Commission K (Electromagnetics in Biology
& Medicine) Activity Report
- March, 2005 to June, 2005 -
July
15, 2005
Masao
Taki and Tsukasa Shigemitsu
1. Meeting
A. Domestic Meeting
(1)March
25-27, 2005: 44th Annual Meeting of Japanese Society for Medical and
Biological Engineering,
(2)
April 4-8, 2005: The 2005 IEEE International Magnetics Conference,
(3)
August, 2008; BIOMAG2008,
B. International Meeting
(1) March 1-5, 2005:
UNESCO seminar and practical workshop on molecular and cellular mechanisms of
biological effects of EMF.
(2) May
16-18, 2005: ElectroMed 2005, Portland, Oregon, http://www.electromed2005.com
(3) June 13-14, 2005: 10th
International Advisory Committee (IAC) Meeting of the WHO International
Electromagnetic Field Project, Geneva, Switzerland
This tenth Meeting
covers activities and outputs for the period June 2004 to June 2005. In the
meeting, the following topics were presented; Research (Research review of the
past year, Update on the INTERPHONE study etc.), Standards (WHO framework for
developing EMF standards, update on the precautionary framework), Summary of
WHO-sponsored workshops (Electrical hypersensitivity, Children and EMF et c.),
Communication activities (WHO publications and website, Research database, world
wide standards database et c), NIR activities, Occupational exposure to EMF
fields (The EU directive, Managing EMF workplace exposures etc.)
Details of this meeting can be
found on homepage at: http://www.who.int/peh-emf/meetings/archive/iac-geneva?june2005/
(4) June 15-16, 2005:
Base stations & wireless networks: exposures & health consequences.
WHO, Geneva, Switzerland, http://www.who.int/peh-emf/meetings/base_stations_june05/
(5) June 19-24, 2005: 27th,
Bioelectromagnetics, Joint Meetings of BEMS and EBEA, Dublin, Ireland. http://www.bioelectromagnetics2005.org
(6) June 19, 2005: The
XVIII International Symposium on Bioelectrochemistry and Bioenergetics,
Coimbra, Portugal. http://www.bes-ise-2005.uc.p
(7) July 1, 2005:
Coherence and Electromagnetic Fields in Biological Systems, Prague, Czech
Republic. http://www.ure.cas.cz/events/cefbios2005/
(8) July 11-13, 2005:
Applying precautionary measures to EMF public health policy. Ottawa, Canada.
http://www.who.int/peh-emf/meetings/ottawa_june05/
2.
Future meeting
A.
Domestic
meeting
(1) July 21-22, 2005: 20th
Annual Meeting of Japan Biomagnetism and Bioelectromagnetics Society, Osaka
http://www2.convention.co.jp/jbbs20/
(2)
November 14-17, 2005: 9th Symposium on New Magneto-Science and 3rd
open symposium on innovative utilization of strong magnetic fields. Yokohama.
B.
International
meeting
(1)August 3-5, 2005:
International Symposium on Antennas and Propergation, Seoul, Korea, http://www.isap05.org/
(2) September 12-16,
2005: The 4th International Seminar on Electromagnetics Fields and
Biological Effects. Kunming, China.guozhengg@hotmail.com
or dingzhao@fmmu.edu.cn
(3) September 19-21,
2005: EMC Europe Workshop 2005, Rome, Italy, http://emcroma2005.ing.univaq.it/
(4) September 26-30,
2005: South American regional meeting on health effects of EMF fields. Brazil. http://www.int/peh-emf/meetings/brazil_sept05/
(5) October
2-9, 2005: Electromagnetic fields and genotoxicity. The School of
Bioelectromagentism,
(6) October
23-29, 2005: URSI 28th General Assembly, New Delhi. http://www.urisga.2005.org
(7) 30 October – 1
November, 2005: Workshop on Application of Proteomics and Transcriptions in EMF
Research. Helsinki, Finland. http://www.who.int/peh-emf/meetings/proteomics_helsinki05/en/
(8) November 5-6, 2005:
European cancer prevention organization annual meeting, gMobile phones and
cancer prevention.h. The Floreal Club Blanenberge, Belgium. http://www.ecpo.org/activities.htm.
(9) November 14-18,
2005: WHO & Australian radiation protection society workshop. Melbourne,
Australia. http://www.int/peh-emf/meetings/melbourne_nov05/
4. Technical Trends
K1 Biological Effects of Electromagnetic Fields
K1.1 DC and ELF Electric Fields@
On dosimetry, Shimizu,
et al. developed user-friendly software to visualize the ELF electric field
exposed to a human body [Shimizu, 2003a]. It provides the distributions of the
surface field and the current induced in the human body within a practical
computation time using a regular personal computer. The GUI made the changes of
body proportion and environmental conditions practically simple. On
instrumentation, Yamashita, et al has developed a ring-type telemeter for the
photoelectric pulse measurement [Yamashita, 2000a]. The variation in the
autonomic nervous system could be measured and analyzed. They have also developed
a telemetry technique to measure EEG and ECG at the subject exposed to strong
ELF electric field. Since it makes unconstrained measurement possible, it is
useful to evaluate the physiological change in field exposure [Yamashita, 2000b]
On cellular
effects, Shimooka, et al. has pursued the possibility of immuno-modulation
caused by the electric stimulation of the current induced in the body on field
exposure [Shimooka, 2004]. They have reported the suppression effects of
macrophage phagocytosis [Fujii, 20002; Kagawa, 2004], histamine release
[Morita, 2002] and the generation of the reactive oxygen species [Tatebe,
2004].
Biological
effects were evaluated with plants. Nitta, et al. has found that bean sprout
has the better growth in the higher electric field in the range of 10-25kV/m
[Kiatgamjorn, 2003]. Nitta, et al. have found the growth rate of ice plants in
the electric field of 28.5kV/m than the no field condition [Rotcharoen, 2003].
In the
experiments with human subjects, Yamashita, et al. exposed ELF electric field
on the skin surface of the human forearm, and measured the physiological
changes such as the skin temperature, the surface blood flow and the blood
volume in the arm. In the local field exposure, the increases in these
parameters were observed. The results of these experiments suggested that this
response was controlled by the central nervous system [Yamashita, 2004].
Shimizu, et al. analyzed the body hair movement caused by ELF electric field
exposure. Through theoretical and experimental study, the mechanism of field
perception was explained in detail. In this study, the cause of the seasonal
variation of the perception threshold was clarified [Shimizu, 2003b, 2004].
Ohsaki, et al. has attempted to apply the strong field exposure to therapeutic
use. Using the apparatus approved by a government, they performed various
fundamental studies and clinical tests. In objective parameters, the
alleviation of pain in various muscles was demonstrated [Ohsaki, 2004]
[Shimizu].
Reference
Chalise.P.R.,
M.S.Rahman, H.Ghomi, Y.Hayashi, M.Watanabe and A.Okino [2004], gBacterial
inactivation using low-energy pulsed-electron beam.h IEEE Transaction on Plasma
Science, vol.32, pp.1532-1539
Fujii,I.,
T.Shimooka,Y.Morita and K.Shimizu [2002], gExperimental verification for the
effect of capacitively coupled electrostimulation on macrophagefs endocytosis,h
Technical Report of IEICE,MBE-2001-176, pp.97-102. (In Japanese)
Ikeya.M.,
Y.Emoto, H.Asahara and C.Yamanaka [2004], gAir bubble movements and animal
behavior as responses to electromagnetic signals before earthquakes: Network
monitoring of catfish.h Proceedings of EMCf04 Sendai, 3E1-3, pp.749-752
Hasegawa.H
and T.Tamura [2003], gDevelopment of sterilization technology by application of
pulsed high.h J Institute of Electrostatics Japan, Vol.27, pp.117-122 voltage
(In Japanese)
Harakawa.S.,
N.Inoue, A.Saito, F.Doge, H.Nagasawa and N.Suzuki [2004a], g60Hz electric field
upregulates cytosolic Ca2+ level in mouse splenocytes stimulated by lectin,h
Bioelectromagnetics, vol.25, pp.204-210
Harakawa.S.,
I.Takahashi, F.Doge and D.E.Martin [2004b], gEffect of a 50Hz electric field on
plasma ACTH, glucose, lactate, and pyruvate levels in stressed rats,h Bioelectromagnetics,
vol.25, pp.346-351
Harakawa.S.,
N.Inoue, A.Saito, F.Doge, H.Nagasawa and N.Suzuki [2004c], g60Hz electric field
upregulates cytosolic Ca2+ level in mouse splenocytes stimulated by lectin.h
Bioelectromagnetics 25 pp.204-210
Kagawa,M.,
T.Shimooka, T.Tatebe and K.Shimizu [2004], gChange of endocytic activity of
macrophage by electrostimulaiton-Fundamental study for possible association of
humoral factors,h Technical Report of IEICE, MBE2003-131, pp.19-24 (In Japanese)
Kiatgamjorn,P.,
W.Khan-ngern and S.Nitta [2003], gThe comparison of electric field intensity
affects to the bean sprouts growing,h Proc.CEEM 2003, pp.142-147.
Kiatgamjorn.P.,
W.Khan-ngern and S.Nitta [2004], gElectric field direction affects on the
growth of bean sprouts.h Proceedings of EMCf04 Sendai, 4D3-1, pp.885-888
Morita,Y.,
T.Shimooka, I.Fujii and K.Shimizu [2002], gEffect of ELF electrostimulation on
histamine release from mast cells,h Technical Report of IEICE, MBE2001-175,
pp.91-96 (In Japanese)
Ohsaki.K. and
A.Hara [2004], gResearch on biological responses related to the effects of
extremely low frequency electric fields,h Proceedings of EMCf04, Sendai, 4B2-3,
pp.785-788.
Rotcharoen,T.,
W.JKhan-ngern and S.Nitta [2003], g The study of rice growing with the electromagnetic
field effect stimulated 300kV switching substation,h Proc.CEEM 2003,
pp.148-152.
Rotscaroen.T.,
P.Kerdonfag, W.Khan-ngren and S.Nitta [2004], gThe study of bending effect on
the growth of the primary root of rice caused by electric field.h Proceedings
of EMCf04 Sendai, 4D4-3, pp.901-904
Sakae.M.,
A.Asakawa, K.Ikesue, T.Shindo, S.Yokoyama and M.Hara [2003], gEffects of
different kinds of live trees and a tree model on discharge characteristics to
an open wire and a nearby tree,h IEEJ Trans. PE, Vol.123, pp.60-67 (In Japanese)
Sato.M [2003], gInactivation of
microorganisms by pulsed electric field,h J Institute of Electrostatics Japan,
Vol.27, pp.106-110
Shimizu,
K., F. Doge and K. Ohsaki [2003a], gDevelopment of user-friendly software to
visualize ELF electric field exposed to human body,h Proc. of CEEM 2003,
pp.122-125.
