Session: 06-05-01: Biomedical Devices

Paper Number: 111897

111897 - Mechanics of Scorpion-Inspired Curved Tip Needle Moving in Soft Tissue 

Soft tissue biopsy is a necessary diagnostic and therapeutic procedure, but traditional biopsy needles can cause harm to the patient, including tissue damage, bleeding, and pain. This can compromise the accuracy of the sample and negatively impact the patient's well-being. Hence, there has been a growing interest in developing bio-inspired biopsy needles that are safer, more effective, and more comfortable for the patient. For successful diagnosis and treatment, accuracy of needle insertion is vital, and previous studies are shown that insertion force, tissue deformation, and tissue damage can affect needle insertion precision. The study of scorpion inspired curved tip needle focuses on analyzing mechanics of needle-tissue interaction and creating needles that traveling through soft tissue with minimum resistance. An essential aspect of the study is the mechanics and geometry of the needle tip, which plays a crucial role in its performance. Traditional needles with sharp tips can easily penetrate tissue, but often damage significantly. On the other hand, rounded tips are gentler but less effective in penetrating tissue. The study incorporates structures of curved insect’s stinger such as scorpion to achieve a balance between penetration and minimal insertion force. In this study, various parameter of scorpion inspired curved tip geometry is studied to decrease the insertion force. The curved tip needles are scaled up with outer diameter of 3mm and length of 180mm due to manufacturing difficulties. They are designed with a computer-aided design (CAD) software and manufactured by using three-dimensional (3D) printing technology with polymer material of Young’s modulus of 2.8 GPa. The needle insertion experimental setup is developed to measure the insertion force and tip deflection. Tests are initially performed on tissue mimicking polyvinyl chloride (PVC) gel with Young’s modulus of 1.5 kPa, which is similar stiffness of bovine cerebrum in white matter. The preliminary study shows that the insertion force is decreased by up to 22% in insertion tests of PVC gel. For further investigation of the proposed needle tip design performance in real tissues, the insertion tests into bovine brain are performed. In terms of Young’s modulus, bovine brain tissue has complex mechanical behavior because white matter and gray matter in cerebrum have significantly different stiffness. Non-homogeneous anisotropic tissue can cause different behavior of test results compare to homogeneous isotropic tissue, which is PVC gel in this study. In conclusion, the result of this study shows that scorpion inspired tip design can minimize insertion force, which will lead to less tissue damage and deformation. Furthermore, proposed tip design has great potential to improve surgical needles for more effective minimally invasive percutaneous procedure with various applications such as biopsy, brachytherapy, tumor ablation, and drug delivery to the brain.

Presenting Author: Doyoung Kim Temple University

Presenting Author Biography: Doyoung Kim is a PhD candidate in the Department of Mechanical Engineering, Temple University. Her research focuses on the study of mechanics of surgical needles. Currently, she is working on a project involving curved tip needle inspired by scorpion stinger for studying insertion force, tissue damage, and target accuracy. She received her BS and MS degrees in Mechanical Engineering from Drexel University in 2020.

Authors:

Doyoung Kim Temple University
Parsaoran Hutapea Temple University