The invention relates to a medical sensor system (10a/10c) for detecting a feature (12a/12c) in a human or animal body (14a/14c), including a signal pick-up unit (16a/16c), which can be implanted in the animal and/or human body (14a/14c), and a signal processing unit (18a/18c), which is spatially separated from the signal pick-up unit (16a/16c) and which includes a transmitter (20a/20c) and a receiver (22a/22c). The transmitter (20a/20c) emits an alternating magnetic field (24a/24c) to act on the signal pick-up unit (16a/16c), and the receiver (22a/22c) receives a response signal (26a/26c) of the signal pick-up unit (16a/16c), which is generated by the magnetic interaction of the alternating magnetic field (24a/24c) with the signal pick-up unit (16a/16c).