Mechanical positioning system for surgical instruments

An external manipulator for positioning surgical instruments within the abdominal cavity, comprising a hybrid kinematics with a parallel structure, able to provide four, active or passive, positional degrees of freedom to a endoscopic unit, placed in the distal end of an instrument shaft. Due to this specific kinematics, the instrument shaft is able to perform two rotations, one translation, and a fourth orientation degree of freedom about a remote centre of rotation, coincident with the surgical incision port. Because of its unique design and kinematics, the proposed mechanism is highly compact, stiff and its dexterity fulfils the workspace specifications for surgical procedures.