• Journal of Biomedical Engineering Research
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• v.43 no.1
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• pp.11-18
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• 2022

An electromagnetic generator with variable stimulation parameters is required to conduct basic research on magnetic flux density and frequency for pulsed electromagnetic fields (PEMFs). In this study, we design an electromagnetic generator that can conduct basic research by providing parameters optimized for cell and animal experimental conditions through adjustable stimulation parameters. The magnetic core was selected as a solenoid capable of uniform and stable electromagnetic stimulation. The solenoid was designed in consideration of the experimental mouse and cell culture dish insertion. A voltage and current adjustable power supply for variable magnetic flux density was designed. The system was designed to be adjustable in frequency and pulse width and to enable 3-channel output. The reliability of the system and solenoid was evaluated through magnetic flux density, frequency, and pulse width measurements. The measured magnetic flux density was expressed as an image and qualitatively observed. Based on the acquired image, the stimulation area according to the magnetic flux density decrease rate was extracted. The PEMF frequency and pulse width error rates were presented as mean ± SD, and were confirmed to be 0.0928 ± 0.0934% and 0.529 ± 0.527%, respectively. The magnetic flux density decreased as the distance from the center of the solenoid increased, and decreased sharply from 60 mm or more. The length of the magnetic stimulation area according to the degree of magnetic flux density decrease was obtained through the magnetic flux density image. A PEMF generator and stimulation parameter control system suitable for cell and animal models were designed, and system reliability was evaluated.

• Journal of Biomedical Engineering Research
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• v.42 no.1
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• pp.25-30
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• 2021

Objective: The aim of this study is to consider the effect of skin tissue necrosis by improving blood flow in animal skin models for low frequency pulsed electromagnetic fields (LF_PEMF) stimulation. Methods: Twenty rats (Wistar EPM-1 male, 280-320 g) were randomly divided into control groups (n=10) and the PEMF groups (n=10). To induce necrosis of the skin tissue, skin flap was treated in the back of the rat, followed by isolation film and skin flap suturing. Subsequently, the degree of necrosis of the skin tissue was observed for 7 days. The control group did not perform any stimulation after the procedure. For the PEMF group, LF_PEMF (1 Hz, 10 mT) was stimulated in the skin flap area, for 30 minutes a day and 7 days. Cross-polarization images were acquired at the site and skin tissue necrosis patterns were analyzed. Results: In the control group, skin tissue necrosis progressed rapidly over time. In the PEMF group, skin tissue necrosis was slower than the control group. In particular, no further skin tissue necrosis progress on the day 6. Over time, a statistically significant difference from the continuous necrosis progression pattern in the control group was identified (p<0.05). Conclusions: It was confirmed that low frequency pulsed electromagnetic fields (LF_PEMF) stimulation can induce relaxation of skin tissue necrosis.

• Journal of Magnetics
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• v.18 no.1
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• pp.14-20
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• 2013

For the treatment of osteoarthritis, pulsed electromagnetic field stimulus has been suggested as a useful therapeutic method in rehabilitative medicine. Most studies have been performed under low-frequency and low-energy to find out biological properties for stimulating chondrocyte with pulsed magnetic field. In this study, the effect of strong pulse magnetic field on the human chondrosarcoma cells (SW-1353) has been investigated by means of cell counting, morphologies, and gene expression of cartilage extracellular matrix genes. The SW-1353 cells were exposed under the field intensities of 270, 100, 55, 36, and 26 mTesla during 6 hours a day in 5 consecutive days. The pulse magnetic field with an LRC oscillating signal has the pulse width of 0.126 msec and stimulation period of 1 sec. For the 270 and 100 mTesla stimulation, the cell proliferation significantly increased in 21-24% as compared with the non-stimulated cells. Gene expression of cartilage extracellular matrix genes (ACAN, COMP and COL2A1) was assayed by quantitative real time-PCR method. The ACAN gene expression showed a significant brightness, which means the increase on gene expression, compared with the non-stimulated cells. Our results suggest that the strong pulse magnetic field stimulation can be utilized to accelerate cell proliferation and gene expression on human chondrosarcoma cells.

