Abstract:
:Hyperthermia has been used in conjunction with radiation and chemotherapy for cancer treatment. When using electromagnetic heating, applicators are critical components in contact with or in proximity to patients and can be the determining factor for effective and safe treatment. Tissue absorption of electromagnetic energy is determined by many factors. Three cases are shown to illustrate the complexity of microwave heating: 1) The BSD MA-151 applicator has good center heating on a muscle-only phantom as shown in the operation manual. When fat slabs of 0.25, 0.5, 1, and 2 cm thick were added, two hot spots near the periphery of the applicator were evident on all fat surfaces, exposed at 631 MHz. At 915 MHz, the heating was elongated on the surface of the models with 0.25- and 2-cm fat, and two hot spots were observed on the 0.5- and 1-cm fat surfaces. 2) Heating patterns of the Clini-Therm applicators on a muscle-only phantom, as indicated in the operations guide, are elliptical with their major axes perpendicular to the electric field. However, when a bolus is used, the elliptical pattern is parallel to the E field. 3) Heating patterns in cylindrical structures were studied with inhomogeneous models of limbs. Arm and thigh models consisting of fat, bone, and muscle material were heated with Clini-Therm L, M, and MS applicators at 915 MHz. In addition to the geometric effect, the results indicated that placing the applicators with E field parallel to the long axis of cylindrical structures can minimize required power, produce less heating of fats and reduce stray radiation. In conclusion, to apply penetrating microwave or other RF fields for tissue heating, one must simulate the clinical exposure conditions as closely as possible to obtain useful heating patterns.
journal_name
Bioelectromagneticsjournal_title
Bioelectromagneticsauthors
Chou CKdoi
10.1002/bem.2250130612subject
Has Abstractpub_date
1992-01-01 00:00:00pages
581-97issue
6eissn
0197-8462issn
1521-186Xjournal_volume
13pub_type
杂志文章abstract::A system is described that uses an oscillating magnetic field to produce power-frequency electric fields with strengths in excess of those produced in an animal or human standing under a high-voltage electric-power transmission line. In contrast to other types of exposure systems capable of generating fields of this s...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/bem.2250050202
更新日期:1984-01-01 00:00:00
abstract::This paper computationally verifies the effect of anesthesia on temperature variations in the rabbit eye due to microwave energy. The main reason for this investigation is that our previous paper suggested a reduction in blood flow due to the administration of anesthesia, resulting in an overestimated temperature incr...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/bem.20251
更新日期:2006-12-01 00:00:00
abstract::Effects of magnetic fields (MFs) on the activities of antioxidant enzymes of suspension-cultured tobacco cells were investigated. Compared with the control cells, exposure of the cells to static MF with the magnitudes of 10 and 30 mT for 5 days, 5 h each day, increased the activity of superoxide dismutase (SOD). In co...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/bem.20262
更新日期:2007-01-01 00:00:00
abstract::Research conducted over the past 5 years has addressed the hypothesis that the reported association between residential magnetic fields and childhood leukemia may be explained by exposure to contact current. The use of multi-grounded neutrals in electrical distribution and residential electrical wiring systems in the ...
journal_title:Bioelectromagnetics
pub_type: 杂志文章,评审
doi:10.1002/bem.20126
更新日期:2005-01-01 00:00:00
abstract::There are public concerns regarding possible carcinogenic or cancer-promoting effects of radiofrequency electromagnetic fields (RF-EMFs) because of the extensive use of wireless mobile phones and other telecommunication devices in daily life. However, so far it is unclear if non-thermal exposure of single EMF exposure...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/bem.20655
更新日期:2011-09-01 00:00:00
abstract::We have previously demonstrated that exposure of Chinese hamster lung (CHL) cells to 50 Hz magnetic fields (MFs) and/or 12-O-tetradecanoylphorbol-3-acetate (TPA)-inhibited gap junctional intercellular communication (GJIC). To explore and compare the mechanisms of GJIC inhibition induced by extremely low frequency (ELF...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/bem.10070
更新日期:2003-02-01 00:00:00
abstract::Childhood cancer has been modestly associated with wire codes, an exposure surrogate for power frequency magnetic fields, but less consistently with measured fields. We analyzed data on the population distribution of wire codes and their relationship with several measured magnetic field metrics. In a given geographic ...
