Pulsed EMF Research Articles

The Effects of Low-frequency Pulsed Electromagnetic Fields on the Cleaning of Household Wastewater

The effect of pulsed EMF with a pulse repetition frequency of 16 Hz on the decomposition of organic compounds in wastewater in the presence of activated sludge microorganisms has been studied. It is shown that aerobic purification of a mixture of wastewater and activated sludge in the presence of a continuous pulsed electromagnetic field with a frequency of 16 Hz and a magnetic induction of no more than 0.5 μT accelerates the process of ammonification by 25 %, nitrification and denitrification by 15 %, reduction of COD by approximately 20 %.The intensity of the increase in the biomass of activated sludge and the rate of its deposition were noted.

Импульсная проводимость в Ag-Pd-резисторах, индуцированная импульсами лазера

Pulsed EMF in resistive thick-film Ag - Pd elements is experimentally studied when their surface is irradiated with a laser beam. The dependences of the pulsed EMF on the coordinate of the action of the laser beam on the film surface are obtained. It is shown that applying a constant bias voltage to a thick-film resistive element can significantly increase the amplitude of unipolar EMF pulses induced by laser pulses. It was found that the amplitude and frequency of the EMF signals depend, respectively, on the power and frequency of laser pulses. It is shown that by the value of the pulsed EMF it is possible to control the parameters of the high-power laser radiation incident on the surface in real time. The design of a receiver for recording the parameters of laser radiation based on an Ag - Pd sensitive element has been developed. The sensitivity of the device for measuring the power and pulse repetition rate is estimated.

Pulse Conductivity in Ag-Pd Resistors Induced by Laser Pulses

Pulsed EMF in resistive thick-film Ag-Pd elements is experimentally studied when their surface is irradiated with a laser beam. The dependences of the pulsed EMF on the coordinate of the action of the laser beam on the film surface are obtained. It is shown that applying a constant bias voltage to a thick-film resistive element can significantly increase the amplitude of unipolar EMF pulses induced by laser pulses. It was found that the amplitude and frequency of the EMF signals depend, respectively, on the power and frequency of laser pulses. It is shown that by the value of the pulsed EMF it is possible to control the parameters of the high-power laser radiation incident on the surface in real time. The design of a receiver for recording the parameters of laser radiation based on an Ag-Pd sensitive element has been developed. The sensitivity of the device for measuring the power and pulse repetition rate is estimated. Keywords: measurement of laser parameters, thick-film resistor, thermo EMF.

Analysis of Broadband Antenna Radiation Pulses

Abstract Electromagnetic energy can alter metabolic and biosynthetic processes and under certain parameters of pulsed EMF it can change pulse repetition frequency, operation cycle, power, exposure, as well as it can slow down and inhibit cell growth. MW irradiation range of RNA and DNA – containing virus reduces their infectivity. Inhibition of bacterial cultures growth, changes in phagocytic activity of protein biosynthesis, ultrastructural changes in the cells when exposed to EMF EHF. It was found in experiments with micro-organisms that biological effects of EMF on microorganisms wore a resonant character. One of the basic mechanisms of inhibitory action of EHF radiation on harmful microorganisms is the role of membranes in biological reactions of microorganisms on the EMR.

Pulsed electromagnetic field (PEMF) prevents pro-oxidant effects of H2O2 in SK-N-BE(2) human neuroblastoma cells

Purpose The redox milieu, together with reactive oxygen species (ROS) accumulation, may play a role in mediating some biological effects of extremely-low-frequency electromagnetic fields (ELF-EMF). Some of us have recently reported that a pulsed EMF (PEMF) improves the antioxidant response of a drug-sensitive human neuroblastoma SH-SY5Y cell line to pro-oxidants. Since drug resistance may affect cell sensitivity to redox-based treatments, we wanted to verify whether drug-resistant human neuroblastoma SK-N-BE(2) cells respond to a PEMF in a similar fashion. Materials and methods SK-N-BE(2) cells were exposed to repeated 2 mT, 75 Hz PEMF (15 min each, repeated 3 times over 5 days), and ROS production, Mn-dependent superoxide dismutase (MnSOD)-based antioxidant protection and viability were assessed after 10 min or 30 min 1 mM hydrogen peroxide. Sham controls were kept at the same time in identical cell culture incubators. Results The PEMF increased the MnSOD-based antioxidant protection and reduced the ROS production in response to a pro-oxidant challenge. Conclusions Our work might lay foundation for the development of non-invasive PEMF-based approaches aimed at elevating endogenous antioxidant properties in cellular or tissue models.

