Robotic assistance in microsurgery

The purpose of this study was to introduce a new robotic system for microsu rgical procedures of the eye, ear, brain, face, and hand. The design and ma in features of the Robot Assisted MicroSurgery (RAMS) work station are desc ribed. In addition, compatibility with the operating-room table is assessed . The engineering components of the RAMS work station consist of a laptop com puter, a joystick, a mouse, slave robot, VME and amplifier chassis, and saf ety control box. The mechanical part of the RAMS, the slave robot, is desig ned to simulate movements of the human upper extremity, which has Five join ts and six degrees of motion. The robot has a zero backlash in five joints, and can sustain full extension of loads over three pounds. The arm measure s 2.5 cm in diameter, and it is 34.6 cm long from its base to its tip. The arm and its base weigh 2.5 kg. Motors and encoders on the robot are easily removable, allowing for the arm to be sterilized in an autoclave. Assessmen t of robotic positioning, time for setup, relative precision, and possible problems in the operating field are compared with human-assisted microsurgi cal procedures, Robotic arm positioning on the operating-room table differs for each type o f procedure. For those involving the hand and upper extremity, the robotic arm base occupies 35 percent of the operating table; this is only 10 to 15 percent for human-assisted procedures. The setup time for robot-assisted pr ocedures is longer than for human-assisted surgery. However, microsurgical manipulations with the RAMS are more rapid than the surgeon's motions. Ther efore, depending on the type of procedure, the total operating time is comp arable to human-assisted procedures. The movement of the RAMS was found to be more precise, in attempting to perform vascular and neural anastomoses. The authors conclude that concurrent use of the remote-controlled RAMS as a microsurgical assistant is applicable in microsurgery, with the advantages of greater precision and more rapid microsurgical manipulation. However, t he long-term cost effectiveness of using this system as an assistant in mic rosurgery warrants further investigation.