Design and optimization of remote center motion mechanism of Minimally Invasive Surgical robotics

Minimally Invasive Surgery (MIS) is less invasive and creating fewer post-operative complications compared with conventional surgery. This results in shorter recover times and, sometimes, outpatient treatment replaces for previously lengthier procedures. So MIS is the latest trend in surgery. However, MIS is usually associated with a limited view of the surgical view area and is difficult to handle of the surgical tools, in order to overcome these difficulties Remote Center Motion (RCM) is proposed. In this paper, a new RCM mechanism which is triangle is proposed, this mechanism is simple and high stiffness. A complete kinematic analysis and optimization incorporating the requirements for MIS are performed to find the optimal link lengths of the manipulator. The results show that for the serial triangle2-link manipulator used to guide the surgical tool, the optimization link angles are (74°,51°). Prior preoperative adjustment is realized by electromagnetic clutch, However, A new preoperative adjustment method which is realized by gravity compensation is proposed without electromagnetic clutch, the joint is simpler and lighter than conventional joint.