Shimizu.H.O.
and K.Shimizu [2003b], gAnalysis of electric force exerted on human hair in ELF
electric field exposure.h Trans.IEICE, Vol.J86-B, No.7, pp.1225-1233 (In Japanese)
Shimizu.H.O.
and K.Shimizu [2004], gAnalysis of human perception of ELF electric fields.h
Proceedings of EMCf04, Sendai, 4B2-2, pp.781-784
Shimooka,T.,
I.Fujii, M.Kagawa, T.Tatebe and K.Shimizu [2004], h Effect of ELF
electrostimulation on function of macrophage.h Proceedings of EMCf04 Sendai,
4B2-1, pp.777-780
Shindo.T.,
A.Asakawa, H.Honda, M.Sakae and S.Tanaka [2003], gNecessary clearance to
prevent side flashes.h IEEJ Trans. PE, Vol.123, pp.90-974 (In Japanese)
Tatebe,T.,
T.Shimooka, M.Kagawa and K.Shimizu [2004], gEffect of ELF electrostimulation on
reactive oxygen generation of macrophage.h Technical Report of IEICE,
MBE2003-130, pp.13-18 (In Japanese)
Taki.M.,
Y.Suzuki and K.Wake [2003], gDosimetry considerations in the head and retina
for extremely low frequency electric fields.h Radiation Protection Dosimetry,
vol.106, pp.349-356
Yamashita.M.,
M.Sugano and K.Shimizu [2000a], gPhotoelectric pulse measurement with a
ring-type telemeter and analysis on the variation in autonomic nerve activity.h
Proc of BPES 2002, pp.325-328 (In Japanese)
Yamashita.M.,
K.Ohsaki and K.Shimizu [2000b], gDevelopment of biotelemetry technique for
EEG/ECG measurement in a strong ELF electric field.h IEEJ, vol.122-C,
pp.1589-1594 (In Japanese)
Yamashita,M.,
K.Ohsaki adnK.Shimizu [2004], gAnalysis of physiological changes caused by
local exposure of ELF electric field.h Technical Report of IEICE. (In Japanese)
Yoshimura.N.,
M.Suzuki and K.Mitobe [2003], gThe research on the sterilization in the
a-thermal process.h J Institute of Electrostatics Japan, Vol.27, 111-116p (In
Japanese)
K1.2 DC Magnetic Fields on cells and genetics
In several kinds of
microbial species, example of reports of the positive effect of DC magnetic
field have been confirmed. SoxR on Escherichia
coli in which there are too many examples of reports until now. Variant
sodAsodB [Zhang et al.,2003] which reports rising, since the mutagenesis
frequency has it by 5 or high magnetic field of 9 teslas in the double mutant. Saccharomyces cerevisiae with the paper
which found the rise in expression strength of several kinds genes of by the
high magnetic field of 14 teslas [Ikehata, 2003]. Rhodobacter sphaeroides [Utsunomiya, 2003] in which the production
of porphyrin reports the increase at 5.3 times in the high magnetic field of
0.3 teslas. There are some inhibition of multiplication by 0.1mT magnetic
field, example of reports of the effect by magnetic field to 0.51mT conidium
formation rate besides on 3 kinds of Plant pathogenic fungi (Ikehata and
Miyakoshi).
There are several
studies to determine the mutagenicity by exposure to strong static magnetic
fields. Takashima et al. reported dose response relationship between magnetic
field density and its mutagenicity using DNA repair-proficient and -deficient
strains of fruit fly Drosophila melanogaster. It was found that exposure
to 2, 5 or 14 T fields for 24h caused a statistically significant enhancement
in somatic recombination frequency in the post-replication repair deficient
flies, whereas the frequency remained unchanged in the nucleotide excision
repair deficient flies and in the DNA repair-proficient flies after
exposure. An increase linearly
dependent on the flux density was observed between 0.5 T and 2 T, while it was
saturated at exposure levels over 2 T. These findings suggest that exposure to
high density magnetic fields induce somatic recombination in Drosophila, and
that the dose-response relationship is not linear.
Zhang et al.
using an Escherichia coli mutation
assay to assess the mutagenic effects of strong magnetic filed. The mutation
frequency was significantly increased by the static magnetic field exposure in soxR and sodAsodB mutants, which are defective in defense mechanisms against
oxidative stress. In addition, the expression of superoxide-inducible socS:: lacZ fusion gene was stimulated
1.4- and 1.8-fold in E.coli when
exposed to 5 and 9 T, respectively. These results indicate that strong static
magnetic field induces mutations through elevated production of intracellular
superoxide radical in E.coli.(Ikehata
and Miyakoshi).
References
Hashimoto.Y.,
M.Kawasumi and M.Saito [2004], gEffect of static magnetic field on cell
migration.h IEEJ Trans EIS, Vol.124, pp.1719-1724
Ikehata.M,
M.Iwasaka, J.Miyakoshi, S.Ueno and T.Koana [2003], gEffects of intense magnetic
fields on sedimentation pattern and gene expression profile in budding yeast,h J.Appl.Phys,
vol.93, pp.6724-6726
Ikehara.M., Y.Takashima,
H.Takeyama, M.Iwasaka, S.Ueno, T.Matsunaga, J.Miyakoshi and T.Koana [2003], gEstimation
of mutagenicity and perturbative effects by exposure to strong magnetic field,h
Proceedings of the WHO 3rd International EMF Seminar in China,
pp.96-98, Oct
Nagy.P and
G.Fiscl [2004], gEffect of static magnetic field on growth and sporulation of
some plant pathogenic fungi,h Bioelectromagnetics, vol.25, pp.316-318
Nakahara,T.,
H.Yaguchi, M.Yoshida and J.Miyakoshi [2002] gEffects of exposure of CHO-k1
cells to a 10 T static magnetic fieldh. Radiology, vol.224, pp.817-822.
Okano.H
and C.Ohkubo [2003], gEffects of static magnetic fields on plasma levels of
angiotensin II and aldosterone associated with arterial blood pressure in
genetically hypertensive rats.h Bioelectromagnetics vol.24, pp.403-412
Takashima.Y.,
J. Miyakoshi, M. Ikehata, M. Iwasaka, S. Ueno and T. Koana, gGenotoxic effects
of strong static magnetic fields in DNA-repair defective mutants of Drosophila melanogaste,h Journal of
Radiation Research (in press)
Utsunomiya.T et al. [2003] J.Biosci.Bioeng, vol.95, pp.401-404
Zhang.Q.M.,
M.Tokiwa, T.Doi, T.Nakahara, P.W.Chang, N.Nakamura, M.Hori, J.Miyakoshi and
S.Yonei [2003], gStrong static magnetic field and the induction of mutations
through elevated production of reactive oxygen species in Escherichia coli soxR,h Int.J.Radiat.Biol., vol.79, pp..281-286.
4.1.2 Magnetic orientation- Agarose and Microorganisms
Bull sperm and
paramecium cilium are oriented in a strong static magnetic field. An
anisotropic diamagnetic susceptibility of microtubules which are one of their
components contributes it [Higashi].
Magnetic fields of 5-10T were
applied to agarose molecules to obtain the random, the planar and the axial
gels. As a result, the electrophoretic velocity depended on the gel structure
as well as the size and structure of DNAs. The magnetically ordered agarose
gels can be used for a new separation method of DNAs at a high resolution
[Higashi, Yamaguchi and Iwasaka].
References
Emura.R.,
T.Takeuchi, Y.Nakaoka and T.Higashi [2003], gAnalysis of anisotropic
diamagnetic susceptibility of a bull sperm,h Bioelectromagnetics., vol.24,
pp.347-355
Higashi. T., R.Emura
and T.Takeuchi [2002], gEffects of on-and-off static magnetic field on fibrinolysis,h
Biological Effects of Electromagnetic Fields, Proceeding of 2nd International
Workshop, 790-797p
Ichioka.S.,
M.Minegishi, M.Iwasaka, M.Shibata, T.Nakatsuka and J.Ando [2003], gSkin
temperature changes induced by strong static magnetic field exposure,h
Bioelectromagnetics, vol.24, pp.380-386
Iwasaka.M.,
J.Miyakoshi and S.Ueno [2003a], gMagnetic field effects on assembly pattern of
smooth muscle cells,h In Vitro Cell Biol-Animal, vol.39
Iwasaka.M.,
K.Yamamoto, J.Ando and S.Ueno [2003b], gVerification of magnetic field gradient
effects on medium convection and cell adhesion,h J Applied Physics, vol.93,
pp.6715-1717
Iwasaka.M
and S.Ueno [2003c], gDetection of intracellular macromolecule behavior under
strong magnetic fields by linearly polarized light.h Bioelectromagnetics,
vol.24, pp.564-570
Iwasaka.M and
S.Ueno [2003d], gDetection of intracellular macromolecule behavior under strong
magnetic field by linearly polarized light,h Bioelectromagnetics, vol.24,
pp.564-570
Sungkhaphun.P,
W.Khan-ngren and S.Nitta [2004], gThe study of magnetic field intensity and
time@variation
affect on the rice growth.h Proceedings of EMCf04 Sendai, 4D3-1, pp.881-884
Takeuchi. T., Y.Nakaoka,
R.Emura.and T.Higashi [2002], gDiamagnetic orientation of bull sperms and
related materials in static magnetic fields,h J. Phys. Soc. Japan., vol.71,
363-368p
Takeuchi.M.,
M.Sekino, N.Iriguchi and S.Ueno [2005], gT2 relaxation and diffusion of
collagen gel oriented.h J Magn Soc Japan, vol.29, pp.347-350 (In
Japanese)Chiba.A and M.Inase [2003], gPhosphate metabolites in muscular
contraction caused by magnetic stimulation,h Bioelectromagnetics, vol.24, pp.366-371
Yamaguchi.M
and I. Yamamoto [2004]: Proc. Int. Workshop on Materials Analysis and
Processing in Magnetic Fields, March 17-19,Tallahassee, USA
K1.3 DC and ELF Magnetic Field
K1.3.1 In vivo studies
Human and AnimalidŒõA‘å‹v•Ûj
References
Kezuka.E.,
M.Masada, T.Shigemitsu and M.Kato [2004], gThe vertically polarized magnetic
field has no effect on the content of pteridine in mouse liver,h Asia-Pacific
Radio Science Conference Proceedings, pp.450-451
Kezuka.E.,
M.Masada, T.Shigemitsu and M.Kato [2005], gEffects of 50Hz magnetic field
exposure on secretion of pteridine in mice is dependent on field polarization.h
2005 BioEM Meeting, Dublin
Kobayashi.M.,
N.Soda, T.Miyo and Y.Ueda [2004], gEffects of combined DC and AC magnetic
fields on germination of hornwort seeds.h Bioelectromagnetics vol.25,
pp.552-559
Kurokawa.Y.,
H.Nitta, H.Imai and M.Kabuto [2003a], gAcute exposure to 50Hz magnetic fields
with harmonics and transient components: lack of effects on nighttime hormonal
secretion in men,h Bioelectromagnetics, vol.24, pp.12-20
Kurokawa.Y.,
H.Nitta, H.Imai and M.Kabuto [2003b], gCan extremely low frequency alternating
magnetic fields modulate heart rate or its variability in humans?h Autonomic
Neuroscience: Basic and Clinical, vol.105, pp.53-61
Mizoue.T.,
Y.Onoe, H.Moritake, J.Okamura, S.Sokejima, and H.Nitta [2004], gResidential
proximity to high-voltage power lines and risk of childhood hematological
malignancies.h J Epidemiology, vol.14, pp.118-123
Oda.T
and T.Koike [2004], gMagnetic field exposure saves rat cerebellar granule
neurons from apoptosis in vitro.h Neuroscience Letters., vol.365, pp 83-86
Okano.H and
C.Ohkubo [2003a], gAnti-stressor effects of whole body exposure to static
magnetic field on pharmacologically induced hypertension in conscious rabbits,h
Bioelectromagnetics, vol.24, pp.139-147
Okano.H and
C.Ohkubo [2003b], gEffects of static magnetic fields on plasma levels of
angiotensin II and aldostrone associated with arterial blood pressure in
genetically hypertensive rats,h Bioelectromagnetics vol.24, pp.403-412
Okano.H.,
H.Masuda and C.Ohkubo [2005], gDecreased plasama levels of nitric oxide
metabolites, angiotesin II, and aldosterone in spontaneously hypertensive rats
exposed to 5mT static magnetic field.h Bioelectromagnetics vol.26, pp.161-172
Shigemitsu.T
[2004], gBiological and health effects of ELF electromagnetic field.h
Proceedings of EMCf04 Sendai, 4B1-1, pp.765-768
Sawaguchi.Y.,
K.Kimura, K.Misawa and J.Arisawa [2004], gEffects of 50Hz magnetic field
exposure on the body color and the urine quantity of goldfish.h Proceedings of
EMCf04 Sendai, 4B1-3, pp.773-776
Ushiyama.A
And C.Ohkubo [2004a], gAcute effects of low-frequency electromagnetic fields on
leukocyte-endothelial interactions in vivo,h In Vivo, vol.18, pp.125-132
Ushiyama.A.,
H.Masuda, S.Hirota and C.Ohkubo [2004b], gSubchronic effects on
leukocyte-endothelial interactions in mice by whole body exposure to extremely
low frequency electromagnetic fields.h In Vivo vol.18, pp.425-432
Ushiyama.A., Y.Suzuki,
H.Masuda, S.Hirota, M.Taki and C.Ohkubo [2004c], gEffects of continuous
whole-body exposure to 50Hz electromagnetic fields with repetitive transient
magnetic fields on the intramicrovascular leukocyte behavior in mice.
