Development of In-Vivo Rabbit Model of Human Finger Skin Injuries for Determining Safety Criteria for Human-Robot Contact

An in-vivo rabbit model was developed to enable experiments for deciding the safety criteria for skin injuries in human-robot contact. The skin of the human finger was considered as a part vulnerable to harm during human-robot collaboration. The forearms and lower legs of rabbits were selected for substituting the human fingers. Computerized tomography imaging of the rabbit subjects and magnetic resonance imaging of human fingers were performed. Based on the captured images, the caudal part of the rabbit forearm and the lateral part of the rabbit lower leg were confirmed to have dimensions similar to the lateral part and the dorsal part of the human finger, respectively. Test equipment was developed to induce dynamic contacts between the rabbit parts and impactors at a velocity of 250 mm/s with a contact duration shorter than 100 ms. The dynamic pinching of fingers was represented by experiments using a wedge-shaped impactor with a rounded ridge to contact the skin and a flat-ended cylindrical impactor with a diameter of 10 mm. The skin opening and the bruising caused by the contact were investigated after the experiments. The model was confirmed to be applicable to the experiments for deciding the safety criteria.