To visually support a catheter ablation in the heart, three-dimensional image data have been used prior to the intervention. Therefore, when subsequently carrying the mask into the mask room, impurities from the outside can be substantially prevented from getting into the optical path inside the mask room. An integral display mount may include a display unit and display screen housed in a display housing that is integral with the steering handle of the vehicle. The rubber composition is prepared by blending a coupling agent therewith subsequent to the addition said silica reinforcement. Connector main body has stopper for bringing midway part of misoperation-preventive member to stop in a position close to opening-operation body against urgence on misoperation-preventive member. The mode of operation is selected based upon a level of traffic between the first and second nodes.