The present invention relates to the stabilization of segmented polyurethanes by the addition of a combination of antioxidants, benzofuranones and or sterically hindered amines and a hydrazine or hydrazide. The sequence may be randomly generated, either in response to the event causing the alert or in a set up phase. Monitoring the sensor makes it possible to increase the reliability of the drive device. Accordingly, many advantages according to the miniaturization of the entire system can be obtained. The aperture can be elastically stretched to enable features on the first surface and second surface of the elastic casing to easily pass through the aperture without much effort and without incurring damage.