Asia-Pacific Radio Science Conference Proceedings pp.424-426
Yamaguchi.S., M.Ogiue-Ikeda, M.Sekino and
S.Ueno [2005], gEffects of transcutaneous magnetic stimulation on tumor and
immune functions in mice.h J Magn Soc Japan., vol.29, pp.360-363 (In Japanese)
Yano.A.,
Y.Ohashi, T.Hirasaki and K.Fujiwara [2004], gEffects of a 60Hz magnetic field
on photosynthetic Co2 uptake and early growth of radish seedlings.h
Bioelectromagnetics vol.25, pp.572-581
Yokoi.S.,
M.Ikeya, T.Yagi and K.Nagai [2003], gMouse circadian rhythm before the Kobe
earthquake in 1995,h Bioelectromagnetics, vol.24, pp.289-291
K1.3.2 In Vitro studies
Cell; proliferation, cell cycle, mutationi‹{‰zj
No or very
little effects of ELF electromagnetic field were found on basic cellular
behaviors (proliferation, survival and cell cycle). Exposure to a high-density
ELF electromagnetic field increased mutation and chromosomal aberration
dose-dependently. Such a result was
more significant under a combined exposure with external factors. Results of
molecular biological analysis for its mechanism revealed that a response to an
ELF electromagnetic field had an effect on the signal transduction system that
was involved with intracellular calcium and protein kinase (Miyakoshi).
References
Fu-Rong
Tian., T.Nakahara, M.Yoshida, N.Honda, H.Hirose and J.Miyakoshi [2002], gExposure
to power frequency magnetic fields suppresses X-Ray-induced apoptosis
transiently in Ku80-deficient xrs5 cells.h Biochemical and Biophysical Research
Communications, vol.292, pp.255-261
Guig-Rong
Ding., T.Nakahara, Fu-Rong Tian, Yao Guo and J.Miyakoshi [2001a], gTransient
suppression of X-ray-induced apoptosis by exposure to power frequency magnetic
fields in MCF-7 cells.h Biochemical and Biophysical Research Communications,
vol.286, pp.953-957
Guig-Rong
Ding., K.Wake, M.Taki and J.Miyakoshi [2001b], gIncrease in
hypoxanthine-guanine phosphribosyl transferase gene mutations by exposure to
electric field,h Life Sciences, vol.68, pp.1041-1046
Guig-Rong.Ding.,
T.Nakahara and J.Miyakoshi [2002], gExposure to power frequency magnetic fields
and X-rays induces GAP-43 gene expression in human glioma MO54 cells.h
Bioelectromagnetics, vol.23, pp.586-591
Guig-Rong
Ding., T.Nakahara and J.,Miyakoshi [2003], gInduction of kinetochore-positive
and kinetochore-negative micronuclei in CHO cells by EMF magnetic field and/or
X-rays.h Mutagenesis. vol.18, pp.439-443
Guig-Rong
Ding, T.Nakahara, H.,Hirose, S.koyama and J.Miyakoshi [2004], gELF magnetic fields promote H2O2
-induced cell death in HL-60 cells.h International Journal of Radiation
Biology., vol.80, pp.317-324
Koyama.S.,
T.Nakahara, H.Hirose, Gui-Rong Ding, Y.Takashima, Y.Isozumi and J.Miyakoshi [2004a], gELF Electromagnetic fields increase
hydrogen peroxide (H2O2)-induced mutations in pTN89
plasmids.h Mutation Research., vol.560, pp.27-32
Koyama.S.,
T.Nakahara, H.Hirose, Y.Takashima, Y.Isozumi and J.Miyakoshi [2004b], gCombined
effects of extremely low frequency electromagnetic fields (ELFMFs) and X-rays
or H2O2 on mutation in pTN89 plasmids.h Asia-Pacific
Radio Science Conference Proceedings pp.414-417
Miyakoshi.J [2004], gCellular and molecular
effects of electromagnetic fields,h Proceedings of EMCf04 Sendai, 4B1-2,
pp.769-772
Sakurai.T.,
A.Satake, S.Sumi, K.Inoue and J.Miyakoshi [2004a], gAn extremely low frequency
magnetic field attenuated insulin secretion from the insulinoma cell line,
RIN-m,h Bioelectromagnetics vol.25, pp.160-166
Sakurai,T.,
S.satake, S.Sumi, K.Inoue, N.Nagata, Y.Tabata and J.Miyakoshi [2004b] gThe
efficient prevasculariation induced by fibroblast growth factor 2 with collagen
coated-device improves the cell survival of a bioartificial pancreash.
Pancreas, vol.28, pp.70-79.
Cell; Time-varying 1.7
T fields, ion channels, bone cell
Exposure to
a time-varying magnetic field (maximum flux density of 1.7T) inhibits K+
influx via Ca2+-dependent K+ channel and an increase in
intracellular Ca2+ concentration ([Ca2+]i) of
HeLa cells incubated in high K+ medium [Ikehara, 2002]. Addition of
Ca2+ ionophore (ionomycin) to the high K+ medium increase
[Ca2+]i to the level of control cells, regardless of
exposure to the magnetic field. But the inhibition of K+ uptake by
exposure to the magnetic field is not restored by addition of the ionophore.
This strong time-varying magnetic field (maximum of 1.51T) also inhibits a
transient increase in [Ca2+]i in bovine adrenal
chromaffin cells induced by bradykinin (BK) in a Ca2+-free medium
[Ikehara, 2002]. The exposure does not affect BK induced production of inositol
1,4,5 trisphosphate (IP3). Inhibition of the BK-induced increase in [Ca2+]i
by exposure for 30 min is mostly recovered 1 hr after exposure ended. Our
results reveal that the magnetic field exposure inhibits Ca2+
release from intracellular Ca2+ stores. Moreover, effects of
exposure to a 50Hz magnetic field (maximum of 41.7 to 43.6mT) on the membrane
structures of living HeLa cells were studied using attenuated total reflection
infrared spectroscopy [Ikehara, 2003]. Exposure to the ELF magnetic field has
reversible effects on the N-H inplane bending and C-N stretching vibrations of
peptide linkages the secondary structure of ƒ¿-helix and ƒÀsheet in
cell membrane proteins.
On the other
hand, in cultured osteoblast-like cells (MC3T3-E1), exposure to ELF magnetic
field (60Hz, 3.0,T) for 3 days, both collagen and non-collagen protein content
by multispectral imaging method, increased in the cells at peripheral; regions
of culture dish than that at central regions of same dish. The treatment of IGF
increased in collagen content at the peripheral cells for 17 days culture. But
the additive effects of the exposure and IGF treatment were not observed
[Yamaguchi, 2004].
ALP activity
was increased significantly by the exposure alone or by combined with NGF
treatment. These results indicate that the mechanisms of differentiation
related to IGF and NGF in the osteoblasts were altered by the magnetic fields
of extremely low frequency [Hosokawa, 2004]
.
References
Ikehara.T., K.H.Park, H.Yamaguchi, K.Hosokawa, K.Yoshizaki, H.Miyamoto,
K.Aizawa and Y.Kinouchi. [2000], gEffects on Rb+ (K+)
uptake of HeLa cells in a high K+ medium of exposure to a switched
1.7 tesla magnetic field.h Bioelectromagnetics vol.21, pp.228-237
Ikehara.T., K.H.Park,
H.Yamaguchi, K.Hosokawa, H.Houchi, M.Azuma, K.Minakuchi, H.Kashimoto, M.Kitamura,
Y.Kinouchi, K.Yoshizaki. and H.Miyamoto [2002], gEffects of a time-varying
strong magnetic field on release of cytosolic free Ca2+ from
intracellular stores in cultured bovine adrenal chromaffin cells.h
Bioelectromagnetics, vol.23, pp.505-515
IkeharaT.,
H.Yamaguchi, K.Hosokawa, H.Miyamoto and K.Aizawa [2003], gEffects of ELF
magnetic field on membrane protein structure of living HeLa cells studied by
Fourier transform infrared spectroscopy,h Bioelectromagnetics, vol.24,
pp.457-464
Hosokawa.K.,
H.Yamaguchi, T.Ikehara, H.Shichijo, M.Kitamura, K.Yoshizaki, Y.Kinouchi, H.Miyamoto and K.Aizawa [2004], gEffects
of ELF magnetic fields on signal for differentiation of cultured
osteoblast-like cell by ImSpector system,h Jpn J Physiol, vol.53, S141
Yamaguchi.H.,
K.Hosokawa, H.Shichijo, M.Kitamura, A.Soda, T.Ikehara, Y.Kinouchi, K.Yoshizaki,
H.Miyamoto and K.Aizawa [2004], gEffects of ELF magnetic fields on signal for
differentiation of cultured osteoblastic cells by multispectral imaging system,h
BEMS Abstract Book, 26th Annual Meeting, 216p
M1.3.3
other studies
Mutation
in yeastsi’r’[j
Takashima et al.
reported that the effect of ELF magnetic fields on the DNA damage repair
process, the gene conversion frequency and cell cycle kinetics in a DNA
repair-proficient and nucleotide excision repair (NER)-deficient strain of
diploid yeast Saccharomyces cerevisiae. DNA repair- or NER-deficient
cells were irradiated with sub-lethal doses of ultraviolet light (UV) radiation
followed by exposure to 50 Hz magnetic fields up to 30mT for 48 h. After exposure,
gene conversion rate was increased by the combined exposure in DNA
repair-proficient cells, whereas it remained unchanged between UV alone and the
combined exposure in NER-deficient cells. The UV-induced G1 arrest was
inhibited by exposure to 30mT ELF magnetic fields in both repair-proficient and
-deficient cells. The results suggest that exposure to high-density (30 mT) ELF
magnetic field decreases the efficiency of NER by suppressing G1 arrest, which
in turn led to enhancement of the UV-induced gene conversion [Ikehata].
