High-intensity Electromagnetic Field Research Articles

Evaluation of the efficacy of the combination of high intensity electromagnetic field and radiofrequency in promoting lipolysis

Introduction: The organization of skeletal muscle is complex, structured in distinct layers. This organization allows skeletal muscles to respond to electrical stimuli with precise and coordinated contractions. Muscle contraction occurs through responses to electrical stimuli sent by the brain to the motor neurons in the muscle fiber, these stimuli can also be induced by technologies, one of which is the high intensity electromagnetic field, also known as the HIFEM current, leading to contractions considered to be supramaximal that cannot be achieved with normal contraction, resulting in muscle hypertrophy. Objective: This study aims to analyze the results of the combination of these technologies to reduce adipose tissue. Methods: This is a clinical, observational, cross-sectional study investigating the effectiveness of the combination of high-intensity electromagnetic field and radiofrequency technologies. The sample consisted of 6 volunteers. Conclusion: It is concluded that the combination of muscle contraction and radiofrequency technologies represents an innovative approach to fat burning, combining the efficiency of lipolysis promoted by muscle energy demand with the thermal effect of radiofrequency, reducing the thickness of the fat layer by 19.53%.

Permittivity Model Selection Based on Size and Quantum-Size Effects in Gold Films

The article is focused on optical properties of nanostructures containing spherical gold nanoparticles of various radii. We explore correlation between the particle radius and the choice of permittivity model applied to describe optical absorption spectra of gold granules. The experiments show splitting of the absorption band of granular gold films to form a second absorption peak. The first peak is associated with the phenomenon of plasmon resonance, while the second one reflects quantum hybridization of energy levels in gold. Quantum effects are shown to prevail over size effects at a granule diameter of about 5-6 nm. The Mie theory gives a rigorous solution for the scattered electromagnetic field on a sphere taking into account optical properties of the latter, however, it does not specify the criteria for selecting a model to calculate dielectric permittivity. Both calculations and experiments confirm the limiting diameter of gold nanoparticles where the Hampe-Shklyarevsky model is applied. Meanwhile, this model is still unable to predict the splitting of the plasma absorption band. The data presented in the article can be used for a predetermined local field enhancement in composite media consisting of a biolayer and metal nanoparticles. The conducted research provides a deeper understanding of the influence of a terahertz high-intensity electromagnetic field localized in the space on quantum dots.

Clinical Outcome of specific therapy using high intensity electromagnetic field in Patients with Carpal Tunnel Syndrome

Background: Carpal tunnel syndrome(CTS) is a compressive mononeuropathy affecting approximately 3-6% of the adult population, having a strong physical, psychological, and economic impact on the patient. The high intensity electromagnetic field applied with Super Inductive System (SIS) therapy has effects on pain relief, myorelaxation or miostimulation. The objective of this study is to assess the clinical outcome of patients with CTS after SIS therapy. Material and method: An observational prospective study was conducted between 2021-2022 on a cohort of 56 patients admitted to the Balneal and Rehabilitation Techirghiol Sanatorium for 2 weeks, with specific symptoms of CTS. The patients underwent treatment for two weeks at the sanatorium, receiving three SIS therapy sessions per week with the BTL-6000 device, and also other daily physical therapies. Results: There was a statistically significant difference in the proportion of patients who experienced pain and paresthesia before treatment and the proportion of patients who experienced the same symptoms after treatment p<0.05 respectively p<0.01. Conclusion: The high intensity electromagnetic field using SIS therapy has been proven to be effective and safe in treating patients with CTS, bringing important benefits to patients by relieving pain, and paraesthesia, and improving the quality of life of patients.

