PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Electromagnetic Fields”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1976

[Changes in the selfexcitation reaction in rats under the effect of modulated electromagnetic field].

The effect of electromagnetic field with various modulation frequencies (2, 7, and 50 hertz) on the reaction of selfstimulation was studied in rats. The frequency of 2 hertz proved to cause a primary increase in the incidence of the selstimulation reaction, followed by its depression; the frequency 7 hertz at first failed to alter the selfstimulation intensity and then led to the gradual reduction of the incidence of the selfstimulation reaction; the frequency of 50 hertz depressed the selfstimulation reaction practically from the very beginning. The changes in the selfstimulation reaction were independent of the localization of the stimulating electrodes, but were determined by the frequency of the EMF modulation.

Animals↗
PubMed1978

[Coagulation properties of the blood and tissues of the cardiovascular system exposed to an electromagnetic field].

The effect of low-frequency electromagnetic field on the coagulant and fibrinolytic properties of blood and tissues of the cardiovascular system was studied. Phase character of changes in the coagulative properties of blood as well as in those of the heart and aorta was established. Irradiation of rats for 8 days is attended by an increase in the coagulating and fibrinolytic activity of blood and simultaneous inhibition of the thromboplastic compounds of the heart and vascular wall. Increase of exposure to 20 days leads to inactivation of tissue and plasma blood coagulation factors. The possible mechanism of these changes is discussed.

Animals↗
PubMed1977

[Hypnogenic action of a modulated electromagnetic field].

Behavioristic and electroencephalographic changes in rats under long-lasting modulated electromagnetic field (frequency of 40 MHz, modulation frequency 50 Hz, intensity 100--120 V/m) were studied. Some phasic disorders in the conditioned feeding and defense reactions were observed, including cataleptic state as a result of the action of modulated electromagnetic field. These behavioristic disorders are determined by the changes in the normal cortico-subcortical relationships.

Animals↗
PubMed1979

[Biological effects of electromagnetic fields (author's transl)].

This résumé deals with thermal and nonthermal effects of electromagnetic fields on man. In consideration of two aspects a limitation is necessary. Firstly, there will be discussed only direct and immediate influences on biological cells and tissues, secondly, the treatment is limited to such phenomena, for which biophysical aproximations, based on experimental data, could be developed. Hazards for the human being may occur only by thermal effects within the microwave range. Regarding frequencies below approximately 30 kHz, excitation processes cannot be excluded in exceptional cases. Thermal effects are predominant, between 30 kHz and 100 kHz, before excitations can appear. Furthermore, by comparing the electrically and magnetically induced currents with the naturally flowing currents in man caused by the brain's and heart's electrical activity, a "lower boundaryline" was estimated. Regarding electric or magnetic field strengths undercutting this boundary-line, direct effects on the central nervous system may be excluded; other mechanisms should be responsible for demonstrated biological effects. The paper closes referring to some reports--presently discussed--on experimental findings of biological effects, which are observed as a result of the influence of electromagnetic fields of small field strengths.

Brain↗
PubMed1976

Electromagnetic field interference and cardiac pacemakers.

The physical and physiological effects of electromagnetic field interference on 440 patients with cardiac pacemakers were determined by reviewing the literature from 1949 to 1973. The sources, mechanisms, and findings of physiological dysfunction and ventricular fibrillation in patients with pacemakers are presented. Shortwave and microwave diathermy and electrical stimulators have been found to have a definite adverse influence on some cardiac pacemakers. The effect of interference may be an increase or decrease in pacemaker rate or rhythm, ventricular fibrillation, a total loss of pacing, or cessation of impulses. Because all pacemaker units are not resistant to interference, no ungrounded electrical equipment and no equipment such as microwave diathermy, short wave diathermy, and electrical stimulators should be placed on, or near, a patient with a cardiac pacemaker.

Diathermy↗
PubMed1978

[The influence of the electromagnetic field on the activity of alkaline phosphatase in immobilised children (author's transl)].

This paper reports the influence of a changing electromagnetic field on the alkaline phosphatase-activity in the sera of immobilised children. The enzyme activity which was considerably reduced in immobilised children, increased significantly after treatment with an electromagnetic field, whereas the acid phosphatase-activity was not changed. A possible influence of the magnetic field on osteoblastic activity is discussed.

Acid Phosphatase↗
PubMed1976

Experimental regeneration in peripheral nerves and the spinal cord in laboratory animals exposed to a pulsed electromagnetic field.

Peripheral nerve section and suture was performed in 132 rats. Postoperatively half the animals were exposed to a pulsed electromagnetic field each day and half were kept as controls. Nerve conduction studies, histology and nerve fibre counts all indicated an increased rate of regeneration in the treated animals. A similar controlled study of spinal cord regeneration following hemicordotomy in cats has been started, and preliminary results indicate that when the animals are sacrificed three months after the hemicordotomy, the pulsed electromagnetic therapy has induced nerve fibre regeneration across the region of the scar.

Animals↗
PubMed1977

A non-operative salvage of surgically-resistant pseudarthroses and non-unions by pulsing electromagnetic fields. A preliminary report.

