x
Preface
scanning. The chapter concludes with a summary of available information on transmitted, reflected, and distributed mmW energy in skin tissues.
Short electric pulses can extend deeply into the cell interior (see Chapter 2) and have
been briefly discussed in Chapter 1. The classical understanding of a majority of the
electric field induced biological effect is the induction of a potential difference across
the cell membrane by the external electric field. For example, the electric field strength
required to achieve electroporation depends on the duration of the applied pulse, because
this process involves the gradual charging of the cell membrane followed by rearrangement of the lipid molecules. The typical pulses range from tens of milliseconds (ms) with
amplitudes in the 10 kV/m ranges to pulses of a few microseconds (ms) or less at field
strengths of several 100 kV/m. More recently, the electrical pulses in the nanosecond (ns)
duration range and pulse amplitudes as high as 30,000 kV/m have been investigated for
triggering purely electrically driven responses without any thermal heating. Such fast
processes as electron transfers between molecules, electrophoretic separation and selforganization, or field induced changes in reaction kinetics are being explored. Chapter 2
presents many potential applications based on intracellular effects produced by the use of
nanosecond, pulsed electric fields (nsPEF) of high-intensity. It is anticipated that nsPEF
may provide versatile non-thermal tools capable of producing cellular electroporation,
intra-cellular calcium release, shrinkage of tumors and cellular apoptosis, temporary
blockage of action potential propagation in nerves, activation of platelets, and release of
growth factors for accelerated wound healing.
Exposure to naturally occurring and human-made static, low-frequency, and pulsed
magnetic fields in biological systems forms the topic of Chapter 3. It is of interest because
changes in the strength and distribution of such fields have been found to be biologically
effective; many questions have been raised as to whether exposure to these fields may be
linked to adverse health effects, and a wide range of biomedical applications have been
developed to take advantage of the interaction of magnetic fields with biological systems. In addition to discussing the coupling of static, low-frequency, and pulsed magnetic fields into biological systems, the chapter summarizes more recent information on
biological effects and medical applications of such fields and discusses mechanisms by
which biological systems sense and respond to magnetic fields.
During the past few decades, the interaction of extremely low frequency (ELF) electromagnetic fields with biological systems has become a major source of health concern,
especially for the 50 and 60 Hz frequencies used by electric power distribution systems.
An essential aspect of health investigations has been the evaluation of induced electric
fields and current densities inside human subjects and phantom models of human and
animal bodies. Chapter 4 is devoted to dosimetry or coupling of ELF fields into biological systems. It provides a description of the historical developments and recent trends in
numerical dosimetry. It also includes a comprehensive review of research efforts from
Japan on induced electric fields and current densities inside phantom models resulting
from ELF exposures.
Cellular communication has evolved into one of the most successfully commercialized technologies. Today, the immense popularity of cell phones is beyond debate.
Worldwide, there are more people who own and use cell or mobile phones than any
other electronic device, regardless of whether the country is rich or poor, developed
Preface
scanning. The chapter concludes with a summary of available information on transmitted, reflected, and distributed mmW energy in skin tissues.
Short electric pulses can extend deeply into the cell interior (see Chapter 2) and have
been briefly discussed in Chapter 1. The classical understanding of a majority of the
electric field induced biological effect is the induction of a potential difference across
the cell membrane by the external electric field. For example, the electric field strength
required to achieve electroporation depends on the duration of the applied pulse, because
this process involves the gradual charging of the cell membrane followed by rearrangement of the lipid molecules. The typical pulses range from tens of milliseconds (ms) with
amplitudes in the 10 kV/m ranges to pulses of a few microseconds (ms) or less at field
strengths of several 100 kV/m. More recently, the electrical pulses in the nanosecond (ns)
duration range and pulse amplitudes as high as 30,000 kV/m have been investigated for
triggering purely electrically driven responses without any thermal heating. Such fast
processes as electron transfers between molecules, electrophoretic separation and selforganization, or field induced changes in reaction kinetics are being explored. Chapter 2
presents many potential applications based on intracellular effects produced by the use of
nanosecond, pulsed electric fields (nsPEF) of high-intensity. It is anticipated that nsPEF
may provide versatile non-thermal tools capable of producing cellular electroporation,
intra-cellular calcium release, shrinkage of tumors and cellular apoptosis, temporary
blockage of action potential propagation in nerves, activation of platelets, and release of
growth factors for accelerated wound healing.
Exposure to naturally occurring and human-made static, low-frequency, and pulsed
magnetic fields in biological systems forms the topic of Chapter 3. It is of interest because
changes in the strength and distribution of such fields have been found to be biologically
effective; many questions have been raised as to whether exposure to these fields may be
linked to adverse health effects, and a wide range of biomedical applications have been
developed to take advantage of the interaction of magnetic fields with biological systems. In addition to discussing the coupling of static, low-frequency, and pulsed magnetic fields into biological systems, the chapter summarizes more recent information on
biological effects and medical applications of such fields and discusses mechanisms by
which biological systems sense and respond to magnetic fields.
During the past few decades, the interaction of extremely low frequency (ELF) electromagnetic fields with biological systems has become a major source of health concern,
especially for the 50 and 60 Hz frequencies used by electric power distribution systems.
An essential aspect of health investigations has been the evaluation of induced electric
fields and current densities inside human subjects and phantom models of human and
animal bodies. Chapter 4 is devoted to dosimetry or coupling of ELF fields into biological systems. It provides a description of the historical developments and recent trends in
numerical dosimetry. It also includes a comprehensive review of research efforts from
Japan on induced electric fields and current densities inside phantom models resulting
from ELF exposures.
Cellular communication has evolved into one of the most successfully commercialized technologies. Today, the immense popularity of cell phones is beyond debate.
Worldwide, there are more people who own and use cell or mobile phones than any
other electronic device, regardless of whether the country is rich or poor, developed