November 22, 1999
New government funding for Harborview crash research
For decades, motor vehicle safety standards have been based on the results of tests with crash dummies. Now research being conducted at Harborview Medical Center that involves real crash victims may help to save lives and reduce injury.
Over the past three years the medical community has begun to share findings with automobile safety engineers through the Crash Injury Research and Engineering Network (CIREN), made up of eight trauma centers nationwide. One of these sites, Harborview, recently obtained renewed funding from the National Highway Traffic Safety Administration (NHTSA), with a five-year grant for $2.2 million. Initial funding was provided by General Motors.
Trauma centers and safety engineers now deposit crash information into a core database located at the Volpe Center in Cambridge, Mass. The data bank includes detailed information on the exterior and interior components of the occupants? cars along with a list of their injuries with corresponding X-rays and CT scans.
The mathematics of crash investigation are complex and injuries vary widely, depending on the degree and force of impact, says Dr. David Grossman, co-director of the Harborview Injury Prevention and Research Center (HIPRC), principal investigator for the project, and a University of Washington (UW) associate professor of pediatrics. After a patient is admitted to Harborview and has consented to the research, HIPRC crash investigator Rob Kaufman visits the crash scene to take measurements and determine how the crash occurred. The damaged vehicle is then measured to calculate the force of the impact and the interior is thoroughly examined for occupant contacts, such as traces of skin and fabric, or even female makeup patterns on the air bag, which reveal the split-second stages of the crash.
Similar findings are often not obtainable through crash-dummy tests. Even when wearing seatbelts, the victim?s thighbones take significant force, depending on their position, says Dr. Allan Tencer, director of the biomechanics laboratory at Harborview and a UW associate professor of orthopaedics. “But about 30 percent more force is added to the femur by contracting muscles when applying brakes or bracing for impact,” he adds. “Dashboard designs don?t take that extra force into account and they may be too stiff, despite dummy tests predicting that the forces acting on the femur are too low for fracture.”
The cars selected for investigation include all makes of passenger vehicles, light trucks and vans, but there is a special focus on later models equipped with airbags. Patients are selected for the severity of injuries, and they must have been restrained by either a seat belt or a deployed airbag, says Kathleen Loeffler, trauma research nurse for the CIREN project at HIPRC. She conducts interviews with survivors, who make up about 80 percent of the crash victims examined. Patients are followed after six to 12 months to see how they have recovered both physically and psychologically. Each trauma center reviews about 50 cases per year.
Injuries are graded by severity and mechanisms. Cases have shown that:
* In a head-on collision, the occupant can slide under the belt and dashboard if the seatbelt is worn too loosely. Sometimes the floor pan and dashboard can intrude and cause injuries. It?s crucial that the seatbelt be worn snugly.
* With more sport-utility vehicles and trucks on the road, many of these vehicles are crashing into smaller cars. In side collisions, there is a greater chance of chest injuries on the near-sided occupants because the impact is higher on the smaller car.
* Children often get injured because the shoulder straps on seatbelts don?t fit properly if they are not using booster seats.
* Passengers who use only the automatic shoulder strap without wearing a manual lap belt have a higher risk of liver lacerations. It is imperative that both of these belts be worn properly.
* Passengers wearing lap belts but no shoulder strap (usually in the back center seat), or who put the shoulder strap behind their back, have a higher risk of breaking the first or second lumbar vertebrae, causing paralysis or perforating the small bowel.
Event data recorders, now contained in late-model GM cars, can be very useful in reconstructing crashes, says Grossman. These record information such as when the airbag deploys, the crash force and whether the occupant was belted.
“Federal vehicle crashworthiness data can take up to two years to be released,” says Kaufman. “CIREN can get feedback to the engineers and NHTSA more quickly on the new models and help improve the safety designs. For the first time the medical community, automotive engineers, crash investigators and other related professions have united to improve trauma care and vehicle safety.”
