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On the design and development of robotic mechanisms for laparoscopic surger

Posted on:2006-04-09Degree:Ph.DType:Thesis
University:Simon Fraser University (Canada)Candidate:Li, Te-meiFull Text:PDF
GTID:2454390008976896Subject:Biomedical engineering
Abstract/Summary:
Laparoscopic surgery is performed in the abdominal area of a patient, through small incisions. Despite advantages to patients, surgeons have difficulties such as loss in manipulation ability, reduction in dexterity and sensation of touch, and indirect vision. Laparoscopic surgery requires the surgeons to learn a new form of hand-eye coordination and to become skillful in the manipulation of instruments.;The objective of this research is in the synthesis, design, and development of new robotic mechanisms to assist surgeons to overcome surgical difficulties. These robotic mechanisms solve existing surgical problems such as inaccuracy in positioning of endoscopic tools, lack of force/tactile feedback, reduced dexterity and pneumoperitoneum.;First, to solve the problem of positioning of endoscopic tools, a compact automated surgical tool-holding mechanism was designed and developed as a four DOF surgical robotic arm. This mechanism manipulates and positions the surgical tools or a laparoscopic camera automatically and thus eliminates the need for human assistance. The design parameters are optimized for a maximal workspace. The kinematics and numerical examples are presented.;Second, to solve lack of force/tactile feedback problem, both gimbal and spherical parallel type devices are designed and developed to provide four DOF force feedback in surgical training or telesurgery. The spherical parallel types utilize a passive support component to support the weight and reduce inertia. The direct and inverse kinematics are discussed with direct kinematics solved by a neural network model for real time application.;Third, design for manufacturing and cost structure model for haptic devices are analyzed. This design for manufacturability is implemented after which the bill of materials, machining process, and analysis of tolerance and accuracy are presented.;Fourth, supporting mechanisms such as a local master-slave mechanism and abdominal surgical space maker are designed. The local master-slave mechanism contains two rotational DOF to increase surgical dexterity for difficult surgical tasks. This mechanism is manually actuated without motor. The abdominal surgical space maker is a foldable structure that can be folded in a tube and inserted into the patient's abdominal wall to expand and create space.
Keywords/Search Tags:Robotic mechanisms, Laparoscopic, Abdominal, Surgical
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