Wearable Computing FAQ

This file was last modified on Wednesday 31 June 1998.
  1. Basic Information
  2. Technical Information
  3. Technical Issues
  4. Biological Issues
  5. Social Issues
  6. Forums and Other Sources
    1. On the Internet
    2. Hard Copy
  7. Meta-FAQ

1. Basic Information

What is a wearable computer, anyway? [Mann|MIT]
Wearable computing facilitates a new form of human-computer interaction based on a small body-worn computer system that is always on and always ready and accessible. In this regard, the new computational framework differs from that of hand held devices, laptop computers and personal digital assistants (PDAs). The "always ready" capability leads to a new form of synergy between human and computer, characterized by long-term adaptation through constancy of user interface.

There are five major characteristics of wearable computers:

portable while operational
The most distinguishing feature of a wearable is that it can be used while walking or otherwise moving around. This distinguishes wearables from both desktop and laptop computers.
hands-free use
Military and industrial applications for wearables especially emphasize their hands-free aspect, and concentrate on speech input and heads-up display or voice output. Other wearables might also use chording keyboards, dials, and joysticks to minimize the tying up of a user's hands.
In addition to user-inputs, a wearable should have sensors for the physical environment. Such sensors might include wireless communications, GPS, cameras, or microphones.
A wearable should be able to convey information to its user even when not actively being used. For example, if your computer wants to let you know you have new email and who it's from, it should be able to communicate this information to you immediately.
always on
By default a wearable is always on and working, sensing, and acting. This is opposed to the normal use of pen-based "Personal Digital Assistants," which normally sit in one's pocket and are only woken up when a task needs to be done.

A more in-depth definition can be found at http://wearcomp.org/wearcompdef.html.

Why do people use something like that? [Mann|MIT]
The idea is to be "always ready", for example, you might look up the definition of "wearable computer" in the encyclopedia, or you might interact with people through the medium, while doing other things. You might also constantly grab images into a circular buffer, and then retroactively record something. In this way, you're always ready, and seldom miss a good shot. Many of the defining features of wearables are the rationale behind wanting to wear them full time:

The HMD allows you to look at the screen and also at something in the real world. This allows you to take notes while looking at the professor, rather than constantly glancing back and forth between paper and blackboard. You can be reading email and still be able to walk down the street without running into people.

Having the wearable with you is equivalent to carrying an entire reference library with instant access. Webster's dictionary and thesaurus are always useful to have, as well as maps and phone books. With the jump to 5 gig drives, it would be trivial to put Compton's encyclopedia onto the wearable and have real-time access to a tremendous wealth of information.

All the notes you ever take -- from trips, classes, business meetings -- are always with you. With a fast search engine, you can pull up needed information in seconds, rather than flipping through dusty notebooks stored in your attic. You will never have to go hunting for a pen or piece of paper again, and never worry about searching for that missing napkin with the new system design scrawled on it.

In a manner similar to the development of multimedia PCs, all consumer electronics -- Music CD players, fax machines, pagers, audio journals -- will be integrated into the wearable design. One device will be able to handle all forms of electronic media, whether it be audio, visual, or wireless digital communication.

A seldom realized aspect of wearable computing is augmented reality: the seamless integration of real and virtual worlds. Electronically stored information is extremely useful when overlayed over a view of the outside world. For example: captions displayed with museum exhibits, names over faces (via face recognition), wiring schematics associated with the current project.

What is it used for normally? [MIT]
Most of the time spent using the wearable is found inside a text editor -- normally emacs. Phone numbers, schedules, class notes, and programs all can be modified or searched. With Internet access, communication becomes very easy -- everything from real-time messaging to full Web access using Netscape is commonplace.

Outside of this, the wearable is used just like your normal (multimedia) desktop computer. In some cases, the wearable is used instead of having a 'main' computer.

