Development of a novel test method for skin safety verification of physical assistant robots

The study mainly concerns a novel blister generation method for the establishment of a safety verification test. This test system focuses on the skin friction trauma, which has been found in the operators of physical assistant robots due to their misuses or overlong operating, and can even deteriorate into serious dermatopathya without preventing and prompt treatment. In the present study, first, we prove that blisters can be generated in the porcine skin. With the histological section of the porcine skin getting micro blisters, the symbols of porcine skin's blister in the dermis-epidermis structure are identified with those of human blisters, and summarized for applying this substitutive material to help researchers avoid the ethical controversy of adopting human subjects. Second, the characteristics of blister generation in the porcine skin were further confirmed with a series of time-gradient tests. After a condition-matching calculation, these characteristics are verified to play a role on extending that of human blister in previous studies and we integrate our results with the previous human blister generation data and clarify an inherently safe condition region in the shear stress - time relationship. Third, with this novel method, we successfully complete a safety validation test on a “stand up and sit down” activity of a user wearing a physical assistant robot, which finally proves our findings are of practical usability in regard to a possible physical stress hazard.