虚拟手术中缝合过程的相关技术

针对虚拟手术缝合过程中软组织与缝合线交互模拟实现困难的问题,提出一种新的缝合模拟方法。首先,采用质点弹簧模型对软组织建模,为使软组织形变更加真实,在软组织质点间引入内摩擦力系数;其次,为更好地保持缝合线的刚体特征的同时,保证软组织和缝合线的交互过程接近物理真实,几何和物理方法相结合建模缝合线,运用质点弹簧模型可以对产生交互的软组织结点和缝合线结点进行受力分析,采用跟踪头结点算法计算缝合线的新位置;最后,考虑到多次缝合时软组织形变相互影响,利用已缝合结点的对应缝合点计算两个软组织的形变。实验表明,该方法有效提高了软组织形变和缝合线运动真实感,同时保证了模拟过程的实时性。

Correlation technology of suturing procedure in virtual surgery

Aiming at the difficulty of achieving interactive simulation between soft tissue and suture,a method to simulate suturing procedure in virtual surgery was proposed.Firstly,mass-spring model was used as the physical model for soft tissue.In order to perform the relative motion between two masses of soft tissue realistically,an internal friction coefficient was introduced first.Secondly,the interaction of suture and soft tissue was aralyzed.A simple linear mass-spring model with following the leader algorithm was used to model the suture.A stress aralysis was carried out,when the suture touch the soft tissue,so the interaction process was close to physical reality.The movement of the whole suture computed by following the leader algorithm gave good performance in suture's rigidity characteristics.Finally,the interaction of the two deformable objects in a continuous pattern suture was considered,for each node of the soft tissue model,the node that attached to it was stored.This information can be used to compute the soft tissue deformation well.Experiment shows that it is realistical to simulate the soft tissue deformation and suture.meanwhile,the simulation is in real time.