The present invention relates to postpartum uterine manipulators and methods of use thereof. 1 atomic percent or smaller, and a thickness configured to reduce Auger recombination in the epitaxially grown doped layer. A filter receives the sensing signal and provides a filtered sensing signal to a sensing circuit. At the lower end of the plastic rod and parallel to its rod axis, an extended electrically conductive element is guided as a coupling conductor, for electromagnetic coupling to the antenna coil, with an overlap of multiple but at least two windings of the antenna coil. This effectuates both a protection of the hair, and a tendency to trap and retain hair treatment products that might have been applied to the hair.