Inter-individual and intra-individual variation of the effects of pulsed RF EMF exposure on the human sleep EEG.

Pulse-modulated radiofrequency electromagnetic fields (RF EMF) can alter brain activity during sleep; increases of electroencephalographic (EEG) power in the sleep spindle (13.75-15.25 Hz) and delta-theta (1.25-9 Hz) frequency range have been reported. These field effects show striking inter-individual differences. However, it is still unknown whether individual subjects react in a similar way when repeatedly exposed. Thus, our study aimed to investigate inter-individual variation and intra-individual stability of field effects. To do so, we exposed 20 young male subjects twice for 30 min prior to sleep to the same amplitude modulated 900 MHz (2 Hz pulse, 20 Hz Gaussian low-pass filter and a ratio of peak-to-average of 4) RF EMF (spatial peak absorption of 2 W/kg averaged over 10 g) 2 weeks apart. The topographical analysis of EEG power during all-night non-rapid eye movement sleep revealed: (1) exposure-related increases in delta-theta frequency range in several fronto-central electrodes; and (2) no differences in spindle frequency range. We did not observe reproducible within-subject RF EMF effects on sleep spindle and delta-theta activity in the sleep EEG and it remains unclear whether a biological trait of how the subjects' brains react to RF EMF exists.

Stimulation of the Brain With Radiofrequency Electromagnetic Field Pulses Affects Sleep-Dependent Performance Improvement

BackgroundSleep-dependent performance improvements seem to be closely related to sleep spindles (12–15 Hz) and sleep slow-wave activity (SWA, 0.75–4.5 Hz). Pulse-modulated radiofrequency electromagnetic fields (RF EMF, carrier frequency 900 MHz) are capable to modulate these electroencephalographic (EEG) characteristics of sleep. ObjectiveThe aim of our study was to explore possible mechanisms how RF EMF affect cortical activity during sleep and to test whether such effects on cortical activity during sleep interact with sleep-dependent performance changes. MethodsSixteen male subjects underwent 2 experimental nights, one of them with all-night 0.25–0.8 Hz pulsed RF EMF exposure. All-night EEG was recorded. To investigate RF EMF induced changes in overnight performance improvement, subjects were trained for both nights on a motor task in the evening and the morning. ResultsWe obtained good sleep quality in all subjects under both conditions (mean sleep efficiency > 90%). After pulsed RF EMF we found increased SWA during exposure to pulse-modulated RF EMF compared to sham exposure (P < 0.05) toward the end of the sleep period. Spindle activity was not affected. Moreover, subjects showed an increased RF EMF burst-related response in the SWA range, indicated by an increase in event-related EEG spectral power and phase changes in the SWA range. Notably, during exposure, sleep-dependent performance improvement in the motor sequence task was reduced compared to the sham condition (−20.1%, P = 0.03). ConclusionThe changes in the time course of SWA during the exposure night may reflect an interaction of RF EMF with the renormalization of cortical excitability during sleep, with a negative impact on sleep-dependent performance improvement.

The Effect of Neurofield Pulsed EMF on Parkinson's Disease Symptoms and QEEG

The purpose of this study was to examine the effect of NeuroField pulsed EMF stimulation on Parkinson's Disease (PD) symptoms. Pretreatment, posttreatment, and follow-up QEEG was analyzed along with patient symptom ratings of PD symptoms. The results show significant differences in pre- versus post- versus follow-up QEEG. PD patient symptom ratings were significantly reduced by posttreatment and remained reduced on 30- and 180-day follow-up. NeuroField appears to have potential in reducing PD symptoms.

