A PORTABLE WIRELESS EYE MOVEMENT CONTROLLED HUMAN-COMPUTER INTERFACE FOR THE DISABLED

A PORTABLE WIRELESS EYE MOVEMENT- 

 CONTROLLED HUMAN-COMPUTER  

  INTERFACE FOR THE DISABLED  

IEEE, APRIL 2009  

Human-Computer  Interface  (HCI)  has  become  an   important  area  of  research and   development   for   the   disabled.   A  portable   wireless   eye   movementcontrolled Human-Computer Interface which can be used for the disabled who have motor paralysis and who cannot speak in multiple applications  (such as communication aid and smart  home applications) is described here.  

This Interface consists of four major parts:  (1) surface electrodes,  (2) a twochannel  amplifier, (3)  a  laptop (or  a  micro-processor),  and (4)  a  ZigBee  wireless  module.  Horizontal  and  vertical  Electro-Oculography  (EOG)  signals are measured using five surface electrodes placed on the head.  

The vertical electrodes are placed about  1.0 cm above the right eyebrow and  2.0  cm  below  the  lower  lid  of  the  right  eye,  the  horizontal  electrodes  are  placed 2.0 cm lateral to the each side of outer canthi and the last electrode is  placed on user's forehead to serve as a ground. The two-channel amplifier is  comprised of instrumentation amplifiers, band-pass filters and shift circuits.  

The EOG signals are sampled at the rate of 250Hz and then sent to a laptop or  a  micro-processor  for  signal  processing  which  is  based  on  the  method  of  mathematical  morphology  to  recognize  the  direction  of  eye  movements  and  voluntary eye blink. The ZigBee wireless communication technology, which is  proved  to  be  reliable,  low -power  and  cost-efficient,  is  used  in  the  portable  interface.  

The subjects can control the wireless device or move a cursor over a screen by using this interface. The delay of this interface is less than 0.5s and errors are very limited. This interface provides a flexible method for the disabled to improve the life quality.