  Recent advances in telecommunications have enabled surgeons to operate
remotely on patients with the use of robotics. The investigation and testing of
remote surgery using a robotic arm is presented. The robotic arm is designed to
have four degrees of freedom that track the surgeon's x, y, z positions and the
rotation angle of the forearm {\theta}. The system comprises two main
subsystems viz. the detecting and actuating systems. The detection system uses
infrared light-emitting diodes, a retroreflective bracelet and two infrared
cameras which as a whole determine the coordinates of the surgeon's forearm.
The actuation system, or robotic arm, is based on a lead screw mechanism which
can obtain a maximum speed of 0.28 m/s with a 1.5 degree/step for the
end-effector. The infrared detection and encoder resolutions are below 0.6
mm/pixel and 0.4 mm respectively, which ensures the robotic arm can operate
precisely. The surgeon is able to monitor the patient with the use of a
graphical user interface on the display computer. The lead screw system is
modelled and compared to experimentation results. The system is controlled
using a simple proportional-integrator (PI) control scheme which is implemented
on a dSpace control unit. The control design results in a rise time of less
than 0.5 s, a steady-state error of less than 1 mm and settling time of less
than 1.4 s. The system accumulates, over an extended period of time, an error
of approximately 4 mm due to inertial effects of the robotic arm. The results
show promising system performance characteristics for a relatively inexpensive
solution to a relatively advanced application.
