Exogenous Electromagnetic Fields Research Articles

Passive IR-UWB Localization System for UAV-Based Electric Facility Inspection During GPS Outage

A practical localization system is proposed for a substation inspection unmanned aerial vehicle (UAV) performing its mission under global positioning system (GPS) signal blockage. The sensor hardware consists of a single transmitter and a cruciform receiver array, which produces the range difference (RD) information used for UAV positioning. The use of impulse-radio ultra wide-band (IR-UWB) devices secures the robustness against RF interference often caused by an exogenous electromagnetic field. With this hardware configuration, the UAV localization can be formulated as the state estimation problem for an uncertain linear state space model and be solved by using the computationally efficient robust weighted least squares (RWLS) estimator. Since the standard RWLS estimator could be sensitive to the imperfectness of prior knowledge on the noise statistic, a geometric constraint expressed in terms of a UAV position is exploited to secure the reliable localization performance in practice. Through experimental results, it is verified that the proposed solution provides reliable UAV positioning performance despite using the imperfect measurement noise statistics for the localization system.

Variable electromagnetic fields in physiotherapy of diseases of the musculoskeletal system

Increasing evidence suggests that the exogenous electromagnetic field may be involved in many biological processes of great importance for therapeutic interventions.
 It is known that variable electromagnetic fields are a non-invasive, safe and effective therapeutic tool without obvious side effects. Numerous studies have shown that variable electromagnetic fields can become an independent or additional method of treating diseases of the musculoskeletal system. However, several questions remain unresolved. Prior to their widespread clinical application, further research is needed based on well-designed, high-quality studies to standardize treatment parameters and develop an optimal protocol for healthcare decision making.
 In this review, we aimed to provide up-to-date data on the mechanism of action, clinical application, and controversy regarding variable electromagnetic fields in the physiotherapy of musculoskeletal disorders.

Effects and Mechanisms of Exogenous Electromagnetic Field on Bone Cells: A Review.

Osteoporosis, fractures, and other bone diseases or injuries represent serious health problems in modern society. A variety of treatments including drugs, surgeries, physical therapies, etc. have been used to prevent or delay the progression of these diseases/injuries with limited effects. Electromagnetic field (EMF) has been used to non-invasively treat bone diseases, such as fracture and osteoporosis, for many years. However, because a variety of cellular and molecular events can be affected by EMF with various parameters, the precise bioeffects and underlying mechanisms of specific EMF on bone cells are still obscure. Here, we summarize the common therapeutic parameters (frequency and intensity) of major types of EMF used to treat bone cells taken from 32 papers we selected from the PubMed database published in English from 1991 to 2018. Briefly, pulse EMF promotes the proliferation of osteoblasts when its frequency is 7.5-15 Hz or 50-75 Hz and the intensity is 0.40-1.55 mT or 3.8-4 mT. Sinusoidal EMF, with 0.9-4.8 mT and 45-60 Hz, and static magnetic field with 0.1-0.4 mT or 400 mT, can promote osteoblast differentiation and maturation. Finally, we summarize the latest advances on the molecular signaling pathways influenced by EMF in osteoblasts and osteoclasts. A variety of molecules such as adenosine receptors, calcium channels, BMP2, Notch, Wnt1, etc., can be influenced by EMF in osteoblasts. For osteoclasts, EMF affects RANK, NF-κB, MAPK, etc. We speculate that EMF with different frequencies and intensities exert distinct bioeffects on specific bone cells. More high-quality work is required to explore the detailed effects and underlying mechanisms of EMF on bone cells/skeleton to optimize the application of EMF on bone diseases/injuries. Bioelectromagnetics. 2020;41:263-278 © 2020 Bioelectromagnetics Society.

Comparison of polymerization and structural behavior of microtubules in rat brain and sperm affected by the extremely low-frequency electromagnetic field

BackgroundMicrotubule proteins are able to produce electromagnetic fields and have an important role in memory formation, and learning. Therefore, microtubules have the potential to be affected by exogenous electromagnetic fields. This study aimed to examine the comparison of microtubule polymerization and its structural behavior in brain and sperm affected by 50 Hz extremely low-frequency electromagnetic field (ELEF).ResultsTwenties adult male rats were randomly and equally divided into control and experimental groups, to evaluate the effect of 50 Hz ELEF on the sperm and brain functions. Plus-maze, serum testosterone and corticosterone, and sperm evaluation were performed. Next, the semen and brain samples were obtained, and they were divided into four experimental groups for investigation of microtubule polymerization. There was no significant difference in testosterone and, corticosterone levels, anxiety behaviors, and sperm morphology between control and ELEF-exposure groups. The sperm viability, total and progressive motility were significantly higher in the ELEF-exposed group than that of the control group. The microtubule polymerization in sperm ELEF was significantly higher than in other groups. The secondary and tertiary structures of tubulins were significantly affected in the brain, and sperm ELEF groups.ConclusionIt seems that the polymerization of microtubules and conformational changes of tubulin dimers are improved by ELEF application.