• Journal of Korean Neurosurgical Society
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• v.64 no.4
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• pp.486-494
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• 2021

The growth of pulsed electromagnetic field (PEMF) therapy and its progress over the years for use in post-operative bone growth has been revolutionary in its effect on bone tissue proliferation and vascular flow. However, further progress in PEMF therapy has been difficult due to lack of more evidence-based understanding of its mechanism of action. Our objective was to review the current understanding of bone growth physiology, the mechanism of PEMF therapy action along with its application in spinal surgery and associated outcomes. The authors of this review examined multiple controlled, comparative, and cohort studies to compare fusion rates of patients undergoing PEMF stimulation. Examining spinal fusion rates, a rounded comparison of post-fusion outcomes with and without bone stimulator was performed. Results showed that postoperative spinal surgery PEMF stimulation had higher rates of fusion than control groups. Though PEMF therapy was proven more effective, multiple factors contributed to difficulty in patient compliance for use. Extended timeframe of treatment and cost of treatment were the main obstacles to full compliance. This review showed that PEMF therapy presented an increased rate of recovery in patients, supporting the use of these devices as an effective post-surgical aid. Given the recent advances in the development of PEMF devices, affordability and access will be much easier suited to the patient population, allowing for more readily available treatment options.

• Journal of Biomedical Engineering Research
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• v.42 no.5
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• pp.211-224
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• 2021

Purpose: The purpose of this study is to present a way to alleviate motion sickness(MS) by stimulating acupoint through PEMFs, and to assess the effectiveness of PEMFs against stimulation previously used to stimulate acupoint using biosignal evaluations and surveys. Materials and Methods: Thirteen healthy men participated in the experiment. MS was induced in the participants, and MS relief stimulation was applied for 30 minutes. There were 4 types of MS relief stimulation, and Sham, Reliefband, Transcutaneous electrical nerve stimulation(TENS), and Pulsed electromagnetic fields stimulation(PEMFs) were used. The biosignals were measured during 30 minutes of applying MS relief stimulation, and the symptoms of MS were evaluated through a questionnaire survey. The measured biosignals are Electrocardiogram(ECG), Electrodermal activity(EDA), Respiration, Skin temperature(SKT), and Electrogastrogram(EGG). A one-way ANOVA test was performed for the rate of change by stimulation for MS relief over time. Results: Participants who were stimulated had a sharp decrease in MS symptoms. Biosignals were analyzed to evaluate autonomic nervous system activity, and the parasympathetic nervous system could be activated through stimulation. Conclusion: TENS and PEMFs were more effective in relieving MS symptoms than Reliefband. It is believed that PEMFs will be effective in consideration of the comfort of participants to be applied to actual vehicles, and studies to further verify the effects of PEMFs on MS should be conducted.

• Korean Journal of Acupuncture
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• v.28 no.3
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• pp.13-23
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• 2011

Objectives : The aim of this study was to develop the combined medical stimulus system consisted of the PEMFs (Pulsed electromagnetic fields) and LED which are able to stimulate local point such as acupoints and trigger points. Methods : To evaluate the therapeutic effect on the musculoskeletal disorders and the possibility of alternative method on manual acupuncture, we compared the fatigue recovery of two groups by analyzing the EMG and peak torque (non-stimulation and, stimulation group) after strenuous knee exercise. We chose the LR9 as a stimulation point. Results : The median frequency (MF) and fatigue index (F.I) of the stimulation group were recovered faster than those of the non-stimulation group. Also the peak torques of both groups were not restored until after 20 minutes. However, the peak torque of the stimulation group was regained higher than that of the non-stimulation group. Conclusions : We confirmed that the proposed combined stimulus system had useful effects as treatment instrument of musculoskeletal disorder using non-invasive method of PEMFs and LED.

