Wearable Computer Systems for Affective Computing
The unique needs of an affective computing system present challenges
to designers of hardware as well as software. We expect to build systems
that maintain not only constant sensing contact with the user, but also
contact via more traditional user interface paradigms. One solution to
these hardware design challenges that we are investigating is the wearable
computer. Several research projects in Affective
Wearable systems are currently underway, and may be seen at the bottom
of this page.
Wearable computers are entire systems that are carried by the user,
from the CPU and hard drive, to the power supply and all input/output devices.
Such systems are under development here at the
Media Lab, where we are also working to create prototypes of uniquely
affective wearable systems. The size and weight of these wearable hardware
systems are dropping, even as durability of such systems are increasing.
We are also designing clothing and accessories (such as watches, jewelry,
etc.) into which these devices may be embedded to make them not only unobtrusive
and comfortable to the user, but also invisible to others.
Wearable computers allow us to create systems that go where the user
goes, whether at the office, at home, or in line at the bank. More importantly,
they provide a platform that can maintain constant contact with the user
in the variety of ways that the system may require; they provide computing
power for the all affective computing needs, from affect sensing to the
applications that can interpret, understand and use the data; and they
can store the applications and user input data in on-board memory. Finally,
such systems can link to personal computers and to the Internet, providing
the same versatility of communications and applications as most desktop
The prototype affective computing system we are currently developing uses
a modified "Lizzy"
wearable. We have several such wearable systems, and plan to use them to
create a uniform set of affective computing hardware platforms, both to
conduct affect sensing/recognizing experiments, and to develop eventual
end user systems. An example of this hardware system is shown below. The
computer module itself is five and a half inches square (about the length
of a pen), by three inches deep. It runs the Linux operating system. The
steel casing can protect the computer in falls from heights up to six feet,
even on hard surfaces like concrete. This system is durable enough that
it can withstand occasional blows, knocks, even the user's accidentally
sitting on various parts of the system without damage.
For more information on affective wearable computers, see the Vision
and Modeling Group's Technical
Report (TR) page, specifically:
The wearable computer module we are using to develop the affective
computing system. The strong steel case is five and a half inches square
by 3 inches deep, shown with the cover on (left) and off (right).
Three interface devices for wearables: The Private Eye (left) provides
a tiny monitor display that only one eye can see, and may be mounted on
a pair of safety glasses. The JABRA net (right) is an earphone device for
listening to auditory output from the system. The green part of the JABRA
fits in the ear; a microphone that sits on the end that is exposed to the
outside is for listening to sound that the ear would normally hear without
the earpiece. The PalmPilot (middle) is a PDA that can be
used without obscuring the user's vision.
The Private Eye
Instead of an LCD screen monitor attached to the computer (as with
a laptop model), the wearable computer uses more robust, personal interfaces
for "hands free" operation which allows the user to walk around freely
and have the computer operational at all times. Currently, the standard
interface for our system is the "Private Eye" (see photo below),
a text only interface that is positioned in front of one of the user's
eyes. This interface uses a row of LED's (light emitting diodes) and a
rapidly spinning mirror to create the illusion of a full screen of text.
The Private Eye is a very low power device (one half watt compared to 3.5
watts for typical VGA, head mounted devices) which means a much lighter
(and therefore slower) drain on the battery.
|The Palm Pilot is an example of a more socially acceptable
interface. While it is uncommon to see someone wearing a head mounted
display or earpiece, it is fairly common to see someone using a Palm Pilot.
This interfaces allows the user to harness the full power of the wearable
while remaining socially inconspicuous.
The JABRA net (as shown, below) is an example of a lightweight,
auditory interface, and a candidate output device for the affective wearable
computer. This interface paradigm leaves the user's eyes unobscured, and
is barely noticeable to the casual observer. An auditory interface like
the JABRA would serve well for a variety of applications, including those
that are not vision intensive. Using this interface, the computer would
use computer generated speech to speak with the wearer; the user would
be able to communicate with the system via several possible means:
A one handed keyboard like the Twiddler (see below);
A PDA style handwriting tablet or miniature keyboard;
Eventually by speaking directly to the system, with a speech recognition
system in tandem with a microphone.
|The Twiddler is currently the preferred input device
for wearable computers. It is a lightweight, one-handed, "chordic" keyboard.
A chordic keyboard, like those used by court stenographers, produces characters
by pressing combinations of buttons. Two handed chordic keyboards are capable
of typing speeds that are much faster than traditional QWERTY keyboards;
an experienced user of the Twiddler can exceed speeds of 50 wpm while using
only one hand. The Twiddler is made by HandyKey,
and is friendly to user modifications such as remapping the keys or reconstructing
the case. The Twiddler shown here has an attached "orthotic spacer" (the
orange lump on the bottom side of the Twiddler in the photo below) which
makes operation more comfortable for some users. A chordic keyboard is
very quiet, and offers the user a way to silently (and, in many cases,
privately) communicate with their computer, a desirable option even after
sophisticated speech recognition systems come of age.
The PalmPilot works as an input device as well as an output
device. It can be used for both functions simultaneously, or it can
be used in conjunction with another device.
Traditional hardware alternatives
|Before we obtained a wearable computer we simply used the sensing
system in conjunction with a lightweight laptop computer (shown
to the right) the Compaq Aero 486. This may still be the best interface
for some researchers until the wearable system is fully developed.
Research projects in Affective Wearable Computing