Thermal Effects of Electromagnetic Energy on Skin in Contact with Metal: A Numerical Analysis

It has been well recognized that interactions between electromagnetic fields and metals are very strong. The consequence of human tissue in contact with metal, when subjected to an alternating electromagnetic field, is an increase in tissue temperature, which results from metals absorbing the energy obtained through induction. However, the electromagnetic induction characteristics and tissue energy absorbed caused by various electromagnetic field exposure conditions have not been well understood. A computational model was developed and employed in this study to assess the temporal and spatial temperature increases in skin due to contact with a highly conductive metallic plate while subjected to a high-intensity electromagnetic field. The effects of plate material, plate thickness, coil distance, and exposure time on temperature increase in the skin were computationally investigated. The electromagnetic and temperature distributions in skin layers during exposure to electromagnetic fields were achieved using models of electromagnetic wave propagation and an unsteady bioheat transfer. The modeling approach used indicates that the plate thickness, plate material, coil distance, and exposure time have a significant impact on the temperature change in the skin. The most important parameter was found to be the metal type. Iron has the greatest effect on skin temperature increase when subjected to external electromagnetic induction. These results allow the researchers to estimate more precisely the exposure limits for induction coils.

Focusing light with a metal film coated patchy particle.

Microsphere-assisted super-resolution imaging is a promising technique that can significantly enhance the resolution of conventional optical microscopes. The focus of a classical microsphere is called photonic nanojet, which is a symmetric high-intensity electromagnetic field. Recently, patchy microspheres have been reported to have superior imaging performance than pristine microspheres, and coating microspheres with metal films leads to the formation of photonic hooks, which can enhance the imaging contrast of microspheres. Understanding the influence of metal patches on the near-field focusing of patchy particles is important for the rational design of a nanostructured microlens. In this work, we theoretically and experimentally showed that the light waves can be focused and engineered using patchy particles. When coating dielectric particles with Ag films, light beams with a hook-like structure or S-shaped structure can be generated. Simulation results show that the waveguide ability of metal films and the geometric asymmetry of patchy particles cause the formation of S-shaped light beams. Compared with classical photonic hooks, S-shaped photonic hooks have a longer effective length and a smaller beam waist at far-field region. Experiments were also carried out to demonstrate the generation of classical and S-shaped photonic hooks from patchy microspheres.

Improved Coil Design for Magnetic Pulse Welding of Metallic Sheets

Magnetic pulse welding of overlapping dissimilar metallic sheets is an emerging technique and usually employs flat electromagnetic coils with rectangular-, H-, I-, and E-shaped cross-sections. The asymmetric cross-section of these coils results in a non-uniform electromagnetic field and in a non-uniform connection in the interface between the overlapping sheets. In this article, the use of a novel O-shaped flat coil is proposed to join an aluminium flyer sheet with a target steel sheet. A finite element-based numerical model is developed to calculate the electromagnetic field, flyer velocity, and its gradual impact onto the target, and the deformations of the sheet assembly. The calculated results with the O-shaped coil show a high-intensity electromagnetic field, the concentration of which decreases radially outwards in a uniform manner. The numerically computed and experimentally measured flyer velocity are found to be in fair agreement. The calculated results show a regularly decreasing impact behaviour between the flyer and target and their resulting deformation. The measured results show the formation of an annular ring-shaped joint profile that is generally found to be stronger compared to that obtained with flat coils with a rectangular cross-section.

Muscle Stimulation for Aesthetic Body Shaping: A Comprehensive and Critical Review.

Aesthetic muscle stimulation (AMS) using high-intensity electromagnetic field (HIFEM) targets skeletal muscle neurons, causing muscle hypertrophy and loss of adipose tissue, thereby cultivating a sculpted physique. Many studies have evaluated AMS for noninvasive body contouring; however, the efficacy, safety, and long-term data remain unclear. To critically evaluate the current literature on the use of electromagnetic muscle stimulation for body contouring and provide a consensus on patient selection and long-term efficacy of AMS. PubMed and Embase were searched using the terms: "HIFEM," "Electromagnetic therapy," and "muscle" or "Electrical stimulation muscle treatments" and "aesthetics." Studies involving the use of muscle stimulation for nonaesthetic/dermatologic, in vitro studies or studies involving animals were excluded. Twenty studies in total were included [9 moderate-quality, 8 low-quality, and 3 very low‒quality studies] based on the Grading of Recommendations, Assessment, Development, and Evaluation scale, representing 521 patients. Body sites evaluated included the abdomen (378 patients), buttock (156 patients), arms (22 patients), and calves (15 patients). Electromagnetic muscle stimulation represents an effective therapeutic intervention for abdominal contouring that yields increased muscle thickness, and reduced abdominal fat thickness, for up to 1 year after treatment. Larger, controlled studies are needed to determine the efficacy of electromagnetic muscle stimulation alone for contouring of buttocks, thighs, arms, and calves.

