Ford is developing one of the world’s first digital human child body models as part of a pioneering programme to make car travel safer for young people. “We study injury trends in the field, and we know that traffic crashes are the leading cause of death for people from age four to 34,” said Stephen Rouhana, senior technical leader for safety at Ford Research and Advanced Engineering. “We want to better understand how injuries to younger occupants may be different.”
“Our restraint systems are developed to help reduce serious injuries and fatalities in the field, and they have proven to be very effective,” Dr Rouhana said. “But crash injuries still occur. The more we know about the human body, the more we can consider how to make our restraint systems even better.”
Building a digital model is no simple task. The work on Ford’s adult human body model took 11 years to complete. Digital models are used in research, not in vehicle development. They don’t take the place of crash dummies, which measure the effect of forces on the body. Instead, they are used as a way to understand how to further improve restraint system effectiveness through better understanding of injury mechanisms.
The digital model is constructed component by component – brain, skull, neck, ribcage, upper and lower extremities – with extensive research included on each part. “Building the model of a person is just like building a model of a car,” said Dr Rouhana. “You start with your surface geometry for each component and any subcomponent it contains – in this case the geometry of the human body and its internal organs.”
After gathering such data through medical scans as well as anatomical texts, the researchers build a model section by section, creating regions of the body. The brain in Ford’s adult human digital model was constructed as a separate component, detailed down to the brain stem, the gray matter and the fluid between the layers.
The components are then joined into a virtual human body, which is extensively validated. Then, using mathematical and analytical tools combined with available data on the properties of human tissues from the medical and engineering literature, researchers are able to determine the effects of a crash – and the pressure of a restraint system – on the body.
“A child’s body is very different from an adult’s,” Dr Rouhana said. “Building a digital human model of a child will help us design future systems that offer better protection for our young passengers.”