| 摘要 |
<p>Method and apparatus for detecting the open or closed state of a pair of manually-operated switches (116), (118) associated with a pair of defibrillation pulse electrodes, the switches being normally open and being manually closed by an operator, the two switches connected in series with discharge control circuitry (32) for initiating a defibrillation energy pulse. The control circuitry (32) is configured so that when the switches (116), (118) are both closed a defibrillation pulse is initiated. Each of the switches is connected in parallel with a corresponding circuit element (124), (126), each having a characteristic impedance, and being shorted out when the corresponding switch (116), (118) is closed. The invention provides for measuring an indication of the series impedance of the discharge control circuitry (32) to determine the open or closed state of the switches by comparing a measured impedance value indication with an impedance value indication calculated for a given open or closed state of the switches.</p> |