journal_title:Bioelectromagnetics
pub_type: 杂志文章,评审
doi:10.1002/(sici)1521-186x(1997)18:2<99::aid-bem2>3.0
更新日期:1997-01-01 00:00:00
abstract::The objective of this study was to develop a model for testing various hypotheses concerning possible mechanisms whereby electromagnetic fields might induce suppression of nighttime melatonin production in rodents. A published method for digesting freshly obtained pineal glands to the single cell level was modified, y...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:
更新日期:1998-01-01 00:00:00
abstract::Atomic force microscopy (AFM), transmission electron microscopy (TEM), and confocal laser scanning microscopy were used to investigate the effects of a 50 Hz 0.4 mT magnetic field (MF) on the clustering of purified epidermal growth factor receptors (EGFRs) and EGFRs in Chinese hamster lung (CHL) cell membrane. The res...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/bem.20293
更新日期:2007-04-01 00:00:00
abstract::Different species of ciliates (Paramecium biaurelia, Loxodes striatus, Tetrahymena thermophila) have been taken as model systems to study the effects of extremely low-frequency electromagnetic fields (50 Hz, 0.5-2.0 mT) on the cellular level. A dose-dependent increase in the mean swimming velocity and a decrease in th...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/(sici)1521-186x(1997)18:7<491::aid-bem4>3.
更新日期:1997-01-01 00:00:00
abstract::The effects of mm-waves 60.22-62.22 GHz and 75 GHz on A-type K+ currents and the effects of 61.22 GHz on Ca2+ currents of Lymnaea neurons were investigated using a whole-cell voltage-clamp technique. The open end of a rectangular waveguide covered with a thin Teflon film served as a radiator. Specific absorption rates...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:
更新日期:1999-01-01 00:00:00
abstract::The objective was to study the risk of cytogenetic damage among high voltage laboratory workers exposed to electromagnetic fields and mineral oil. This is a cross sectional study of 24 exposed and 24 matched controls in a Norwegian transformer factory. The exposure group included employees in the high voltage laborato...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/bem.33
更新日期:2001-04-01 00:00:00
abstract::Several investigators have reported robust, statistically significant results that indicate that weak (approximately 1 microT) magnetic fields (MFs) increase the rate of morphological abnormalities in chick embryos. However, other investigators have reported that weak MFs do not appear to affect embryo morphology at a...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/(sici)1521-186x(1997)18:6<431::aid-bem5>3.
更新日期:1997-01-01 00:00:00
abstract::Pulsed electromagnetic fields (PEMF) have been proven to be effective for promoting bone mass and regulating bone turnover both experimentally and clinically. However, the exact mechanisms for the regulation of PEMF on osteoclastogenesis as well as optical exposure parameters of PEMF on inhibiting osteoclastic activit...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/bem.22070
更新日期:2017-12-01 00:00:00
abstract::To be able to correlate real time membrane potential or ion flux changes with further downstream gene transcription responses due to extremely low frequency (ELF) electromagnetic field (EMF) exposure, we devised an experimental system consisting of a pair of symmetric circular coils. This system can be used on an inve...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/bem.10151
更新日期:2004-01-01 00:00:00
abstract::We have previously reported that the exposure to an abnormal magnetic field simulating the one encountered by the International Space Station (ISS) orbiting around the Earth may enhance autonomic response to emotional stimuli. Here we report the results of the second part of that study which tested whether this field ...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/bem.20438
更新日期:2009-01-01 00:00:00
abstract::Experiments were conducted to see whether the cellular response to electromagnetic (EM) fields occurs through a detection process involving temporal sensing. L929 cells were exposed to 60 Hz magnetic fields and the enhancement of ornithine decarboxylase (ODC) activity was measured to determine cellular response to the...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/(sici)1521-186x(1997)18:5<388::aid-bem6>3.