Experience in the Use of Physical Factors in the Rehabilitation of Patients after Pneumonia Associated with COVID-19

To date, a new coronavirus disease caused by the SARS-CoV-2 virus (also known as COVID-19) has become a serious public health problem worldwide. Unfortunately, there are no specific drugs for the treatment of this infection until now. It is known that COVID-19 is caused by the SARS-CoV-2 betacoronavirus, which mainly affects the cells of the respiratory and digestive systems. There are scientific data on the effectiveness of a number of physiotherapy methods for a new coronavirus infection, which justifies their inclusion in the complex rehabilitation within the in-patient stage. Aim. This work aimed at the scientific justification of the physical factors use in the rehabilitation programs of patients after pneumonia associated with COVID-19. Material and methods. 60 patients (40 women and 20 men) who had suffered from COVID-19 pneumonia were examined. The time from the onset of the disease was on average 2 months. The study involved patients with mild and moderate pneumonia. The patients were randomly divided into 2 groups. The first group (30 patients) received low-intensity magnetic therapy for the chest area, infrared laser therapy for the lung roots, chest massage, therapeutic gymnastics and a course of hyperbaric oxygenation. The second group (30 patients) received high-intensity magnetic stimulation of the respiratory muscles, infrared laser therapy on the lung roots, chest massage, therapeutic gymnastics and a course of hyperbaric oxygenation. Results. As a result of the conducted rehabilitation programs, there was an improvement in the well-being of patients in both groups.There was a decrease in shortness of breath, an increase in physical activity, a decrease and disappearance of pain in the chest area. This was confirmed by a significant reliable dynamics of the 6-minute walk test and the laser Doppler flowmetry parameters and spirometry. Positive dynamics in the C — reactive protein parameter and a tendency to improve the D –dimer parameter were revealed. The changes in the studied parameters were more significant in patients of the second group. Conclusion. Thus, analyzing the results obtained, it can be argued that the developed comprehensive treatment programs for patients who have suffered pneumonia associated with COVID-19 lead to clinical improvement in this category of patients. However, more significant changes in the studied parameters were noted in the group of patients that received a comprehensive program that included a high-intensity electromagnetic field.

Generalized model for the charge transport properties of dressed quantum Hall systems

We present a generalized mathematical model for predicting the transport properties of a quantum system exposed to a stationary magnetic field and a high-intensity electromagnetic field. The new formulation, which applies to two-dimensional (2D) dressed quantum Hall systems, is based on Landau quantization theory and the Floquet-Drude conductivity approach. We model our system as a two-dimensional electron gas (2DEG) that interacts with two external fields. To analyze the strong light coupling with the 2DEG, we employ the Floquet theory as a nonperturbative procedure. Moreover, the Floquet-Fermi golden rule is adopted to explore the impurity scattering effects on charge transport in disordered quantum Hall systems. We derive fully analytical expressions to describe longitudinal components in the conductivity tensor in dressed quantum Hall systems. Subsequently, we demonstrate that the conductivity characteristics of quantum Hall systems can be manipulated using strong external light. Our results align with well-established and experimentally verified theoretical descriptions for undressed systems while providing a more generalized analysis of the conductivity characteristics in quantum Hall systems. Thus our model can be applied to accurately interpret the usage of strong external radiation as a tool in nanoscale quantum devices.

Short time effects of a low-frequency, high intensity magnetic field in the treatment of chronic neck and low back pain.

IntroductionNeck and back pain afflicts millions of people. Magnetotherapy has shown to have anti-inflammatory effects that could act on pain generation, but the literature lacks provide a precise therapeutic protocol.MethodsA high-intensity electromagnetic field with a dedicated applicator was administered to 38 patients with low-back pain and 30 patients with neck pain. The device provides 60 mT and a frequency of 50 Hz for 30 minutes, the session was repeated 4 times.ResultsThe mean VAS of the low-back pain group decreased from 6.56 to 4.54, with a significant reduction of 30.8%. The mean VAS of the neck pain group decreased from 6.51 to 1.96, with a significant reduction of 69.9%.DiscussionThe treatment used showed good results in both groups of the patient, without side effects. The therapeutic protocol adopted is safe, provide rapid relief from the pain and is not time demanding. This treatment could represent an effective non-pharmacologic physical therapy option in the treatment of low-back pain and cervical pain.

