Low Frequency Pulsed Magnetic Fields Research Articles

Investigation of the influence mechanism of shield on the strong magnetic field during electromagnetic launch

The electromagnetic launch process generates low-frequency pulsed magnetic fields with peak values reaching Tesla-levels, imposing greater demands on the interference immunity of electronics within projectiles. However, during the propagation of low-frequency pulsed strong magnetic fields, their characteristics are affected by the shielding properties of the surrounding medium materials, resulting in modifications to the actual internal magnetic fields of the devices. This paper presents a theoretical analysis, numerical simulation, and experimental investigation based on the shielding mechanisms of conductive and magnetic materials to elucidate their impact on the pulsed magnetic fields. Additionally, leveraging previous work on electromagnetic railgun projectile magnetic field calculations, the shielding model is established to determine the shielding effects of different material combinations on the magnetic field during electromagnetic launch. The results reveal that both conductive and magnetic materials influence the amplitude, pulse width, and initiation time of the pulsed magnetic field, a finding validated through dynamic projectile-borne magnetic field testing.

Glycocalyx transduces membrane leak in brain tumor cells exposed to sharp magnetic pulsing

Mechanisms by which electric (E) or magnetic (B) fields might be harnessed to affect tumor cell behavior remain poorly defined, presenting a barrier to translation. We hypothesized in early studies that the glycocalyx of lung cancer cells might play a role in mediating plasma membrane leak by low-frequency pulsed magnetic fields (Lf-PMF) generated on a low-energy solenoid platform. In testing glioblastoma and neuroblastoma cells known to overexpress glycoproteins rich in modifications by the anionic glycan sialic acid (Sia), exposure of brain tumor cells on the same platform to a pulse train that included a 5 min 50Hz Lf-PMF (dB/dt ∼ 2 T/s at 10 ms pulse widths) induced a very modest but significant protease leak above that of control nonexposed cells (with modest but significant reductions in long-term tumor cell viability after the 5 min exposure). Using a markedly higher dB/dt system (80 T/s pulses, 70 μs pulse-width at 5.9 cm from a MagVenture coil source) induced markedly greater leak by the same cells, and eliminating Sia by treating cells with AUS sialidase immediately preexposure abrogated the effect entirely in SH-SY5Y neuroblastoma cells, and partially in T98G glioblastoma cells. The system demonstrated significant leak (including inward leak of propidium iodide), with reduced leak at lower dB/dt in a variety of tumor cells. The ability to abrogate Lf-PMF protease leak by pretreatment with sialidase in SH-SY5Y brain tumor cells or with heparin lyase in A549 lung tumor cells indicated the importance of heavy Sia or heparan sulfate glycosaminoglycan glycocalyx modifications as dominant glycan species mediating Lf-PMF membrane leak in respective tumor cells. This “first-physical” Lf-PMF tumor glycocalyx event, with downstream cell stress, may represent a critical and “tunable” transduction mechanism that depends on characteristic anionic glycans overexpressed by distinct malignant tumors.

Exposure to 10 Hz Pulsed Magnetic Field Induced Slight Apoptosis and Reactive Oxygen Species in Primary Human Gingival Fibroblasts.

Extremely low frequency pulsed magnetic fields (MFs) have been increasingly used as an effective method in oral therapy, but its potential impact on health has not been clarified. In this study, we investigated the impact of 10 Hz pulsed MF exposure on primary human gingival fibroblasts (HGFs) derived from eight healthy persons (four males and four females). Cells were exposed to 10 Hz pulsed MFs at 1.0 mT for 24 h. Cell apoptosis, cell cycle progression, intracellular reactive oxygen species levels, DNA damage, and cell proliferation were determined after exposure. The results showed that 10 Hz pulsed MFs exposure have slight effects on cellular apoptosis, cell cycle progression, and DNA damage in primary HGFs from some but not all samples. In addition, no significant effect was found on cell proliferation. © 2022 Bioelectromagnetics Society.

