Suchergebnisse

An anthropometric description was developed for the fetal region of women at three, six, and nine months of pregnancy. This involved superimposing a fetal ellipse on abdominal and pelvic ellipses of seated women from a previous study. The data were developed for women of 5th, 50th, and 95th percentile size. The ellipses identify body contact zones on the side and front which would interact with the fetal region in a crash. The new information provides spatial characteristics of pregnant women for the development of test dummies, accommodating restraints, and friendly interiors and for enhancing crash protection. This research addresses the 342 deaths of pregnant women estimated to occur annually in motor vehicle crashes.

Left arm position was determined from movies taken by the Insurance Institute for Highway Safety of 1890 vehicles approaching an intersection on a normal two-lane road. The dynamics of driving were apparent as the drivers shifted their left arms from the armrest to place their hands on the steering wheel 23.8% of the time when stopping at intersections. Whereas drivers used the armrest 34.4% of the time on the open road, the armrest was used only 10.6% of the time at the intersection. The driver's left hand was on the steering wheel 69.6% of the time at the intersection. Use of the windowsill to rest the arm varied among passenger cars, trucks/vans, and sports cars primarily because of differences in shoulder and windowsill height. A lower relative position in trucks and vans promoted use of the windowsill to rest the arm. Given that serious injury in multivehicle side impacts most frequently occurs in intersection crashes, design improvements of the side interior should focus on direct loading of the chest and abdomen. In addition, crash tests should be set up with the dummy's left hand on the steering wheel and arm away from the side.

A novel method for the study of repetitive mild traumatic brain injury (rmTBI) that models the most common form of head injury in humans is presented. Existing animal models of TBI impart focal, severe damage unlike that seen in repeated and mild concussive injuries, and few are configured for repetitive application. Our model is a modification of the Marmarou weight drop method and allows repeated head impacts to lightly anesthetized mice. A key facet of this method is the delivery of an impact to the cranium of an unrestrained subject allowing rapid acceleration of the free-moving head and torso, an essential characteristic known to be important for concussive injury in humans, and a factor that is missing from existing animal models of TBI. Our method does not require scalp incision, emplacement of protective skull helmets or surgery and the procedure can be completed in 1-2 minutes. Mice spontaneously recover the righting reflex and show no evidence of seizures, paralysis or impaired behavior. Skull fractures and intracranial bleeding are very rare. Minor deficits in motor coordination and locomotor hyperactivity recover over time. Histological analyses reveal mild astrocytic reactivity (increased expression of GFAP) and increased phospho-tau but a lack of blood-brain-barrier disruption, edema and microglial activation. This new animal model is simple and cost-effective and will facilitate characterization of the neurobiological and behavioral consequences of rmTBI. It is also ideal for high throughput screening of potential new therapies for mild concussive injuries as experienced by athletes and military personnel.