Compressing magnetic field into a high-intensity electromagnetic field with a relativistic flying mirror

Ultrahigh electromagnetic fields (≥~1023 W cm−2) are necessary for the study of strong-field quantum electrodynamics (QED). In this study, for the first time, we propose the compression of a pre-seeding static magnetic field with a relativistic flying mirror to generate a high electromagnetic field. The produced field intensity can be further amplified to be 5 × 1023 W cm−2 owing to the multiple reflections between the flying mirror and a stationary solid target; this produced field intensity is approximately four orders of magnitude larger than that of the seeding field and far exceeds that of the driver laser field (9.6 × 1022 W cm−2). Therefore, the ultrahigh electromagnetic field can significantly facilitate strong-field QED effects such as high-energy gamma photon emission. An analytical theory is developed to self-consistently describe the motion of the flying mirror and the field amplification. The predications from the theory are well demonstrated by numerical simulations. The scheme of producing high-intensity electromagnetic fields proposed in this letter provides a new, powerful means to study strong-field QED with a relatively low laser intensity.

The application of high intensity and low intensity magnetotherapy in rehabilitation of patients with COVID-19 - a randomized controlled pilot study.

Background: rehabilitation of patients after severe pneumonia associated with the new coronavirus infection requires the searching for effective tools to restore impaired functions, including methods of hardware physiotherapy.
 Aims: to evaluate the effectiveness of the application of high-intensity electromagnetic field (HIEF) in rehabilitation of patients after pneumonia associated with COVID-19.
 Materials and methods: 40 patients were examined and treated at the outpatient stage of rehabilitation after severe pneumonia associated with COVID-19. All patients received a set of rehabilitation measures, including daily sessions of therapeutic exercises (No. 15) and magnetotherapy procedures (No. 15). Patients were randomly separated into 2 groups - 20 patients in the treatment group (TG) who received HIEF therapy (BTL-6000 Super Inductive System) and 20 patients in the control group (CG) who received low-intensity magnetotherapy (BTL-4000 Premium device).
 Results: during the course of therapy, there were no patients who dropped out of the study, and no undesirable side effects and complications were identified. The high clinical effectiveness of the complex of rehabilitation measures has been proven, more pronounced in the group of patients receiving HIEF therapy. The results were confirmed by reliable dynamics of clinical indicators according to the valid questionnaire and positive changes in spirometry data.
 Conclusions: application of high-intensity electromagnetic field (HIEF) is advisable in complex outpatient rehabilitation of patients after severe pneumonia associated with COVID-19 .
 Keywords: COVID-19, pneumonia, magnetotherapy, high-intensity electromagnetic field, physical and rehabilitation medicine.

Application of Spectral Pyrometry Under Conditions of Intense Microwave Electromagnetic Fields

The paper discusses practical application of spectral pyrometry for controlling the temperature of a dielectric object subjected to heating in a high-intensity microwave electromagnetic field. The authors describe the advantages of using spectral versus color and brightness pyrometry when measuring high temperatures (500°C and above). To eliminate a negative impact of the electromagnetic field on a fiber-optic cable, which is exposed to thermal radiation from a microwave field-heated object and may fail in case of overheating, it is proposed to place a below-cutoff waveguide inside instead of outside of the microwave heating chamber. It is shown that such solution completely eliminates the negative impact of the electromagnetic field on the fiber-optic cable and allows positioning the receiving end of the cable in close proximity to the heated object. A calculation of geometric parameters of the below-cutoff waveguide is provided given the operating frequency of the electromagnetic field of 2450 MHz.

