Investigating Tissue Targeting Accuracy in Needle Insertion with Pause and Pullback by Optical Imaging and Cohesive Based Finite Element Modeling

• Main Authors: Chun-JungYen, 嚴焌榮
• Other Authors: Chi-Lun Lin
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/942m34

碩士 === 國立成功大學 === 機械工程學系 === 107 === Pause and pullback are seldom applied in needle insertion, but limited studies have shown its positive impact. From the view of enhancing accuracy, it is important to elucidate how to decrease the displacement responses in a large design space of needle pause and pullback. A two-dimensional dynamic finite element model is combined with the Taguchi method of experimental design. Cohesive elements were arranged in the finite element model to simulate realistic tissue damage during needle insertion. The model is verified by the optical insertion experiment, which allow to observe the interaction of tissue and needle at axial section through the non-contact method (Digital Image Correlation). Design optimization based on the Taguchi method with simulation model is carried out to find the optimal cutting parameters of the insertion design with pause and pullback. The effects of the cutting parameters to the targeting tissue displacement and the interactions between the parameters are investigated. The goal is to provide a guidance for selecting the needle cutting parameters in various conditions. In experimental results, it was found that both needle pause and pullback have a significant impact on tissue displacement. When performing needle insertion with pause, results show that tissue displacement can effectively be reduced by a range from 17% to 26%; while with pullback, it increases tissue displacement by a range from 21% to 24%. In simulation result, the main effect plot shown that factors pullback distance, pause distance, and second pause period, which was lack of investigation, can affect the tissue displacement