While external cardiac massage can help to prolong survival in such emergencies, CPR alone cannot restore the heart to its correct rhythm. Time is critical in this situation, as failure to restore the rhythm within five minutes usually either proves fatal or renders the fibrillation more difficult to treat.
Automatic external defibrillators (AEDs) analyse and interpret the patient’s heart rhythm in order to administer electric shocks to the heart through the patient’s chest wall via conductive adhesive pads at the correct point in the cycle to restore normal heartbeat. Medical personnel are guided through this process by voice and visual prompts. ZF Electronics has developed a custom reed sensor, similar to its standard MP2017 series, for one AED manufacturer, who wanted to market a model with two shock settings. The machine features a “paediatric key” with embedded magnets to actuate a Cherry reed sensor, allowing the operator to deliver a safer, lower energy shock when used to treat a child. ZF Electronics’ Cherry reed sensor was suitable for this application because it has zero power consumption and therefore does not deplete the AED’s battery. More, the sensor is also small enough to fit easily along the plastic housing in close proximity to the key.