Influence of impulse magnetic fields of extremely low frequencies on H2O2- and Fe2+-induced free radical lipid oxidation in liposomal suspensions

Background: For a long time, special attention in experimental biology and medicine is paid to free radical processes involving reactive oxygen species. In electromagnetic biology, the interest in free radical oxidation in biological membranes has increased significantly due to the discovery of spin mechanisms of magnetic fields on free radical processes. In the present day, these mechanisms are considered to be key in the processes of magnetoreception in living organisms. Liposomes, as the simplest models of biological membranes, are often used to study the primary mechanisms of action of different factors on the structural and functional properties of membranes. However, the influence of ecological significant extremely low-frequency magnetic fields on free radical oxidation in liposomal suspensions has not been studied enough. Objectives: The elucidation of the peculiarities of the influence of the extremely low frequency pulsed magnetic fields (ELF PMF) on H2O2- and Fe2+-induced peroxidation of natural phospholipids in liposomal suspensions. Materials and methods: The liposomal suspensions in phosphate buffer pH=7.4 were used. According to the literature and own results on light scattering the average diameter of liposomes was about 500Å. Ultra-weak chemiluminescence of liposomal suspensions was recorded using a device that operated in the mode of single photons counting. It consisted of a light-insulated cuvette unit where the test samples were placed, as well as a temperature sensor and a solenoid, which was used to create the PMF. Optical contact of the test samples with the photoelectron multiplier was carried out using a light guide. The recording system consisted of a broadband photomultiplier tube detector — FEU-130, which was at a temperature of –20°C. The pulse analyzer AI-256 was used to separate the useful signal that corresponded to the registration of single chemiluminescence light quanta. The voltage on the photomultiplier tube detector was applied in the range of current-voltage characteristics of this detector, in which a random voltage fluctuation had a minimal effect on the measurement of the useful signal. The number of light quanta that were recorded for defined time intervals characterized the overall intensity of the process of free radical oxidation of lipids in the experimental samples. The pulsed magnetic field was created using a solenoid coil located in the cuvette part. PMF was created using a serial generator G6-28. The magnetic field pulses were rectangular in shape with variable polarity for a period of oscillations. The induction of PMF was monitored using microteslameter G-79. The series of extremely low frequencies (5–80 Hz) and induction (5–500 μT) of PMF was chosen due to their environmental and physiological significance. Results: PMF of different frequencies with induction of 5 and 50 μT did not affect (p>0.05) H2O2- and Fe2+-induced lipid oxidation in liposomal suspensions. Statistically significant changes (p<0.05) were revealed only when liposomal suspensions were exposed to PMF with induction of 500 μT. It was found that the action of PMF with the frequency of 8 Hz 500 μT significantly inhibited H2O2-induced and enhanced Fe2+-induced chemiluminescence. This effect is associated with inhibition of the decomposition and with the accumulation of phospholipid hydroperoxides, which decompose and recombine in the presence of Fe2+ ions, which is accompanied by stronger chemiluminescence. The study of the dependence of the dynamics of the chemiluminescence intensity on the frequency of the PMF indicates the presence of a certain dependence of the effects in the range of up to 30 Hz. However, the inhibitory effect of PMF for the H2O2-induced oxidation phase is not always accompanied by a statistically significant increase in the amplitude of Fe2+-dependent light flash of chemiluminescence that indicates the general inhibitory effect of PMF at a certain frequency. Conclusions: PMF of extremely low frequencies statistically significantly affects the free radical oxidation in liposomal suspensions only at inductions exceeding several hundred microteslas. This indicates the effect of PMF on free radical processes for the conditions of the selected membrane model is realized mainly through spin interactions that determine the recombination of free radicals. The decrease of induction by one or two orders of magnitude, as well as increasing in frequency of the PMF above 50 Hz, leads to a decrease in the effectiveness of the influence of this physical factor on the intensity of lipid-free radical oxidation in liposomal suspensions. The most sensitive to the influence of ELF PMF is the phase of H2O2-induced free radical oxidation of lipids.