Moreover, there are several fundamental research
activities to clarify ELF or combined fields with static and ELFs.
References
Ikehara.T.,
H.Yamaguchi, K.Hosokawa, H.Miyamoto and K.Aizawa [2003], gEffects of ELF magnetic
field on membrane protein structure of living HeLa cells studied by Fourier
transform infrared spectroscopy,h Bioelectromagnetics, vol.24, pp.457-464
Ikehata.M.,
Y. Takashima, Y. Suzuki, H. Shimizu, J. Miyakoshi and T. Koana [2001], gExposure
to a power frequency magnetic field (50 Hz, 40 mT) did not cause point mutation
in bacteria.h Environ. Mut Res., vol.23, pp.215-222
Ikehata.M.,
M.Iwasaka, T.Nagai, Y.suzuki, M.Taki and T.Koana [2004a], gEstimation of biological
effects of complex environmental magnetic fields with various frequency
components,h Proceedings of the ICNIRP/WHO International NIR Workshop and URSI
Symposium, May
Ikehata.M.,
Y.Takashima, J.Miyakoshi and T.Koana [2004b], gEstimation of biological effects
of extremely low frequency magnetic fields,h 11th International
Congress of the International Radiation Protection Association, May
Ikeda.K.,
Y.Shnmura, H.Mizoe, H.Yoshizawa, A.Yoshida and H.Hirose [2003], gNo effects of
extremely low frequency magnetic fields found on cytotoxic activities and cytokine
production of human peripheral blood mononuclear cells in vitro,h
Bioelectromagnetics, vol.24, pp.21-31
Kobayashi.M.,
N.Soda, T.Miyo and Y.Ueda [2004], gEffects of combined DC and AC magnetic
fields on germination of hornwort seeds,h Bioelectromagnetics, vol.25,
pp.552-559
Mizoue.T., Y.Onoe, H.Moritake, J.Okamura,
S.Sokejima and H.Nitta [2004], gResidential proximity to high-voltage power
lines and risk of childhood hematological malignancies,h J Epidemiology,
vol.14, pp.118-123p
Sakurai.T.,
A.Satake, S.Sumi, K.Inoue and J.Miyakoshi [2004], gAn extremely low frequency
magnetic field attenuates insulin secretion from the insulinoma cell line,
RIN-m,h Bioelectromagnetics, vol.25, pp.160-166
Takashima.Y., M. Ikehata, J. Miyakoshi and T. Koana [2003],
gInhibition of UV-induced G1 arrest by exposure to 50 Hz magnetic fields in
repair-proficient and -deficient yeast strains.h Int J Radiat Biol., vol.79, pp.919-924
K1.4 IF Magnetic fieldiŽRèA—é–ØAdŒõj
WHO defines the intermediate frequency
(IF) region of the EMF spectrum as being between 300Hz to 10MHz. Compared to
ELF and RF fields, little research has been done of the effects of IF fields.
There are two reports on the biological effects of IF magnetic fields. Haga et
al. used a highly sensitive mutagenesis assay method (umu system) to evaluate the direct impact of exposure to 20kHz, 60ƒÊT for DNA destruction
gene mutation [Haga, 2004]. This exposure experiment induced bacterial umu DNA repair response in one experimental
case. Tachi et al. also investigated whether IF magnetic field (20kHz, 0.5mT,
1mT) induce the DNA damage and physiological abnormality in bacterial cells
containing bacteriophage ă[Tachi,
2005]. After about 4 and 8 hourfs exposure, this result suggests IF magnetic
fields induce physiological damage in bacterial cells. Further studies are
needed (Yamazaki and Suzuki).
References
Haga.A.,
Y.Kumagai, H.Matsuki and G.Endo [2004], gEvaluation of damage in DNA molecules
by very low frequency magnetic fields using bacterial cells with
bioluminescence gene.h Proceedings of EMCf04 Sendai, 4D4-2, pp.897-900
Tachi.S,
M.Kakikawa, S.Hashimoto, M.Iwahara and S.Yamada [2005], gEffects on bacterial
cells of exposure to very-low-frequency magnetic fields.h J Magn Soc Japan.,
vol.29. pp.356-359
K.1.5 RF and Microwaves – Animal
Learning and Memory Study
Effects of
exposure to electromagnetic waves (EMW) used in cellular phones on learning and
memory processes were examined in Sprague-Dawley rats using a carousel type
exposure system [Tsurita, 2000 and T-maze [Yamaguchi, 2003]. This study
suggests that the exposure to a TDMA field at levels about four times stronger
than emitted by cellular phones does not affect the learning and memory
processes when there are no thermal effects
References
Jarupat.S.,
A.Kawabata, H.Tokura and A.Borkiewicz [2003], gEffects of the 1900MHz electromagnetic
field emitted from cellular phone on nocturnal melatonin secretion,h J Physiol
Anthropol, vol.22, pp.61-63
Kojima.M.,
I.Hata, K.Wake, S.Watanabe, Y.Yamanaka and Y.Kamimura [2004], gInfluence of
anesthesia on ocular effects and temperature in rabbit eyes exposed to
microwaves,h Bioelectromagnetics, vol.24, pp.28-233
Tsurita.G., H.Nagawa, S.Ueno, S.Watanabe and M.Taki
[2000], gBiological and morphological effects on the brain after exposure of
rats to a 1439 MHz TDMA field,h Bioelectromagnetics, vol.21, pp.364-371
Yamaguchi.H., G.Tsurita, S.Ueno, S.Watanabe, K.Wake, M.Taki and H.Nagawa [2003],
g1439MHz pulsed TDMA fields affects performance of rats in a T-maze task only
when body temperature is elevated,h Bioelectromagnetics, vol.24, pp.223-230
RF-cell (‹{‰z)
Genotoxic effect
of high frequency electromagnetic field (HFFMF) at 2.45GHz with a wide range of
specific absorption rates (SARs) was examined in cultured cells. The
micronucelus (MN) frequency of cells exposed to a HFEME at SAR of up to 50 W/kg
was not different to that in sham-exposed cells, while those at SARs of 100 and
200 W/kg were significantly higher than in the sham-exposed controls. An
increase in SAR causes a rise in temperature and this may be connected to the increase
in MN formation generated by exposure to HFEMF. Effect of HFEMF on DNA damage
was also examined using alkaline comet assay method. There was no significant
difference in the tail moments between HFEMF- and sham-exposed groups. This finding
suggests that exposure to HFEMF does not cause DNA strand breaks even at a SAR
of 100 W/kg. For the gene expression, effect of HFEMF on the synthesis of heat
shock protein 70 (Hsp70) was examined. Exposure to a HFEMF induced hsp70
expression at a high SAR of more than 20 W/kg but not at 5 W/kg in human glioma
cells. In addition, there were no significant differences in Hsp27 and Hsp70
expressions between RF (1950 MHz)-exposed and sham-exposed cells at a SAR of
lower than 10 W/kg. However, exposure to the RF field at 10 W/kg decreased the
protein level of phosphorylated Hsp27 (78Ser) significantly.
Referfences
Fu-Rong Tian., T.Nakahara, K.Wake, M.Taki and
J.Miyakoshi [2002], gExposure to 2.45GHz electromagnetic fields induces hsp70
at a high SAR of more than 20W/kg, but not at a lower SAR of 5W/kg, in human
glioma MO54 cells,h International Journal of Radiation Biology, vol.78,
pp.433-440
Koyama.S., T.Nakahara, K.Wake, M.Taki,
Y.,Isozumi and J.Miyakoshi [2003], gEffects of high frequency electromagnetic
fields on micronucleus formation in CHO-K1 cells,h Mutation Research, vol.541,
pp.81-89
Koyama.S.,
Y.Isozumi, Y.Suzuki, M.Taki and J.Miyakoshi [2004], gEffects of 2.45GHz electromagnetic
fields with wide range of SARs on micronucleus formation in CHO-K1 cells.h The
Scientific World Journal. vol.4, pp.29-40
Miyakoshi.J.,
M.Yoshida, Y.Tarusawa, T.Nojima, K.Wake and M.Taki [2002], gEffects of
high-frequency electromagnetic fields on DNA strand breaks using Comet assay
method,h Electrial Engineering in Japan, vol.141, pp.9-15
Miyakoshi,J.,
K.Takemasa, Y.takashima, G.-R.Ding, H.Hirose and S.Koyama [2005] gEffects of
exposure to a 1950 MHz radio-frequency field on expression of Hsp70 and Hsp27
in human glioma cellsh. Bioelectromagnetics, vol.26, pp.251-257.
K2 Tissue Properties, Materials, and Phantoms
K.2.1 Design Methods of the Electromagnetic
Environmenti‹{ìj
In
order to use the EM power effectively in dairy life without losing the safety
in every respect, only the EM waves which are actually needed inside the living
space should be transmitted into the space. A stratified construction material
that is consisted of two low loss materials has been developed for satisfying
such a demand. The new functional material can absorb more than 70 percent of
the incident EM power at specific frequencies that are pre-designed according
to the demand (Miyakawa).
References
Ishii.N., M.
Miyakawa and K. Sakai: "Method for Achieving Electromagnetic Wave
Absorption by Low-loss Stratified Construction Materials", IEEE Trans. EMC
(in press).
