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2. GENERAL OVERVIEW
2.1 CONTROL METHODS
Direct selection
To be able to select one of the 88 cells on the keyboard overlay a number of control
methods is available. Direct selection with a laser pointer by means of head
movements is the fastest and most comfortable control method. In some cases control
with a mouse or a trackball can be a good alternative.
Laser pointer
The laser pointer is a laser light in the shape of a small tube that can
be attached to a headband or to a pair of spectacles. The pointer
throws a clear light spot on the keyboard overlay. Photosensitive
cells in LUCY ensure that the chosen characters are passed on to
the computer. For users who can move their head reasonably well,
laser control is the best control method. The achievable speed is
higher and the use is much less tiring than working with an onscreen system or head stick. The laser pointer can also be used
handheld. In that case the achievable speed will be somewhat lower.
Mouse
LUCY has a connection for a normal USB computer mouse. Moving
the mouse will result in the lighting up of the LEDs behind the
characters on the keyboard overlay. As soon as the LED behind the
chosen character lights up, the character can be sent to the computer
by a mouse click. To be able to use a mouse, the user should be
reasonably proficient with arm and hand. In some cases a
considerable improvement can be reached by mounting a suitable
handle on the mouse. The supplier of LUCY can advise you on such
an adaption.
Trackball
Instead of a mouse, an USB trackball can be connected to LUCY. A
trackball is a ball in a holder which can be rolled with small finger
movements. The movements of the ball correspond with the lighting
up of the LEDs behind the characters on the front of LUCY. As soon
as the correct character has been selected, this can be sent to the
computer. Because the trackball has a fixed place on the table, this
method can be used by people with only minimal motor control over
arm and hand.
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