Volvo Cars Develops World's First Pregnant Crash Test Dummy

IRVINE, Calif., June 24 -- There are comprehensive safety systems in modern cars to protect just about every occupant -- except the unborn child. Researchers still know surprisingly little about what happens to a fetus in a car crash.

To expand engineers' and designers' understanding in this area, Volvo Car Corporation has developed the world's first official computer model of a pregnant crash dummy.

This 'virtual' crash dummy is a woman at a late stage of her pregnancy, since that is when the unborn baby is at greatest risk in an accident. The basic geometry was completed in January and much time has been devoted since then to refining the model.

"Now it's finished and we've started running simulated front-end impact tests on it," says Camilla Palmertz, a biomechanical engineer at the Volvo Cars Safety Centre in Goteborg, Sweden. "One big advantage is that both mother and baby can be scaled up or down to the size we want to study."

The purpose of these initial tests is to study how the virtual mother-to-be and her unborn baby are affected by the seat belt and airbag in simulated collisions. The computer model makes it possible to study -- in great detail -- how the belt moves, the influence of belt and airbag on the uterus, placenta and fetus, and how the fetus moves in relation to the mother's body, among other things. The model can also be used to test new designs for seat belts and other safety systems.

"I'm certain that there's room for further development of the three-point belt, to make it more comfortable and to provide even better protection," says Palmertz.

Many pregnant women wonder whether the seat belt could harm their unborn baby if they are involved in a car accident. Researchers all agree, however, in recommending that they should always wear their seat belt.

"But it's important to wear it in the right way. It should be between the breasts and as low as possible over the hips. The lap section of the belt mustn't be allowed to ride up in front of the woman's tummy," says Palmertz. "That could harm the baby."

In a crash, the pregnant woman's thorax and pelvis are both restrained by the belt, but her abdomen is free to move in the direction determined by the particular forces arising from the impact. Because the fetus is floating free inside her, injuries tend to fall into two main types. The more common of the two occurs when the placenta becomes either partially or completely detached, which means that the baby cannot get enough oxygen. Another, less likely scenario is for the head of the baby to be injured if it hits one of the bones of the mother's pelvis.

"We think that the placenta may become detached because, while the uterus is relatively elastic and can therefore change shape, the placenta is not equally resilient under acceleration," Palmertz explains.

"But we don't know yet," she continues. "That's why this model is so important. We have to find out more to be able to protect the fetus in the best possible way."

Even though there is still a great deal to learn, Palmertz is philosophical about the project. "Now we've covered the whole life-cycle," she says.

Volvo Cars of North America, LLC (VCNA), based in Irvine, CA, is a subsidiary of the Volvo Car Corporation of Gothenborg, Sweden. Volvo Cars celebrates its 75th anniversary in 2002.

VCNA provides marketing, sales, parts, service, technology and training support to Volvo automobile retailers in the U.S., Canada, Mexico and Puerto Rico.

The 2002 Volvo automobile line includes the sporty S60 and the new S60 AWD, the flagship S80 luxury sedan, the versatile V70 wagon and rugged Cross Country, C70 Coupe and convertible, and the compact S40 and V40 models.

Mothers-to-be want more information on where best to place seat belt

Study shows pregnant women don't always know exactly where to place the belt to best protect their unborn baby.

Researchers at the University of Halmstad, in Sweden, gathered initial data from a sample of pregnant women and new mothers using questionnaires. The Biomechanical Engineers then followed up with interviews.

-- All but one of the 139 women surveyed always used a seat belt before their pregnancy -- Several women in the final stages of pregnancy said that they were now using their seat belts less. The reasons: "the belt chafed;" "afraid the baby might be affected;" and, "difficult to put on the belt." -- Almost half of the women in the late stages of pregnancy had experienced problems with the belt moving upwards onto the tummy instead of remaining across the hips.

In a similar study in the United States the majority of the sample of 200 said that wearing a seat belt was uncomfortable, that it chafed, and that it slipped upwards onto their tummies.

-- Far more of the American women said they thought the belt caused discomfort. -- Far more of them also stopped using seat belts while pregnant. These differences could well be a question of habit.

In Sweden, wearing seat belts in the front car seats became compulsory in 1975. In the U.S. Safety Belts were mandated by Federal law in 1973.

Visit the Volvo Media Website: http://www.volvocars-pr.com

Comparative Studies USA and Sweden:

Percentages of women reporting discomfort caused by ...

belt chafing on lower abdomen: USA 65% Sweden 46% belt chafing and pressing against abdomen: USA 62% Sweden 43% belt too tight on breasts: USA 48% Sweden 10% belt not long enough: USA 50% Sweden 7%

Percentages of women who sometimes decide not to use seat belt because of comfort problems:

USA 13% Sweden 7%

Source:

United States - 2000, Laura Thackray sample: 200 women Sweden - 2002, Selime Eriskin and Sara Lund sample: 139 women