Effectiveness of repetitive magnetic stimulation in improving upper extremity function in post-stroke hemiparesis – A case report

Upper extremity (UE) motor deficits lead to significant disability and dependence in individuals, poststroke. Intense physiotherapy has found to be beneficial in restoring the UE function. Repetitive Magnetic Stimulation (rPMS) is a novel therapeutic modality which aids in the rehabilitation of stroke patients. It utilizes high-intensity electromagnetic field to stimulate neuromuscular tissue which is found to be beneficial in pain management and other effects such as fracture healing, myostimulation, joint mobilization and spasticity reduction. The rPMS have found to decrease spasticity and bring about muscle balance by relaxing spastic muscles and stimulating antagonistic muscles respectively. Although rPMSis widely used all over the world, literature on the Indian population is lacking. This case report is the first from India which describes the beneficial effects of rPMS in UE rehabilitation of a post-stroke individual using BTL- 6000 Super Inductive System. Keywords: Repetitive magnetic stimulation, Upper limb rehabilitation, Stroke hemiparesis, Super inductive system, Spasticity.

High-temperature spectral thermometry in conditions of intense microwave electromagnetic fields

In this paper, a practical application variant of the high-temperature spectral thermometry method for controlling the temperature of a dielectric object heated in a high-intensity microwave electromagnetic field is proposed. The advantages of using the spectral pyrometry method over the methods of color and brightness pyrometry when registering high temperatures (from 500 °C and above) are described. The optical fiber cable used in this method, which receives thermal radiation from an object heated in the microwave field, is subject to the negative influence of the electromagnetic field, which leads to its unacceptable heating and failure. To eliminate this phenomenon, a non-standard use of an cutoff waveguide placed not outside, but inside the microwave heating chamber is proposed. It is shown that this solution completely eliminates the negative influence of the electromagnetic field on the fiber optic cable and allows placing the receiving end of the cable in close proximity to the object being heated. The calculation of geometric parameters of the cutoff waveguide for the operating frequency of the electromagnetic field of 2450 MHz is given.

Radiated and guided optical waves of a magnetic dipole-nanofiber system

Nanophotonics–photonic structures with subwavelength features–allow accessing high intensity and localized electromagnetic field and hence is an ideal platform for investigating and exploiting strong lightmatter interaction. In particular, such a strong light-matter interaction requires investigating the interaction of a magnetic dipole with the electromagnetic field– a less-explored topic, which has usually been ignored within the framework of electric dipole approximation. Motivated by recent advances in the emerging field of multipolar nanophotonics, here we develop an analytical model that provides a new insight into analyzing a magnetic dipole and a nanofiber. This method enables us to examine the effect of second term in the multipolar expansion of light-matter interaction, magnetic dipole approximation, with individual guided and radiation modes of the nanofiber. This is a critical key in developing nanophotonic integrated devices based on magnetic nature of light for super-imaging, biosensing, and optical computing.

Analysis of the Effects of High-Voltage Transmission Line on Human Stress and Attention Through Electroencephalography (EEG)

Knowing the variable-frequency, high-intensity electromagnetic field plays an important role in the humans’ surroundings, numerous studies have been carried out on stress and attention based on EEG data. In this study, a comparison was drawn between the brain waves of individuals living near high-voltage transmission towers and those of people living outside of these zones. The levels of stress and attention were also assessed based on the brain activity of the participants. First, a general questionnaire is completed by the volunteers, and the predisposed samples are included in the research following the screening process. Two 10-member groups (average age of 27 years) of adult males were selected for the research. In one of the groups, the participants are not exposed to high-voltage electric fields. The homes of the members of the second group are located beneath or near high-voltage transmission towers (at a maximum distance of 20 m). Using a 14-channel EEG system, the brain waves of each participant were recorded 5 times over 2 days in the eyes-open resting state while the participants were looking at a white screen. (Ten records of data were obtained per person.) The saliva samples of each participant were also obtained to assess the basal cortisol hormone. The mean EEG stress and attention indices were obtained based on the data on each person, and the mean cortisol level of each group was compared to that of the other group. The investigation and comparison results proved that the mean EEG attention indices of people exposed to high-voltage electric fields were lower than those of the ordinary people. On the other hand, the mean levels of basal EEG stress and salivary cortisol hormone were higher in the people exposed to high-voltage electric fields than the ordinary people. Given the variations of the mean indices of stress and attention in the EEGs and salivary samples of the participants as a result, self-efficacy decreases over time.