Comparative Analysis of Biological Effects Induced on Different Cell Types by Magnetic Fields with Magnetic Flux Densities in the Range of 1–60 mT and Frequencies up to 50 Hz

Moderate static magnetic fields (SMFs) are generated from sources such as new-generation electric trams and trains, electric arc welding, and magnetic resonance imaging (MRI) devices, as well as during the industrial production of aluminium, while extremely low frequency pulsed magnetic fields (ELF-PMFs) are produced by house power installations, household appliances, and high voltages transmission lines. Moderate SMFs and ELF-PMFs with magnetic flux densities (B) in the range of 1–60 mT and frequencies (f) up to 50 Hz are common MF exposure sources for the population. Even though humans are continually exposed to these MFs, to date no definitive endpoint has been drawn about their safety. In this review, the state of knowledge about the biological effects induced by these MFs on different cell types will be addressed. In our own observation, the putative modulation of Ca2+/H+ and Na+/H+ plasma membrane antiporters of human peripheral blood lymphocytes (PBLs) was found to occur after a 24 h exposure to a 6 mT SMF, and the bystander effect observed on U937 cells cultivated for up to 6 h in the conditioned medium harvested from human PBLs previously exposed for 24 h to the same MF (secondary necrosis induction) will be also herein discussed.

Elektromagnetoterapija u lečenju preloma radiusa na tipičnom mestu

Introduction. Radius fracture at typical site - fractura radii loco typico, is one of the most common fractures (more than 10% of all fractures). It is frequent in the fall on the palm of the hand. It happens at all ages. Objective. To examine the efficacy of electromagnetotherapy in the treatment of patients with radius fracture at typical site in order to reduce pain, swelling and increased mobility of injured tissue and reduce the possibility of complications. Material and methods. The study includes 100 patients with radius fracture at the typical site of which 55 women and 45 men, aged 20 to 70 years. The study included patients undergoing bone trauma treated conservatively by plaster immobilization, immediately after orthopedic treatment patients were treated with lowfrequency pulsed electrical magnetic fields produced by the machine MAGNEMED MT - 91 results. Pain in the wrist after physiotherapy treatment static isometric contractions and after the application of electromagnetic therapy was significantly more intense in the control group. Swelling in the wrist were significantly reduced in patients treated with electromagnetic fields. In all patients, after 20 applied electromagnetic field therapy achieved a significant increase in flexor and extensor muscle strength. Electromagnetotherapy is important in the prevention of complex regional pain syndrome.

Studies on the Effect of Pulsed Magnetic Field on the Productivity of Algae Grown in Dye Industry Effluent

Magnetic fields are capable of eliciting in vivo and in vitro effects in many biological systems. Increasing attention is being directed towards bio-electromagnetic stimulation using the low frequency pulsed magnetic fields (PMF). Currently, microalgae have been considered to be the most promising candidates for biomass production. PMF may affect organisms in both negative and positive manner which includes acceleration of growth and metabolism. The present study deals with the studies on the effect of pulsed magnetic field (PMF) on the productivity selected micro algae Desmococcus sp. grown in the dye industry effluent. Desmococcus sp. was grown in photo bioreactors (1L) with a pulsed magnetic field facility. The magnetic field is set in a circular form from which the solenoid coil system set to a highly homogenous sinusoidal magnetic field intensity of 3mg for a period of 4hrs duration per day for 12 days. Aeration and light (intensity 2000-3000lux) have been provided for 12hr per day. Division rate, growth studies and physicochemical parameters have been analyzed that gave positive results by reducing the BOD, COD and the nitrates level in the effluent. By the end of the 12th day the effluent colour changed and a two fold increase in the algal biomass productivity in the dye effluent treated with PMF exposure is observed.

