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Moore, Randy

University of British Columbia

Transoral robotic surgery (TORS) is a minimally invasive surgical technique performed using the da Vinci Surgical System and is used to treat head and neck cancers. During this procedure the surgeon removes tumours without haptic feedback, with limited field of view, in an area with critical neurovasculature. Ultrasound image-guidance can potentially improve the surgeon’s recognition and removal of the tumour while minimizing damage to healthy tissue. Transcervical ultrasound imaging, where the oropharynx is imaged using extracorporeal ultrasound, shows promise in enabling image-guidance because it provides continuous imaging during surgery. However, a suitable ultrasound probe placement strategy is not defined. This thesis details the identification, development, and evaluation of two ultrasound probe placement methods for TORS. In the first, the surgeon uses a da Vinci hand-controller to control a patient-side manipulator to place the ultrasound. In the second, the surgeon controls a human via human teleoperation, whereby the human is shown where to place the probe using a mixed reality headset. Both a six-degree-of-freedom (6DOF) mouse and the da Vinci hand-controller were used for this purpose. The robotic placement method was evaluated by 9 participants on a healthy volunteer in ultrasound tasks that occur during TORS. Scanning performance measured by the average Hausdorff distance from the ultrasound images to the registered MRI images provided no statistically significant difference between robot-assisted scanning versus freehand scanning. Nevertheless, robot-assisted tasks took longer than freehand (2.09x longer; p=0.001) and had higher operator workload (2.12x higher; p=0.004). Operator-rated performance in robotic scanning was reasonably close to freehand (avg robotic/avg freehand = 0.66; p=0.017). The human teleoperation approach was evaluated in a four participant study where the mixed reality headset was also registered to the da Vinci (error = 6.7 ± 4.3 mm). The da Vinci hand-controllers outperformed the 6DOF mouse in completion time, operator workload, and the ability to center anatomy in the image. The human teleoperation method outperformed the robotic one in terms of operator workload but took longer. Selection of the optimal method for TORS requires evaluation in the operating room and may ultimately depend on surgeon preference.

Text

2024-10-11

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/89397

Electrical and Computer Engineering

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/