High-frequency, high-intensity electromagnetic field effects on Saccharomyces cerevisiae conversion yields and growth rates in a reverberant environment

Studies of the effects of electromagnetic waves on Saccharomyces cerevisiae emphasize the need to develop instrumented experimental systems ensuring a characterization of the exposition level to enable unambiguous assessment of their potential effects on living organisms. A bioreactor constituted with two separate compartments has been designed. The main element (75% of total volume) supporting all measurement and control systems (temperature, pH, agitation, and aeration) is placed outside the exposure room whereas the secondary element is exposed to irradiation. Measurements of the medium dielectric properties allow the determination of the electromagnetic field at any point inside the irradiated part of the reactor and are consistent with numerical simulations. In these conditions, the growth rate of Saccharomyces cerevisiae and the ethanol yield in aerobic conditions are not significantly modified when submitted to an electromagnetic field of 900 and 2400 MHz with an average exposition of 6.11 V.m−1 and 3.44 V.m−1 respectively.

ИССЛЕДОВАНИЕ ВЛИЯНИЯ ЭЛЕКТРОМАГНИТНОГО ПОЛЯ ВЫСОКОЙ НАПРЯЖЕННОСТИ НА ПЛАМЯ

Background Development of a fundamentally new method of preventing and fighting fires is of current concern. It should be noted that by now no universal method is found to fight fires of different categories. Aims and Objectives Study of the impact of high-intensity electromagnetic field on flame. Methods A developed experimental unit consists of a high voltage generator with special electrodes, and a source of burning between them. Electromagnetic field generated between the electrodes affects the flame of the source of burning. A series of experiments was conducted with variation of parameters the shape of the electrodes, the voltage and the distance between the electrodes, the current strength, and flame resistance. Conclusion It was determined that the flame placed in a high intensity electromagnetic field (over 1 kV) extinguishes. Before the point of extinguishing, the flame deviates toward the negative electrode. Results of the study can serve the basis for new experiments, where a full-scale site of ignition may be used instead of the flame of the source of burning. An experimental electric fire extinguisher can be designed on the basis of results of conducted tests.

High-intensity pulsed electromagnetic field induces the differentiation of neural stem cells from neonatal rats into neurons in vitro

Objective To Investigate the influence of high-intensity pulsed electromagnetic field (HIPEMF) on neural differentiation of neonatal rats neural stem cells in vitro.Methods Neural stem cells (NSCs) were isolated from the subventricular zone of 3-day-old neonatal rats and cultured with serum-free condition medium for 14 days.All the NSCs were then randomly classified into an experimental group which received the stimulation of HIPEMF (0.1 Hz,4 T,8 pulses) and a control group which received no special intervention.Differentiation of the culture was induced by addition of 10％ fetal bovine serum on the first day after intervention,the morphological changes of cells were observed under the microscope at different time points.The NSCs adhered to the wall and differentiated for seven days,the immunofluorescence was employed to observed and calculate the ratio of differentiated cells with astrocyte marker GFAP or neuronal markers TUJ1.RT-PCR and western blotting were used to measure the expression levels of the differentiated cells based on gene and protein levels,respectively.Results Immunofluorescence staining showed the number of TUJI positive cells in the experimental group(33.4％ ± 5.1％)was significantly more than the control group (26.5％ ± 7.0％),while the number of GFAP positive cells was decreased(23.9％ ± 5.0％) as compared with the control group(36.2％ ± 2.2％).RT-PCR showed that the TUJ1 mRNA expression levels in the experimental group was (1.682 ± 0.086) times of the control group.Western blot showed that the expression of TUJ1 (0.729 ±0.061) in the experimental group was higher than in the control group (0.590 ± 0.157),while the expression of GFAP in the experimental group (0.566 ± 0.056) was less than in the control group(1.034 ± 0.051).Conclusions HIPEMF facilitates differentiation of neural stem cells to neurons,at the cost of reducing astrocytic differentiation. Key words: Neural stem cells; High-intensity pulsed electromagnetic field; Differentiation; Neuron