The effect of electromagnetic field emitted by a mobile phone on the inhibitory control of saccades

To investigate whether exposure to a pulsed high-frequency electromagnetic field (pulsed EMF) emitted by a mobile phone has short-term effects on the inhibitory control of saccades. A double-blind, counterbalanced crossover study design was employed. We assessed the performance of 10 normal subjects on antisaccade (AS) and cued saccade (CUED) tasks as well as two types of overlap saccade (OL1, OL2) task before and after 30 min of exposure to EMF emitted by a mobile phone or sham exposure. After EMF or sham exposure, we observed a slight but significant shortening of latency in the CUED and OL2 tasks. AS amplitude decreased as well as the saccade velocities in the AS, CUED, and OL1 tasks after exposure. These changes occurred regardless of whether exposure was real or sham. The frequencies of pro-saccades in the AS task, saccades to cue in the CUED task, and prematurely initiated saccades in the overlap (OL2) task did not change significantly after real or sham EMF exposure. Thirty minutes of mobile phone exposure has no significant short-term effect on the inhibitory control of saccades. The cortical processing responsible for saccade inhibition is not affected by exposure to EMF emitted by a mobile phone.

Effects of thirty-minute mobile phone exposure on saccades

Objective To investigate whether exposure to pulsed high-frequency electromagnetic field (pulsed EMF) emitted by a mobile phone has short-term effects on saccade performances. Methods A double blind, counterbalanced crossover design was employed. In 10 normal subjects, we studied the performance of visually guided saccade (VGS), gap saccade (GAP), and memory guided saccade (MGS) tasks before and after exposure to EMF emitted by a mobile phone for thirty minutes or sham exposure. We also implemented a hand reaction time (RT) task in response to a visual signal. Results With the exception of VGS and MGS latencies, the parameters of VGS, GAP and MGS tasks were unchanged before and after real or sham EMF exposure. In addition, the latencies of VGS and MGS did not change differently after real and sham exposure. The hand RT shortened with the repetition of trials, but again this trend was of similar magnitude for real and sham exposures. Conclusions Thirty minutes of mobile phone exposure has no significant short-term effect on saccade performances. Significance This is the first study to investigate saccade performance in relation to mobile phone exposure. No significant effect of mobile phone use was demonstrated on the performance of various saccade tasks, suggesting that the cortical processing for saccades and attention is not affected by exposure to EMF emitted by a mobile phone.

Studying gene expression profile of rat neuron exposed to 1800 MHz radiofrequency electromagnetic fields with cDNA microassay

A widespread use of mobile phone (MP) evokes a growing concern for their possible adverse effects on human, especially the brain. Gene expression is a unique way of characterizing how cells and organism adapt to changes in the external environment, so the aim of this investigation was to determine whether 1800 MHz radiofrequency electromagnetic fields (RF EMF) can influence the gene expression of neuron. Affymetrix Rat Neurobiology U34 array was applied to investigate the changes of gene expression in rat neuron after exposed to the pulsed RF EMF at a frequency of 1800 MHz modulated by 217 Hz which is commonly used in MP. Among 1200 candidate genes, 24 up-regulted genes and 10 down-regulated genes were identified after 24-h intermittent exposure at an average special absorption rate (SAR) of 2 W/kg, which are associated with multiple cellular functions (cytoskeleton, signal transduction pathway, metabolism, etc.) after functional classification. The results were further confirmed by quantitive real-time polymerase chain reaction (RT PCR). The present results indicated that the gene expression of rat neuron could be altered by exposure to RF EMF under our experimental conditions.

Effects of thirty-minute mobile phone use on visuo-motor reaction time

Objective To investigate whether exposure to pulsed high-frequency electromagnetic field (pulsed EMF) emitted by a mobile phone has short-term effects on the visuo-motor choice reaction time (RT) and movement time (MT). Methods A double blind, counterbalanced crossover design was employed. In 16 normal subjects, we studied the performance of a visuo-motor precued choice reaction time task (PCRT) before and after exposure to EMF emitted by a mobile phone for 30 minutes or sham exposure. Results The RTs and MTs under different conditions of precue information were not affected by exposure to pulsed EMF emitted by a mobile phone or by sham phone use. Conclusions Thirty minutes of mobile phone use has no significant short-term effect on the cortical visuo-motor processing as studied by the present PCRT task. Significance This is the first study to investigate visuo-motor behavior in relation to mobile phone exposure. No significant effect of mobile phone use was demonstrated on the performance of the visuo-motor reaction time task.

