Introduction - Powering Biomedical Devices - page 1

CHAPTER 1
Introduction

The increase of world population is a challenge itself for world
resources. The sustainability of food supplies, energy resources, and
the environment are being questioned by analysts, while climate
change just adds more pressure to the equation. The life expectancy of
the world as a whole is rising while the fertility rate is declining. This
will create a challenge in health care for the ageing population
(Gavrilov and Heuveline, 2003). The United States alone will have
20% of the population over the age of 65 by 2050. In contrast, Europe
will see rates close to 30% while Japan will arise to almost 40%, as
summarized in Table 1.1 . It is anticipated that in the near future,
specialized health-care services will be in higher demand due to this
increase. This demand will be characterized by medical resources not
only to attend to this segment of the population, but also to keep them
active as well. Therefore, the monitoring of physiological responses as
well as specialized drug or other therapy delivery applications will be
needed for portable, wearable, or implantable biomedical autonomous
devices. In addition, wireless communication promises new medical
applications such as the use of wireless body sensor networks for
health monitoring (Jovanov et al., 2005; Hao and Foster, 2008;
Varshney, 2007).

These biomedical devices, however, come with their own issues,
mainly power source challenges. Batteries are commonly used to energize
most of these applications, but they have a finite lifetime. As biomedical

Table 1.1 Percentage of Population Over 65 Years Old a
Region 1950 2000 2050

World 5.2 6.8 16.2
USA 8.3 12.4 21.6
Europe 8.2 14.8 27.4
Japan 4.9 17.2 37.8
a Population Division of the Department of Economic and Social Affairs of the United Nations Secretariat,
World Population Prospects: The 2008 Revision, http://esa.un.org/unpp .