Hall sensor (Hall effect sensor)
Hall effect sensor is the modern replacement for the reed switches in pacemakers and ICDs (implantable cardioverter-defibrillator). It is used in MRI-conditional (magnetic resonance imaging) devices. Hall effect is the generation of electrical voltage across a conductor when the magnetic field is perpendicular to the direction of current flow in the conductor. In MRI-conditional devices, the Hall effect can be used to lock out the device during the scan.
Read more on MRI conditional pacemakers…