| 摘要 |
<p>An electrode (10, 35, 50, 65) for use in cardiac pacing has a substrate (15, 87) composed of a material conventionally employed for pacing electrodes, and a surface layer or film (20, 75, 85, 95) 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's 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 (65) to which the iridium oxide layer may be confined. An iridium oxide layer may be provided on both the cathode and the anode for effecticient transduction at the electrode-electrolyte interface formed by the surface of the iridium oxide layer and the surrounding body fluid and tissue.</p> |