How often is the computer worn? [MIT]
Most people with functional systems wear it about 16 hours a day, seven days a week. Basically, all the time except during sports, showers, sleep, and other such activities.
Can the computer be worn in the shower or while sleeping? [Mann]
Most of the time one wears the system during most of the waking hours. Sometimes it is worn during sleeping, especially "crashing" somewhere in which there is not a suitable place to undress or change clothes. Ironically, one often becomes so accustomed to the hard disk activity that one will wake up from a deep sleep if there is something wrong with the system (e.g. power failure or total inactivity of the hard drive). Current systems are not waterproof and must be removed prior to showering. As mentioned above, with respect to the sports test and the swim test, there are obvious limitations that make it impossible to wear it all the time. Nevertheless, it is often worn so much that it becomes inextricably intertwined to the wearer.
Where can it be used? [MIT]
Since one of the defining features of wearable computers is their portability, wearables can be used anywhere a person can work comfortably. With 8-10 hour battery life and digital cellular modems providing internet access, working on a wearable allows the same level of productivity just about anywhere as a conventional desktop stuck in an office.
How long have these systems been around? [Mann]
The systems have evolved over a number of years, early versions in the 1970s gave way to more sleek and slender systems in the 1980s, so it's been evolving, for more than 20 years.
I don't have much hardware knowledge, can't I just buy one? [Mann]
Yes. The two main players right now are Xybernaut (http://www.xybernaut.com/) and ViA (http://www.flexipc.com/).

2. Technical Information

What is used for a keyboard and other input? [Mann|MIT]
The standard text input device is the Twiddler (http://www.handykey.com/), a one-handed, chorded keyboard and mouse combination. It allows fairly rapid typing (up to 60 words a minute) in any body position. You may also want to buy a BAT keyboard (http://www.infogrip.com/Options.007.html), to which you can connect microswitches, so that you will be able to plug directly into the keyboard port. You can sometimes negotiate a good deal on a bare board (e.g. without the housing) from Infogrip.

If you're going on the cheap, use a collection of pushbutton microswitches. These switches can be found in many old appliances or equipment, and are often driven by camshafts. Collect as many as you can, and try to arrange them in order of stiffness, so that the baby finger pushes the most gentle one, while the stiffest is at the thumb position. See http://wearcomp.org/ieeecomputer.html for pictures of this kind of keyboard.

Video input has been accomplished through a wide range of video capture devices. For still images, the Color QuickCam (http://www.connectix.com/html/hardware.html) has been used with a great deal of success. It also works well for low frame-rate movies.
Multiple types of microphones have been used for both speech and musical input.
A very diverse set of input devices have been attached to the wearables: GPS locators, Affective sensors (blood pressure, GSR, heart beat, EMG), infrared positional beacons and probes, digital cellular modems, PalmPilots (http://palmpilot.3com.com/) and other PDAs, etc.
What is used for a monitor and other output? [Mann|MIT]
The Private Eye, made by Reflection Technology, is our primary display, able to handle 720x280 monochrome video. Unfortunately, this display has been discontinued and a myriad of others have fallen short of its quality. Circuit Cellar (June 1998) describes how you can build a cheap display from a viewfinder salvaged from a broken video camera. You can also check out http://wearcomp.org/head-mounted-displays.html
We have a SoundBlaster compatible PC104 board , and a variety of speakers.
Tons of other output devices are being played with: PalmPilots, tactile feedback, speech, just to name a few.

3. Technical Issues

Isn't NTSC resolution too low for a VGA image? [Mann]
There are many good video camera viewfinders that can display 24 rows of 80 characters. While many of the modern LCD viewfinders are not capable of 80x24 text, there are a good many older black and white viewfinders that can display a sharp and clear 80x24 screen, and many can be had for $10 or less. As a parts scavenger, just be on the lookout for studio quality video cameras.
How can you see a display that close to your eye? [MIT]
Most HMDs appear to be farther away than they actually are. For example, when you look into the PE, you see the equivalent of a 15" monitor at about two feet away.
How long do the batteries last in a wearable? [Mann]
Batteries are generally swapped once, twice, or maybe three times a day, depending on how much equipment is being used at any given time. Most computers run about eight hours on a single charge.
Why isn't speech recognition used for input? [Mann]
Early systems, in the 1970s, were voice controlled, but more recently it has been found that voice control is unsuitable for most occasions. Besides the fact that people will think you're strange when you talk to yourself, it is very impolite to speak while others are speaking. For example, in class, if you use it to take notes, you would be disrupting others with your speech. You may not always merely want a transcript (or recording) of what the instructor is saying, but often you will want to record your own thoughts that may be triggered by what the instructor has said. For this, you would want a medium of your own that can be used unobtrusively.
Doesn't the movement wreck the hard drive? [Mann]
Many hard drives commonly used in laptop computers can withstand 100G operational shock. It is common to go jogging while editing, and sometimes to shoot documentary video while on horseback or riding a mountain bike down the center of a railway line, bumping over every railway tie, and capturing the experience on a hard drive.
What challenges remain in making the wearable suitable for constant use?
It was said that the three tests of personal imaging would be:
  1. the casino test
  2. the sports test
  3. the swim test

