September 1, 2008 Biomechanical and safety engineers added a more lifelike abdomen to models representing children between the ages of four and eight. The new design is constructed from silicon and filled with sensors to measure the strain of the seatbelt against the abdomen. Because a child's hips are more roundly shaped than an adult's they allow the seatbelt to rise up higher on the vulnerable abdomen, researchers needed an accurate model in order to improve safety.
Seat belts save lives, but older kids are more at risk for injuries during an accident than younger children. Now, car makers are working to reduce that risk. A new child crash test dummy is being put to the test to help save more lives.
Concerned parent Sylviane Hannon does her best to keep her kids safe.
"It’s a peace of mind for me at least to know that they’re okay, even if we get into a fender bender," says Hannon.
When kids grow up and out of car seats and boosters, they wear adult seat belts; but for kids from 4 to 8, those seat belts can ride up, causing harm.
"The lap belt would load the abdomen with high forces, causing severe internal organ injuries," says Randa Radwan Samaha, Ph.D., an engineer at the George Washington University National Crash Analysis Center. Now, to help invent seat belts that protect children against abdominal injuries, physicists at Ford have redesigned the traditional child-size crash test dummy and added a new real-life midsection.
"That’s one of the first things we set out to do, was mechanically develop an abdomen insert for the dummy that has the right properties to make it similar to a human," says Steve Rouhana, Ph.D., a physicist at Ford Motor Company.
The new abdomen is made of a squishy silicone material filled with sensors that measure how much the seatbelt pushes into the abdomen. The measurement helps researchers understand what happens to children's bellies during an accident.
"This will tell us for sure which region of the abdomen the belt penetrated into, and it will give us a measure of the risk of injury," Dr. Rouhana says. "We could never get that before."
How do you know if your child's safe in his or her seat belt? Engineers say a good test is if a seat belt rides up the child’s pelvis or neck, they should stay in a booster seat.
"My two youngest sons stayed in their booster seats until they were 11 years old each," Dr. Rouhana said. Hopefully, the new test dummy technology will help keep kids safe at any age.
WHAT HAPPENS DURING A CRASH? The laws of physics say that an object in motion will stay in motion, with the same speed and direction, unless it is acted upon by an outside force. So if you are traveling at 60 mph and your car hits a solid wall and comes to an immediate stop, your body will continue going at 60 mph until it is stopped by, say, a seat belt, airbag, or, at worst, a windshield. If the car has a rigid body, the rapid deceleration caused by the impact will produce injuries and fatalities. Because the stopping time is only a split second, the force on the passengers is very high.
WHY IS A NEW CRASH TEST DUMMY NECESSARY? Children from age four to eight often no longer use booster seats, but are many times more likely to sustain abdominal injuries than younger children. Seat belts are not designed for such small frames, and often rest too high, on the abdomen as opposed to along the hips. The new dummies are designed to represent the average six year old, and include an insert that mimics the hip shape of children, allowing researchers to perform experiments to improve seat belt design.
The American Industrial Hygiene Association, the American Physical Society, the Human Factors and Ergonomics Society, the Institute of Electrical and Electronics Engineers, Inc., and the Materials Research Society contributed to the information contained in the TV portion of this report.
Editor's Note: This article is not intended to provide medical advice, diagnosis or treatment.