INTRODUCTION - Injury Biomechanics and Control: Optimal Protection from Impact - page 6

of the occupant is used to simulate the response of an occupant in a seat to
a vertical load.
Chapter 6 deals with thoracic injury control. A two-degree-of-freedom
thoracic injury model is used. A frontal impact of a car against an obstacle
is considered with the seat belt playing the role of a shock isolator. An
optimal control is constructed for the force produced by the seat belt on
the occupant's thorax. Both open-loop and feedback control modes are
considered.
A limiting performance analysis for the protection of the human head
from injuries caused by an impact against a fixed obstacle is performed in
Chapter 7. The expected severity of the injury is evaluated using HIC (Head
Injury Criterion), which is an integral criterion defined by the National
Highway Traffic Safety Administration (NHTSA) in 1972. Currently, the
HIC is used as a standard injury criterion in automobile crash tests and drop
tests of helmets. To mitigate the impact load transmitted to the brain, the
head is isolated from the surface being hit by a reasonably soft structure, for
example, a liner in a helmet or a shock isolation coating on a playground
surface. A minimal displacement of the head during the impact deceleration
is evaluated, provided that the HIC is lower than a prescribed tolerable value
and, vice versa, that the HIC is minimized, provided that the displacement
of the head does not exceed a prescribed quantity.
Chapter 8 deals with the protection of a person traveling in a wheelchair
who is involved in a frontal vehicular crash. To improve the protection, it is
proposed to attach the wheelchair to a movable platform separated from the
vehicle body by means of a shock isolator. The control of the platform is
designed to reduce the occupant's injury risk, relative to what could happen
if the wheelchair were attached directly to the vehicle. The isolator design
is based on the minimization of the force transmitted to the wheelchair
occupant, provided that the space allowed for the platform to move relative
to the vehicle is constrained. Both the control without pre-action and the
pre-acting control are considered.

1.2 RELATED STUDIES

The major studies carried out by the authors of the topic are briefly sum-
marized below.

1.2.1 Development of the Theory of Optimum Shock Isolation

Balandin, Bolotnik, and Pilkey (1999) considered a limiting performance
problem for the shock isolation of a simple deformable system with “one