Bio-soliton model that predicts non-thermal electromagnetic frequency bands, that either stabilize or destabilize living cells

ABSTRACTSolitons, as self-reinforcing solitary waves, interact with complex biological phenomena such as cellular self-organization. A soliton model is able to describe a spectrum of electromagnetism modalities that can be applied to understand the physical principles of biological effects in living cells, as caused by endogenous and exogenous electromagnetic fields and is compatible with quantum coherence. A bio-soliton model is proposed, that enables to predict which eigen-frequencies of non-thermal electromagnetic waves are life-sustaining and which are, in contrast, detrimental for living cells. The particular effects are exerted by a range of electromagnetic wave eigen-frequencies of one-tenth of a Hertz till Peta Hertz that show a pattern of 12 bands, and can be positioned on an acoustic reference frequency scale. The model was substantiated by a meta-analysis of 240 published articles of biological electromagnetic experiments, in which a spectrum of non-thermal electromagnetic waves were exposed to living cells and intact organisms. These data support the concept of coherent quantized electromagnetic states in living organisms and the theories of Fröhlich, Davydov and Pang. It is envisioned that a rational control of shape by soliton-waves and related to a morphogenetic field and parametric resonance provides positional information and cues to regulate organism-wide systems properties like anatomy, control of reproduction and repair.

The implications of non-linear biological oscillations on human electrophysiology for electrohypersensitivity (EHS) and multiple chemical sensitivity (MCS).

The 'informational content' of Earth's electromagnetic signaling is like a set of operating instructions for human life. These environmental cues are dynamic and involve exquisitely low inputs (intensities) of critical frequencies with which all life on Earth evolved. Circadian and other temporal biological rhythms depend on these fluctuating electromagnetic inputs to direct gene expression, cell communication and metabolism, neural development, brainwave activity, neural synchrony, a diversity of immune functions, sleep and wake cycles, behavior and cognition. Oscillation is also a universal phenomenon, and biological systems of the heart, brain and gut are dependent on the cooperative actions of cells that function according to principles of non-linear, coupled biological oscillations for their synchrony. They are dependent on exquisitely timed cues from the environment at vanishingly small levels. Altered 'informational content' of environmental cues can swamp natural electromagnetic cues and result in dysregulation of normal biological rhythms that direct growth, development, metabolism and repair mechanisms. Pulsed electromagnetic fields (PEMF) and radiofrequency radiation (RFR) can have the devastating biological effects of disrupting homeostasis and desynchronizing normal biological rhythms that maintain health. Non-linear, weak field biological oscillations govern body electrophysiology, organize cell and tissue functions and maintain organ systems. Artificial bioelectrical interference can give false information (disruptive signaling) sufficient to affect critical pacemaker cells (of the heart, gut and brain) and desynchronize functions of these important cells that orchestrate function and maintain health. Chronic physiological stress undermines homeostasis whether it is chemically induced or electromagnetically induced (or both exposures are simultaneous contributors). This can eventually break down adaptive biological responses critical to health maintenance; and resilience can be compromised. Electrohypersensitivity can be caused by successive assaults on human bioelectrochemical dynamics from exogenous electromagnetic fields (EMF) and RFR or a single acute exposure. Once sensitized, further exposures are widely reported to cause reactivity to lower and lower intensities of EMF/RFR, at which point thousand-fold lower levels can cause adverse health impacts to the electrosensitive person. Electrohypersensitivity (EHS) can be a precursor to, or linked with, multiple chemical sensitivity (MCS) based on reports of individuals who first develop one condition, then rapidly develop the other. Similarity of chemical biomarkers is seen in both conditions [histamines, markers of oxidative stress, auto-antibodies, heat shock protein (HSP), melatonin markers and leakage of the blood-brain barrier]. Low intensity pulsed microwave activation of voltage-gated calcium channels (VGCCs) is postulated as a mechanism of action for non-thermal health effects.