Ishii.N.,
M. Miyakawa and K. Sakai [2003], gAnalysis and design on EM wave absorption by stratified
construction materials – a case of vertically incident wave,h Proc. IEEE
Symposium on EMC, pp.800-805
Miyakawa.M.,
K. Sakai, and N. Ishii [2001a], gSelective use of EM waves in the closed space
constructed by traditional but new construction materials with various surface
structures,h Proc. IEEE EMC International Symposium, 2, pp.794-798
Miyakawa.M.,
M. Shimada, N. Ishii, T. Saeki, and Y. Kanai [2001b], gModel-based permittivity
measurement of construction materials by the standing wave method,h Proc. IEEE
EMC International Symposium, 2, pp.1135-1140
Miyakawa.M
and S. Hoshina [2002a], gA self-supporting gel phantom used for visualization
and/or measurement of the three-dimensional distribution of SAR,h Proc. IEEE
EMC International Symposium, 2, pp.809-814
Miyakawa.M.,
K. Yaguchi, N. Ishii, T. Saeki and Y. Kanai [2002b], gAccuracy improvement in permittivity
measurement of construction materials by use of a model of the standing wave method
in free space,h Proc. IEEE EMC International Symposium, 2, pp.671-676
Miyakawa.M.,
N. Komiyama and N. Ishii [2003], gQuick search for a permittivity value in model-based standing wave method
used for construction material measurement,h Proc. 2003
IEEE Symposium on EMC, pp.372-377
Tamada.T., N. Ishii and
M. Miyakawa [2003], gAnalysis on the standing wave method in free space using spectral
domain approach,h Proc. IEEE Symposium on EMC, pp.759-764
K2.2 Tissue Properties- Bioelectromagnetics
parametersi“n•ÓA㑺j
The
radio frequency safety guideline compliance for mobile phones has been
evaluated by measuring the specific absorption rate (SAR) in the phantom
material. The electromagnetic properties of bio-tissues and phantom material
need to be specified in order to achieve precise and accurate SAR measurements.
Recently, there are many research activities focused on Liquid phantoms
(Watanabe and Kamimura).
References
Fukunaga.K.,
S.Watanabe, Y.Yamanaka, H.Asou, Y.Ishi and K.Sato [2004a], gDielectric properties
of liquid phantoms for evaluations of mobile phones,h Proceedings of EMC f04
SENDAI, 4B3-5, pp.805-808
Fukunaga.K.,
S.Watanabe and Y.Yamanaka [2004b], gDielectric properties of tissue-equivalent
liquids and their effects on specific absorption rate.h IEE EMC, vol.46,
pp.126-129
Kamimura.Y [2004], gHuman body impedance for
contact current measurement in Japan,h Proceedings of EMC f04 SENDAI, 3B4-1,
pp.585-588
Kato.H
[2002], gPhantoms for electromagnetic waves in medical use,h IEICE Trans.
J-85-B, pp.597-608 (In Japanese)
Kawai.H, et al [2002], gEffects of inaccurate electric
constants of the tissue-equivalent phantom on the local SAR and the SAR distribution,h
IEICE trans. J85-B, pp.619-630 (In Japanese)
Kuriyama.Y
[2004], gLiquid materialfs complex permittivity measurement using a rectangular
waveguide and a dielectric tube at 800 and 900MHz band,h Proceedings of EMC f04
SENDAI, 3C3-3, pp.645-648
Hashimoto, et al [2003], gA study on measurement
of dielectric constant by free space transmission method at C band,h IEICE
Trans. J86-B, pp.1089-1095 (In Japanese)
Ueda.N, et al [2002], gInfluence of through hole
on liquid materialfs complex permittivity measurement using a rectangular waveguide
and a dielectric tube,h Tec. Rep. of IEICE, EMCJ2002-80, pp.21-26 (In Japanese)
K2.3 PhantomsiˆÉ“¡j
Various
phantoms for the SAR (Specific Absorption Rate) estimation have been studied. A
real-shaped torso bust phantom is developed to achieve an accurate evaluation
of the SAR in the head as well as the characteristics of an antenna for a
mobile terminal placed close to the human body [Ito, 2004]. The shape and size
of the torso bust phantom are based on the average Japanese youths in their
twenties. Moreover, an abdomen phantom of pregnant women including the amniotic
fluid and the fetus is developed to estimate the SAR in the fetus [Kawai, 2003,
Ito, 2005]. The targeted frequency range of this phantom is the VHF band. The dielectric
constants of the amniotic fluid and the fetus of rabbits were measured to
determine the dielectric constants of the phantom. In addition, solid phantoms,
whose targeted frequency range is up 3 to 6 GHz, are investigated [Ishido, 2004].
The phantoms can reproduce the electrical properties of human biological
tissues in the range of 3 to 6 GHz without changing their compositions.
In IEICE
Transactions, the special issue on phantom has been published, and a review
concerning the tissue equivalent phantoms has been reported [Ito, 2002].
High-molecular gel phantom with high transparency and viscosity has been
proposed to realize the evaluation of the three dimensional EM wavesfexposure
using a micro-capsulated thermo-chromic liquid crystal [Sunaga, 2003; Baba,
2004a, 2004b; Fukunaga, 2004; Suzuki, 2004]. Moreover, the phantom test phantom
for implantable medical device to estimate the impact from RF EMF has been
presented [Ohshita, 2004] [Ito].
References
Baba.M.,
Y.Suzuki, A.Ishi, M.Taki, K.Fukunaga and S.Watanabe [2004a], gDevelopment of a
transparency high molecular gel phantom for three-dimensional visualization of
radio frequency electromagnetic power absorption with capsulate thermo-chromic
liquid crystal.h Asia-Pacific Radio Science Conference Proceedings, pp.418-419
Baba.M.,
A.Ishi, Y.Suzuki, S.Watanabe and M.Taki [2004b], gVisualization of
three-dimensional lectromagnetic power absorption using gel containing liquid
crystal.h Proceedings of EMCf04 Sendai, 3B5-3, pp.605-608
Fukunaga.K.,
S.Watanabe, Y.Yamanaka, H.Asou, Y.Ishi and K.Sato [2004], gDielectric
properties of liquid phantoms for evaluations of mobile phones.h Proceedings of
EMCf04 Sendai, 4B3-5, pp.805-808
Ishido.R.,
T. Onishi, K. Saito, S. Uebayashi, and K. Ito [2004], gA study on the solid
phantoms for 3-6 GHz and evaluation of SAR distributions based on the
thermographic method,h Proceedings of 2004 International Symposium on
Electromagnetic Compatibility, EMC'04 Sendai, 3B3-2, pp.577-580
Ito.K., H.Kawai and K.Saito [2002], gState of
the art and future prospects of biological tissue-equivalent phantom.h
Transaction on IEICE, vol.J85-B, n0.5, pp.582-596 (In Japanese).
Ito.K and H. Kawai [2004], gPhantoms for
evaluation of interactions between antennas and human body,h Proceedings of
URSI Symposium on Electromagnetic Theory, (Pisa, Italy), 2, pp.1104-1106
Ito.K.,
H.Kawai, M.Takahashi, K.Saito, T.Ueda, M.Saito, H.Ito, H.Osada, Y.Koyanagi and
K.Ogawa [2005], gA simple abdomen phantom of pregnant women at VHF band.h
Proceedings of USNC.URSI United States National Committee, Colorado, USA, K1-6,
P.460, Jan.
Kawai.H., Y.
Koyanagi, K. Ogawa, K. Saito, and K. Ito [2003], gA study on the evaluation of
the electromagnetic exposure in the human fetus model at 150 MHz,h IEEE
Antennas and Propagation Society International Symposium Digest (Columbus,
USA), 3, pp.1087-1090
Ohshita.K., Y.Tarusawa,
S.Uebayashi and T.Nojima [2004], gThe test phantom for implantable medical
device to estimate the impact from RF EMF.h Proceedings of EMCf04 Sendai,
2B4-1, pp.341-344
Onishi.T and
S.Uebayashi [2004], gThe influence of a phantom shell on SAR measurement in the
higher frequency range (3-6GHz).h Proceedings of EMCf04 Sendai, 3B3-1, 573-576
Sunaga.T.,
H.Ikehira, S.Furukawa, M.Tamura, E.Yoshitome and T.Obata [2003], gDevelopment
of a dielectric equivalent gel for better impedance matching for human skin,h
Bioelectromagnetics, vol.24, pp.214-217
Suzuki.Y.,
M.Baba, M.Taki, K.Fukunaga and S.Watanabe [2004]. gNew method for visualizing
three-dimensional electromagnetic power absorption by capsulate liquid crystal
dispersed in transparency high-molecular gel phantom,h Annual Report Conference
on Electrical Insulation and Dielectric Phenomena, pp.194-197
K3 Field Measurement, Dosimetry and exposure
assessment
K.3.1 DC and ELF fieldsidŒõAŽRèj
Several
analyses have been conducted focusing on induced currents inside the human
body. Chiba et al conducted calculations of induced currents for grounded and
ungrounded simple homogeneous human model when exposed to vertical uniform
electric field, using finite element method (FEM) [Chiba, 2004]. Matusmoto et
al developed a method for the analysis of the induced current using two-step
process achieved by combination of the surface charge method and the FEM
[Matsumoto, 2004].
In the
analysis of magnetically induced currents, non-uniformity of the fields has
been an key issue especially when assessing compliance with existing
guidelines. Kamimura et al calculated the induced currents in human head using
both analytical formulae and numerical computations when exposed to magnetic fields
produced by AC driven electric shaver, that represents localized magnetic
dipole sources [kamimura, 2002, 2004]. Nishizawa et al introduced equivalent magnetic
source model which consists of multiple magnetic dipoles assumed to be
distributed on a cylindrical surface to simulate magnetic fields around
electric appliances, and calculated induced current in a simple homogeneous
human model [Nishizawa, 2003, 2004a, 2004b]. Related to he characterization of
the magnetic field sources, Yagitani et al studied a method of MUSIC algorithm
and applied it to identification of localized field sources [Yagitani, 2004].
Tarao et al calculated the induced current due to usage of a hair dryer for a
realistic human head model [Tarao, 2003]. Yamazaki et al characterized the
effects of the field uniformity on maximum induced current fro homogeneous
spherical human model for easy assessment of compliance with the guidelines
[Yamazaki, 2005].
Yoshitomi et
al measured environmental ELF magnetic filed in an apartment I Japan and
proposed reduction method for the fields [Yoshitomi, 2002; Moriyama, 2005a].
They also measured ELF magnetic fields originating from equipments used for
medical diagnoses and treatments. Sakurazawa et al measured personal exposure
to ELF magnetic fields in working environments such as electric power
substations, VDT operator, electric furnace operators, and arc welders
[Sakurazawa, 2003].
Sasada
reported a simple three-square-coil system to produce a uniform magnetic field
in a fairly large volume inside the coil system which is advantageous over the
formely proposed systems [Sasada, 2003]. Nagai et al reported exposure setups
fro in vitro experiment for complex magnetic fields with static and
time-varying components [Nagai, 2004].(Yamazaki)
References
Chiba.A.,
K.Isaka, K.Shoukura and T.Matsumoto [2004], gAnalysis of induced current
density inside grounded and ungrounded human model exposed to electric field.h
Proceedings of EMCf04 Sendai, 4C1-1, pp.809-812
Hayami.T., O.Watanabe and O.Hiwaki
[2004a], gSimulation study on estimation of current sources in a nerve fiber
using L1-norm method with magnetic measurement.h IEEJ Trans. EIS, Vol.124,
pp.1712-1718 (In Japanese)
Hayami.T
and O.Hiwaki [2004b], gA method to estimate the condition of the path of a
nerve by measuring neural generation of magnetic fields.h IEEJ Trans.FM,
Vol.124, pp.381-386 (In Japanese)
Hayami,T and O.Hiwaki [2004c], gSimulation
study of magnetic fields produced by an active bundle of nerve fibers to
estimate the distribution of fiver diameterh, Trans. Japanese Society for
Medical and Biological Engineering, Vol.42, pp.261-268.