This report documents, for the first time, to the authors' knowledge, the therapeutic use in humans of low energy, electromagnetic fields pulsing in the extremely low frequency (E.L.F.) range. These fields, established outside the body, were used to treat congenital and acquired pseudarthroses and non-unions. Energy of this type appears to affect biological processes, not through heat production, but through electrically-induced changes in the environment of cells within the organism. Of the 29 patients included in the study, 17 had experienced at least one failure of surgical repair and, in each of these, amputation had been recommended. The overall success rate, including those patients treated with inadequate pulse characteristics and those who failed to follow the protocol, was in excess of 70 per cent. Improvements in the specificity of pulse characteristics hold promise for increasing the rate of success. The simple, clinical methodology, which is conducted on an out-patient basis, appears to be both safe and effective. It can be applied with or without surgery. This approach requires additional controlled investigations before it is ready for general use in the orthopaedic community. The indications for amputation of surgically-resistant pseudarthroses, however, should be reassessed. The principles and technology, which have been established during this endeavor, may have physiologic and practical significance for processes other than pseudarthrosis and non-union.

Adolescent↗
PubMed1976

[Sudden, unexpected death of infants and electromagnetic fields (author's transl)].

The examination of 337 cases of Sudden Infant Death Syndorme (SIDS) ro Crib Deaths in Philadelphia, Penn., USA, and 294 cases in Hamburg, Federal Republic of Germany, shows regional concentrations which are close to uncommon magnetic fields or stray electric currents in the ground. The risk in the cellar and first floor of houses is higher than in the other floors. Therefore a possible causal relationship between electromagnetic fields and SIDS cases must be considered and checked by on-site measurements, animal experiments, and by more research on magnetic fields as stressor for infants.

Age Factors↗
PubMed1978

Effects of electromagnetic fields on the motion of Euglena gracilis.

The orientation behavior of Euglena gracilis cultures in electromagnetic fields is shown to agree with the predictions of a model involving only a passive mechanism. The increase in Euglena motor activity with increasing field intensity is demonstrated by measuring various motion parameters by the laser scattering technique. The effect of electric field on the speed of Euglenas is compared with that of temperature. We conclude that the electric field warms up the culture, thus inducing an increase in cell motility.

Cell Movement↗
PubMedDate not supplied

[Modulated electromagnetic field as a factor of selective influence on animal mechanisms of goal-directed behavior].

Proceeding from P.K. Anokhin's theory of the functional systems, the paper considers the action of a modulated electromagnetic field (MEMF) on different stages of the central architectonics of purposeful behaviour of rats: afferent synthesis, decisions making, acceptor of the action results. The action of MEMF was studied in different experimental situations: choice of an alimentary or defensive reaction to one conditioned stimulus in different situations; extinction of conditioned alimentary reactions; elaboration and extinction of alimentary conditioned reactions in animals group contacts; choice of the side of reinforcement in a T-shaped maze, and, lastly, self-stimulation reactions. The experiments have shown that MEMF has a selective effect on the animals' emotional reactions. Greater disturbances are observed in the mechanisms of the animals' appraisal of the action of situational and trigger stimuli or surrounding individuals of their species and, hence, of decisions making and anticipation of future results of the action, the acceptor of the action results.

Agonistic Behavior↗
PubMed1976

[Behavior of reactive shaft pseudarthroses of the canine radius in the electric and electromagnetic fields].

In 27 beagles, 19 radius shaft pseudarthroses and 8 tibia were stimulated either by directly applied alternating current of low frequency and strength, delivered from an implanted battery source, or by a pulsing electromagnetic field inductively coupled to bone. Increase of periosteal callus was only found beneath parallel sling electrodes placed on pseudarthroses parallel to the radius shaft. Stimulation by transverse electrodes implanted into bone produced no significant increase of osteogenesis and bone healing, evaluated by x-rays, scintigrams, and morphometry when compared with contralateral leg controls.

Animals↗
PubMed1979

Relation between suicide and the electromagnetic field of overhead power lines.

Laboratory studies have shown that electromagnetic fields similar to those from high-voltage transmission lines can produce biological effects. Surveys of the actual effects of such lines on exposed individuals usually have been hampered by complicating factors tending to blur the data. By means of a new approach, however, correlation has been established between the presence of transmission-line fields and the occurrence of suicides in part of the Midlands of England.

Adolescent↗
PubMed2026

The Effect of Pulsed Electromagnetic Field on Pain and Foot Function Index in Patients With Plantar Fasciitis.

The plantar fascia is a thick band of connective tissue that originates from the heel, and its inflammation is the most common cause of heel pain in adults. The Pulsed Electromagnetic Field (PEMF) is a non-invasive modality in the field of physiotherapy. This study aimed to determine the effects of PEMF on pain scores and the Foot Function Index (FFI) in patients with plantar fasciitis (PF). In this clinical trial study, 40 patients with PF, aged between 20 and 68 years, were randomly assigned in a block design into two groups: the Conventional Physiotherapy (CP) group and the CP plus PEMF (CPP) group. The Numerical Pain Rating Scale (NPRS) and the FFI questionnaire were used to assess the pain score (morning and evening pain) and foot function, respectively. Assessments were conducted before the study, at the tenth session of the CP and CPP groups, and 4 weeks later. The study variables in both the CP and CPP groups changed significantly (p&#x2009;<&#x2009;0.05). In comparing the results between the two groups, the reduction in evening pain scores in the CPP group was significant compared to the CP group (p&#x2009;<&#x2009;0.05). In comparison, there was no significant difference in morning pain scores between the two groups. The FFI score in the CPP group significantly decreased compared to the CP group. Both CP and CPP are effective in reducing pain and the FFI in patients with PF. The addition of PEMF to CP demonstrates a more significant effect on reducing evening pain and somewhat on reducing the FFI in patients compared to CP alone. However, it did not have an additional effect on reducing morning pain. Bioelectromagnetics. 00:00-00, 2026. &#xa9; 2026 Bioelectromagnetics Society.

Humans↗