Вашето ниво на обучение

Ние предварително сме избрали "Всички нива" за вас, но вие можете да промените нивото на обучение по всяко време, като изберете една от опциите на това меню. Промяната на вашето ниво на учене ще ви върне към началото на модула.

Затвори
Въведение
Boy with glasses takes part in visual
                  tracking exercise

Развитията в технологията означават, че има повече ПАК (ПАК) устройства с посочване с поглед, отколкото когато и да било. От по-традиционната рамка за прехвърляне на погледа до маркиращи системи за проследяване на погледа, които позволяват на хората с много ограничени физически движения да общуват.

Eye Transfer Frame
Teacher in pink top stands behind
                  Etran frame

Some people with severe, profound and complex needs can find it difficult to point to a book or chart or to handle communication cards. If they have good control over their eyes, they may be able to use an Etran Frame. This is a sheet of stiff, transparent plastic (Perspex) onto which symbols or words can be stuck with Blu-Tack or Velcro.


The communication partner faces the user and holds the chart up between them. The user gazes at the letter, symbol, or word they want to say. Initially, one symbol or word will be placed at each corner. As the user and communication partner become more skilled, symbols can be added in the middle of each side. The method can be developed further by using colour or number coding systems so that more items can be accessed.  

Eye tracking and/or gaze interaction
A teacher helps a young girl to communicate
                  using a screen at eye level

When a user sits in front of the computer screen, a specialised video camera mounted below the screen observes one of the user's eyes. Image processing software in the computer continually analyses the video image of the eye and determines where the user is looking on the screen. Nothing is attached to the user's head or body.


A user can operate a computer programme by looking at rectangular keys that are displayed on the control screen. To 'press' an eyegaze key, the user looks at the key for a specified period of time. The gaze duration required to visually activate a key, typically a fraction of a second, is adjustable. An array of menu keys and exit keys allow the user to navigate the programmes independently.

Eye tracking and/or gaze interaction
Visual tracking equipment

Eye gaze systems are particularly useful for anyone who has little or no control over movement in the arms or legs. Support of the user's head may be necessary to ensure a steady gaze.


This technology is very expensive but highly effective and motivates young people whose only steady access to a switch is through their gaze.

 

The following two websites provide further information about this technology.

Using an eye tracking system: early stages

In the following clip, a young person who is in the early stages of using eye gaze technology has already made great strides in development.

  • He already has good eye pointing skills and scanning skills, but little or no meaningful control over his hand or leg movements.
  • He is now learning to hold his gaze for longer periods in order to make a choice between a number of icons.
  • Poster
                  Image
Using an eye tracking system: early stages
A teacher helps a young girl to communicate
                  using a screen at eye level
  • Unlike when using a communication book or Etran Frame frame, he can now make choices that are independent of adult support.
  • In the future, he will take this technology home with him so that his 'voice' stays with him at all times – at school, at home and in his wider local community.

At all times, his family will need to understand how to support this new system.

Using an eye tracking system: progression

In the following video, a young person uses an eye tracking system. The progression of acquired skills that enable her to use the system are:

  • Choice making through simple switches.
  • Scan for using a switch to choose.
  • Increased scanning skills.
  • Eye pointing.
  • Poster
                  Image
Using an eye tracking system: progression
Visual tracking equipment

She has now got to the point where the eye tracking system is mounted on her wheelchair. This enables her to:

  • Take her communication device everywhere with her.
  • Demonstrate her understanding within the lesson.
  • Socialise.
  • Become a self-advocate.