Abstract:
Robotic minimal invasive surgery has proven to increase the quality of sur gical operations and has also made possible new types of surgical procedures
which were not previously achievable with conventional minimal invasive
surgery. Various mechanical structures/mechanisms have been utilized as
minimally invasive surgical manipulators. In particular, spherical mecha nism and the double parallelogram mechanism are the most widely used. In
this thesis, we provide a kinematic analysis of the double parallelogram mech anism for its use as the external (arm) manipulator for minimally invasive
robotic surgery. Two kinematic models of the said mechanism are developed
with varying degrees of freedom. To have a quantitative analysis we provide
certain indices of dexterity for the mechanism including mechanism singular ities, isotropy and manipulability.
A comparative study of the spherical and double parallelogram mechanisms
is performed. It is shown that the latter has certain advantages over its
spherical counterpart. It was further noted that the link lengths do not af fect the kinematics of the double parallelogram mechanism. Evaluation of the
kinematic properties like isotropy and manipulability ensures complete dex terity necessary for minimally invasive robotic surgery. Moreover, attempts
have been made to propose, optimized manipulators designs using different
performances indices and validated through simulations.
