Japan is recognized as a country that has advanced pediatric care standards. It has the lowest infant mortality rate in the modern world due to rapid improvements in the results of perinatal treatments. Japan's policies to prevent childhood accidents, however, are inadequate compared to those of various other foreign countries, and accidental death is the leading cause of childhood deaths. Many children are still injured in moter vehicle collision. Upon examining the number of fatalities in children aged 12 years and younger and by evaluating the situation in which the loss of life occurred, it can be seen that approximately half the pediatric casualties were pedestrians. Thus, the subject of updating policies to prevent pedestrian accidents is very important. Additionally, since 2000, infants aged 6 years or younger have been required to be strapped into child restraint system（CRS）when they are riding in a vehicle. However, even now, more than 15 years later, the percentage of children who are made to ride in CRS is low, and this percentage decreases as the child's age increases. Consequently, injuries have been observed resulting from the improper and inadequate use of CRS in vehicles. To quickly solve these types of problems, it is first necessary to have personnel who deal with children's public health to look out for the safety of children in familiar settings. As part of this plan to protect small children, it is also necessary for these people to promote awareness about the use of CRS and to educate and instruct the guardians of every child on the advantages of CRS.

View full abstract

28％ of traffic accidents in Japan are rear-end collision. Multiple collision is 13％ in rear-end collision. Post crash brake system is one of post crash safety technology. Post crash brake system supports driver to stop vehicle in short distance after rear-end collision, to prevent secondary collision. In this study, effectiveness of post crash brake system was examined using driver recorder database. In 64％ of rear-end collision, driver interrupted the brake after the collision. Stopping distance was estimated with time data recorded in drive recorder. The brake assist by post crash system would be effective in 21％ cases to prevent secondary collision. However it is not possible to avoid the secondary collision at a high speed accident. Considering the velocity distribution of striking vehicle in rear-end collision in Japan, the brake assist by post crash system would be effective in 668 cases per year for normal passenger car.

View full abstract

The Curtain Side Airbag（CSA）is the supplemental restraint system for the occupant head protection during the side impact accidents. In Japan, pole side impact regulation will be effective at September 2018. CSA is one of the items for satisfying the pole side impact regulation, so most vehicles will be equipped with CSAs. Most CSAs protect not only front seat occupants but also rear seat occupants. So when CSA is deployed, there is a possibility that CSA influence child occupant seated in Child Restraint System（CRS）fixed in rear seat. However, the influence of CSA to child occupants seated in CRS has not studied so much. In this study, we conducted side impact tests based on the specifications of UN Regulation No.95 except for the installing CRS and Q3s dummy at rear seat. To investigate the influence of CSA for child occupant seated in CRS, these tests were conducted for struck vehicles with and without CSA for two types of vehicles. In this test series, we confirmed that the CSA was deployed between dummy heads and CRS side wings in both vehicles. As for the head injury measures, those in vehicles with CSA were smaller than those in vehicles without CSA. As for the neck injury measures, the lateral moments in the vehicles with CSA were larger than those in vehicles without CSA. Extension forces in the vehicles with CSA were smaller than those in vehicles without CSA. So in this research, CSA was effective to protect the child occupant head seated in CRS installed at rear seat. However, as for the neck injury, there were both cases that CSA protected and CSA attacked. So it is necessary to research more.

View full abstract

Mortality of severe acute subdural hematoma is very high, therefore decompression craniotomy as soon as possible is recommended. We examined the cases of severe acute subdural hematoma by traffic accidents, operated in emergency room, about the time coarse, outcome and efficacy. Between April 2011 and December 2016, we operated 7 patients of severe acute subdural hematoma in emergency room, and traffic cases were 6. We examine duration of onset to arrival to hospital, duration of arrival to diagnosis by computed tomography and duration of diagnosis to operation, and outcome on discharge. Mean duration of onset to arrival to hospital is 38.8 minutes, mean duration of arrival to diagnosis is 25.2 minutes, and mean duration of diagnosis to operation is 25.8 minutes. On discharge, the results were 3 good outcomes（GR 1, MD 2; 50.0％）, and death is 1（16.7％）. Decompression craniotomy in emergency room is able to be started within 30 minutes, therefore there is a possibility that it improves the outcomes of severe acute subdural hematoma.

View full abstract

In Japan, tall minivans are very popular recently. The center of gravity height of those vehicles are rather higher. So they tend to rollover after even slight collisions. Rolling over of tall minivans cause the occupants to fall down to the road surface, and their heads are squeezed by the pillars of rolling vans. We carried out a crash test using a tall minivan simulating the real accident and reconstructed it using the computer simulation PC-Crash. Through them we realized that the rollovers happen when the yaw rate of the vehicles after collisions are synchronized with the rolling resonance frequency of the vehicles. So we recommend car manufacturers to announce the danger of tall minivans to the users and to equip curtain shield airbags in the minivans to prevent occupants being thrown out of the vehicles.

View full abstract