Nanosecond pulsed electric fields activate intracellular signaling pathways

In cellular electrochemistry, ions respond to stimuli by constantly shuffling across cellular membranes to perform their physiological roles. This flow of ions, the electromotive force, leaves cells vulnerable to exogenous electromagnetic fields that can stimulate and/or modulate cellular activity. An irreparable link exists between changes in ionic concentration and the electric gradient of the cell (or its potential energy). Consequently, we can manipulate the physiology of the cell by altering its permeability to various ions, thereby modulating its electrical gradient. Only a few millivolts in excess of the resting membrane potential can stimulate a dramatic change in ion distribution within the cellular microenvironment. In excitable neural-type cells, electrical-stimulation-induced changes in membrane potential lead to the generation or inactivation of action potentials (AP). These AP trigger activities, such as nerve impulses in

Effect of Pulsed Electromagnetic Fields on Human Osteoblast Cultures

Exogenous electromagnetic fields (EMFs) affect bone metabolism, but the mechanisms responsible for this phenomenon are unclear. Pulsed EMFs (PEMFs) can be effective in the management of congenital pseudarthrosis or delayed union or non-union of fractures. We investigated the effects of PEMFs used in clinical practice on human osteoblast cultures. Primary osteoblastic cells were isolated from a human femoral head. Cultures were exposed to the PEMF stimulation for 72 hours, 7 and 10 days and compared with a control group of primary osteoblastic cells non-exposed to PEMF. Cell growth and alkaline phosphatase activity were evaluated in the osteoblast cell cultures at each observation time. At each observation time, the differences in cell numbers between PEMF-exposed cells and control group were statistically significant (p < 0.05). The alkaline phosphatase-specific activity of PEMF-exposed osteoblast cultures showed a statistically significant (p < 0.05) increase when compared with the control group after 7 and 10 days of exposure. The application of PEMF stimulation on human osteoblasts accelerates cellular proliferation when compared with a control group of non-PEMF-exposed cells.

How living systems recognize applied electromagnetic fields

Natural and man-made magnetic and electromagnetic fields are important factors in the contemporary life. The paper discusses the role of environmental magnetic and electromagnetic fields in origin and evolution of life. A brief review of the characteristics of Earth magnetic field, Earth magnetosphere, and their role as a shield for cosmic radiation follows. The role of endogenous and exogenous magnetic fields is discussed in respect of the clarification of the potential hazard and benefit of electromagnetic fields. The second part of the paper discusses the mechanisms of detection and response to exogenous electromagnetic fields, as well as threshold versus window hypothesis for mechanisms of interactions. Finally, the necessity of accurate dosimetry at the target site and the importance of relevant research and clinical protocols in studying biological responses are pointed out.

Plasma effects in electromagnetic field interaction with biological tissue

AbstractTheoretical analysis is presented of the nonlinear behavior of charge carriers in biological tissue under the influence of varying low-intensity electromagnetic (EM) field. The interaction occurs because of the nonlinear force arising due to the gradient of the EM field intensity acting on free electrons in the conduction band of proteins in metabolically active biological cell membrane receptors leading to a redistribution of charge carriers. Field dependence of the resulting dielectric constant is investigated by a suitable modification to include an additional electronic contribution term to the three-term Debye model. The exogenous EM field propagating in this nonlinear cellular medium satisfies the nonlinear Schrödinger equation and can be affected significantly. Resulting field effect can be substantially augmented and effective rectification/demodulation can occur. Possible implications of this modification on biological processes in white and grey matter are discussed.

Effects of Exogenous Electromagnetic Fields on a Simplified Ion Channel Model

In this paper, we calculate the effect of an exogenous perturbation (an electromagnetic field [EMF] oscillating in the range of microwave frequencies in the range of 1 GHz) on the flux of two ion species through a cylindrical ion channel, implementing a continuous model, the Poisson-Smoluchowski system of equations, to study the dynamics of charged particle density inside the channel. The method was validated through comparison with Brownian dynamics simulations, supposed to be more accurate but computationally more demanding, obtaining a very good agreement. No EMF effects were observed for low field intensities below the level for thermal effects, as the highly viscous regime and the simplicity of the channel do not exhibit resonance phenomena. For high intensities of the external field (>10(5) V/m), we observed slightly different behavior of ion concentration oscillations and ion currents as a function of EMF orientation with respect to the channel axis.

Bioelectrodynamics in living organisms

This article introduces an interdisciplinary subject of bioelectrodynamics in living organisms and its related research challenges and opportunities. Bioelectrodynamics in living organisms is aimed to reveal critical roles of electromagnetism and mechanics in biology, to correlate biophysical functions of living organisms with biochemical processes at the cellular level, and to introduce theoretical basis and methodology, such as modeling and simulations, for stimulating technical innovations and promoting technology development in biomedicine as well as for the study of human healthcare issues related to environments among others in our modern society. The article reviews some important issues in bioelectrodynamic modeling. This includes the modeling of living cells, blood, bones and soft tissues that may have unique properties, such as active control, regulation and remodeling capabilities that are completely different from those of conventionally man-made materials. Possible biological effects and potential biomedical usages of endogenous and exogenous electromagnetic fields and mechanical stresses in living organisms are also reviewed, which indicate promising future of biomedical imaging and therapeutic methods based on bioelectrodynamic techniques. The fact that living organisms may have well-organized structures, actively controlled actions and responses, extremely sensitivity in electromagnetic fields and mechanical actions, and amazing signal amplification functions may not only cause complexity and variety of the biological world, but also create opportunities for technical innovations in biomedicine to improve future quality of human life.

