  The human-machine interface is of critical importance for master-slave
control of the robotic system for surgery, in which current systems offer the
control or two robotic arms teleoperated by the surgeon's hands. To relax the
need for surgical assistants and augment dexterity in surgery, it has been
recently proposed to use a robot like a third arm that can be controlled
seamlessly, independently from the natural arms, and work together with them.
This report will develop and investigate this concept by implementing foot
control of a robotic surgical arm. A novel passive haptic foot-machine
interface system and analysis of its performances were introduced in this
report. This interface using a parallel-serial hybrid structure with springs
and force sensors, which allows intuitive control of a slave robotic arm with
four degrees of freedom (dof). The elastic isometric design enables a user to
control the interface system accurately and adaptively, with an enlarged
sensing range breaking the physical restriction of the pedal size. A subject
specific (independent component analysis, ICA) model is identified to map the
surgeon's foot movements into kinematic parameters of the slave robotic arm. To
validate the system and assess the performance it allows, 10 subjects carried
out experiments to manipulate the foot-machine interface system in various
movements. With these experimental data, the mapping models were built and
verified. A comparison between different mapping models was made and analyzed
proving the ICA algorithm is obviously dominant over other methods.
