EOG signal processing and analysis for controlling computer by eye movements B. Estrany, P. Fuster, A. Garcia, Y. Luo University of Balearic Islands Palma de Mallorca, Spain (34)971173208 dmilyu0@uib.es ABSTRACT We have successfully designed and built a human computer interface system to interface with the computer by human eye EOG signal (Electrooculography). The EOG signal has very low voltage and very sensitive to interference. This paper introduces the software we developed for processing the EOG signal which lead to a reliable human computer interface by eye movements. Categories and Subject Descriptors H.5.2 [User Interfaces] User-centered design General Terms Software, Measurement, Design, Experimentation, Human Factors Keywords Human-Computer Interaction, EOG (Electrooculography), eye movement tracking 1. INTRODUCTION There is no magic now to control a machine by pushing a button by a finger. Human-machine interaction has never been so easy. Are there even easier way to control a machine without even pushing a button? Our answer is yes. For example, one can control a machine by only looking at it. As the advance of computer technology, to control any machinery that is equipped with a computer has become a common fact. The lacking element of controlling a machine by eyes becomes how to control a computer by eyes. Many studies have been done towards this goal such as [5][6][8][9][10], among others. Towards this goal, we have studied the characteristics of the EOG signal and its possibility to be an accurate human machine interface. We successfully built an experimental system that can study the bio-physiological signal to control the computer only by eye movements [1]. The system recorded the EOG signal[2][3][4] from user eye movement and positions the cursor on the monitor to control the computer as a normal cursor does. See Figure 1 of the system modules. For the novelty of the system, please refer to [1] for more details. In this paper, we will introduce a key element in the system which is the software subsystem for the experiments on the EOG signal. It serves for the processing and analysis of the signal for cursor position control. This is the base for the software module in Figure 1. The development has two stages. The first stage is the development of the software subsystem for the experiments. The second stage is a modification on this experimental subsystem to form the software module in the global system. Important technical issues in this subsystem will be presented with testing results. The software subsystem will be presented first. The subsequent sections will describe its elements one by one. Control software Hardware amplification noise filtering User eye system EOG signal recording Figure 1. Cursor positioning by EOG signal 2. THE EXPERIMENTAL SUBSYSTEM The objective of building the software subsystem in the experimental user interface is to use an inverse engineering approach to generate ideal cursor movement patterns for the user eyes to follow. The EOG signal from the user eye movement following these patterns are recorded and compared with ideal signals. These helped us to identify all the important issues in building the final software module to control the cursor by eyes. The basic functions of the software subsystem are designed according to the need of the experiments. The basic functions are: configuration of the system parameters, recording the detected EOG signal, comparison of the recorded signal and the perfect Permission to make digital or hard copies of part or all of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. Copyrights for components of this work owned by others than ACM must be honored. Abstracting with credit is permitted. To copy otherwise, to republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee.