As for this invention, desirably the arrangement possible stooge effective vessel (100) with including in one end of the arm and the aforementioned arm which are formed to the one for arrangement inside the oral stomach, being the medical equipment which becomes, the aforementioned stooge effective vessel (100) through fluid pressure operating mechanism (1), to be operational, the aforementioned fluid pressure operating mechanism (1) at least 1 where it communicates with inside the cylinder 1 holes (22a, 22b, 22b, 22c, 22c, 22d and 22d) via at least, desirably 2, 3 and 4 or 5 these pressure fluid overflow roads (21a and 21b21c and 21d) the cylinder where it is provided (20) to possess, the piston which mobility is done (30) to be arranged aforementioned cylinder (20) the aforementioned cylinder (20) according to vertical axis inside, the aforementioned piston (30) as the aforementioned cylinder (20) the internal room (23) the 1st cylinder room (23a) with the 2nd cylinder room (23b) with it divides, the piston rod (31) through, the aforementioned stooge effective vessel (100) with be connected, the aforementioned 1st cylinder room (23a) in order to introduce the pressure fluid at least 1As the pressure fluid connected mouth (41) is provided, the aforementioned cylinder (20) furthermore it regards the medical equipment where the difference which 1 where it is provided these overflow roads (21a, 21b, 21c and 21d) with is communicated at least 1 pressure fluid connected mouths (41a, 41b, 41c and 41d) is provided at least.本発明は、好ましくは経口胃内配置用に構成されたアームと、前記アームの一端に配置可能な手先効果器(100)とを含んでなる医療機器であって、前記手先効果器(100)は流体圧操作機構(1)を介して操作可能であり、前記流体圧操作機構(1)は少なくとも1個の孔(22a,22b,22b’,22c,22c’,22d,22d’)を通じてシリンダ内部と連通した少なくとも1本、好ましくは2本、3本、4本または5本の圧流体オーバーフロー路(21a,21b,21c,21d)の設けられたシリンダ(20)を有し、前記シリンダ(20)の内部には前記シリンダ(20)の縦軸に沿って可動するピストン(30)が配置され、前記ピストン(30)は前記シリンダ(20)の内部室(23)を第1のシリンダ室(23a)と第2のシリンダ室(23b)とに分割すると共に、ピストンロッド(31)を介して前記手先効果器(100)と連結され、前記第1のシリンダ室(23a)に圧流体を導入するための少なくとも1個の圧流体接続口(41)が設けられていると共に、前記シリン
