Qin Jing, Choi Kup-Sze, Poon Wai-Sang, Heng Pheng-Ann
Department of Computer Science and Engineering, The Chinese University of Hong Kong, China.
Comput Methods Programs Biomed. 2009 Dec;96(3):205-16. doi: 10.1016/j.cmpb.2009.06.008. Epub 2009 Jul 23.
Research on collaborative virtual environments (CVEs) opens the opportunity for simulating the cooperative work in surgical operations. It is however a challenging task to implement a high performance collaborative surgical simulation system because of the difficulty in maintaining state consistency with minimum network latencies, especially when sophisticated deformable models and haptics are involved. In this paper, an integrated framework using cluster-based hybrid network architecture is proposed to support collaborative virtual surgery. Multicast transmission is employed to transmit updated information among participants in order to reduce network latencies, while system consistency is maintained by an administrative server. Reliable multicast is implemented using distributed message acknowledgment based on cluster cooperation and sliding window technique. The robustness of the framework is guaranteed by the failure detection chain which enables smooth transition when participants join and leave the collaboration, including normal and involuntary leaving. Communication overhead is further reduced by implementing a number of management approaches such as computational policies and collaborative mechanisms. The feasibility of the proposed framework is demonstrated by successfully extending an existing standalone orthopedic surgery trainer into a collaborative simulation system. A series of experiments have been conducted to evaluate the system performance. The results demonstrate that the proposed framework is capable of supporting collaborative surgical simulation.
协作虚拟环境(CVE)的研究为模拟外科手术中的合作工作提供了机会。然而,实现一个高性能的协作手术模拟系统是一项具有挑战性的任务,因为要在最小网络延迟的情况下保持状态一致性存在困难,特别是当涉及复杂的可变形模型和触觉时。本文提出了一种使用基于集群的混合网络架构的集成框架来支持协作虚拟手术。采用多播传输在参与者之间传输更新信息以减少网络延迟,同时由管理服务器维护系统一致性。可靠多播通过基于集群合作和滑动窗口技术的分布式消息确认来实现。框架的健壮性由故障检测链保证,该链使得参与者加入和离开协作(包括正常离开和非自愿离开)时能够顺利过渡。通过实施一些管理方法,如计算策略和协作机制,进一步降低了通信开销。通过成功地将现有的独立骨科手术训练器扩展为协作模拟系统,证明了所提出框架的可行性。已经进行了一系列实验来评估系统性能。结果表明,所提出的框架能够支持协作手术模拟。