Virtual Reality 2

Virtual Reality - What it is and How it Works

Imagine being able to point into the sky and fly. Or
perhaps walk through space and connect molecules together.
These are some of the dreams that have come with the
invention of virtual reality. With the introduction of
computers, numerous applications have been enhanced or
created. The newest technology that is being tapped is that
of artificial reality, or "virtual reality" (VR). When
Morton Heilig first got a patent for his "Sensorama
Simulator" in 1962, he had no idea that 30 years later
people would still be trying to simulate reality and that
they would be doing it so effectively. Jaron Lanier first
coined the phrase "virtual reality" around 1989, and it has
stuck ever since. Unfortunately, this catchy name has
caused people to dream up incredible uses for this
technology including using it as a sort of drug. This became
evident when, among other people, Timothy Leary became
interested in VR. This has also worried some of the
researchers who are trying to create very real applications
for medical, space, physical, chemical, and entertainment
uses among other things.

In order to create this alternate reality, however, you
need to find ways to create the illusion of reality with a
piece of machinery known as the computer. This is done with
several computer-user interfaces used to simulate the
senses. Among these, are stereoscopic glasses to make the
simulated world look real, a 3D auditory display to give
depth to sound, sensor lined gloves to simulate tactile
feedback, and head-trackers to follow the orientation of the
head. Since the technology is fairly young, these
interfaces have not been perfected, making for a somewhat
cartoonish simulated reality.

Stereoscopic vision is probably the most important
feature of VR because in real life, people rely mainly on
vision to get places and do things. The eyes are
approximately 6.5 centimeters apart, and allow you to have a
full-colour, three-dimensional view of the world.
Stereoscopy, in itself, is not a very new idea, but the new
twist is trying to generate completely new images in real-
time. In 1933, Sir Charles Wheatstone invented the first
stereoscope with the same basic principle being used in
today's head-mounted displays. Presenting different views
to each eye gives the illusion of three dimensions. The
glasses that are used today work by using what is called an
"electronic shutter". The lenses of the glasses interleaveÔe inflating air bladders in a glove,
arrays of tiny pins moved by shape memory wires, and even
fingertip piezoelectric vibrotactile actuators. The latter
method uses tiny crystals that vibrate when an electric
current stimulates them. This design has not really taken
off however, but the other two methods are being more
actively researched. According to a report called "Tactile
Sensing in Humans and Robots," distortions inside the skins
cause mechanosensitive nerve terminals to respond with
electrical impulses. Each impulse is approximately 50 to
100mV in magnitude and 1 ms in duration. However, the
frequency of the impulses (up to a maximum of 500/s) dependsÔoration simulations. Such things as virtual wind
tunnels have been in development for a couple years and
could save money and energy for aerospace companies.

Medical researchers have been using VR techniques to
synthesize diagnostic images of a patient's body to do
"predictive" modeling of radiation treatment using images
created by ultrasound, magnetic resonance imaging, and X-
ray. A radiation therapist in a virtual would could view
and expose a tumour at any angle and then model specific
doses and configurations of radiation beams to aim at the
tumour more effectively. Since radiation destroys human
tissue easily, there is no allowance for error.
Also, doctors could use "virtual cadavers" to practice
rare operations which are tough to perform. This is an
excellent use because one could perform the operation over
and over without the worry of hurting any human life.
However, this sort of practice may have it's limitations
because of the fact that it is only a virtual world. As
well, at this time, the computer-user interfaces are not
well enough developed and it is estimated that it will take
5 to 10 years to develop this technology.

In Japan, a company called Matsushita Electric World Ltd.
is using VR to sell their products. They employ a VPL
Research head-mounted display linked to a high-powered
computer to help prospective customers design their own
kitchens. Being able to see what your kitchen will look
like before you actually refurnish could help you save from
costly mistakes in the future.

The entertainment industry stands to gain a lot from VR.Ô