PROBLEM TO BE SOLVED: To constantly set an observation object in a captured image, when an oblique-viewing endoscope is inserted into the inside of a human body and operated.SOLUTION: A medical support arm according to the present disclosure includes: a support arm for supporting an oblique-viewing endoscope； and a calculation part that calculates a rotation angle of the oblique-viewing endoscope rotating about a longitudinal axis of the oblique-viewing endoscope and an insertion amount of the oblique-viewing endoscope into the inside of a human body on the basis of a first expression prescribing coordinates of a subject in a coordinate system with an insertion port when inserting the oblique-viewing endoscope into the inside of the human body, defined as an original point, and a second expression prescribing the coordinates of the subject located in an optical axis direction of an objective lens disposed at a distal end of the oblique-viewing endoscope in the coordinate system with the distal end of the oblique-viewing endoscope defined as the original point.SELECTED DRAWING: Figure 1【課題】斜視鏡を人体内部に挿入して操作した場合に、観察対象物を常に撮像画像の領域に収める。【解決手段】本開示に係る医療用支持アームは、斜視鏡を支持する支持アームと、前記斜視鏡を人体内部へ挿入した際の挿入口を原点とする座標系において被写体の座標を規定した第１の式と、前記斜視鏡の先端を原点とする座標系において前記斜視鏡の先端に配置された対物レンズの光軸方向に位置する前記被写体の座標を規定した第２の式とに基づき、前記斜視鏡の長手方向の軸周りの回転角と前記斜視鏡の人体内部への挿入量を演算する演算部と、を備える。【選択図】図１
