下颌角缩小术是一种非常流行、有效、并广泛用于修饰脸部轮廓的手术方式。手术中所用到的主要工具有往复锯和圆头磨钻，这两种手术工具工作时有一个共同的特点：通过其高速运转去除骨质。缺乏经验的医生通常需要较长周期的训练，来学习和熟悉如何操作这两种手术工具，并在操作过程中避免由于无法控制好工具与骨骼的触碰以及工具运转时的在骨骼上的移动所造成的危险。具有视觉和触觉反馈的虚拟手术模拟系统为医生们练习手术技巧提供了一种可行并且安全的方式。然而，创建高速运转的手术工具与坚硬的骨骼之间的真实触觉交互模型是一个非常有挑战性的任务。 / 这篇论文设计并实现了虚拟下颌角缩小手术模拟系统，并且创建高保真度的视觉和触觉反馈来增强虚拟手术环境的真实性。文章提出了基于冲量理论的力反馈模型用来模拟作用在工具上的碰撞力和力矩。在不同的往复速率或者旋转速度的情况下，所提出的模型都可以为医生提供可信真实的力感反馈。并且针对磨钻在磨骨是震动明显对磨骨操作有较大影响的特点，论文还提出了一个三维震动模型来模拟磨骨时作用在钻轴上的橫向震动和轴向震动。同时，论文还提出了用于模拟手术中骨质去除以及重建的实时绘制方法。为了验证力模型的真实性，我们还创建了机械平台，采集磨骨和截骨过程中产生的真实力数据，从而用来与虚拟手术中产生的力数据进行比较。最后，还引入真实病人的CT扫描数据来对虚拟手术系统进行实证研究，评估创建的系统是否可以用于训练具有不同手术经验的医生。实证研究的结果也验证了所提出的虚拟手术系统的有效性。 / Mandibular angle reduction is a popular and efficient procedure widely used to alter the facial contour. The primary surgical instruments, the reciprocating saw and the round burr, employed in the surgery have a common feature: operating at a high-speed. Generally, inexperienced surgeons need a longtime practice to learn how to minimize the risks caused by the uncontrolled contacts and cutting motions in manipulation of instruments with high-speed reciprocation or rotation. Virtual reality (VR)-based surgical simulations with both visual and haptic feedbacks provide novice surgeons with a feasible and safe way to practise their surgical skill. However, creating realistic haptic interactions between a high-speed rotary or reciprocating instrument and stiff bone is a challenging task. In this work, a virtual reality-based surgical simulator for the mandibular angle reduction was designed and implemented. High-fidelity visual and haptic feedbacks are provided to enhance the perception in a realistic virtual surgical environment. The impulse-based haptic model was proposed to simulate the contact forces and torques on the instruments. It provides convincing haptic sensation for surgeons to control the instruments under different reciprocation or rotation velocities. Also, in order to mimic the lateral and axial burring vibration forces, a three dimensional vibration model has been developed. The real-time methods for bone removal and reconstruction during surgical procedures have been proposed to support realistic visual feedbacks. The simulated contact forces were verified by comparing against the actual force data measured through the constructed mechanical platform. An empirical study based on the patient-specific data was conducted to evaluate the ability of the proposed system in training surgeons with various experiences. The results confirm the validity of our simulator. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Wang, Qiong. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 100-114). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / Abstract --- p.i / Acknowledgement --- p.v / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Contributions of the Thesis --- p.5 / Chapter 1.2 --- Thesis Roadmap --- p.7 / Chapter 2 --- Related Work --- p.9 / Chapter 2.1 --- Virtual Orthopaedic Surgical Simulator --- p.9 / Chapter 2.2 --- Haptic Rendering for Virtual Surgery --- p.11 / Chapter 2.3 --- Evaluation of the Virtual System --- p.14 / Chapter 3 --- System Design --- p.17 / Chapter 3.1 --- Overall System Framework --- p.17 / Chapter 4 --- Bone-burring Surgical Simulation --- p.21 / Chapter 4.1 --- Impulse-Based Modeling of Haptic Simulation of Bone-Burring --- p.22 / Chapter 4.1.1 --- Basic Assumptions --- p.22 / Chapter 4.1.2 --- Bone-Burring Contact Description --- p.25 / Chapter 4.1.3 --- Burring Force Modeling --- p.29 / Chapter 4.2 --- Simulation of Bone Removal --- p.41 / Chapter 4.2.1 --- Bone Removal model --- p.41 / Chapter 4.2.2 --- Adaptive Subdividing Removal Surface --- p.42 / Chapter 4.3 --- Implementation and Experimental Results --- p.52 / Chapter 4.3.1 --- Force Evaluation --- p.53 / Chapter 4.3.2 --- Task-based Evaluation --- p.57 / Chapter 4.3.3 --- Time Performance --- p.61 / Chapter 5 --- Bone-sawing Surgical Simulation --- p.64 / Chapter 5.1 --- Impulse-Based Modeling of Haptic Simulation of Bone-Sawing --- p.65 / Chapter 5.1.1 --- Haptic Saw Instruments Description --- p.65 / Chapter 5.1.2 --- Sawing Force Modeling --- p.67 / Chapter 5.1.3 --- Sawing Torque Constraint --- p.70 / Chapter 5.2 --- Real-time Bone Mesh Reconstruction --- p.74 / Chapter 6 --- Evaluation --- p.78 / Chapter 6.1 --- Haptic Feedback Evaluation --- p.79 / Chapter 6.1.1 --- Mechanical Platform Setup --- p.79 / Chapter 6.1.2 --- Comparison of The Measured and Simulated forces --- p.81 / Chapter 6.2 --- Empirical Study --- p.85 / Chapter 6.2.1 --- Patient Specific Data --- p.87 / Chapter 6.2.2 --- Objective Performance Metrics --- p.89 / Chapter 6.2.3 --- Evaluation Results --- p.90 / Chapter 7 --- Conclusion --- p.94 / Publication List --- p.98 / Bibliography --- p.100
| Identifer | oai:union.ndltd.org:cuhk.edu.hk/oai:cuhk-dr:cuhk_328079 |
| Date | January 2012 |
| Contributors | Wang, Qiong, Chinese University of Hong Kong Graduate School. Division of Computer Science and Engineering. |
| Source Sets | The Chinese University of Hong Kong |
| Language | English, Chinese |
| Detected Language | English |
| Type | Text, bibliography |
| Format | electronic resource, electronic resource, remote, 1 online resource (xiii, 114 leaves) : ill. (chiefly col.) |
| Rights | Use of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/) |
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