영상 유도 내비게이션 기반 이과수술로봇의 개발과 전임상 연구

Abstract

In this dissertation, an image-guided navigation based robotic system for a otologic surgery has been developed and a pre-clinical study using it has been conducted. Among the fields of otorhinolaryngology, the otology field is a medical science for handling very small structures having a limited space which are located close to a brain and important nerves and blood vessels. Therefore, in the otologic surgery, it is important to secure a surgeon's clear view and apply precise surgical technique, which affect significantly surgery prognosis. In the proposed otologic surgical robot system, an imaged-guided navigation has been integrated in order to secure the surgeon's view during surgery. The image-guided navigation provides the operator with warning function in real time by indicating invisible organs and surgical devices within the 3D model of the mastoid bone. A large amount of bone has been removed approximately in the existing surgery but minimally invasive surgery can be realized by utilizing the image-guided navigation. Also, by using the developed warning algorithm, the damage of the target organs due to surgical devices has been prevented. An otologic surgical robot has been developed with two types; an active type robot and a passive type robot. For the active type robot, two types (i.e., a 6 DOF parallel robot and a 5 DOF serial robot) have been developed, and for the passive robot, a stackable structure along with counter-balancing sfunction has been developed. In the active type 6 DOF parallel surgical robot, an automatic mastoidectomy has been implemented by using a temporal bone model. The full-scale temporal bone model is constructed by using CT data of actual patients. The mastoidectomy is an operation for removing a lesion of temporal bone by using a surgical drill, which is a frequent surgery in the otology field. In this experiment, an operator performs the mastoidectomy and records the location of surgical drill and then the operations are reproduced by a robot. To optimize the workspace and mobility of devices, the architecture singularity has been analyzed and the design variables have been optimized. In the active 5 DOF surgical serial robot, a human-robot collaboration control has been implemented by using admittance control law based on a force/torque sensor data. The human-robot collaboration control protects the important organs from being damaged using the warning algorithm. As the surgical drill approaches the target organ during operation, visible and audible warnings with different intensity level are displayed. And when the surgical drill invades within the predetermined minimum safety distance, the robot is forced to stop by activating the magnetic brakes installed at joints of the robot. By using a phantom, the collaboration and warning algorithm experiments have been conducted and then the results have been analyzed through CT scan after the experiment. The passive surgical robot has been developed in order to overcome slow driving speed and realize zero gravity movement of the drill by the surgeon. This robot is designed by using the counter balancing mechanism such that an operator cannot feel the weight of the robot and the surgical drill. And, it protects the important organs from being damaged by using a magnetic break and a warning algorithm. In this passive surgical robot experiment, the pre-clinical study has been conducted by using phantoms as well as cadavers. The mastoidectomies using the robot have been performed in both ears of total seven cadavers. After the experiment, the usefulness of the robot has been verified by CT scan.