SURGICAL INSTRUMENT

To provide a surgical instrument that allows a surgeon to freely move the head section by simple manual operation and that provides high safety with a reduced number of components.SOLUTION: Provided is a surgical instrument that includes a tool head 30 in a distal part and a first operation section 10 and a second operation section 20 in a proximal part, the tool head comprising a movable section 31 and a base section 32, and the surgical instrument further including a first connection structure and a second connection structure. The first connection structure includes a first conversion mechanism 40A, a first shaft 41, a universal joint provided at the distal end of the first shaft, a second conversion mechanism, and a crank 30 provided at the distal end of the second conversion mechanism and connected to the proximal end of the movable section. The second connection structure has a cylindrical shaft on which distal part a pinion is formed, and a rack base section on which top face a rack is provided, the rack meshing with pinion and being formed in a substantially semicircular shape. The intersection of axes of two pivots of the universal joint is on the axis of rotation of the rack.SELECTED DRAWING: Figure 1 【課題】術者による簡単な手元操作で、ヘッド部を自由に動かすことができ、かつ、部品点数を減らした安全性の高い外科用器具を提供する。【解決手段】遠位部にツールヘッド３０を備え、近位部に第１操作部１０と第２操作部２０を備え、ツールヘッドは可動部３１と基盤部３２とを備え、第１連結構造体と第２連結構造体を備えている。第１連結構造体は、第１変換機構４０Ａと、第１シャフト４１と、第１シャフトの遠位端部に備えられたユニバーサルジョイントと、第２変換機構と、第２変換機構の遠位端部に備えられ、可動部の近位端部とつながるクランク３０とを有している。第２連結構造体は、遠位部にピニオンが形成された筒状シャフトと、ピニオンと噛み合うラックが、略半円周状に形成され、当該ラックを上面に備えるラック基盤部と、を有し、ユニバーサルジョイントの２つの枢軸の軸心の交点が、ラックの回旋軸の軸心上にある。【選択図】図１