基于肝脏力模型的机器人辅助进针策略

Robot-assisted Needle Insertion Strategies Based on Liver Force Model

针对机器人辅助穿刺手术中软组织形变引起的安全性和准确性问题,基于猪肝进针力模型,在分析猪肝组织结构和力学特性的基础上提出了机器人辅助进针策略.它主要包括两点:一是在穿刺针进入肝脏瞬间,机器人自动停止进针,待软组织松弛片刻后,再以减半速度继续进针,以尽可能减小软组织形变对穿刺精度的影响,提高手术准确性.二是在穿刺针进入肝脏后,如果进针力超出猪肝力模型中的"临界线",机器人立即停止进针,待排除异常后再继续进针,以防进针过程中发生意外,提高手术安全性.实验结果验证了本文进针策略的有效性.

Considering the safety and accuracy issues caused by soft tissue deformation in robot-assisted percutaneous surgery,this paper presents two strategies for robot-assisted needle insertion into porcine liver based on needle insertion force model,structure and force characteristics of porcine liver.The first strategy requires the robot to automatically stop propelling the needle in the moment that the needle enters into the liver,and then continue to propel the needle with the half speed after the liver returns to relaxed state,aiming to minimize the inaccuracy caused by soft tissue deformation and improve surgical accuracy.The second strategy requires the robot to automatically stop propelling the needle if the needle insertion force exceeds＂critical line＂of the liver force model after the needle enters into the liver,and then continue to propel the needle after troubleshooting,aiming to avoid accidents during the needle insertion into the liver and improve surgical safety.The experimental results verify the effectiveness of our strategies for robot-assisted needle insertion.