Externally programmable implantable heart stimulator - enables operation in several selectable modes including the detection of imminent defibrillation

摘要

The stimulator comprises an input stage (12) for receiving the output signals of various sensors and status monitors including an impedance sensor output derived from electrodes connected to the heart, an electrocardiograph (ECG) output, and an external command signal alerting the implanted stimulator to the fact that a magnet has been placed on the skin surface in proximity to the stimulator. A reed switch located just under the skin surface is actuated by the presence of the magnet thus providing a stimulator control signal by external means. The stimulator forming a combined pacer and defibrillator features an output stage (22) for providing pacing outputs to atrium and ventricle of the heart. It can also provide a defibrillating output and a patient warning that defibrillation is imminent.