Adaptive keyboard for the Blind, Development of tactile Systems "Dynamic Braille" and 1 dot=1 sign for the Blind.

The progress of reading systems for the blind can be shown as:

1 stage: Relief letters (Valentin Haüy)

2 stage: 6 dots (Braille cell) = 1 letter (sign)

3 stage:1 dot = 1 letter (sign)

6 tactile points are placed on the each phalanx of fingers. Each point corresponds to the letter i.e. a principle “One point - one sign” fulfils. Placing 6 elements (microactuators) on each from 4 fingers it is possible to place 72 elements totally. And the position of a key can correspond to the position of a keyboard QWERTY. The elements are placed at a glove.

Fig.1. Adaptive keyboard

Fig.2 shows the possible key layout.

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Fig.2. Key layout

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Spatial resolution

Creating the adapting key a question “Can a man realize the press of elements on the phalanxes of fingers?” is one of the impotant problems. Conducted reseaches proved that 2 points threshold of tactile perception on phalanxes is from 2 to 3 mm (Fig.6). The press is fulfilled on tactile receptors located on the the phalanxes of fingers. The density of afferents exceeds more than 200 on cm2 and spatial resolution - not less than 2 mm on 1 phalanx, on 2 and 3 phalanxes - about 3 mm.

Advantages of the proposed device:

low weight and small size
ergonomic;
adaptive;
allows working in various positions (lying, sitting, staying).

For some tasks only a fey keys are necessary, so the keyboard transfers into one band (fig.3, foto3). For some programs (games, for example) only a few keys are needed, so keyboard turns into a single band. Such band can be used be several people simultaneously.

Fig.3. Special input.

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Fig.4 shows possible application of the keyboard.

Fig.4. Keyboard and input-output devices

It is necessary to stress that handicapped people also can use this keyboard. I the keyboard is equipped with tactile elements (thermal, mechanical etc.) the input signal can be sent right on the skin. Such keyboard could use either standard keyboard layout or layout following the Braille system (fig. 5). This keyboard can be used for both input and output of information in everyday situations and will help social rehabilitation of handicapped people.

Fig.5. Input of information for handicapped people.

Input Information

The standard keyboard supports the following sequence:

hand moves from the initial position to reach the necessary key;
key strike;
hand returns to the initial position.

It is impossible to shorten the distance between hands and keys (not enough fingers), so the useful work (key strike) always involves shift of hand position and therefore loss of time.

The proposed keyboard is to decrease that idle movement. Keys are places right at the phalanxes of fingers and are stroked by the thumb of the same hand. Keys can be placed either on the glove or on the separated stripes (fig.1, foto1). The device supports the following sequence:

thumb moves to the key located on the one of phalanxes, in the same
time the key finger also moves to the thumb, so the key reaches the
thumb;
key strike;
return to the initial position.

The adaptive keyboard also can be used for training on the regular keyboard. In this case tactual elements are located at the top of fingers (fig. 6). Than it is necessary to strike a certain key, the tactual element sends a signal to the finger required, thus making training more efficient.

Fig. 6. Keyboard training.

The device also can be used as a remote control (fig.7).

Fig.7. Remote control