Effect of magnetic pulse treatment on the magnetic characteristics of yttrium–iron garnets

The effect weak (10–100 kA m–1) low-frequency (10–20 Hz) pulsed magnetic fields have on the surface structure and magnetic characteristics of yttrium–iron garnet Y3Fe5O12 is studied by means of electron and Mossbauer spectroscopy. A mechanism is proposed for the variation of saturation magnetization in Y3Fe5O12 after magnetic pulse treatment. The mechanism is associated with the change in the spin state of iron ions localized in the tetrahedral sublattice.

Time resolved dosimetry of human brain exposed to low frequency pulsed magnetic fields

An accurate dosimetry is a key issue to understanding brain stimulation and related interaction mechanisms with neuronal tissues at the basis of the increasing amount of literature revealing the effects on human brain induced by low-level, low frequency pulsed magnetic fields (PMFs).Most literature on brain dosimetry estimates the maximum E field value reached inside the tissue without considering its time pattern or tissue dispersivity. Nevertheless a time-resolved dosimetry, accounting for dispersive tissues behavior, becomes necessary considering that the threshold for an effect onset may vary depending on the pulse waveform and that tissues may filter the applied stimulatory fields altering the predicted stimulatory waveform’s size and shape.In this paper a time-resolved dosimetry has been applied on a realistic brain model exposed to the signal presented in Capone et al ( J. Neural Transm. 116 257–65), accounting for the broadband dispersivity of brain tissues up to several kHz, to accurately reconstruct electric field and current density waveforms inside different brain tissues.The results obtained by exposing the Duke’s brain model to this PMF signal show that the E peak in the brain is considerably underestimated if a simple monochromatic dosimetry is carried out at the pulse repetition frequency of 75 Hz.

Effects of extremely low frequency pulsed magnetic fields on diabetic nephropathy in streptozotocin-treated rats.

BackgroundExtremely low frequency pulsed magnetic fields (ELFPMF) have been shown to induce Faraday currents and measurable effects on biological systems. A kind of very high frequency electromagnetic field was reported that it improved the symptoms of diabetic nephropathy (DN) which is a major complication of diabetes. However, few studies have examined the effects of ELFPMF DN at the present. The present study was designed to investigate the effects of ELFPMF on DN in streptozotocin (STZ)–induced type 1 diabetic rats.MethodsAdult male SD rats were randomly divided into three weight-matched groups: Control (non-diabetic rats without DN), DN + ELFPMF (diabetic rats with DN exposed to ELFPMF, 8 h/days, 6 weeks) and DN (diabetic rats with DN exposed to sham ELFPMF). Renal morphology was examined by light and electron microscopy, vascular endothelial growth factor (VEGF)-A and connective tissue growth factor (CTGF) were measured by enzyme linked immune sorbent assay.ResultsAfter 6 weeks’ ELFPMF exposure, alterations of hyperglycemia and weight loss in STZ-treated rats with DN were not found, while both positive and negative effects of ELFPMF on the development of DN in diabetic rats were observed. The positive one was that ELFPMF exposure attenuated the pathological alterations in renal structure observed in STZ-treated rats with DN, which were demonstrated by slighter glomerular and tubule-interstitial lesions examined by light microscopy and slighter damage to glomerular basement membrane and podocyte foot processes examined by electron microscopy. And then, the negative one was that ELFPMF stimulation statistically significantly decreased renal expression of VEGF-A and statistically significantly increased renal expression of CTGF in diabetic rats with DN, which might partially aggravate the symptoms of DN.ConclusionBoth positive and negative effects of ELFPMF on the development of DN in diabetic rats were observed. The positive effect induced by ELFPMF might play a dominant role in the procession of DN in diabetic rats, and it is suggested that the positive effect should be derived from the correction of pathogenic diabetes-induced mediators.