Kamimura,Y.,
K.Kojima and Y.Yamada [2002], gInduced current inside a spherical model of a
human head due to magnetic current sources of AC drive electic shaverh. IEICE
Trans.B, vol.J85-B, pp.706-714 (in Japanese).
Kamimura.Y., T.Akutsu, Y.Yamada nd K.wake
[2004], gInduced current inside of the human head in the vicinity of an
electric shaver.h Proceedings of EMCf04, Sendai, 4B3-2, pp.793-796
Kawahito.S.,
A.Cerman, K.Aramaki and Y.Tadokoro [2003], gA weak magnetic field measurement
system using micro-fluxgate sensors and delta-sigma interface,h IEEE IM,
pp.103-110
Kawakatsu.M.,
H.Ishibashi, M.Adachi, Y.Uchikawa and M.Kotani [2004], gA study on noise
reduction using ICA for magnetoencephalography.h IEEJ Trans.EIS, vol.124,
pp.1685-1691 (In Japanese)
Kobayashi.K.,
Y.Sato, D.Ando, K.Osashi, B.S.Kim and Y.Uchikawa [2004], gAnalysis of
exercise-induced magnetocardiogram of normal subjects using three-dimensional
magnetic measurement.h J Magnetic Society of Japan, vol.28, pp.747-751 (In
Japanese)
Matsumoto.T.,
A.Chiba, K.Shoukura, H.Ikeda and K.Isaka [2004], gAnalysis of current density
induced in an ungrounded human model by the method combining the surface-charge
integral equation and the finite element method.h IEEJ Trans.PE, Vol.124,
pp.778-784 (In Japanese)
Moriyama.K and K.Yoshitomi [2005a], gApartment
electrical wiring: a cause of extremely low frequency magnetic field in
residential areas.h Bioelectromagnetics, vol.26, pp.238-241
Moriyama,K.,
H.sato, K.Tanaka, Y.Nakashima, and K.Yoshitomi [2005b], gExtremely low
frequency magnetic fields originating from equipment used for assisted
reproduction, umbilical cord and peripheral blood stem cell transplantation,
transfusion, and hemodynamicsh. Bioelectromagnetics, vol.26, pp.69-73.
Nagai.T.,
Y.Suzuki, T.Tanaka, M.Ikehata and M.Taki [2004], gExposure setups for in vitro
experiment on biological effects of complex magnetic fields with static and
time-varying components.h Asia-Pacific Radio Science Conference Proceedings,
pp.422-423
Nishizawa.S
and F.Landstorfer and O.Hashimoto [2003], gExperimental study on equivalent
magnetic source in ELF range (in Japanese).h IEICE Trans.B, J86-B, pp.1251-1254
Nishizawa.S.,
H.Ruoss, F.Landstorfer and O.Hashimoto [2004a]. gNumerical study on an
equivalent source model for inhomogeneous magnetic field dosimetry in the low
frequency range,h IEEE on BME, Vol.51, pp.612-616
Nishizawa,S.,
F.Landstorfer and O.Hashimoto [2004b], gStudy of the magnetic field properties around
household appliances using coil source model as prescribed by the European
standard EN50366h, IEICE Trans Electron, Vol.E87-C, pp.1636-1639.
Sakurazawa.H.,
A.Iwasaki, T.Higashi, T.Nakayama and Y.Kusaka [2003], gAssessment of exposure
to magnetic fields in occupational settings,h J Occup Health, vol.45,
pp.104-110
Sasada.I
[2003], gThree-coil system for producing uniform magnetic fields.h J Magnetic
Society of Japan, Vol.27, pp.612-615 (In Japanese)
Tarao.H.,
N.Hayashi and K.Isaka [2003], gNumerical analysis of induced current in human
head exposed to nonuniform magnetic field including harmonics.h IEEJ Trans.FM,
Vol.123, pp.1100-1107 (In Japanese)
Yagitani.S., K.Ishibana, I.Nagao,
Y.Nishi, Y.Yoshimura, H.Hayakawa and K.Tsuruda [2004], gLocalization of
low-frequency electromagnetic sources.h IEICE Trans, Vol.J87-B, pp.1085-1093
(In Japanese)
Yamada.K
and O.Hiwaki [2004], gEstimation of damaged area of nerve fiber by neural
magnetic stimulation.h IEEJ Trans.FM, Vol.124, pp.375-380 (In Japanese)
Yamazaki.K.,
T.Kawamoto, H.Fujinami and T.Shigemitsu [2005], gSimplified dosimetry for human
exposure to non-uniform ELF magnetic field.h IEEJ Trans FM, Vol.125,
Yoshitomi.K
[2002], gMeasurement and reduction of power frequency magnetic fields in a
residential areah, IEICE Trans Vol.J85-B, pp.538-546 (in Japanese).
K3.2 IF magnetic fieldi—é–ØAŽRèAdŒõj
In recent
years, electric appliances that utilize magnetic fields with frequency higher
than the power frequency, defined as IF (intermediate frequency), for heating,
detecting and switching, has raised new interest in health effects. An IH
(induction heater) cooker is one of those appliances that utilize the IF
magnetic field for heating ferromagnetic pans. The typical frequency of the IH
cooker ranges from 20kHz to 100kHz. A similar frequency range is utilized in a
metal detector usually installed at the security gates of airports, and
electric article surveillance (EAS) system. Since higher frequency induces
induced current inside the human body in proportion to the frequency, stricter magnetic
field levels are set for the higher frequency range in some existing exposure
guidelines.
Kamata et al.
characterized the magnetic fields generated by induction cooking by a series of
measurement [Kamata, 2004]. Yamazaki et al. proposed a simple method to characterize
the magnetic field distribution around appliances in the IF range by
identifying equivalent magnetic dipole moments [Yamazaki, 2004a, 2004b]. Suzuki
et al. conducted numerical calculation of induced currents inside an
anatomically correct human model when exposed to IF magnetic field [Suzuki,
2004a, 2004b, 2005] (Suzuki and Yamazaki).
References
Kamata.K and
A.Haga [2004], gMeasurement of magnetic fields produced by induction cooking
heaters.h Proceedings of EMCf04 Sendai, 4D2-2, pp.869-872
Kamimura.Y.,
K.Komori, M.Shoji, Y.Yamada, S.Watanabe and Y.Yamanaka [2004], gHuman body
impedance for contact current measurement in Japan.h Proceedings of EMCf04
Sendai, 3B4-1, pp.585-588
Suzuki.Y.,
K.Wake, S.Watanabe, M.Taki, S.Watanabe and Y.Yamanaka [2004a], gNumerical
calculation of induced current densities in the human body due to intermediate frequency
magnetic fields.h Proceedings of EMCf04, Sendai, 4B3-4, pp.801-804
Suzuki.Y.,
K.Wake, S.Watanabe, M.Taki, S.Watanabe and Y.Yamanaka [2004b], gNumerical
dosimetry for induced current densities within Japanese adult male and female
voxel models due to magnetic field from induction heat hob.h Asia-Pacific Radio
Science Conference Proceedings, pp.420-421
Suzuki,Y
and M.Taki [2005], g h IEEJ Trans FM, Vol.125-A, pp.427-433.
Takeda.M.,
Y.Bannno, H.Hirata, Y.Okita, M.Kimura and T.Sugiura [2004], gElectromagnetic
field stimulation around implantable cardiac pacemakers caused by EAS system.h
Asia-Pacific Radio Science Conference Proceedings, pp.444-446
Yamazaki.K.,
T.Kawamoto, H.Fujinami and T.Shigemitsu [2004a], gEquivalent dipole moment
method to characterize magnetic fields generated by electric appliance:
extension to intermediate frequencies of up to 100kHz.h. IEEE EMC 46,
pp.115-120
Yamazaki.K.,
T.Kawamoto, H.Fujinami and T.Shigemitsu [2004b], gEquivalent dipole estimation
for characterization of magnetic fields and induced currents near household
appliance eELF to 100kHz).h Proceedings of EMCf04, Sendai, 4B3-1, pp.789-792
K3.3 RF and MWi“¡Œ´A—é–ØA“n•Ój
There has been increasing concern about
adverse health effect in RF and microwave frequency range due to proliferation
of mobile phones. In order to investigate this problem, computational and
experimental works haven been conducted. Recent trends in Japan are summarized
as follows:
1)
Measurement techniques for electric constants of lossy dielectric
For reliable dosimetry, it is essential
to measure electrical constants of human tissue and then to develop material
for phantom [Fukunaga, 2004]. Additionally, uncertainties of an electric probe
have been evaluated [Watanabe,2004b].
2)
Development of experimental setups for small animals and in-vitro study
Some new techniques using ferrite
material or high permittivity materials to realize a highly localized exposure
in small animals has been developed [Wang, 2003b, 2004c], and detailed analysis
for various uncertainties in exposure setups has been conducted [wang, 2002b,
2004b].
3) Dosimetry
for child
Based on the report by
the NRPB, it is concerned that children might be more vulnerable to any adverse
effects of RF radiation than adults. In order to give some insight on this
problem, dosimetry has been conducted using a realistic child head model
[Fujiwara, 2003, 2004]. A scaling technique for producing a realistic child
model has been developed and adopted widely in the world [Wang, 2003a]. A
parallel FDTD technique based on PCs has also been developed for large-scale
dosimetry of mobile phones [Wang, 2004a].
4)
Temperature rise due to RF exposures
Peak-spatial averaged SAR is used as a
measure in the ICNIRP guideline to evaluate the safety of humans for RF electromagnetic
field exposure, while temperature increase would be a direct cause of physical
burning and physiological effect. In order to bridge this gap, a correlation
between peak SAR and temperature increase has been investigated [Fujimoto,
2003a, 2003b, 2004a, 2004c; Hirata, 2002, 2003a, 2003b, 2004a, 2004b]
(Fujiwara).
References
Fujimoto.M.,
A.Hirata and T.Shiozawa [2003a]. gTemperature increase in the heads of adult
and children due to dipole antenna.h Proc of IEEE AP-S International Symposium
Fujimoto.M.,
A.Hirata, J.wang, O.Fujiwara and T.Shiozawa [2003b], gComparison of maximum
temperature increase in the head models of children and adult due to dipole
antenna.h Proc of IEEE Topical Conf.on Wireless Communication Technology, 14-2.
Fujimoto.M.,
A.Hirata and T.Shiozawa [2004a], gCorrelation between temperature increase and
SAR in the child head due to dipole antenna.h IEICE Trans B, vol.J87-B,
pp.320-322.
Fujimoto.M.,
A.Hirata, J.Wang, O.Fujiwara and T.Shiozawa [2004b], gCorrelation of maximum
temperature increase and peal SAR in the child and adult head models due to
dipole antenna.h Proceedings of EMCf04 Sendai, 3B5-2, pp.601-604
Fujimoto.M.,
A.Hirata, J.Wang, O.Fujiwara and T.Shiozawa [2004], gTime constant of
temperature increase in the human head models due to dipole antenna at
microwave frequencies.h Asia-Pacific Radio Science Conferencde Proceedings,
525p.
