Skin-fat-muscle urethane model for palpation for muscle disorders

Rehabilitation therapists are required to palpate human muscles and to correctly judge whether the hardness of tissues is abnormal or not. We developed artificial urethane models of muscles for educational purposes. Most of the earlier studies and commercial products addressed tumors caused by internal diseases. We produced several types of urethane models with different layered structures, and with fabric sheets inserted between the layers, after the measurement of the stress-strain characteristics of the skin, fat, and muscle tissues of the human gluteal region. Furthermore, 10 therapists subjectively evaluated each model concerning its similarities to the actual human gluteal region. As a result, a model that exhibited the most similar mechanical and haptic sensational properties to the actual tissue was specified. Our methods of measurement and the design of the urethane model, which includes multiple urethane layers of different hardness and fabric sheets, allowed us to create human-like muscle tissue models for palpation.