Impact of low-frequency pulsed electromagnetic fields and interference currents in the formation of heterotopic ossification after total hip instalation in the hip joint

Due to the extension of life expectancy, the number of elderly people increases, and thus the number of disease and injuries of the locomotor system, especially the hip joint. One of the persistent trend is an increasing trend in the number of patients with coxarthrosis and implanted total hip endoprosthesis. One of the postoperative complications that occurred after implantation a total hip endoprosthesis is heterotopic ossification (HO). HO is the most common complication that occurs after the implantation a total hip endoprosthesis with recorded cases in the range of 9-90%. HO are insufficiently understood phenomenon, which is characterized by the formation of bone in periarticular tissues. We prospectively followed patients who implanted total hip endoprostheses in the department of orthopedics ZC in Kos. Mitrovica in 2008. and 2009. year. We examined the influence of physical agents on the prevention of HO near the hip joint. In these patients the treatment was carried out kinesiotherapeutic at the Center for Rehabilitation Health Center Kosovska Mitrovica, as well as pulse therapy low frequency magnetic field frequency of 30 Hz, 30 minutes, 8 mT intensity and 15 minutes interferential current, 0-100 Hz frequency. All patients were on the rehabilitation of one month (20 days). Based on this research we confirmed the assumption that the use of low frequency pulsed magnetic fields, interference currents and kinesitherapy prevents HO in patients after implantation of total endoprosthesis of the hip joint.

Atomic-force microscopy of Fe3(SiAl) alloys under magnetic-pulse treatment

The influence of weak (10–100 kA/m) low-frequency (10–20 Hz) pulsed magnetic fields on the surface structure and physical and mechanical parameters of Fe3(SiAl) alloys is studied by atomic-force microscopy and porometry.

Research on brain induced effect by extremely low frequency pulsed magnetic stimulation.

In order to evaluate the influence of extremely low frequency pulsed magnetic fields (ELF PMF) on human brain, we conducted the magnetic stimulation experiments (1 Hz, 10 mT, 20 min), and analyzed the changes of spontaneous EEG activity from 10 subjects. Compared with sham exposure group, the EEG power of theta band (3.5-7.5 Hz) and lower-alpha band (7.5-10 Hz) from the stimulation group increased significantly after magnetic stimulation. By analyzing the latency period and amplitude of P300 in auditory oddball task, we found that the latency period extended and the amplitude decreased. We suggested that these results might be explained via event-related synchronization induced by magnetic stimulation.

Assessing LINE-1 retrotransposition activity in neuroblastoma cells exposed to extremely low-frequency pulsed magnetic fields

Mobile genetic elements represent an important source of mutation and genomic instability, and their activity can be influenced by several chemical and physical agents.In this research we address the question whether exposure to extremely low-frequency pulsed magnetic fields (EMF-PMF) could affect the mobility of the human LINE-1RP retrotransposon. To this purpose, an in vitro retrotransposition assay was used on human neuroblastoma BE(2) cells exposed for 48h to 1mT, 50Hz PMF, or sham-exposed. Moreover, since it is well known that retrotransposition causes DNA double-strand breaks (DSB), an estimation of γ-H2AX foci, which is a marker of DNA DSB, was carried out on PMF- and sham-exposed samples. The results show that PMF-exposed cells had a lower number of both retrotransposition events and DNA DSB compared with sham-exposed samples. These results suggest that exposure to PMF can interfere with retrotransposition activity by inducing a decrease of retrotransposition events.

Biological effects of low-frequency pulsed magnetic fields on the embryonic central nervous system development. A histological and histochemical study.

