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Design and Development of a Haptic training System for Sinus and Skull based Surgery

Sadeghnejad, Soroush | 2019

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  1. Type of Document: Ph.D. Dissertation
  2. Language: Farsi
  3. Document No: 51850 (08)
  4. University: Sharif University of Technology
  5. Department: Mechanical Engineering
  6. Advisor(s): Vossoughi, Gholamreza; Farahmand, Farzam; Moradi, Hamed
  7. Abstract:
  8. Performing a safe and effective endoscopic sinus and skull based surgery (ESSS), requires special training programs to gain sufficient hand-eye coordination and instrument manipulation skills. In this regard, virtual-based haptic surgical training systems have been considered among the medical students and residents as an effective approach for training practices. Therefore, in this study, the development of a haptic training system for ESSS, based on an animal model has been addressed. By conducting various indentation and relaxation experiments, mechanical properties of the specific sino-nasal regions of sheep head, as a function of force, displacement and tool insertion rate, for three phases of deformation, fracture, and cutting are presented by considering the modified Kelvin-Voigt and the data fitting models. To develop a virtual-based haptic ESSS training system, it is required to exploit the dynamic model for every three components of the haptic system, including the haptic interface, the human user, and the virtual environment. The dynamics of the sino-nasal virtual environment is characterized as a linear parametric variable problem with input constraints, based on a phenomenological tissue fracture model, and the Novint Falcon haptic device, equipped with a calibrated force sensor, is considered as a haptic interface. Redefining the type of cost function and deriving the one-step-ahead prediction, a novel modified online robust approach for the quasimin-max output feedback model predictive control scheme is proposed. Employing a five-parameter dynamic model for the dynamic model of the user’s hand, the simulations and the experimental results of a one- egree-of-freedom virtual-based haptic system indicated the robust stability and the convergence of the output signals to the desired impedance values; besides, a reduction in the unwanted disturbances of the control efforts’ signals caused by switching in the piecewise linear dynamics. It is important to consider components in this research which guide trainees to improve their hand movements control in the orbital floor removal in an ESSS operation. Therefore, we defined three tasks to perform: pre-experiment learning, training, and evaluation. In these tasks, the critical regions introduced in the virtual training environment are orbidden to be touched. Recruiting 20 participants, divided in two groups, we investigated the performance metrics: quality (the percentage of the realism for the generated force for orbital floor removal and the sefulness of the proposed training system for the surgical educational curricula.), efficiency (time, path length) and safety (touching the goal and forbidden wall). All recruited participants answered a post-evaluation questionnaire regarding their perceptions of training system realism, potential educational benefits, and practiced skills. The acquired results showed that the proposed method is promising for practical use in ESSS training, considering its capability of providing a proper tradeoff between the performance and stability. Utilizing a standardized environment, trainers and trainees are able to carry out a process with the regular features. In addition to traditional education methods, they can learn to the risk of surgical treatment. They can, also, provide a standard method for assessing the skills of surgical and medical students
  9. Keywords:
  10. Endoscopic Sinus Surgery ; Haptic System ; Virtual Reality (VR)Environment ; Education ; Model Predictive Control ; Performance Metric ; Safety ; Rate Dependent Behavior ; Novint Falcon ; Phenomenological Property

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