Home' Defence Technology Review : DTR OCT 2014 Contents 43
DEFENCE TECHNOLOGY REVIEW | ISSUE 03 | OCT 2014
BATTLEFIELD EYE DAMAGE
MULTIFUNCTION RADIO FREQUENCY (MFRF)
In a recent 60-year review of 244 articles repor ting injuries associated
with explosive blasts, ocular injuries occurred at ver y high frequency,
af flicting more than 28 per cent of blast survivors. Ocular injuries now
account for 13 per cent of all battlefield injuries and are the four th
most common military deployment-related injury.
The incidence of ocular injury in combat is 20 to 50 times greater than
one would expect based on exposed surface area alone. Eye injury
rates in active duty military personnel increased from 1996 to 2005,
reaching a maximum of 26 and 21 per 1000 person-years in men and
Approximately 80 per cent of ocular injuries in military conflicts are
associated with blast fragmentation. One potential explanation for the
high incidence of ocular injury relative to its exposed area is that the
eye may be more mechanically susceptible to blast-related injuries
than other tissues.
In addition, soldiers nearly always wear head and chest protection,
but not eye protection. In the majority of these ocular injury cases
(85–90 per cent), the subjects were not wearing eye protection.
Source: Anatomical Manifestations of Primary Blast Ocular Trauma Observed in a
Postmortem Porcine Model; Daniel Sherwood, William E. Sponsel, Brian J. Lund,
Walt Gray, Richard Watson, Sylvia L. Groth, Kimberly Thoe, Randolph D. Glickman
and Matthew A. Reilly, Investigative Ophthalmology and Visual Science, Volume 55,
No. 2, February 2014.
The MFRF program seeks to develop a multifunction onboard
sensor to perform a variety of tasks that enhance the survivability
of rotorcraft and also provide lethality improvements for combat
missions in zero-zero conditions.
The sensor is intended to give pilots the following: ability to land
safely in brownout/whiteout conditions; collision avoidance with
other aircraft, obstacles and cables; terrain following; weather
avoidance; and ground mapping.
Planned lethality enhancements include intelligence, surveillance
and reconnaissance for target detection and identification, weapons
guidance, and data link. The program does not intend to perform
at currently accepted frequencies but to develop a common RF
system that will use agile frequencies, waveforms and apertures
to optimally interweave these functions according to the aircraft’s
This program seeks to demonstrate a multifunctional, software-
adaptable system architecture which will provide for future
expanded capability without adding new hardware. It is expected
that this ‘plug and play’ multifunctional system could be employed
as a replacement sensor on existing aircraft, as an insertion into
future aircraft, such as the Joint MultiRole rotorcraft, or as a sensor
suite suitable for unmanned aircraft. This will require antenna
architectures that are flexible and consume as little area and power
as possible. – DARPA
PROTECTIVE EYEWEAR HAS for some years been standard
kit for combat soldiers on operations and in training as a barrier
against fragments and foreign bodies entering the eye. A new
study, however, has found that protective glasses do little to
mitigate the effects of blast damage on eyes.
The study, by the University of Texas San Antonio (UTSA) and
the US Army Institute of Surgical Research, found that the shock
waves themselves – not just the dirt and debris created by the
blast – can cause significant and permanent damage to the eyes.
US Department of Defense data shows that ocular injuries
account for 13 per cent of all battlefield injuries and roughly 80
per cent of eye injuries in combat are associated with blasts.
Matthew Reilly, assistant professor of biomedical engineering at
UTSA, said his team undertook the study because while medical
evidence has shown that blast waves appear to cause eye damage,
few studies have been done to actually document the injury.
The research, he said, could lead to improved diagnosis at the
time of injury and, eventually, better eyewear.
Conducted over two years, the study involved researchers,
including Reilly, US Army ocular trauma expert Colonel Jeff
Cleland and others, a high-powered shock tube and pig eyes
obtained from a slaughterhouse.
They exposed the porcine eyes to pressure waves of various
levels, simulating different sizes of improvised explosive device
(IED) blasts at various proximities, monitoring the tests with
high-speed videography and measuring pressure with sensors.
Post impact photography, ultrasonography and histopathology
were performed and ocular damage subsequently assessed.
The results indicated clearly that the shock wave from an IED
alone, even in the absence of shrapnel or other particles, can
cause significant damage to the eyes that could lead to partial
or total blindness. The results also showed that even eyeballs
exposed to lower pressures had damage.
Of note is that pig eyes are similar in structure to human eyes
but with one key and relevant difference – they are firmer.
“This could mean that our results underestimate the level of
damage caused by a shock wave to the human eye,” Reilly said.
Particularly concerning was the finding that shock waves can
damage the optic nerve, which transmits information from the
eye to the brain. Optic nerve injuries occur even at low pressures
and could be the cause of many visual deficits, which until now
have been associated with traumatic brain injuries.
Future research, he said, will look at computer models for
protective eye wear and similar experiments to test materials
developed by those models to protect soldier’s vision from a
– Ian Bostock
ABOVE: Protective eyewear appears to go only so far in
preventing eye injuries amongst combat troops. Image: USMC
can damage eyes
Research shines light on potential
for permanent sight impairment.
THE US DEFENSE ADVANCED Research Projects Agency
(DARPA) successfully completed flight demonstrations in
September of its new Multifunction RF (MFRF) system aimed
at overcoming the challenges faced by helicopters operating in
degraded visibility conditions.
Poor visibility caused by severe weather, fog, dust, salt spray
and poor visual contrast against background terrains is often the
nemesis of tactical helicopter operations. Current sensor systems,
says DARPA, that are able to provide the necessary visual clarity
through obscurants struggle with latency and tend to be “...too
large, heavy and power-intensive to comply with military rotary-
The MFRF program seeks to develop multifunction sensor
technology that would enable sensor packages small, light and
efficient enough for installation on existing and future rotary-wing
aircraft designs. The MFRF would enable pilots to:
• Take off, fly and land safely in degraded and zero-visibility
• Avoid collisions with other aircraft, terrain and man-made
obstacles (e.g power lines) during flight or while landing
• Improve target detection, identification and engagement
The MFRF flight demonstrations on a UH-60L Black Hawk
(refer embedded video) demonstrated the Synthetic Vision
Avionics Backbone (SVAB) technology portion of the program.
The SVAB technology demonstration fused millimeter-wave
radar with multiple terrain databases and onboard platform
navigation to create high-resolution 2D and 3D visualisations of
local environmental conditions. Pilots referred to the visualisations
in real time to distinguish terrain features (slope, roughness,
landing suitability), detect objects in a landing zone, detect and
avoid obstacles, and navigate in GPS-denied conditions. The
software architecture of the SVAB also demonstrated plug-and-play
sensor control and display.
– Mario Attopardi
A HH-60M Black Hawk medevac helicopter fights through
a dust storm on approach to Contingency Operating Site
Cobra, Iraq. Helicopter operations hamstrung by low visibility
conditions due to airborne sand and dust have been a feature
of operating in Iraq and Afghanistan. Image: US Army
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