> These cardiac devices have switches which respond to an external magnet to change how the device functions. For a defibrillator, a magnet can be used to turn

> These cardiac devices have switches which respond to an external magnet to change how the device functions. For a defibrillator, a magnet can be used to turn the device off. > “Obviously, we can’t perform surgery every time we need to control one of these devices, which is why they are engineered to allow us to use strong magnets over the chest to control their function,” said Dr. Singh.