion of each stimulus, the electrode is capable of abruptly sensing, within an interval less than 100 ms thereafter, the electrical activity of the heart in response to the stimulus to reliably verify capture. The surface of the electrode may be provided with recesses to which the iridium oxide layer may be confined. An iridium oxide layer may be provided on both the cathode and the anode for efficient transduction at the electrode-electrolyte interface formed by the surface of the iridium oxide layer and the surrounding body fluid and tissue. |
