Minimally-invasive-surgery parallel robot with non-identical limbs

The robots have revolutionized the traditional minimally invasive surgery procedures. The successful usage of the current commercial robots in hospitals encourages the researchers to further develop and propose new medical robots. This paper presents a preliminary study of a novel parallel manipulator for minimally invasive surgery. The parallel robot has three limbs, two of them have identical structure and third one is different. The robot has four degrees of freedom in total, three for the parallel mechanism and the fourth one is a translation along the longitudinal axis of the surgical instrument. The parallel manipulator provides remote center of motion located at the incision point of the patient´s body. The kinematics and workspace of the considered manipulator are obtained and parameters effecting the performance and workspace are discussed. The results are graphically illustrated. The forward and inverse position problems for the manipulator under study are obtained.