I. INTRODUCTION
I N the European Union, it is estimated that 10–15% of the total
population is disabled and the population aged 60 years and
older have a ratio at nearly 1 person in 10. This means that in EU
there are about 80 million elderly or disabled people [1]. Besides,
various reports also show that there is a strong relation between
the age of the person and the handicaps suffered, the latter being
commoner in persons of advanced age. Given the growth in life
expectancy in the world (in the countries of the Organization for
Economic Cooperation and Development (OECD) it is expected
that the proportion of older persons aged 60 years and older will
have reached a ratio of 1 person in 3 by the year 2030), a large part
of its population will experience functional problems. Aware of
the dearth of applications for this sector of the population, governments
and public institutions have been promoting research in
this line in the recent years. Various types of research groups at a
world level have begun to set up cooperation projects, projects to
aid communication and mobility of elderly and/or disabled perManuscript
received March 23, 2001. This work was supported by the
Interdepartmental Science and Technology Committee (CICYT), Spain under
SIAMO project (TER96-1957-C03-01), and by the Electronics Department of
the University of Alcalá of Spain and the “Comunidad de Madrid” by projects
UAH2002/020 and 07T/0057/2000, respectively.
The authors are with the Electronics Department, University of Alcalá,
Alcalá de Henares, 28871, Spain (e-mail: barea@depeca.uah.es; http://www.depeca.uah.es/personal/barea;
boquete@depeca.uah.es; mazo@depeca.uah.es;
elena@depeca.uah.es).
Digital Object Identifier 10.1109/TNSRE.2002.806829
sons with the aim of increasing their quality of life and allowing
them a more autonomous and independent lifestyle and greater
chances of social integration [2], [3].