Modeling electromagnetic fields detectability in a HH-like neuronal system: stochastic resonance and window behavior

Noise has already been shown to play a constructive role in neuronal processing and reliability, according to stochastic resonance (SR). Here another issue is addressed, concerning noise role in the detectability of an exogenous signal, here representing an electromagnetic (EM) field. A Hodgkin-Huxley like neuronal model describing a myelinated nerve fiber is proposed and validated, excited with a suprathreshold stimulation. EM field is introduced as an additive voltage input and its detectability in neuronal response is evaluated in terms of the output signal-to-noise ratio. Noise intensities maximizing spiking activity coherence with the exogenous EM signal are clearly shown, indicating a stochastic resonant behavior, strictly connected to the model frequency sensitivity. In this study SR exhibits a window of occurrence in the values of field frequency and intensity, which is a kind of effect long reported in bioelectromagnetic experimental studies. The spatial distribution of the modeled structure also allows to investigate possible effects on action potentials saltatory propagation, which results to be reliable and robust over the presence of an exogenous EM field and biological noise. The proposed approach can be seen as assessing biophysical bases of medical applications funded on electric and magnetic stimulation where the role of noise as a cooperative factor has recently gained growing attention.

BIOMEMBRANE EXCITABILITY STUDIED WITHIN A WIDE-BAND FREQUENCY OF AN INTERACTING EXOGENOUS ELECTRIC FIELD

There does exist increasing experimental and theoretical evidence that supports the existence of a coupling between exogenous electromagnetic fields and ion channels located within the membrane of excitable cells. One of the most tantalizing consequences of such interactions points to a resonant-like behavior of this class of electrical non-linear systems leading to an optimized information transfer along excitable membranes. Herein, we present novel evidence showing that action potentials may occur in biomembranes within even the subthreshold excitation range, provided that concomitantly with the depolarizing stimulus, an exogenous low-amplitude oscillatory electric field of proper frequency (centered around 10 kHz) interacts with the biomembrane. As we present it, this phenomenon may be explained if one takes into consideration the resonant-like electrical properties of the linearized, small-signal impedance of the simplified, equivalent electrical representation of the studied biomembrane.

Fokker–Planck analysis of the Langevin–Lorentz equation: Application to ligand-receptor binding under electromagnetic exposure

The statistical properties of the solution of the Langevin–Lorentz equation are analyzed by means of the Fokker–Planck approach. The equation describes the dynamics of an ion that is attracted by a central field and is interacting with a time-varying magnetic field and with the thermal bath. If the endogenous force is assumed to be elastic, then a closed-form expression for the probability density of the process can be obtained, in the case of constant magnetic exposure and, for the time-varying case, at least asymptotically. In the general case, a numerical integration of the resulting set of differential equations with periodically time-varying coefficients has been implemented. A framework for studying the possible effects of low-frequency, low-intensity electromagnetic fields on biological systems has been developed on the basis of the equation. The model assumes that an exogenous electromagnetic field may affect the binding of a messenger attracted by the endogenous force field of its receptor protein. The results are applicable to the analysis of experiments, e.g., exposing a Petri dish, containing a biological sample, to a periodically time-varying magnetic field generated by a pair of Helmholtz coils, most widely used in the scientific literature. The proposed model provides a theoretical mean for evaluating the biological effectiveness of low-frequency, low-intensity electromagnetic exposure.

Mechanical and electrical interactions in bone remodeling

The natural remodeling and adaptation of skeletal tissues in response to mechanical loading is a classic example of physical regulation in biology. It is largely because it involves forces that do not seem to fit into the familiar schemes of biochemical controls that bone adaptation mechanisms have intrigued us for at least a century. The effect of electromagnetic fields on organisms is another example of this, and the two have become linked in an attempt to explain bone remodeling ("Yasuda's hypothesis"). This paper re-examines the roles of endogenous and exogenous electromagnetic fields in the response of bone to mechanical forces. A series of experiments is reviewed in which mechanical and electrical stimuli were applied to implants in the medullary canal of rabbit long bones. The results suggest that endogenously generated electrical currents are not required to initiate mechanically stimulated bone formation, but that direct mechanical effects on bone cells is the more likely scenario. Based on this and other evidence from the literature, it is suggested that when exogenous electromagnetic stimuli are applied, bone cells respond by modulating the activity of more primary activators such as hormones, growth factors, cytokines, and mechanical forces.