Needle Cutting of Skin Simulants

Tissue simulants are commonly used in medical procedure training and research to test the insertion and cutting mechanics of medical devices. Accurate representation of the forces and tissue properties is important for the efficacy of the training and research studies. This paper provides a quantitative method of determining the performance of tissue simulants. A force model was used to determine the three component forces: tearing, spreading, and friction forces, of a needle passing through six different skin simulants. Experiments were performed to determine the fracture toughness, shear modulus, friction between the simulant and needle, and the crack length in the simulant made by the needle. Polyurethane with Shore hardness 40 A was shown to be the best simulant by having the composition of forces most similar to porcine skin tissue: 39% and 61% for the tearing force, 18% and 32% for the spreading force, and 29% and 21% for the friction force for the polyurethane and porcine skin respectively.