面向腹腔镜肠道手术的人机交互缝合模拟关键问题研究

On the basis of our previous development of virtual surgery, this project is aimed to provide suture simulation laparoscopic virtual surgery, and systematically investigates the interaction mechanism between suture needle, suture and soft tissue, intestinal tissue modeling, suture modeling, and the design and control of the haptic device for virtual surgery. We propose a hybrid model of intestinal tissue to simulate the deformation and topological changes of intestinal tissue during suturing suitable in virtual laparoscopic surgery, including the features of the structure of intestine tissues, biomechanics, and deformable tissue in surgical sutures and non-stitched regions. Furthermore, we propose a complete suture dynamics model to effectively provide the axial force, torsion, bending, inextensibility of the suture, and rapid stop motions due to air drag. Moreover, we not only develop a haptic device for laparoscopic surgery simulation, but also propose a stable, accurate, and efficient adaptive impedance controller that use human hand force and virtual surgical instruments position and velocity as impedance constraints, by introducing optimal spring gravity compensation and hybrid differentiator into the haptic device. Eventually, we develop a virtual simulation system for intestinal sutures to implement real-time suture interaction in virtual laparoscopic bowel surgery. This project is of great significance in promoting independent innovation in human-computer interaction and virtual surgery in China.

课题组在前期研究基础上，以实现虚拟腹腔镜手术缝合模拟为研究目标，深入研究缝合针-缝合线-软组织之间交互机理、肠道组织和缝合线建模以及虚拟手术力触觉交互装置设计及控制。考虑肠道组织生物力学以及手术缝合和非缝合区域特点，提出一种适用于腹腔镜虚拟缝合的肠道组织混合模型，用于模拟缝合时肠道组织形变和拓扑改变；考虑缝合线形状、结构、材质和机械力学特点，提出一种完备的缝合线动力学模型，有效模拟缝合线轴向反馈力，呈现缝合线弯曲、扭转、不可拉伸等动态行为；设计适用于腹腔镜手术模拟的力触觉交互装置，采用人手受力和虚拟手术器械位置和速度作为阻抗约束，引入最优弹簧重力补偿和混合微分器，实现力触觉交互装置稳定、准确和高效的自适应阻抗控制；最终，通过建立肠道组织缝合模拟系统，实现虚拟腹腔镜肠道手术人机交互实时缝合。该项目对于推动我国人机交互和虚拟手术领域自主创新具有重要意义。

本项目以面向腹腔镜肠道手术的人机交互缝合模拟为研究目标，围绕缝合交互行为研究、腹腔软组织建模、缝合线建模、缝合动态交互物理建模、力触觉交互技术研究。首先，提出了一种面向缝合交互行为的连续空间哈希算法和连续包围盒连续碰撞检测算法，提高了缝合交互检测的剔除率和检测速度，改善了交互性能。其次，提出了一种基于径向基点插值法与质点弹簧法的混合软组织建模方法，兼顾了两种方法的优点，在保证精度的前提下，提高了计算效率，适用于软组织的形变、切割和缝合。然后，提出了一种基于kirchhoff弹性杆理论的缝合线模型，可以有效模拟缝合线弯曲、扭转等结构特点，实现缝合线的高效打结。再者，基于前面的缝合交互行为研究，开展了缝合动态交互建模研究，提出了一种缝合动态交互模型，实现了逼真有效的缝合动态交互模拟。此外，提出了一种基于最优弹簧重力补偿方法和混合微分器的自适应快速滑模终端阻抗控制算法，具有高效的力反馈性能。最后，开发了一套腹腔镜肠道手术缝合模拟系统，包含力触觉交互装置和仿真软件各1套。以通讯/第一作者在权威期刊上发表SCI论文17篇，申请和授权发明专利26项，实用新型专利1项，培养研究生19人。相关研究成果获江西省科技进步二等奖和入选江西省VR创业人才团队。该项目对于推动我国人机交互和虚拟手术领域自主创新具有重要意义。