PROBLEM TO BE SOLVED: To accurately acquire arrangement of a tubular device with respect to a lumen.SOLUTION: A relative position detection system for a tubular device for being inserted into a subject's lumen includes a shape sensor for detecting a shape of the tubular device, and relative position detection means for detecting a relative positional relationship between at least one location in a first range enabling the shape to be detected by the shape sensor in the tubular device and at least one location on the lumen.【課題】管空に対する管状装置の配置を正確に取得すること。【解決手段】被検体の管空に挿入する管状装置の相対位置検出システムであって、前記管状装置の形状を検出する形状センサと、前記管状装置において前記形状センサにより前記形状を検出可能とする第１の範囲における少なくとも一箇所と、前記管空上の少なくとも一箇所との相対的な位置関係を検出する相対位置検出手段とを具備する。【選択図】図１