The underwearable made it possible to shoot documentary videos in gambling casinos, and it has been ruggedized to the point where it can be used in some sports, but the swim test probably remains as the most difficult of these three.

4. Biological Issues

Does the display hurt your eyes, being so close? [Mann|MIT]
The displays can actually be very comfortable to use for extended durations. The virtual image of the display is quite far away, and in fact, if it is adjusted so that parallel rays of light enter the eye, then one experiences light equivalent to an infinitely large image, infinitely far away. The focus can be adjusted from 10" to infinity, allowing almost ideal viewing focus. No vision problems have been noticed after five years of heavy use. Eye damage from excessively bright light, over extended time periods, is however still a possibility, but dark glasses can help to minimize the quantity of light needed to balance with the ambient light.
Does the vibration of the PE (one of the HMDs) get annoying? [MIT]
After wearing the PE for a few hours, the noise and vibration really isn't noticed. It's equivalent to the hum of most computer monitors and the fan noise - you stop being aware of them after a while.
Can I lead an active lifestyle while wired? [Mann]
Early systems of the 1970s were quite cumbersome and delicate. Although they were sometimes worn while playing road hockey, or the like, they were delicate and not suitable for rough sports. Durability and unrestrictiveness have been partly addressed but truly durable construction still remains as a challenge.
Can you actually type while walking or jogging? [Mann]
Yes, with a properly designed keyboard, you can type while walking around, jogging, running, or doing other activities. Typical wearcomp keyboards are held in one hand and are easy to use, leaving the other hand free.
Doesn't the computer get hot while you are wearing it? [Mann]
One thing that comes to mind, that might not at first be obvious, is that one adapts to the heat produced by the apparatus. After several years, the body's metabolism slows down, and resting heart rate is much lower. This condition is similar to someone who has an "athletic heart", or someone who comes from a warm climate in which the blood has "thinned". Normally the body operates inefficiently, but with the device on, producing waste heat, the body reduces its heat dissipation. The only way for the body to reduce its production of waste heat is to become more efficient, or "athletic". Thus even when one does not engage in a great deal of physical activity, one becomes more similar to an athlete in one's body efficiency.

A related side-effect of wearing the apparatus for many years is that one becomes unable to tolerate cold when removing the device, and tends to need to wear heavy clothing in place of the device, even when it is not extremely cold. On very cold winter days, the difference is not so noticable (e.g. since it is additive not multiplicative), but the difference between a "cyborg" who has taken off the machine, and someone who doesn't normally wear the machine, is most evident in the summer time, where the cyborg will be found wearing long-sleeved shirts. Also the difference between the cyborg and the non-cyborg is not so evident during physical activity as it is during sleeping. The cyborg who has stripped off the machine will need more blankets than the non-cyborg during sleeping, but during active moments, the two will be approximately the same (except perhaps the cyborg who has recently removed the apparatus will be better able to run farther on a hot day).

