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Abstract
This thesis is concerned with increasing capabilities associated with instruments for laparoscopic surgery. Surgeons practicing in Victoria and Vancouver highlighted two current limitations: a lack of instrument mobility and difficulties associated with laparoscopic suturing.
Limited instrument mobility requires abdominal wall stretching, which is potentially damaging to both patient and surgeon, to obtain full spatial motion capabilities. A reduction in stretching is sought through the introduction of additional joints to the tool end of the current basic laparoscopic instrument. The addition of one further joint is found to eliminate stretching for tasks requiring only tool pointing. Two additional joints are concluded necessary for general location and orientation.
Analytical representations of current and enhanced laparoscopic tools are derived using concepts of manipulator mechanics. Forward/inverse displacement and velocity degeneracy solutions are derived. These solutions are necessary to compare the performance of each instrument and for the instruments to be used within a tele-operated master-slave manipulator setting.
Preliminary concepts for automating suture knotting within the laparoscopic environment are proposed. A design for an assistive device based on knot loop forming is presented and should reduce required surgeon effort.
