Biomedical Engineering Reference
In-Depth Information
other small-scale applications, the spatial extent of the environments means that it is
technically feasible to implement walking by tracking users in an empty room that
contains the environment on a 1:1 scale, but a hybrid real/virtual walking interface
may prove more practical [
10
].
Motor rehabilitation applications are concerned with a patient's gait, and so only
require translational body-based information. This may be provided via a linear
treadmill or a specialist exoskeleton-based device, but questions remain about the
medical benefits of integrating such devices within a VE [
36
].
5.5.3 Large-Scale Environments
For applications that use large-scale VEs the consensus result is that a full walking
interface is required [
13
,
15
,
26
], and probably necessary in applications that also
require maneuverability (e.g., military training for searching a building; but see also
[
7
,
8
]). However, in a study that was unique in including a Trans condition, that
condition was as effective as a Full condition in allowing participants to acquire
spatial knowledge [
17
]. This highlights an opportunity for preserving the benefit to
users while simplifying the technology used for walking interfaces. For example,
although omnidirectional treadmills can be constructed [
37
], linear treadmills are
simpler to design and so are smaller, cheaper and more reliable.
An exception is likely to be data visualization applications, because the scale
involved (e.g., in genomics) is several orders of magnitude greater than other large-
scale applications. Given that “magic” interfaces (interfaces that allow users to make
movements that would be impossible in the real world, e.g., jump between widely
separated places) [
4
] will always be needed if users are to move rapidly and precisely
between levels of detail such as chromosome
base pair, such applications are
likely to remain based on abstract navigation interfaces.
→
5.5.4 Further Research
The main area that requires further research into navigation interfaces is applica-
tions that use large-scale environments. One priority is to thoroughly evaluate tech-
niques that allow the navigation of large spatial extents via walking movements made
within amuch smaller locality (treadmill, walking-in-place [
38
], and redirectedwalk-
ing [
39
]). Such interfaces are currently unproven, and we need to understand their
effect on participants' navigational performance and the rate at which they develop
route- and survey-type spatial knowledge. A second priority is to evaluate these inter-
faces with projection displays, because they hold advantages over HMDs in terms
of image resolution and field of view.