5. Social Issues

Do I need to look weird to be wired? [Mann]
Covert wearcomp/wearcam systems developed in the early 1990s took an important first step toward making it possible to look normal and be connected. Currently the so-called "underwearable computer" makes it possible to be wired without looking weird.
Does typing distract or annoy other people? [Mann]
The loud clicky switches of the 1970s and 1980s have given way to much quieter soft-touch switches. Modern one-handed keyboards can be much quieter than the quietest of soft-touch laptop computer keyboards. Moreover, since you can hide your hand under the table or in a pocket, the typing sounds are that much more diminished, as is the distracting movement of the hand.
Does airport security pose a problem? [Mann]
It is interesting the manner in which the paranoia has increased together with the reduction in size of the apparatus, and so what is most notable, is that there has been a roughly constant level of aggravation at the airport. As the apparatus has gotten smaller, over the years, so too has the paranoia level gotten higher. Words like "lead-acid" and "lithium ion" are frightening to them -- it's better to call them "camcorder batteries" when they ask what kind of batteries they are. They'd like it to go in the cargo hold (e.g. as checked luggage), or at least off-body (carry-on rather than wear-on). If you wear it, expect to find yourself sometimes in a private search area in your underwear, pulled back, or the like, and the nose of a specially trained dog at the point of contact between your body and the apparatus. Sometimes one may be asked to shut down during takeoff and landing. One might half-expect "please turn off all pacemakers during takeoff and landing". It's been a lot better, working directly with the FAA, on what's acceptable. It kind-of ruins the experiment if you've got to strip it off and lose data (e.g. if keeping a year-long ECG, respiration, video, etc. record), but they're paranoid about emissions during takeoff and landing.

6. Forums and Other Sources

6.1. On the Internet

Is there a mailing list that deals with wearable computing? [MIT]
There are actually two mailing lists devoted to this subject. The more active of the two is wear-hard@haven.org. To subscribe, send an e-mail to wear-hard-request@haven.org with the text "subscribe" in the body. This list deals mainly with the construction of wearable computers.
Is there a newsgroup on wearable computing?
On 6 June 1998, comp.sys.wearables came into existence. This is a moderated group that deals with all aspects of wearable computing.
Is any of this stuff archived?
Archives for wear-hard@haven.org and comp.sys.wearables are both held at http://wearables.ml.org/.
Where can I learn more about wearable computing? [Mann]
MIT has a good site about wearable computing at http://wearables.www.media.mit.edu/projects/wearables/. Other universities also maintain sites on their own progress in the field. Here are a few of them: Steve Mann <mann@eecg.toronto.edu> also maintains a wearable computing site at http://wearcomp.org/.

6.2. Hard Copy [MIT]

Cyborg Handbook, The. New York: Routledge, 1995. Ed. Chris Habels Gray. ISBN: 0415908493.
Gibson, William. Virtual Light. New York: Bantam Books, 1993. ISBN: 0553566067.
Mirrorshades: The Cyberpunk Anthology. Ed. Bruce Sterling. New York: Arbor House, c1986. ISBN: 0441533825
Stephenson, Neal. Diamond Age, The or Young Lady's Illustrated Primer, A. New York: Bantam Books, c1995. ISBN: 0553573314.
Stephenson, Neal. Snow Crash. New York: Bantam Books, 1992. ISBN: 0553562614.
Vinge, Verner. Across RealTime. Baen Books, 1991. ISBN: 0671720988.
Vinge, Verner. Fire Upon the Deep, A. New York: TOR, 1992. ISBN: 0812515285.

7. Meta-FAQ

Who is responsible for this FAQ?
This FAQ began as a compendium of FAQs. The component parts are still available in their original forms. The MIT Wearable Computing FAQ (http://lcs.www.media.mit.edu/projects/wearables/FAQ/FAQ.txt) -- referenced by [MIT] -- is maintained by Josh Weaver <weaverj@mit.edu>. The Wearcam FAQ (http://wearcomp.org/faq.txt) -- referenced by [Mann] -- is maintained by Steve Mann <mann@eecg.toronto.edu>. Gregory Martin Pfeil <pfeilgm@jmu.edu> is the current maintainer of this FAQ.
How can I add my input?
Send an e-mail to pfeilgm@jmu.edu with the subject "Wearcomp FAQ". If you don't wish to have your name or e-mail address added to our contributor list, please say so.
Who has contributed to this FAQ?
Steve Mann <mann@eecg.toronto.edu>, Greg Pfeil <pfeilgm@jmu.edu> Bradley Rhodes <rhodes@media.mit.edu>, Josh Weaver <weaverj@mit.edu>.