31-12-2010, 05:08 PM
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1. INTRODUCTION
A wearable computer is a computer that is subsumed into the personal space of the user, controlled by the user, and has both operational and interactional constancy, i.e. is always on and always accessible. Most notably, it is a device that is always with the user, and into which the user can always enter commands and execute a set of such entered commands, and in which the user can do so while walking around or doing other activities. This transformation allows it to be worn constantly, with the goal of becoming a seamless extension of body and mind, equipped with various sensors which measure heart rate, respiration, footstep rate etc, and can help in body maintenance. The ‘wearable computer’ apparatus is embedded within nontransparent clothing which provides shielding.
Electronic circuits are built entirely out of textiles to distribute data and power and perform touch sensing.The most salient aspect of computers, in general, (whether wearable or not) is their reconfigurability and their generality, e.g. that their function can be made to vary widely, depending on the instructions provided for program execution. With the wearable computer (Wear Comp), this is no exception, e.g. the wearable computer is more than just a wristwatch or regular eyeglasses: it has the full functionality of a computer system but in addition to being a fully featured computer, it is also inextricably intertwined with the wearer. This is what sets the wearable computer apart from other wearable devices such as wristwatches, regular eyeglasses, wearable radios, etc.
Unlike these other wearable devices that are not programmable (reconfigurable), the wearable computer is as reconfigurable as the familiar desktop or mainframe computer
2. HISTORY
The concept of wearable computing was first brought forward by Steve Mann, who, with his invention of the ‘Wear Comp’ in 1979 created a pioneering effort in wearable computing. Although the effort was great, one of the major disadvantages was the fact that it was nothing more than a miniature PC. Absence of lightweight, rugged and fast processors and display devices was another drawback.
The 1980s brought forward the development of the consumer camcorder, miniature CRTs etc. brought forward the development of the eyeglass mounted multimedia computer. With the advent of the internet and wireless networking technologies, wearable devices have developed a great deal.
After its invention wearables have gone through 18 generations of development, with research going on at prestigious institutions like MIT, Georgia Tech and Carnegie Mellon University.
3. DISCUSSION
3.1 OPERATIONAL MODES
There are three operational modes in this new interaction between human and computer.
• Constancy:
The computer runs continuously, and is ‘always ready’ to interact with user. Unlike hand-held device, laptop computer, or PDA, it does not need to be opened up and turned on prior to use. The signal flow human to computer to human, runs continuously to provide a constant user interface.
• Augmentation:
Traditional computing paradigms are based on the notion that computing is the primary task. Wearable computing, however, is based on the notion that computing is NOT the primary task. The assumption of wearable computing is that the user will be doing something else at the same time as doing computing. Thus the computer should serve to augment the intellect, or augment the senses.
• Mediation:
Unlike hand held devices, laptop computers, and PDAs, the wearable computer can encapsulate us. It doesn’t necessarily need to completely enclose us, but the concept allows for a greater degree of encapsulation than traditional portable computers.
There are two aspects to this encapsulation:
(i) Solitude:
It can function as an information filter, and allow us to block out material we might not wish to experience, whether, it be offensive advertence or simply a desire to replace existing media with different media in less severe manifestations, it may simply allow us to alter our perception of reality in a very mild sort of way.
(ii) Privacy:
Mediation allows us to block or modify information leaving the encapsulated space. In the same way that ordinary clothing prevents other from seeing our naked bodies, the wearable computer may, for example, serve as an intermediary for interacting with untrusted systems, such as third party digital anonymous clash “cyber wallets”.
3.2 ATTRIBUTES
There are four information flow paths associated with this new Human – machine synergy. The signal flow paths are, in fact, attributes of wearable computing, and are described, that follows, from the human’s Point of view:
• UNRESTRICTIVE to the user:
Ambulatory, mobile, roving “you can do other things while using it”, e.g. you can type while jogging, etc.
• OBSERVABLE by the user:
It can get your attention continuously if you want it to. Almost always observable. Within reasonable limitation (e.g. that you might not see the screen while you blink or look away momentarily) the output medium is constantly perceptible by the wearer.
• CONTROLLABLE by the user:
It means responsive to the user. You can grab control of it at any time you wish. Even in automated processes you can manually override to break open the control loop and become part of the loop at any time you want to. (E.g.: A big Halt button you want as an application mindlessly opens all 50 documents that were highlighted when you accidentally pressed “Enter” would make a computer more CONTROLLABLE.)
Infinitely-often-controllable means the constancy of user-Interface results from almost-always observability and infinitely-often controllability in the sense that there is always a potential for manual override which need not be always exercised.
• COMMUNICATIVE to others:
It can be used as a communications medium when you want it to.
3.3 PROPERTIES
The five properties for a wearable computer are given below:
• CONSTANT:
Always ready. May have “sleep modes’ but never “dead” Unlike a laptop computer which must be opened up, switched on, and booted up before use, it is always on and always running.
• PERSONAL:
Human and computer are inextricably intertwined.
• PROSTHETIC:
You can adapt to it so that it act as a true extension of mind and body. After some time you forget that you are wearing it.
• PRIVATE:
Others can’t observe or control it unless you let them. Others can’t determine system status unless you want them to, e.g. clerk at refund counter in department store where photography is prohibited can’t tell whether or not you are transmitting wireless video to a spouse for remote advice, in contrast to camcorder technology where it is obvious you are taking a picture when you hold it up to your eye.
• EXPRESSIVE:
Allows the wearable to be expressive through the medium, whether as a direct communication medium to others, or as means of assisting the production of expressive media.
4. DIGITAL FABRIC
Cotton, polyester or rayon don't have the needed properties to carry the electrical current needed for digital clothing. However, metallic yarns are not new to the clothing industry. We have seen these metallic fabrics worn to make fashion statements for years. Researchers at MIT's Media Lab are using silk organza, a unique fabric that has been used to make clothes in India at least a century.
Silk organza is ideal for computerized clothing because it is made with two fibres that make it conductive to electricity. The first fibre is an ordinary silk thread; running in the opposite direction of the fibre silk thread that is wrapped in a thin copper foil. It's this copper foil that gives the silk organza the ability to conduct electricity. Copper is a very good conductor of electricity and some microprocessor manufactures are beginning to use copper to speed up microprocessors. The metallic yarn is prepared just like cloth core telephone wire, according to the MIT researchers. If you cut open a coiled telephone cable, there's usually a conductor that is made out of a sheet of copper wrapped round a core of nylon or polyester threads. These metallic yarns can withstand high temperatures; the yarn can be sewn or embroidered using industrial machinery. This property makes it very promising for mass producing computerized clothing.
A strip of the fabric would basically function like a ribbon of cable. Ribbon cables are used in computers to connect disk drives to controllers. One problem with using silk organza would result if the circuits were to touch each other; therefore MIT scientists use an insulating material to coat or support the fabric.
Once the fabric is cut into suitable shape, other components need to be attached to the fabric, like resistors, capacitors and coils. These components are directly sewn to the fabric. Other electronic devices can be snapped into the fabric by using some kind of gripper snaps, which pierce the yarn to create an electrical contact. These devices can then easily removed in order to clean the fabric.
At Georgia Tech, researchers have developed another kind of thread named as plastic optical fibres and other specialty fibres woven into the fabric. These optical and electrical conductive fibres will allow the wear comp to wirelessly communicate with the other devices, transferring data from the sensors embedded in it.
