Combined telemetry and magnetic field detector unit for a medical implant

摘要

The invention relates to a magnetic field detector (2) and a combined telemetry and magnetic field detector unit (52) in a medical implant (50). The magnetic field detector (2) and the combined unit (52) contain a magnetic field sensor (6) with a coil (18) and a diode (16). In determinations of the presence of a magnetic field, the coil (18) is charged by a source of voltage (V+) for a defined period of time (22), the time for the coil's (18) discharge (24) through the diode (16) depending on whether a magnetic field is present. A detection signal (30) indicating the presence of a magnetic field is generated if the discharge time (24) is less than a defined time threshold value (32). <IMAGE>