Senior Design Crash Test

74 year old Grace Browne has been driving since she was a teenager. But, today, it's with much caution, even some trepidation when she gets behind the wheel. "My bones are not as strong as they used to be." Like Grace, for many senior citizens driving a car just isn't the simple procedure it used to be.

Grace suffers from arthritis and she knows all too well about the repercussions of a car crash. "I broke my collar bone because the car jammed into the right hand side." says Grace. Recently, a group of engineering seniors at Johns Hopkins University invented a harness and vest system that could possibly help senior citizens like Grace in the event of a car crash. The goal was to devise a restraint system that could protect senior citizens who battle osteoporosis and brittle bone disorders. "Ultimately it would result in less bone fractures or contusions or just general injuries to the thoracic region." says Andrew Merkle, associate researcher at Johns Hopkins University.

Unfortunately, a bad fall or car crash can do tremendous damage to senior citizens. According to Dr. Barbara Paris,a geriatrician with Maimonides Hospital, "Most elderly people do have fragile, thin bones because there's a shift in the metabolism toward breaking down bone as you get older." Osteoporosis is a disease characterized by low bone mass and structural deterioration of bone tissue, which leads to bone fragility and an increased susceptibility to fracture, especially of the hip, spine and wrist.

According to the National Osteoporosis Foundation, 10 million Americans are estimated to have the disease and almost 34 million more have low bone mass, placing them at increased risk for osteoporosis. In a crash lab facility at Johns Hopkins University, students tested a foam filled vest and a harness on high-tech crash dummies. "We're using 3 different densities of foam layered together inside the vest, and when the stress waves goes in it kind of tends to propagate inside." explains engineering student, Patrick Danaher.

The idea is that the foam vest will absorb some of the energy that causes a motorist's chest to compress during a crash. The students also replaced a conventional three-point shoulder belt with a four-point race car harness, which distributes the crash forces across a wider area of the body. "It comes over both shoulders, it makes it so that the dummy will stay in the seat a lot better." says Danaher. A high-speed camera mounted on the crash sled captured close-up images of the dummy as it was jarred by impact.

Students discovered that the vest and harness helped to significantly decrease sternal compression. The students may have their first customer in Grace. "I would feel more comfortable and yes, more secure with having something that would protect me better than just a plain seatbelt, it would give me more confidence while driving." says Grace, glad that people are realizing the importance of developing senior citizen services that make life easier for the older section of society.

For more information on osteoporosis, click here.