Mercedes-Benz is further extending its PRE-SAFE® occupant protection system by adding the innovative PRE-SAFE® impulse side function. If an imminent side collision is detected, it moves the occupant as far away as possible from the acute danger zone before impact. Mercedes-Benz has been protecting car occupants with its PRE-SAFE® concept in many accident situations for more than ten years. The concept includes various measures to move the occupants into the best possible position prior to an imminent impact. Unlike in the case of a frontal collision, there is only a limited crumple zone available in the event of a side impact.
To increase the size of this zone, the new PRE-SAFE® impulse side function moves the occupant in the danger zone away from the door and towards the centre of the vehicle just before an imminent side impact.
Reducing the risk of injury.
To do this, the system inflates the air chambers in the side bolsters of the backrest within a fraction of a second when an imminent side impact is detected. This impulse can move the occupant to the side, away from the acute danger area and towards the vehicle centre, thus increasing the distance between occupant and door.
At the same time, the impulse is imparted moderately to the occupant, lessening the forces acting on them during the side impact. This can substantially lessen the load exerted on the rib cage by the side collision and greatly reduce the risk of injury. Extensive tests have shown that the brief impulse does not critically affect the driver's ability to control the vehicle. The system is available as an optional extra for the front seats.
Making use of natural reflexes.
In a first, Mercedes-Benz is making use of a natural reflex to prepare the occupants' ears for the loud noise normally associated with an accident. Nature has cleverly thought of this: a muscle in our ears known as the stapedius reacts to loud noises reflexively by contracting. The contraction of this tiny muscle briefly changes the link between the eardrum and the inner ear, providing greater protection against high sound pressures.
Mercedes-Benz uses this natural reflex as biomechanical ear protection for the PRE-SAFE® Sound innovation, since an accident may cause noise to which some people react sensitively. PRE-SAFE® Sound therefore emits a short interference signal through the vehicle's sound system if the risk of a collision is detected. This signal can trigger the stapedius reflex, which prepares the ears for the noise and thus lessens the risk of hearing discomfort or damage.