Fujino.T.,
A.Hirata and T.Shiozawa [2003], gEvaluation of induced SAR in the human body
due to EM waves emitted from a dipole antenna at 400MHz band,h Proc of IEEE
Topical Conf. on Wireless Communication Technology, 14-1.
Fujiwara.O.,
J.Wang, T.,Hisada, S.Watanabe and Y.Yamanaka [2003], gComparison of local SAR
in realistic head models of adult and children for portable telephones.h IEICE
Trans. Vol.J86-B, pp.1219-1224 (In Japanese)
Fujiwara.O.,
K.Miyamoto and J.Wang [2004], gThermal index evaluation of local SAR in
MRI-based head models of adult and children for portable telephones.h IEEJ
Trans.EIS, vol.124, pp.2427-2432.
Fukunaga.K.,
S.Watanabe and Y.Yamanaka [2004], gDielectric properties of tissue-equivalent
liquids and their effects on specific absorption rate,h IEEE EMC, vol.46,
pp.126-129
Hanada.E and
T.Kudou [2004], gMedical electronic equipment safety in hospital environments
with@wireless
communication systems.h Proceedings of EMCf04 Sendai, 2B4-2, pp.345-348
Hanazawa.M.,
R.Kumahara, S.Mochizuki, K.Wake, S.Watanabe, M.Taki, Y.Kamimura, Y.Yamanaka and
H.Shirai [2004], gDevelopment of a millimeter-wave exposure setup for rabbit
eye.h Asia-Pacific Radio Science Conference Proceedings, pp.457-458
Hikage.T.,
T.Nojima, S.Watanabe and T.Shinozuka [2004], gA study on implantable cardiac
pace maker EMI from cellular radios in semi-echoic environments.h Proceedings
of EMCf04 Sendai, 3B2-2, pp.565-568
Hirata.A.,
H.Watanabe and T.Shiozawa [2002], gSAR and temperature rise in the human eye
induced by obliquely incident plane waves.h IEEE EMC, vol.44, pp.594-596.
Hirata.A.,
M.Morita and T.Shiozawa [2003], gTemperature increase in the human head due to
a dipole antenna at microwave frequencies,h IEEE EMC, pp.109-116
Hirata.A
and T.Shiozawa [2003], gCorrelation of maximum temperature increase and peak
SAR in the human head due to handset antennas.h IEEE MTT, vol.51, pp.1834-1841.
Hirata.A.,
T,Fujino and T.Shiozawa [2003]:, g SAR in the human body due to EM waves
emitted from a dipole antenna at 400MHz band.h Proc of IEEE Internaitonal
Symposium on EMC, Jun 2003.
Hirata.A.,
T.Fujino and T.Shiozawa [2004], gSAR and temperature increase induced in the
human body due to body-mounted antenna.h Proc of IEEE AP-S International
Symposium.
Hirata.A.,
T,Fujino, M.Fujimoto and T.Shiozawa [2004], gCorrelation of SAR and temperature
increase induced in the human body due to body-mounted antennas at 400MHz and
900MHz.h Proc of International Symposium on Antenna and Propagat., pp.785-788.
Iyama.Y.,
H.Ebara, Y.Tarusawa, S.Uebayashi, M.Sekijima and T.Nojima [2004], gLarge scale
in vitro experiment system for 2GHz exposure.h Bioelectromagnetics, vol.25,
pp.599-606
Kita.M.,
A.Hirata and T.Shiozawa [2002], gTemperature rises in the human eye exposed to
EM waves emitted fron a dipole antenna at various microwave frequencies.h IEICE
Trans.B, vol.J85-B, pp.132-139.
Koyanagi.Y.,
H.Kawai, K.Ogawa and K.Ito [2003], gEstimation of the local SAR in the human
abdomen using a human body phantom and small antennas at 150MHz.h IEICE Trans.B,
Vol.J86-B, pp.1207-1218 (In Japanese)
Morita.M.,
A.Hirata and T.Shiozawa [2002], gPrediction of temperature rise in the human
head in terms of localSAR.h IEICE Trans.B, vol.J85-B, pp.723-725.
Nagaoka.T.,
S.Watanabe, K.Sakurai, E.Kunieda, S.Watanabe and M.Taki [2004], gDevelopment of
realistic high-resolution whole-body voxel models of Japanese adult male and
females of average height and weight, and application of models to
radio-frequency electromagnetic-field dosimetry,h Phys Med Biol, vol.49, pp.1-15
Nakamatsu.S.,
R.Yamaguchi and S.Uebayashi [2004], gLoop antenna for localized exposure of
small animals.h Asia-Pacific Radio Science Conference Proceedings, pp.442-443
Ohshima.T.,
J.wang and O.Fujiwara [2002], gDependence on human body modeling of electromagnetic
interference of cardiac pacemaker by portable telephones.h Trans.B, IEICE,
vol.J85-B, pp.726-728.
Ohshima.T.,
E.Takahashi, J.Wang and O.Fujiawra [2002], g Verification of electromagnetic
interference testing of cardiac pacemakers by portable terminals with an
MRI-based anatomical human model.h Trans.B, IEICE, vol.J85-B, pp.2419-2421.
Ohtake.Y
and S.Kuwano [2004], gFDTD analysis of induced currents in a realistic
heterogeneous model of man exposed to RF plane wave.h IEICE Trans. B, J87-B,
pp.1116-1118 (In Japanese).
Tokunaga.R.,
Y.Suzuki, T.Tanaka and M.Taki [2004], gThermal field analysis for in vitro
exposure apparatus in rectangular waveguide with transversal slits.h
Proceedings of EMCf04 Sendai, 3B4-2, pp.589-592
Toyoshima.T
[2004], gElectromagnetic interference in implantable cardiac pacemaker and
cardioverter defibrillator.h Proceedings of EMCf04 Sendai, 2B4-3, pp.349-352
Wang.J.,
O.Fujiwara and T.Nojima [2002], gDependence on use position of localized
electromagnetic absorption in human head for 2GHz portable telephones.h
Trans.B, IEICE, vol.J85-B, pp.649-655.
Wang.J.,
O.Fujiwara and T.Ono [2002], gDosimetry evaluation of a whole body exposure
setup for small animal at 2.45GHz.h IEICE Trans. Commin, vol.E85-B,
pp.2963-2965.
Wang.J
and O.Fujiwara [2003a], gComparison and evaluation of electromagnetic
absorption characteristics in realistic human head models of adult and children
for 900-MHz mobile telephones.h IEEE MTT, vol.51, pp.966-971
Wang.J and
O.Fujiwara [2003b], gRealizing highly localized exposure in small animals with
absorbing material covered holder to test biological effects of 1.5GHz cellular
telephones.h IEICE Trans.Commun, pp.1660-1665.
Wang.J.,
O.Fujiwara, S.Watanabe and Y.Yamanaka [2004a], gComparison with a parallel FDTD
system of human-body effect on electromagnetic absorption for potable
telephones.h IEICE Trans MTT, vol.52, pp.53-57.
Wang.J.,
T.Saito and O.Fujiwara [2004b], gUncertainty evaluation of dosimetry due to
plastic holder for restraining small animal in In Vivo near field exposure
setup,h IEEE EMC, vol.46, pp.263-267
Wang.J
and O.Fujiwara [2004c], gA new method for realizing local exposure to young rat
heads using electric flux concentration for bioeffect test of mobile
telephones.h Proceedings of EMCf04 Sendai, 3B3-3, pp.581-584
Watanabe.S.,
N.Hirose, T.Nagaoka, N.Hatakenaka, Y.Tanaka, M.Takahashi, Y.Suzuki, M.Taki,
J.wang, O.Fujiwara and Y.Yamanaka [2004a], gDevelopment of smart voxel models
of whole human-bodies for numerical dosimetry.h Proceedings of EMCf04, Sendai,
4B3-3, pp.797-800
Watanabe.S.,
Y.Miyota, M.Takabe, H.Asou, Y.Ishi, K.Satoh, K.Fukunaga, A.Syzuki, T.Sugiyama,
I.Nishiyama, T.Shinozuka and Y.Yamanaka [2004b], gUncertainties of SAR-probe
calibration and of SAR measurement for compliance tests of cellular phones.h
Proceedings of EMC04 Sendai, 3B1-3, pp.557-560
K4 Biomedical Applications
K4.1 Thermal Therapy (ˆÉ“¡)
In recent
years, various types of medical applications of microwaves have been
investigated. Among them, minimally invasive microwave thermal therapies are of
great interest. They are interstitial hyperthermia and microwave coagulation
therapy for thermal treatment of cancer, cardiac catheter ablation for
ventricular arrhythmia treatment, etc. Previously, a coaxial-slot antenna, which
is one of the thin antennas for interstitial heating, has been studied. In this
research, the heating characteristics of the antenna are investigated by
numerical simulation based on FDTD calculations [Saito, 2003] and phantom
experiments. Moreover, the results of hyperthermic treatments for neck tumor by
use of the coaxial-slot antenna and the array applicator composed of several
coaxial-slot antennas are reported [Saito, 2004a]. In addition, the improvement
of the characteristics of the coaxial-slot antenna especially the input
impedance of the antenna is considered [Saito, 2004b] and the feeding technique
of the array applicator composed of several antennas is investigated [Saito,
2004c] [Ito].
References
Saito.K., H. Yoshimura, and K. Ito [2003], gNumerical simulation
for interstitial heating of actual neck tumor based on MRI tomograms by using a
coaxial-slot antenna.h IEICE Transactions on Electronics, vol. E86-C,
pp.2482-2487 (In Japanese)
Saito.K.,
H.Yoshimura, K.Ito, Y.Aoyagi and H.Horita [2004a], gClinical trials of
interstitial microwave hyperthermia by use of coaxial-slot antenna with two
slots.h IEEE Transactions on Microwave Theory and Techniques vol.52, no.8,
pp.1987-1991.
Saito.K., K.
Miyata, H. Yoshimura, and K. Ito [2004b], gTreatment system of interstitial
microwave hyperthermia: clinical trials for neck tumor and improvement of
antenna elements,h Digest of International Union of
Radio Science (URSI) National Radio Scientific Meeting (Monterey, USA), p. 195,
June
Saito.K.,
H.Yoshimura and K.Ito [2004c], gStudy on feeding technique of array applicator
for uniform heating of large-volumed tumor in interstitial microwave heating.h
IEICE Trans. B, Vol.J87-B, pp.410-420 (In Japanese)
K4.2 Microwave Imaging of the Human Body (‹{ì)
Chirp Pulse
Microwave Computed Tomography is a noninvasive imaging modality which enables
microwave imaging of a human body using a chirp pulse microwave signal and
signal processing techniques. The prototype model using a microwave from 1 to 2
GHz showed that the spatial resolution is better than 10 mm and temperature
variation less than 0.3 degree Celsius can be measurable. The higher resolution
model which works at 2 to 3 GHz has also been developed for diagnostic imaging
of an early stage breast tumor. Feasibility of the practical application of
CP-MCT has been investigated through a series of computational studies and
basic studies using those two models. A new CP-MCT with fan beam geometry which
is able to collect projection data very quickly is now being developed for a
high speed imaging of experimental animals [Miyakawa].
