New crash-test dummies to help save lives.

General Motors recently added a new model to its crash-test dummy line. The innovation is a dummy with a "tummy" representing a pregnancy--a rounded polyurethane container holding a model of a 28-week fetus floating in gel with the same density as amniotic fluid. (Matthew L. Wald, Dummies Get Smarter for Car-Crash Tests, N.Y. Times, Jan. 23,1994, at 1.)

Researchers will be able to study some of the effects of auto collisions on pregnant women and their unborn offspring. One goal is to find the safest configuration for scat belts. Currently, pregnant women are advised to wear a lap belt low on the hips and a shoulder belt that crosses the sternum and passes around, not over, the belly.

Researchers want to know if wider webbing would help spread the impact of a collision, and whether it would be safer if a pregnant rider could switch off an air bag so it wouldn't deploy. Ballooning air bags hit passengers hard.

The greatest danger to fetuses in collisions comes from placental separation, which may be caused either by a direct blow to the mother's abdomen or by inertial forces that affect her body when brakes are slammed. Unfortunately, scientists do not know how much force it takes to tear the placenta loose or whether the amount varies depending on the stage of the pregnancy The next generation of dummies will have umbilicus-and-placenta-like structures so researchers can at least measure the internal forces experienced in different types of collisions.

Current crash-test dummies were developed using data from human bodies that had been donated to science. If real flesh and bone had not been subjected to measured impact and then autopsied to find out what happened, engineers say they could not have developed mechanical dummies with the right flexibility and tensile strength.

Better dummies and better tests led to the development of safety equipment like shoulder harnesses and air bags. Crash testing is still important. With better protection to passengers, heads and upper bodies, more people survive collisions, but many have serious injuries to legs or arms.

In the 30 years since crash testing began, corpses of men, women, and children of different ages have been used, but not the corpses of pregnant women. Some animal testing was done using live pregnant baboons in the 1960s, but researchers say this is out of the question now due to animal rights activism. So researchers must use dummies to simulate impacts on fetuses.

Plaintiffs, lawyer and engineer Arnold Bortner of Birmingham, Michigan, said he welcomes the development of the new dummies. Since safety sells cars and reduces automaker liability, he commented, both the public and the auto industry should benefit from the new collision research.