Research On Mechanical Properties Of Soft Tissue In Percutaneous Puncture Operation And Puncture Force Modeling

The needle puncture operation is a significant part of modern clinic medicine, and needle puncture minimally invasive operations such as group testing and drug injection and targeted therapy of cancer have already been developed in clinical application. How to improve the accuracy of the minimally invasive surgery to reduce the damage to the patient, such security problems has always been the focus of attention. During the needle puncture operation, we need control the puncture needle tip into the target area. Due to the anisotropy and deformation characteristics of soft tissue, When in the actual operation, the soft tissue and the needle would be deformed because of the interact of the needle and the surrounding tissue so that the needle may deviate the ideal trajectory and cannot arrive the target area accurately. It will seriously affect the operation effect. So how to achieve precise positioning of the needle has become a key research of the needle puncture operation.With the development of virtual operation, robot auxiliary has become an important method to solve the needle puncture operation in recent years. Among them, the key of surgery needle control and precise positioning is the research that the mechanism of interaction between needle and soft tissue features and Puncture force modeling. Therefore, to carry out the relevant theory and simulation research is of great significance for the needle puncture operation.In this paper, we use typical soft tissue----pork liver as the research object in percutaneous puncture operation, and discuss mechanical properties of soft tissue as well as the precise control of needle puncture during the operation. And detailed research described as following:(1) Based on X-Y platform, we design a biological soft tissue mechanical characteristics calibration system which based on PMAC. Through the needle puncture experiment, this system can achieve real liver mechanical characteristics curves and measure and calibrate mechanical characteristics of soft tissue and also can calculate deformed parameters of tissue, which can build accurate measuring tools.(2) We model a series of deformed mechanical models based on soft tissue mechanical characteristics, and propose control strategies of needle puncture. The establishment of this model optimizes the control path of operation equipment, at the same time, improves the virtual operation of soft tissue simulation accuracy.(3) We use ANSYS to verify and receive a satisfied result. This method meet the requirements of virtual surgery.