Head injury criterion

In the design of robotic systems that safely interact with people, it is useful to have validated criteria for measuring injury risks. To this end, some researchers have advocated the use of metrics developed for assessing automotive safety, with the head injury criterion (HIC) receiving particular attention. The aims of this commentary are to clarify the proper use of the HIC, to briefly discuss its relationship to the risk of injury, and to give a closed-form formula for the HIC value produced by a simple mass-spring model of impact. We emphasize that there are many other factors besides HIC to consider before a robot system can be considered safe to interact with humans.