3D Printed Multi-material Medical Phantoms for Needle-tissue Interaction Modelling of Heterogeneous Structures

Jun Yin,Hongzhao Zhou,Yixiong Zheng,Liang Ma,Guangli Dai,Manqi Li

doi:10.1007/s42235-021-0031-1

Jun Yin, Hongzhao Zhou + Show 4 more

Open Access

https://doi.org/10.1007/s42235-021-0031-1

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Abstract

The fabrication of multi-material medical phantoms with both patient-specificity and realistic mechanical properties is of great importance for the development of surgical planning and medical training. In this work, a 3D multi-material printing system for medical phantom manufacturing was developed. Rigid and elastomeric materials are firstly combined in such application for an accurate tactile feedback. The phantom is designed with multiple layers, where silicone ink, Thermoplastic Polyurethane (TPU), and Acrylonitrile Butadiene Styrene (ABS) were chosen as printing materials for skin, soft tissue, and bone, respectively. Then, the printed phantoms were utilized for the investigation of needle-phantom interaction by needle insertion experiments. The mechanical needle-phantom interaction was characterized by skin-soft tissue interfacial puncture force, puncture depth, and number of insertion force peaks. The experiments demonstrated that the manufacturing conditions, i.e. the silicone grease ratio, interfacial thickness and the infill rate, played effective roles in regulating mechanical needle-phantom interaction. Moreover, the influences of material properties, including interfacial thickness and ultimate stress, on needle-phantom interaction were studied by finite element simulation. Also, a patient-specific forearm phantom was printed, where the anatomical features were acquired from Computed Tomography (CT) data. This study provided a potential manufacturing method for multi-material medical phantoms with tunable mechanical properties and offered guidelines for better phantom design.

Highlights

In recent decades, medical phantoms play an important role in medical resident training and surgical planning
Several force peaks appear in the insertion force-depth curve due to the process of needle tip contact, deforming and penetrating through the infill of soft tissue layer
Medical phantoms with multi-layer structure and tuneable mechanical properties were fabricated by a multi-material 3D printing system

Summary

Introduction

Medical phantoms play an important role in medical resident training and surgical planning. In the field of surgical planning, traditional medical imaging techniques, i.e. Computed Tomography (CT), Magnetic Resonance Imaging (MRI), are main tools for diagnosis and preoperative planning, but these approaches fail to provide precise information of orientation and dimension, leading to misinterpretation and on-site improvisation[1]. Medical phantoms, working as tangible objects, benefit surgeons by providing spatial sense and tactile feedback, and help decreasing medical error during surgery. Biological tissues, i.e. cadavers and animal models, have been widely used in medical training, these materials still have several disadvantages. Biological tissues degrade too fast with very limited durability. Cadavers are not always feasible due to practical issues and bioethical considerations

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