Human Factors Guidelines for Interactive 3D and Games-Based ...

Facial Hair. There was an early proposal to include substantial facial hair on the virtual casualty.
However, this was advised against, as members of the Armed Forces (and especially those in the
Army) are encouraged to remain as clean-shaven as possible at all times in order to ensure a good
seal between the facial skin and nuclear, biological and chemical protective respirators (such as the
UK’s S10 assembly). A similar proposal was
put forward to animate a fly landing on the
casualty during the procedure. The final rightarm
tattoo was a concession and, interestingly,
did not attract adverse comments from the early
users! The casualty’s nipples also appeared
later in the development process!
Stethoscope Tubing Dynamics. In the
original ITT, developers had programmed quite
dramatic flexing algorithms into the stethoscope
tube object. During the Airway-Breathing-
Circulation (ABC) animation sequence, as the
avatar hand moved the stethoscope towards the
casualty, the tube flailed quite dramatically
around the scene (Figure 25) which many end
users found both comical and distracting.
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Figure 25: Excessive virtual stethoscope tube
flexing effects.
Source: Author’s Image Archive
“Hovering canula”. This is actually not a significant item but was noticed by one or two surgeons
during the early reviews of the original ITT. Once the virtual canula had been acquired for blood
extraction and fluids had been administered, the animated process by which the surgeon inserted it
into the casualty’s right arm depicted the canula “hovering” slightly in front of the surgeon’s hands,
describing its own insertion path
just ahead of the surgeon’s hand
movements.
Laryngoscope Environment
Mapping. This was considered to
be so distracting that it even
created a virtual “glare” effect
when using the laryngoscope in
conjunction with the suction and
intubation tubes. Some users also
noted – having stopped the
intubation procedure – that the
reflection on the laryngoscope
surface was actually wrong,
showing the casualty’s body, DPM
trousers and nurse instead of
parts of the surgeon’s own virtual
body (Figure 26)! This may
appear too critical, but it was
surprising that this was actually
detected by at least 3 of the early
users of the system!
Figure 26: “Impossible” reflections on virtual laryngoscope
surface.
Source: Author’s Image Archive
Do not assume that end users will not notice shortcomings in fidelity and
other aspects of game design. Hypo- and hyper-fidelity effects or task-
irrelevant features may adversely affect an end user’s acceptance of and
performance on a part-task simulation.