Effects of thirty minutes mobile phone use on the human sensory cortex

Objective To investigate whether the pulsed high-frequency electromagnetic field (pulsed EMF) emitted by a mobile phone for 30 min has short-term effects on human somatosensory evoked potentials (SEPs). Methods We studied somatosensory evoked potentials (SEPs) in 12 normal volunteers before and after exposure to the electromagnetic field emitted by a mobile phone for 30 min compared with sham exposure. In 7 out of the subjects we also measured the recovery function of the SEP. Results Neither SEPs nor their recovery function was affected by exposure to pulsed EMF emitted by a mobile phone or sham phone use. Conclusions As far as the present methods are concerned, 30 min mobile phone use has no short-term effects on the human sensory cortex. Significance This is the first study of SEPs after electromagnetic exposure by the mobile phone. Our results support the safety of the mobile phone.

Low-frequency electromagnetic pulses enhance Ca 2+ uptake by chick small intestine in vitro

The effect of external EMF on Ca 2+ uptake by the chick small intestine was investigated in vitro by use of the accumulating preparations of epithelial tissue. The intestinal tissue preparations were exposed to EMF in specific zones of Helmholtz coils. The steady magnetic field (SMF) having an induction value B 0 = 1.14 mT, as well as pulsed EMF—constant pulse rate ( f = 80 Hz) and randomized pulse rate (in range of 40–120 Hz)—with amplitude B M = B 0 was used. The fall time of the pulse was changed stepwise in the range 0.15–0.55 ms. It was found that SMF, as well as pulsed EMF significantly enhanced the uptake of Ca 2+ by the small intestine. A SMF was found to enhance uptake by up to 40–50% for both normal (D) and rachitic chicks. The effects of the induced E rot depended essentially of vitamin D status of chicks due to the complex action of vitamin D-dependent factors. The effect of randomized pulse EMF was qualitatively similar to that of constant pulse EMF, but quantitatively it was less. Data indicate the contribution of the B-, as well as E-component to the modification of the Ca 2+ uptake.

Low-frequency electromagnetic pulses enhance Ca 2+ uptake by chick small intestine in vitro

The effect of external EMF on Ca 2+ uptake by the chick small intestine was investigated in vitro by use of the accumulating preparations of epithelial tissue. The intestinal tissue preparations were exposed to EMF in specific zones of Helmholtz coils. The steady magnetic field (SMF) having an induction value B 0 = 1.14 mT, as well as pulsed EMF—constant pulse rate ( f = 80 Hz) and randomized pulse rate (in range of 40–120 Hz)-with amplitude BM = B 0 was used. The fall time of the pulse was changed stepwise in the range 0.15–0.55 ms. It was found that SMF, as well as pulsed EMF significantly enhanced the uptake of Ca 2+ by the small intestine. A SMF was found to enhance uptake by up to 40–50% for both normal (D) and rachitic chicks. The effects of the induced E rot depended essentially of vitamin D status of chicks due to the complex action of vitamin D-dependent factors. The effect of randomized pulse EMF was qualitatively similar to that of constant pulse EMF, but quantitatively it was less. Data indicate the contribution of the B-, as well as E-component to the modification of the Ca 2+ uptake.

Effect of Torsion on Magnetostrictive Delay Lines

In this study a method is suggested for the simultaneous production of two different stress pulses in a magnetostrictive material. The magnetostrictive effect for a wire subjected exclusively to a longitudinal tension is introduced and the study extended to the case where the material is also twisted. It is shown that when the twisted wire is excited by a longitudinal magnetic field, because of the easy magnetization axis skew, it is possible to obtain not only the simultaneous production of extensional and torsional pulses, but also the production of a pulsed emf at the ends of the wire. Finally, a possible application of the phenomenon is shown to the study of second-order elastic effects in magnetostrictive materials.