by John Hutchinson
For the first time scientists and engineers have achieved the
construction of an artificial human head using simulated tissue and
bone that can measure and assess the ways in which brain injuries are
caused by impacts.
The head, named DERAMan by the British team developing it, contains a
simulated brain made with realistic materials that mimic the brain in
the ways they reflect, transmit and dissipate energy. Uniquely, these
advanced polyurethane materials contain banks of small
ultra-sensitive sensors that monitor potentially harmful stress waves
passing through the brain during and after impact to give researchers
a highly accurate picture of the impact's effect on different regions
of the brain.
DERAMan - or Dynamic Event Response Analysis Man - has been
constructed by researchers at Britain's Defence Evaluation and
Research Agency (DERA) in southern England. Here, Dr Sandra Bell and
her colleagues have drawn together widely differing strands of high
technology research being undertaken at DERA to gain a much clearer
understanding of impact-related head injuries and to identify ways of
reducing them.
More than 100,000 deaths are caused by head injuries each year
worldwide and about 90,000 people are left disabled, many in motor
vehicle, sporting and defence environments. Researchers are confident
that DERAMan will pioneer a standard test methodology to cover these
and all other causes of head injuries based on the quantification of
the actual work done to components of the head by impact-related
energy waves.
Such a method would enable scientists to calculate accurately all
risks of potential head-impact injuries and to assess the real
effectiveness of head-protection equipment, while at the same time
acting as a design tool to develop better protective systems.
Whiplash injury is one specific project on which DERAMan will focus
soon, enabling researchers to discover the exact mechanisms by which
injuries are received. Its smart range of piezoelectronic sensors
buried in the middle of its brain between the two cerebral
hemispheres and lining the inner surface of the skull, will be able
to identify the physical phenomena responsible for whiplash injuries.
This instrumentation allows the assessment of all likely events
inside the brain including gross movement after impact,
three-dimensional high-amplitude stress wave propagation and relative
movement between components of the brain. Linked to these instruments
are advanced analysis techniques that can chart the spread of the
energy involved in the impact and identify the critical parameters
responsible for injuries.
British-developed materials and technologies in DERAMan include
ultra-thin film arrays that monitor the spread of shock waves,
conducting polymer array devices that provide acoustically
transparent sensing materials forming part of the brain's structure,
and accelerometers and gauges to define the relative movements of
brain components.
Its 90 channels of information are fed into a computer for real-time
analysis, enabling researchers to build a three-dimensional
understanding of the ways energy waves propagate within the brain and
injure or kill the cells in tissue.
For the defence industry, DERAMan will pioneer an accurate way to
assess the risk of injury to personnel using various types of body
armour. By giving precise information both on deformation of tissue
behind the armour system and on the shape and form of the transmitted
stress, the head's technology will enable injury mechanisms
associated with behind-armour trauma to be identified and improved
armour to be designed as a result.
The safety of aircrew ejecting from stricken military aircraft is
another vital application for the DERA system, whose technology will
allow scientists to quantify the serious threats to the spine caused
by the initial explosive release of the seat (that sends a
high-frequency stress wave up the pilot's spine) and by the rapid
acceleration forces, that load the pilot's head with massive amounts
of injury-risking energy.
DERAMan's capability stems from the use of various world-leading
technologies developed by DERA scientists. These include materials
with specific dynamic properties used for stealth applications on
submarines, new sensing array and imaging technologies used by
surface ships and submarine sonars, and simulation techniques that
replicate exactly the properties of human tissue and bone.
Through DERAMan these British defence-related technologies are now
becoming available to the world's civil sector, where sporting and
automotive applications are particularly urgent. Every sport that
carries a heavy risk of impact injury, such as motor racing, boxing,
karate, and rugby, is set to benefit by the new technology - as is
the automotive field where safer vehicles can be designed using its
ability to record accurately the injury mechanisms occurring on
impact.
This innovation is to become the focus of the DERAMan Club, open to
defence specialists, academics, automotive researchers, sporting
equipment manufacturers and everyone else involved with head-related
injuries. And DERA is seeking commercial partners worldwide for this
initiative.
Meanwhile, the technology in this smart artificial brain is set to
lead to follow-on work involving other parts of the body that are
particularly prone to impact injury, such as the chest and lower
limbs.
So the leading-edge technologies that have come together in DERAMan's
head will help make the 21st century a safer era for people in a
range of potentially hazardous environments around the world.
For more information contact:
Dr Sandra Bell
Griffith Building (A7), Structural Materials Centre,
DERA Farnborough
Hampshire, United Kingdom, GU14 0LX
Telephone: +44
1252 397555
Fax: +44 1252 392035