論文ID: 24-00175
Personal care robots are assumed to be frequent contact with humans. Thus, the limitation of mechanical inputs should be clarified for the development of safety standards on human-personal care robot interactions. In our previous studies, in vivo impact tests has been conducted using anesthetized pigs in order to obtain the injury resistance threshold caused by human-robot interactions. The impact points in this tests were selected the porcine chest and extremities. As a result, the bleeding threshold value of the porcine extremities was lower than that of the chest. However, the bleeding threshold of the porcine extremities has not been clarified yet. In this study, to investigate the threshold value for bleeding of the porcine extremities, we performed in vivo impact tests under the low impact energy conditions. Moreover, in vivo impact tests were simulated using a finite element model at the part of porcine thigh based on CT images to identify the tissue-level injury resistance evaluation index and the threshold value for bleeding. As a result, when the maximum stress based on the maximum impact force and contact area was used as the injury resistance evaluation index, the injury resistance threshold value for bleeding was 1.16 MPa in the in vivo impact test. The part of first principal stress concentration in the finite element analysis was in good agreement with the bleeding point obtained from in vivo impact tests. Moreover, when the first principal stress was used as the tissue-level injury resistance evaluation index, the threshold value for bleeding was 0.74～0.80 MPa.
