3.2. The “character selection” method
The “characters selection” method uses eye tracking glasses in order to select characters from a virtual
keyboard, composing free sentences in this way.
Using the “eye tracking” glasses, the patient may move the focus over a selected key and keep it still for
a given time.
This pause shows that the key has been selected and that character is displayed on the message area.
One difficulty of this method is caused by the oscillations of focus position due to the reflections on the eyeglasses.
Because of these oscillations there may be more than one key selected during a small time period.
In order to filter these false selections, the application counts the key selections on that time interval and selects the key which has the biggest number of selections.
In the same time, the keys selected by these oscillations are magnified in order to make the selection easier for the patient.
This method allows the composition of more complex messages, but, in order to obtain good results, the method requires patient skills for working with the eye tracking sensor.
In time, when the patient has had enough practice combined with autocomplete facility, the method can become an easy and fast way to interact with the computer.