Least square evaluation of head injury criterion (HIC) for various situations

Accurate evaluation of fall accidents is needed on the effect of protectors such as helmet or safety cap to reduce the shock from the impact to head is very important. We have done the experiment in JARI using human-type robot which simulates the human accidental injury. The precise data of acceleration has been taken from the robot, then HIC has been calculated for all the experiment. We have done the least square analysis to analyze the effects of various situations (variables) for stepwise process. Finally we calculate separate effect of HIC (average) of each variable, which is most plausible. Form the result, It is concluded that the effect of the helmet is amazing, which reduces HIC by 5903. On the other hand, the effect of the safety cap is not so large, the reduction is 1833 (about one third of helmet). The increase of the cart and bicycle is similar. In this way, we determine the reduction values of HIC using least square method. This values are valuable to predict or summarize the various effects of the situation.