A system comprises a housing, a light source, a light guide configured to guide a light from the light source. The light guide includes a plurality of detection target configured to provide optical effect on the light in accordance with a bend state of the light guide. A light detector is configured to detect the light emitted from the light guide and provide information of the detected light. A communication unit is configured to transmit wirelessly the information of the detected light. The communication unit is disposed in the housing.
