Functional Expression of Low Puncture Resistance and Physical Property Evaluation of a Suture Training Model Made of Polyurethanes

Polyurethanes are applied as artificial skin materials for medical simulators. There is a difference between human skin and artificial skin for simulators with respect to "puncture resistance." Based on comments from medical doctors who perform puncture procedures in clinical sites, puncturing human skin is expressed as "low needle resistance," whereas the artificial skin for simulators is expressed as "high needle resistance." It is possible to practice medical procedures with a more realistic sensation if the artificial skin's puncture resistance is brought closer to that of the human skin. In this study, sensory evaluations via needle suturing and quantitative evaluation via measuring devices were performed to clarify the relationship between the puncture resistance force and physical properties of three artificial skin samples for a suture training model made of polyurethanes. The composition and molecular structures of the materials were confirmed using Fourier transform infrared spectroscopy and nuclear magnetic resonance. The puncture resistance force measurements showed that Regina's artificial skin: MODEL A was the lowest in three samples. Additionally, we discovered that low Young's modulus and the amount of plasticizer contributed to the decreasing puncture resistance of MODEL A. This study proposes methods to combine sensory evaluation by humans and experimental data of the materials for the suture training model.