Development of 7-degree-of-freedom Passive Manipulator for Arthroscopy

Surgery is a medical treatment requiring specific manual procedures and instruments. Arthroscopy is a minimally invasive surgery for diagnosing and treating joint problems. The operation is performed by using special instruments and an arthroscope through incisions. This is involves complex manipulation that generally needs an assistant surgeon to hold the arthroscope. A vibration problem due to an unstable holding induces motion sickness of the lead surgeon. This research aims to design and construct a passive manipulator for holding an arthroscope during surgical operation. The designed passive manipulator consists of 7 degrees of freedom (DOF) with integrated electromagnetic brakes. A single switch is used to control the brakes, thus the surgeon can manipulate the arthroscope and fix its position and its orientation as needed. The provided range of motion of the designed device is verified by simulation that it is sufficient for knee arthroscopy and shoulder arthroscopy. The deflection due to the weight and loads is analyzed. The downward drift of the end effector is evaluated and the result is 3.90 mm which needs further improvement.