Airbag and vehicle passenger restraint system

A vehicle passenger restraint system, comprising:

• a sensor configured to generate a detection signal in response to detecting a collision event;
• a controller configured to receive the detection signal from the sensor and generate an actuation signal in response to the detection signal;
• an inflator device configured to receive the actuation signal from the controller and produce gas in response to the actuation signal;
• and
• a passenger airbag coupled to the inflator device to receive gas from the inflator device;
• wherein the passenger airbag includes an inflatable cushion including an upper rear portion with a convex surface and a lower rear portion with a concave outer surface when the airbag is deployed;
• and
• wherein the passenger airbag further includes a longitudinal tether secured to the lower rear portion to limit longitudinal expansion of the inflatable cushion and form the concave surface in the lower rear portion;
• wherein the passenger airbag further includes a lateral tether traversing the longitudinal tether when the inflatable cushion is deployed;
• wherein the passenger airbag further includes a supplemental tether interconnecting the lateral tether and the lower rear portion;
• wherein the convex outer surface is configured to support a head of an occupant when the airbag is deployed, and the concave outer surface is configured to support a pair of shoulders of the occupant to provide an initial predetermined clearance for a chest of the occupant when the airbag is deployed;
• wherein the concave outer surface is adjacent to a bottom portion of the inflatable cushion.