Numerous experiments have yielded contradictory results on the harmful action of magnetic fields on embryonic development. Pulsed magnetic fields appear to be able to delay normal development of embryos. In the present study, fertilized Gallus domesticus eggs were exposed during incubation to pulsed magnetic fields (harmonic signals of 10 µT for 1 second with silences of 0.5 seconds) of 50 or 100 Hz frequency. Embryos extracted at 45 h of exposure to fields of 50 Hz or 100 Hz frequency had significantly (p<0.05) fewer somite pairs compared with controls of the same age. At 15 days of incubation, only embryos exposed to a 10 µT- 50 Hz field had a significantly (p<0.05) higher somatic weight. At 21 days of incubation, a significantly lower somatic weight (p<0.01) and development stage (p<0.05) was found in embryos exposed to a 10 µT-100 Hz field than in controls, while a lower development stage (p<0.05) alone was observed in those exposed to a 10 µT-50 Hz field. In addition, animals showed higher expression of the neural marker NSE (neural specific enolase) after 21 days of development as determined by immunohistochemistry, with very low expression of glycosaminoglycans identified by alcyan blue staining. These results suggest that pulsed magnetic fields may be able to hinder normal embryonic development in vivo and to alter normal neural function, at least at the intensities and frequencies analyzed in the present study.

The effects of low frequency pulsed magnetic fields with different waveforms on cardiac microvascular endothelial cells

Objective To investigate the effects of low frequency pulsed magnetic fields (LF-PMFs) on proliferation, the cell cycle, apoptosis, migration, cytoskeleton formation and nitric oxide (NO) secretion in cardiac microvascular endothelial cells (CMECs). Methods LF-PMFs with rectangular and triangular waveforms at 15 Hz were tested. The CMECs were randomly divided into a control group, 0.6 mT group, 1.2 mT group, 1.8 mT group and 2.4 mT group. Except for the control group, the CMECs were exposed to LF-PMFs 4 h/day for 5 days. Results After 5 days of intervention with rectangular wave LF-PMFs the proliferation of CMECs accelerated and NO secretion was enhanced significantly. The percentages of cells at ( S+G2 ) phase increased significantly, whereas apoptosis rates were significantly lower than in the control group. The migration of CMECs was facilitated, stress fibers increased and cytoskeleton components were reorganized. After 5 days of intervention with triangular wave LF-PMFs proliferation of CMECs accelerated and NO secretion was significantly enhanced. The percentages of cells at(S+G2)phase and migration increased, while apoptosis was inhibited. Cytoskeleton components were reorganized after exposure to 0.6 mT and 2.4 mT triangular waveform LF-PMFs. No significant change was detected with 1.2 mT and 1.8 mT triangular waveform LF-PMFs with regard to these variables. Conclusions The effects of LF-PMFs on proliferation, the cell cycle, apoptosis, migration, cytoskeleton formation and NO secretion function of CMECs were infiuenced by the waveform in addition to it's intensity and frequency. Key words: Low frequency pulsed magnetic fields; Cardiac microvascular endothelial cells; Proliferation; Cell cycle; Apoptosis; Migration; Cytoskeleton; Nitric oxide

Clinical update of pulsed electromagnetic fields on osteoporosis

To understand the effects of low-frequency pulsed electromagnetic fields (PEMFs) on chronic bony pain, bone mineral density (BMD), bone strength and biochemical markers of bone metabolism in the patients of osteoporosis. Using the key words "pulsed electromagnetic fields" and "osteoporosis", we searched the PubMed for related studies published in English from January 1996 to December 2007. We also searched the China National Knowledge Infrastructure (CNKI) for studies published in Chinese from January 1996 to December 2007. (1) all articles which referred to the effects of low-frequency pulsed magnetic fields on osteoporosis either in primary osteoporosis or secondary osteoporosis; (2) either observational studies or randomized controlled studies. (1) articles on experimental studies about osteoporosis; (2) repetitive studies; (3) case reports; (4) meta analysis. Totally 111 related articles were collected, 101 of them were published in Chinese, 10 were in English. Thirty-four were included and the remaining 84 were excluded. Low-frequency PEMFs relieves the pain of primary osteoporosis quickly and efficiently, enhances bone formation and increases BMD of secondary osteoporosis. But the effects of PEMFs on bone mineral density of primary osteoporosis and bone resorption were controversial.

