• 대한의용생체공학회:의공학회지
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• 제43권1호
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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 electromagnetic engineering and science
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• 제18권1호
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• pp.70-72
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• 2018

We propose a microwave signal generation system for brain stimulation. The existing brain stimulation system uses a signal of several tens of kHz, and the magnetic field distribution is wide. Microwave is used to locally limit the distribution of the electromagnetic field and to change the action potential of the cell with less power. The switch modulates the microwave signal to obtain a pulse envelope. The action potential of the cell can be controlled to the excitation/inhibition state by adjusting the repetition frequency. These results are confirmed by measuring the cell potential of the mouse brain.

• 대한의용생체공학회:의공학회지
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• 제42권1호
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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.

• 한국전자파학회논문지
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• 제27권5호
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• pp.482-485
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• 2016

본 논문에서는 쥐 뇌의 감각 피질을 자극하기 위해 변조신호를 이용하여 경두개 자기자극(TMS) 동물실험을 수행하였다. 제안한 TMS 시스템은 인버터, 변압기, 커패시터, 가변 인덕터, 자극 코일로 구성되어 쥐 뇌의 감각피질에 약 1.5 mT의 자기장이 생기도록 시스템을 설계하였다. 자극 신호는 구형파 변조되었으며, 반송 주파수는 85~91 kHz의 범위로 변화시키며, 자극 효과를 관찰하였다. 자극 결과 반송 주파수가 89 kHz 미만일 때에는 자극의 효과를 볼 수 없었고, 반송 주파수가 89 kHz 이상일 때에는 압력 자극에 반응하는 역치 값이 낮아지는 효과를 볼 수 있었다.

• 한국정보통신학회논문지
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• 제13권7호
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• pp.1399-1410
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• 2009

통증을 치료하기 위한 방법으로 약물요법, 신경차단법, 외과적 수술 등이 있으며, 대체물리요법으로 침구치료, 초음파, 전기 치료, 자기장 치료 등이 응용되고 있다. 이중 전기치료 요법이 많이 이용되고 있으나, 피부나 피하조직의 임피던스에 큰 영향을 받으며, 주로 경피자극이 주된 방법으로 효과가 매우 확률론적이다. 본 연구에서는 집속형 자기장을 이용하여 경혈이나 치료점에 대한 국소 부위를 비침습적으로 자극 할 수 있는 새로운 시스템을 개발하였다. 수기자극과 유사한 자극을 유도할 수 있는 새로운 자기장 침 전극(자기장 자극의 효율성을 고려하여 새로운 형태)을 설계하였다. 개발된 시스템의 임상적 유효성 및 신뢰성을 평가하기 위하여 수기자극과 자기장 자극에 대한 경락전위변화를 측정하여 비교하였다. 실험 결과 자기장 자극 시 수기자극을 할 때 나타나는 충전 방전 형태의 전위변화와 유사한 경락전위변화가 측정되었으며, 자극방식, 세기, 빈도를 조절함에 따라 다양한 반응특성이 나타남을 확인하였다. 또한, 전자기장 자극에 의해 경락전위변화를 유도할 수 있어 이를 이용한 새로운 경혈자극 및 통증치료기로써의 가능성을 확인하였다.

• 대한의용생체공학회:의공학회지
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• 제42권5호
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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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• 제28권3호
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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.

• 대한전기학회논문지:시스템및제어부문D
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• 제55권2호
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• pp.82-89
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• 2006

The electroencephalogram generated by light stimulation in human body of dark adaption state was measured and analyzed in the cases that electromagnetic wave was put in and not put in, respectively. Shieldroom being able to interrupt the light and the electromagnetic wave of outer was constructed, and the experimental system being able to apply any light and any electromagnetic wave was designed. When the electromagnetic wave was applied to body or not, the variation characteristics of each component in the electroencephalogram were i3s follows. The 6 wave was increased and the $\alpha$ wave and the $\beta$ wave were decreased in the case that the electromagnetic wave was applied, and the variation range of the $\Theta$ wave was small. And the influence of electromagnetic wave on human body was that the appearance time of the $\beta$ wave was late, and it moaned that the time of visual recognition was delayed.

• Clinical and Experimental Pediatrics
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• 제49권5호
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• pp.558-564
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• 2006

목 적 : 경뇌 전자기 자극법은 변조 자기장을 이용하여 뇌세포에 대한 직접적인 영향을 주지 않으면서 중추 신경계를 자극할 수 있는 비침습적인 방법이다. 이전의 연구들은 대부분 생체 동물을 대상으로 수행되어져 왔으며 배양 조직에서의 연구는 별로 이루어진 바 없다. 이에 본 연구에서는 배양된 해마 절편에서 다른 주파수의 전자기 자극이 신경원에 미치는 영향과 약물에 의한 세포 손상 후 전자기 자극의 세포보호효과 여부에 대해 알아보고자 하였다. 방 법 : 생후 8일된 실험쥐의 대뇌를 적출하여 dissection microscope 하에서 양쪽 해마 부위를 분리하고 tissue chopper를 이용하여 $450{\mu}M$ 두께로 절편을 만든 후 Stoppini가 고안한 방법대로 배양을 시행하였다. 각각 5개의 건강한 해마 절편이 포함된 inserts를 선택하고, 전자기 자극군에 대해 0.67 Hz와 50 Hz의 주파수로 각각 배양 5일부터 3일 간격으로 6차례 전자기 자극을 가하였다. 또한, 배양 제 14일에 inserts 2개에 $100{\mu}M$ NMDA에 노출시키고 3일 후부터 3일 간격으로 insert 1개에 전자기 자극을 3차례 시행하였고 다른 1개의 insert와 대조군에는 자극을 가하지 않았다. 결 과 : 전자기 자극 후 신경원의 활성도를 알아보기 위해 NeuN 단백 발현을 western blotting을 이용하여 측정한 후 ${\beta}$-actin 단백 발현과의 비를 얻어 각 군에서 비교 분석하였다. 대조군($1.01{\pm}0.27$)에 비해 전자기 자극군에서 NeuN의 발현이 증가되어 있었으며, 특히 저주파 자극군($1.12{\pm}0.14$)에서보다 고주파 자극군($1.27{\pm}0.17$)에서 현저하였고 고주파 자극군에서는 대조군에 비해 통계적으로 유의한 증가를 보였다(P<0.05). 또한, NMDA 노출 후 실험군(전자기 자극군 : $1.15{\pm}0.27$, 전자기 비자극군 : $0.92{\pm}0.09$)에서 대조군($1.26{\pm}0.04$)에 비해 NeuN 발현이 감소되었으나 전자기 비자극군에서 더 많이 감소한 것을 알 수 있었다. 결 론 : 배양된 해마조직의 신경세포에 대한 전자기 자극은 저주파 자극군에 비해 고주파 자극군에서 대조군보다 통계적으로 유의한 수준의 NeuN 발현의 증가를 관찰할 수 있었고, NMDA 노출 후 전자기 자극을 가한 군에서 대조군보다 NeuN 발현 감소가 관찰되기는 하였으나 고주파 자극군에서는 통계적으로 유의하지 않은 정도였던 것으로 보아 전자기 자극이 신경원 활성을 증가시켜 신경세포의 발생 및 증식을 유도하며 세포 손상에 대한 신경보호효과도 보인다는 것을 알 수 있었다. 따라서 전자기 자극은 여러 신경 질환에 있어서 치료적 역할을 할 수 있는 가능성이 있다고 사료된다.

• Journal of Magnetics
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• 제18권1호
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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.