Previously, the systems were installed only to prevent crashes. These were deployed based on defined speed and set for generalized passenger size. But, these prevented injuries only if you were short and of less weight. Noticing this, the car companies realized the issues with the technology and steadily refined it. So, now the new system developed is able to detect differences in height, weight, width and also deployed based on certain criteria which made these systems more safer and effective than the past systems.
Some of the high-integrated model cars have more sensors, which can tell if the passengers wore a seat belt or not, even if the passengers are awkwardly sitting in the seat.
How it works?
This system helps in reducing the risk of severe head and the chest injuries in case of accidents or certain collisions. When it exceeds the force needed to trigger the bag, then the airbag control system ignites the gas generated and then it inflates the bag in steering wheel and the instrumental panel. This process will occur within 30-40 milliseconds. When it is inflamed, the airbag observes the energy from the opposite/forward movement of the head and the upper part of the body and then it distributes the loads over a much greater area. The gas escapes from the airbags and collapses within 120 milliseconds. These systems are part of the finely tuned safety systems which include safety belt pretensioners.
These are only supplemental restrains, which will not deploy in case of all the accidents. Better always use safety seat belts and make the children seated only in the rear-end, while using the restrain systems which are appropriate to their age and to their size. If all the occupants wear their safety belts properly, then the optimum protection can be achieved.