An implantable sensor is proposed comprising a ring shaped element and a coil. The ring shaped element is made of a silicone and is electrically conductive. The coil may be formed by a wire with a number of windings, wherein at least the free ends of the wire, i.e. of the coil are enclosed by the silicone of the ring shaped element, wherein an electrical resistance of the ring shaped element varies upon a deformation of the ring shaped element.