Impact of low frequency pulsed magnetic fields on pain intensity, quality of life and sleep disturbances in patients with painful diabetic polyneuropathy

Aim The aim of this randomized, placebo-controlled, double-blind study was to assess whether a low frequency magnetic field can influence pain intensity, quality of life and sleep, and glycaemic control in patients with painful diabetic polyneuropathy. Methods Sixty-one patients were randomized into two groups: the study group comprised 32 patients exposed to a low frequency magnetic field, average pain duration 23 months; the control group included 29 patients who received sham exposure, average pain duration 28 months. Patients were exposed for three weeks, 20 min a day, five days a week. The magnetic field generator was a Viofor JPS device (Med & Life, Komorow, Poland). All subjects filled out the following questionnaires five times (at the beginning and after one, two, three and five weeks): SFMPQ-VAS (pain evaluation), EuroQol EQ-5D and MOS Sleep Scale. HbA 1c was evaluated at baseline and after five weeks. Results Significant reductions in pain intensity were seen in both the study group (visual analogue scale [VAS] value of 73 mm at baseline versus 33 mm after three weeks) and controls (VAS 69 mm at baseline versus 41 mm after three weeks). The extent of pain reduction did not differ significantly between the groups at any time. Also, both groups had similar improvements in EuroQol, MOS and HbA 1c values. Conclusion Genuine magnetic field exposure has no advantage over sham exposure in reducing pain intensity, improving quality of life, and decreasing sleep disturbances and HbA 1c.

Radiological workers sensitivity to 50 Hz pulsed magnetic fields: preliminary results.

In the present study the effect of extremely low frequency pulsed magnetic fields (PMF) was evaluated in lymphocyte cultures from 12 subjects occupationally exposed to low doses of ionising radiations. The PMF signal characteristics were repetition frequency 50 Hz, triangular shape, rise time about 1.2 ms and peak intensity 2.5 mT. The cytokinesis-block technique was employed to evaluate genotoxicity and cytotoxicity in terms of micronucleus frequency and cell proliferation, respectively. When PMF-exposed cultures were compared with their respective controls, a slight but statistically significant increase was detected in both the biological parameters investigated ( p<0.05). The results obtained suggest a possible role of specific employments involving exposure to ionising radiation, in the risk associated with electromagnetic field exposure.

Human subjects exposed to a specific pulsed extremely low frequency magnetic field: Effects on standing balance

Extremely low frequency pulsed magnetic fields (±200 μT, ∼400 mT/s, 0–1 kHz) may produce electric currents similar to action potentials, which in turn would be expected to produce detectable physiological or behavioral effects in human subjects. This thesis reports on the effects of pulsed extremely low frequency magnetic fields (ELFMFs) on human standing balance by measurement of postural sway on a force platform utilizing a double blind protocol with four randomly assigned 2 min exposure conditions (eyes open/closed, sham/ELFMF) within each subject's session. Historically, and in current research by others, normal postural sway has been well characterized. Standing balance in humans is a largely automatic behavior and with “eyes open” is a robust behavior not easily disrupted by small perturbations. However, with “eyes closed” standing balance becomes very sensitive to perturbation by a wide variety of stimuli. Since we have shown that ELFMF perturbs human postural sway, measurements of standing balance may be an ideal method of investigating bioelectromagnetic coupling mechanisms in humans (i.e., peripheral versus central nervous system mechanisms). Ideal because, being under automatic control, standing balance is an objective measure not subject to placebo effects. The coupling mechanisms can be studied by examining the effects related to different anatomical location of ELFMF exposure, or studying patients with different pathology. This thesis has established that normal standing balance is perturbed by weak ELFMF for both eyes open/eyes closed conditions. Also, it has been established that this human assay may indeed be appropriate to study coupling mechanisms, since the ability of ELFMF to affect sway varies between patients with diseases affecting different anatomical and physiological centers.