References
Bertero.M., F. Conte, M. Miyakawa and M. Piana [2001], gComputation
of the response function in Chirp-Pulse Microwave Computerized Tomography,h
Inverse Problems, vol.17, pp.485-500
Bertero.M., P. Boccacci, F. Conte, M. Miyakawa and M. Piana
[2002], gA linear model for CP-MCT,h Proc. PIERS 2002 in Cambridge, July 1-5,
p.591
Miyakawa.M.,
Y. Kawada and M. Bertero [2001a], gImage generation of chirp pulse microwave computed
tomography (CP-MCT) by numerical computation –Computation of the human head
model-,h Trans. IEICE Japan, J84-D-II, pp.1512-1521
Miyakawa.M.,
M. Eiyama, and N. Ishii [2001b], gAn attempt of time-domain microwave computed
tomography for biomedical use,h Proc. IEEE EMB International Symposium.
Miyakawa.M.,
K. Orikasa, M. Bertero, P. Boccacci, F. Conte and M. Piana [2002a], gExperimental
validation of a linear model for data reduction in Chirp-Pulse Microwave CT,h
IEEE Trans. Medical Imaging, vol.27, pp.385-395
Miyakawa.M.,
K. Orikasa, and M. Bertero [2002b], gEvaluation of the response function and
its space dependence in Chirp Pulse Microwave Computed Tomography (C‚o-MCT),h
IEICE, Trans. Inf. & Syst., Vol. E85-D, pp.52-59
Miyakawa.M., Wu Jing, K. Sugawara and M. Bertero [2002c], gFDTD-based
computation to find an optimal configuration of the printed array antenna used
for a fan beam scanner of chirp pulse microwave computed tomography (CP-MCT),h
Proc. PIERS 2002 in Cambridge, July 1-5, p.592
Miyakawa.M., K. Sugawara, M. Bertero and M. Piana [2002d], gComputational
Imaging of the Breast- and Head-Models in CP-MCT,h Proc. PIERS 2002 in
Cambridge, July 1-5, p.593
Miyakawa.M.,
E. Harada, N. Ishii, and M. Bertero [2002e], gDevelopment of a printed dipole
array antenna for fan beam-type chirp-pulse microwave computed tomography
(CP-MCT),h Proc. PIERS 2002 in Cambridge, July 1-5, p.871
Miyakawa.M., E. Harada
and Wu Jing [2003], gChirp pulse microwave computed
tomography(CP-MCT) equipped with a fan beam scanner for high-speed imaging of
a biological target,h Proc. 25th Annual International Conference on
Engineering in Medicine and Biology Society, pp.1031-1034
K4.3 Thermal therapy- Inductive heating (¬’Ë)
A novel
implant with the function of a high efficient temperature raise is proposed to
achieve a local high temperature hyperthermia or ablation therapy. The idea of
the new implant with a heating function is based on not material component but
on resonant circuit theory viewpoint 1) .The new implant proposed
here consists of a small coil and a microchip condenser to make a resonant
circuit. By applying an RF magnetic field to the implant, large current flows
in the coil based on the resonance and elevate the coil temperature
efficiently. As a coil, a silver wire or a stainless is used. The temperature
rise of more than 70Ž from the initial value is obtained at 15 cm depth of agar
phantom in a case of implant with the diameter of 3 mm and the length of 4 mm,
using a ferrite core applicator with output power of 500 W at the resonant
frequency of 4 MHz. This idea of the implant can be applied to a stent with a
heating function [Kotsuka].
References
Kotsuka.Y
and H.Okada [2003], gDevelopment of Small and High Efficiency Implant for Deep
Local Hyperthermia,h Jap. J. of Hyperthermic Oncology, vol.19, pp.11-22
K4.4 Radiometry (™‰Y)
Multi-frequency
microwave radiometer system for noninvasive temperature measurement of
biological tissues has been at the final stage of its development as well as
the temperature retrieval method from measured brightness temperatures of
biological tissues. Chirp radar-type microwave computed tomography which can provide a cross sectional image of temperature change
has been also under development [Sugiura].
References
Hand.J.W.,
G.M.J.Van Leeuven, S.Mizushina, J.B.Van de Kamer, K.Maruyama, T.Sugiura,
D.V.Azzopardi and A.D.Edwards [2001], gMonitoring of deep brain temperature in
infants using multi-frequency microwave radiometry and thermal modelling,h
Phys. Med. Biol, vol.46, pp.1885–1903
Harada.E.,
J.Wu and M.Miyakawa [2002], gExperimental determination
of the optimal arrangement of a receiving antenna consisted of dipole antennas
for microwave imaging,h Rep. of IEICE, MBE2002 73-84, pp.29-32
Kouno.Y., A.Hashizume, S.Hoshino, H.Hirata,
Y.Okita and T.Sugiura [2004], gDevelopment state of multifrequency microwave
radiometer system for noninvasive measurement of infantfs deep brain
temperatures.h Asia-Pacific Radio Science Conference Proceedings, pp.438-441
Miyakawa.M
[2002], gExperimental validation of a linear model for data reduction in
chirp-pulse microwave CT,h IEEE Trans. Med. Imaging, pp.385-395
Sugiura.T.,
G.Mukumoto, H.Hirata, K.Ohashi, Y.Okita, S.Mizushina, G.M.J.Van Leeuwen and
J.W.Hand [2002a], gDevelopment of a five-band microwave radiometer system for
non-invasive measurement of deep brain temperature in new-born babies,h
Proceedings of 2002 Asia-Pacific Microwave Conference, pp.914-917
Sugiura.T.,
H.Hirata, K.Ohashi, Y.Okita, S.Mizushina, G.M.J.Van Leeuwen and J.W.Hand
[2002b], gA study of the influence of tissue conductivity for microwave
radiometric weighting functions in non-invasive measurement of babyfs brain
temperature,h Proceedings of 2002 Asia-Pacific Microwave Conference,
pp.1091-1094
Sugiura.T.,
Y.Kouno, A.Hashizume, H.Hitara, J.W.Hand, Y.Okita and S.Mizhusina [2004], gFive
band microwave radiometer system for non-invasive measurement of brain temperature
in new-born infants: system calibration and its feasibilityh Proceedings of
2004 Annual Conference of IEEE EMBS, pp.2292-2295
Yonemura.Y.,
N.Ishi and M.Miyakawa [2003], gAn Absolute Gain
Measurement of Printed Dipoles for Microwave CT,h Rep. of IEICE, AP2003
145-179, pp.117-122
K4.5
Soft heatingi¼–Øj
In hypertnemia, the soft-heating method has been
proposed. This is an inductive heating method that uses as a hear element a thermosensitive
magnetic material. The feature of this method is automatic temperature control
using Curie-point of the magnetic material. When the element is implanted into
the tumor tissue, however, authors have to adjust the size of element to that
of each tumor tissue. Therefore, the purpose of this study is to clarify heat
characteristics of heat elements with various volumes.
The heat
element is composed of a thermosensitive magnetic material and a metal ring.
The thermosensitive magnetic material used to experiment is Ni-Cu-Zn ferrite
and Curie-point is 90Ž. Moreover,
the copper ring is wrapped around the ferrite. The aim of wrapping copper ring
is increase of the heat quantity generated compared with that using only the magnetic
material. When temperature of the thrmosensitive magnetic material is lower
than the Curie-point, the magnetic flux is concentrated by the effect of high
permeability of the magnetic material. Then, short-circuit current induced in
the copper ring, raises the temperature of heat element. In experiments, this
element is put in the heat insulator, then excited by solenoidal coil. The
specification of this coil is 8mT at 100 kHz.
The results
provided evidence that the temperature characteristics show a saturation
tendency with an increase of the element volume. Based on this tendency, it
seems reasonable to suggest that sufficient heating can be obtained, even on
smaller element volumes. Therefore, when considering heating per unit volume,
it is expected that a volume with the most effective heating temperature can be
obtained. For further research, we will continue to analyze the temperature
characteristics, aiming to achieve the high hyperthermia [Matsuki].
Deger.S.,
D.Boehmer, I.Toerk, J.Roigas, V.Budach and S.A.Loening [2002], gInterstitial
Hyperthermia using Self-Regulating Thermoseeds Combined with Conformal
Radiation Therapy,h European Urology, vol.42, pp.147-153
Sato.F.,
M.Jojo, H.Matsuki, T.Sato, M.Sendoh, K.,Ishiyama and K.I.Arai [2002], gThe
Operation of Magnetic Micromachine for Hyperthermia and Its Exothermic
Characteristics,h IEEE Trans. Magn, vol.38, pp.3362-3364
K4.6 current distribution MRIiã–ìAŠÖ–ìj
Magnetic resonance imaging of electrical phenomena
in living bodies is potentially useful for quantitative evaluations of
biological effects of electromagnetic fields, and for direct detection of
neuronal electrical activities in the brain. Magnetic field in an object causes
a shift in the resonant frequency [Sekino, 2004a]. Stationary electric current
causes an increase in the apparent diffusion coefficient [Yamaguchi, 2003].
Spatial distributions of externally applied magnetic field and electrical
current can be estimated from these changes in magnetic resonance signals.
These methods have potential medical applications such as imaging of current
distributions in electrical defibrillation. Detection of electrical currents
associated with neuronal or muscular electrical activities requires extremely
high sensitivity. The sensitivity for detecting weak magnetic fields was
estimated using numerical simulations [Hatada, 2005a, 2005b] and experiments
[Hatada, 2005c]. The theoretical limit of sensitivity was approximately 10-8
T. These studies potentially lead to a new method for visualizing brain
function with a spatial resolution of millimeters and a temporal resolution of
milliseconds. The ADC reflects electrical conductivity of a tissue, which
enables an estimation of anisotropic conductivity of the tissue [Sekino, 2003a,
2004b, 2004c]. This method was applied to imaging of electrical conductivity in
the human brain. Several regions in the white matter such as the corpus
callosum and the internal capsule exhibited high anisotropy in conductivity.
Magnitude and phase of magnetic resonance signals are affected by permittivity
[Sekino, 2005; Mihara, 2005]. A distinctive signal inhomogeneity arises in
images of objects whose dimension is comparable to the wavelength of
electromagnetic fields at the resonant frequency. This phenomenon, dielectric
resonance, particularly appears in scanners with high static fields. Electric
current in electrolyte solution give rise to fluid motion. Magnetic resonance
imaging was applied to visualization of the flow velocity [Sekino, 2003b, 2003c,
2004d]. In strong static magnetic field, biological macromolecules such as
fibrin and collagen are oriented in the direction parallel or perpendicular to
the magnetic field. The magnetic orientation causes a change in the spin-spin
relaxation time of gels, which contain these macromolecules [Takeuchi, 2003,
2004a, 2004b, 2005].
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