PROBLEM TO BE SOLVED: To accurately obtain a three-dimensional relative positional relationship between an optical axis position of a long instrument such as a rigid endoscope and a position and attitude detecting marker by using an optical axis position measurement device which is lightweight, has a simple structure, and has excellent operability and convenience.SOLUTION: An optical axis position measurement device 80 has a target image that can be captured by a rigid endoscope 11, and an optical axis position measuring marker 91 capable of measuring a three-dimensional shape. Calculation means stores in advance a three-dimensional relative positional relationship between the target image and the optical axis position measuring marker 91, acquires a three-dimensional relative positional relationship between a distal end part 14 of the rigid endoscope 11 and a marker sphere 12 and a three-dimensional relative positional relationship between the marker sphere 12 and the optical axis position measuring marker 91 by processing three-dimensional data obtained by the three-dimensional shape measurement, and acquires a point on the target image corresponding to a center position of the captured image from the target image captured by the rigid endoscope 11. The calculation means obtains a three-dimensional relative positional relationship between an optical axis of the rigid endoscope 11 and the marker ball 12 on the basis of the stored data and the acquired data.SELECTED DRAWING: Figure 8COPYRIGHT: (C)2018,JPO&INPIT【課題】軽量かつシンプルな構造であって操作性や利便性に優れる光軸位置測定装置を用いて、硬性内視鏡等の長尺状器具の光軸位置と位置姿勢検出用標識体との3次元相対位置関係を精度よく求める。【解決手段】光軸位置測定装置80は、硬性内視鏡11により撮像可能なターゲット画像と、3次元形状測定可能な光軸位置測定用標識体91とを有する。演算手段は、ターゲット画像と光軸位置測定用標識体91との3次元相対位置関係を予め記憶し、3次元形状測定により得られる3次元データを処理して硬性内視鏡11の先端部14と標識球12との3次元相対位置関係及び標識球12と光軸位置測定用標識体91との3次元相対位置関係を取得し、硬性内視鏡11が撮像したターゲット画像から撮像画像の中心位置に相当するターゲット画像上の点を取得する。演算手段は、記憶してあるデータと取得したデータに基づき、硬性内視鏡11の光軸と標識球12との3次元相対位置関係を求める。【選択図】図8