• Journal of Biomedical Engineering Research
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• v.44 no.6
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• pp.443-449
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• 2023

The purpose of this study was to observe cell death in human keratinocytes stimulated against the infectious cytokines TNF-α and IFN-γ, and to observe the expression of Phospho-NF-κB due to phosphorylation of IkB to confirm the mechanism of inhibiting the expression of inflammatory cytokines. As a result of cell viability analysis, differences in PEMF stimulation time were observed little by little after 1 hour, 3 hours, 6 hours, 12 hours, 24 hours, and 48 hours, but there was no statistical significance according to PEMF stimulation time for each time (p>0.05). No significant difference was observed in the total amount of NF-κB present in the cytoplasm and nucleus, but a significant decrease in the expression of phosphorylated NF-κB was observed in the group exposed to PEMF stimulation for 24 hours (^*p<0.05). The expression of IL-1β was observed in all inflammation-induced groups, and the concentration of IL-1β compared to α-Tubulin expression was reduced by about 54% in the PEMF-stimulated group for 24 hours compared to the control group (^***p<0.001). As a result of the study, it is shown that PEMF stimulation does not negatively affect HaCaT cells from 0 to 48 hours and can inhibit the expression of inflammatory cytokines by inhibiting the pathway of NF-κB.

• The korean journal of orthodontics
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• v.20 no.3 s.32
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• pp.499-517
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• 1990

Electrical stimulation among several factors that influence bone remodeling has been studied by many investigators with great enthusiasm in orthodontic field. The action mechanisms of Pulsed Electromagnetic Field (PEMF) are different from those of the conventional electrode application method in that PEMF induces endogenous current in the living tissues. PEMF is known to have the healing effect in nonunion of bone and osteoporosis. It is widely used in orthopaedic scopes and the possibility of using the method in clinical orthodontics Is also conceivable. But the exact mechanisms by which the PEMF exerts its effects are not clearly understood. Therefore, the author wanted to see the effect of PEMF on five groups of rat calvarial cells obtained by sequential enzyme digestion method, and observed the changes in enzyme activation, collagen synthesis and $^3H-thymidine$ incorporation. The results were as follows: 1. Under the effect of PEMF, there were no changes in the alkaline phosphatase activity in five groups of cell populations. 2. Both the PEMF group and the PTH with PEMF group shelved no changes in acid phosphatase activities and there were no differences between two experimental groups. 3. Under the effect of PEMF, there was significant increase of collagen synthesis in the group V cell population. 4. Under the effect of PEMF, there were significant increases of $^3H-thymidine$ incorporation in the group IV and V cell populations.

• Medical Lasers
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• v.10 no.1
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• pp.15-21
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• 2021

As technology advances at a rapid rate, innovations in regenerative medicine will eventually include the use of energy-based therapeutics, such as low intensity-pulsed ultrasound stimulation (LIPUs), pulsed electromagnetic field stimulation (PMFs), and low-level laser/light therapy (LLLt) or photobiomodulation therapy (PBMt). Among these treatments, LLLt/PBMt attracted significant attention by the turn of the century, as evidenced by the numerous publications compared to LIPUs and PMFs, particularly for augmented bone regeneration (ABR). This is a testament of how the maturation of technology and scientific knowledge leads to latent compounded applications, even when the value of a technique is reliant on empirical data. This article reviews some of the notable investigations using LLLt/PBMt for bone regeneration published in the past decade, focusing on how this type of therapy has been utilized together with the existing regenerative medicine landscape.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.38 no.4
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• pp.195-203
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• 2012

Dental implants using titanium have greatly advanced through the improvement of designs and surface treatments. Nonetheless, the anatomical limits and physiological changes of the patient are still regarded as obstacles in increasing the success rate of implants further, even with the enhancement of implant products. So there have been many efforts to overcome these limits. The intrinsic potential for bone regeneration can be stimulated through adjuvant treatments with the continuous improvement of implant properties, and this can play an important role in achieving optimum osseointegration toward peripheral bone tissue and securing ultimate long-term implant stability in standard surgical procedures. For this purpose, various chemical, biological, or biophysical measures were developed such as bone grafts, materials, pharmacological agents, growth factors, and bone formation proteins. The biophysical stimulation of bone union includes non-invasive and safe methods. In the beginning, it was developed as a method to enhance the healing of fractures, but later evolved into Pulsed Electromagnetic Field, Low-Intensity Pulsed Ultrasound, and Low-Level Laser Therapy. Their beneficial effects were confirmed in many studies. This study sought to examine bone-implant union and its latest trend as well as the biophysical stimulation method to enhance the union. In particular, this study suggested the enhancement of the function of cells and tissues under a disadvantageous bone metabolism environment through such adjunctive stimulation. This study is expected to serve as a treatment guideline for implant-bone union under unfavorable circumstances caused by systemic diseases hampering bone metabolism or the host environment.