更新日期:1997-01-01 00:00:00
abstract::In this study, we measured and analyzed the spectral characteristics of a low-frequency magnetic field (MF) inside several gasoline-powered cars while driving on busy city roads. The spectra obtained upon measurements in the interior of the cars are compared with those measured in office locations at different times o...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/bem.22269
更新日期:2020-07-01 00:00:00
abstract::This study examined whether 60 Hz magnetic field (MF) exposure alters intracellular calcium levels ([Ca(2+)](i)) in isolated bovine adrenal chromaffin cells, a classic model of neural responses. [Ca(2+)](i) was monitored by fluorescence video imaging of cells loaded with the calcium indicator fluo-4 during exposures t...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/bem.10045
更新日期:2002-12-01 00:00:00
abstract::The use of wireless digital communication devices like GSM, WCDMA, HSPA, DECT, and WiFi changes the exposure of electromagnetic waves toward the user. Concentrating on the power variations on a slow and fast time scale, these new systems are discussed. Experimental results for both uplink and downlink are included for...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/bem.20569
更新日期:2010-05-01 00:00:00
abstract::The aim of our study was to test the feasibility and reliability of personal dosimetry. Twenty-four hour exposure assessment was carried out in 42 children, 57 adolescents, and 64 adults using the Maschek dosimeter prototype. Self-reported exposure to mobile phone frequencies were compared with the dosimetry results. ...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/bem.20175
更新日期:2006-01-01 00:00:00
abstract::In this article, the transmembrane voltage induced on erythrocyte, codocyte, ovalocyte and spherocyte cell models exposed to a linearly polarised electromagnetic plane wave of frequency 1800 MHz is calculated. For this purpose, a finite element (FE) numerical technique with adaptive meshing is used. The results show t...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/bem.20065
更新日期:2004-12-01 00:00:00
abstract::The Minnesota Environmental Quality Board completed a 3-year study of the space charge plume outside the right of way of a bipolar (+/- 400 kV) direct current transmission line in rural west central Minnesota. The purpose of the study was to determine the levels of DC potential gradient and small airs ions in the down...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/bem.2250070404
更新日期:1986-01-01 00:00:00
abstract::Drosophila larvae reared inside a micro-metal box with an internal field strength 0.004 microT, were treated with a magnetic field of 50 Hz, 8 microT. for 20 min. Control experienced 0.004 microT. Cellular transcript levels were assessed using slot blots and quantified using a Phosphorimager. Blots were hybridised usi...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:
更新日期:1999-01-01 00:00:00
abstract::In the present experiment, the effect of a single 30 min inhomogeneous static magnetic field (SMF) exposure on thermal pain threshold (TPT) was examined in 15 young healthy human volunteers. The SMF had a maximum peak-to-peak amplitude of 330 mT with a maximum gradient of 13.2 T/m. In either of two experimental sessio...
journal_title:Bioelectromagnetics
pub_type: 杂志文章,随机对照试验
doi:10.1002/bem.20622
更新日期:2011-02-01 00:00:00
abstract::This study describes the effects of a static magnetic field (SMF) on cell growth and DNA integrity of human umbilical vein endothelial cells (HUVECs). Fast halo assay was used to investigate nuclear damage; quantitative polymerase chain reaction (QPCR), standard PCR, and real-time PCR were used to evaluate mitochondri...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/bem.20591
更新日期:2010-12-01 00:00:00
abstract::Mice were exposed in the far field in an anechoic chamber to 2,880-MHz pulsed microwaves 3 to 7.5 h daily, 5 days/week for 60 to 360 h. Three experiments were performed at average power densities of 5 mW/cm2 and six at 10 mW/cm2, corresponding to averaged specific absorption rates (SARs) of 2.25 and 4.50 mW/g, respect...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/bem.2250040409
更新日期:1983-01-01 00:00:00
abstract::Extremely low-frequency (ELF) magnetic field exposure systems are usually subject to field disturbances induced by external sources. Here, a method for designing a feedback control system for cancelling the effect of external ELF magnetic field disturbances on the magnetic field over the exposure area is presented. Th...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/(sici)1521-186x(1997)18:4<299::aid-bem2>3.
更新日期:1997-01-01 00:00:00
abstract::This paper traces the history of the development of the Radiofrequency Radiation Dosimetry Handbook and its subsequent impact on radio frequency radiation exposure standards. The author's recollections are used to illustrate the behind the scenes efforts of the individuals involved in this project. The development of ...
journal_title:Bioelectromagnetics
pub_type: 历史文章,杂志文章
doi:10.1002/(sici)1521-186x(1999)20:4+<9::aid-bem3>3.3
更新日期:1999-01-01 00:00:00
abstract::Non-thermal plasmas can be generated by electric discharges in gases. These plasmas are reactive media, capable of superficial treatment of various materials. A novel non-thermal atmospheric plasma source (plasma needle) has been developed and tested. Plasma appears at the end of a metal pin as a submillimetre glow. W...
journal_title:Bioelectromagnetics
pub_type: 杂志文章
doi:10.1002/bem.20005
更新日期:2004-07-01 00:00:00