• Title, Summary, Keyword: pulsed electromagnetic fields

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Coaxial Marx Type Pulse Generator for UWB EM Pulse (UWB 펄스전자파 발생용 원통형 Marx 펄스발생장치개발)

  • Chang, Yong-Moo;Lee, Sang-Wook
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.121-121
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    • 2010
  • As the industrial technology is getting higher, the pulsed power technology is required from various fields such as thermonuclear fusion energy sources, military applications, electric power distribution, and a variety of new specialized needs. This technology deals with the generation of very high power electromagnetic pulses through fast switching. We fabricated a pulsed power generator, named EMD pulse generator, by using Marx circuit with 200 kV high, 50 ns fast rise time. In this paper, we described about an effect of stray capacitance of coaxial Marx generator, EPG-AM200k, and a comparing the results of experiments and circuit analysis.

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Study of Defect Prevention on Weld Zone of Magnesium Alloy by Pulse Control of Nd:YAG Laser (Nd:YAG 레이저의 펄스 제어에 의한 마그네슘 합금 용접부의 결함 방지에 관한 연구)

  • Kim, Jong-Do;Lee, Jung-Han;Kim, Jang-Soo
    • Journal of the Korean Society for Precision Engineering
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    • v.27 no.1
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    • pp.99-104
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    • 2010
  • Magnesium and magnesium alloys, the lightest structural materials, have been received plenty of global attention recently. These alloys could be applied in various fields, especially the electronics industry, because of their excellent electromagnetic interference shielding. However, the welding technique of magnesium alloys has not been established. This study is related to the welding of AZ31B magnesium alloy by a short-pulsed a Nd:YAG laser. Two types of pulse waves, square pulse and variable pulse, were used to control weld defects. Results show that the crack and porosity, generated in the weld, had not been controlled by general square pulse. But through the application of variable pulse, the defects could be prevented and the good weld zone was obtained.

THE EFFECT OF PULSED ELECTROMAGNETIC FIELDS ON ${\beta}$-TCP GRAFT IN RABBIT CRANIAL BONE DEFECT (가토 두개골 결손부에 이식된 ${\beta}$-TCP의 골치유과정에서 맥동전자기장의 영향에 관한 연구)

  • Kim, Sang-Woo;Hwang, Kyung-Gyun;Lim, Byung-Sup;Park, Chang-Joo;Chung, Il-Hyuk;Paik, Seung-Sam;Shim, Kwang-Sup
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.32 no.4
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    • pp.360-373
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    • 2006
  • The purpose of this research was to investigate whether pulsed electromagnetic field (PEMF) stimulation applied to the rabbit cranial defects grafted with ${\beta}$-tricalcium phosphate (${\beta}$-TCP) could affect the new bone formation. With 16 New Zealand white rabbits under the same condition, bilateral calvarial bone defects were formed around the sagittal suture line. The defect on the left side was grafted with ${\beta}$-TCP, while on the right side was grafted by harvested autogenous bone. PEMF was applied to 8 rabbits for 8 hours per day. The bony specimen were divided into 3 groups, the group 1 was autogenous bone grafted specimen, the group 2 was ${\beta}$-TCP grafted with PEMF, and the group 3 was ${\beta}$-TCP grafted without PEMF. We investigated the bone regeneration & growth factor expression at 2, 4, 6, and 8 weeks. As a result, BMP 2 was expressed in the group 1 from 2 weeks, the group 2 from 4 weeks, and the group 3 from 6 weeks. BMP 4 was expressed in the group 1 from 2 weeks, in the group 2 and the group 3 from 4 weeks. 4. There was no significant difference in expression pattern of BMP 7, PDGF, VEGF, and TGF-${\beta}$1 during grafted bone regeneration in group 1, 2, and 3. According to our results, PEMF stimulation could be effective on the new bome formation in animal study, and have a feasibility of clinical use.

Analysis of Pupil Size Variability for Effectiveness Verification of Activation Level of Autonomic Nerve System by Electromagnetic Acupuncture System (자화침 시스템의 자율신경계 활성화 효과 검증을 위한 동공크기변이 분석)

  • Liu, Wenxue;Lee, Na-Ra;Choi, Woo-Hyuk;Kim, Soo-Byeong;Lee, Young-Heum;Shin, Tae-Min
    • Korean Journal of Acupuncture
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    • v.29 no.4
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    • pp.554-562
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    • 2012
  • Objectives : The purpose of this research is to verify the effects of the Electromagnetic acupuncture(EMA) on BL15 by Pupil size variability(PSV) which is directly related to the activation of the Autonomic Nervous System. Methods : Thirty male subjects participated in this study and were divided into three groups(non-stimulated, manual acupuncture and EMA group). The size of pupil was measured in the cube place of $60{\times}60{\times}60$ cm in order to avoid the effect of the surrounding circumstances. All subjects were measured the size of left pupil about 200sec in the constant illumination. Results : We observed the decrease in PSV of manual acupuncture group compared to non-stimulation group, but it was not significant statistically(p>0.05). The decrease in PSV of EMA group was observed in comparison to two groups, and we confirmed the result of significant difference statistically(p<0.05). Conclusions : We concluded that EMA treatment method is enough to activate in the parasympathetic nerve system by inducing the biotransformation.

The Analysis of the Muscle Fatigue Recovery Effect on LR9 by Compound Stimulation of the PEMFs and LED (음포혈(陰包, LR9)에서 펄스형 전자기장 및 가시광 LED 복합 자극이 대퇴부 근피로 회복에 미치는 영향 분석)

  • Lee, Na-Ra;Kim, Jung-Yoon;Park, Sun-Woo;Kim, Soo-Byeong;Lee, Hee-Young;Ahn, Soon-Jae;Kim, Young-Ho;Lee, Yong-Heum
    • 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.

Effect of Pulse Magnetic Field Stimulus on Blood Flow using Digital Infrared Thermal Imaging (체열진단을 통한 펄스자기장 자극기의 혈류개선효과 고찰)

  • Lee, Hyun-Sook
    • Journal of the Korean Magnetics Society
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    • v.21 no.5
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    • pp.180-184
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    • 2011
  • The changes in the blood flow in the peripheral vascular system under strong pulsed magnetic fields (pMF) were studied by digital infrared thermal imaging (DITI). After pMF stimulus temperatures in stimulated area were commonly increased in both groups of age and gender. In order to reduce heat generated from coil in pMF stimulus system plastic moldings were fabricated, so that certain distance was kept between stimulus system and the skin and to prevent direct contact to the skin. It is believed that skin temperature is increased by internal electromagnetic energy stimulated the peripheral vascular system by non-contact method.

Evaluation of Muscle Fatigue Recovery Effect and Meridian Potential Change using Magnetic Acupuncture System (자화침 시스템을 이용한 경락전위 유발효과 및 근피로 회복 평가)

  • Kim, Soo-Byeong;Park, Sun-Woo;Ahn, Soon-Jae;Lee, Na-Ra;Lee, Seung-Wook;Min, Se-Eun;Kim, Young-Ho;Lee, Yong-Heum
    • Korean Journal of Acupuncture
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    • v.29 no.1
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    • pp.83-92
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    • 2012
  • Objectives : The purpose of this research was to develop the magnetic acupuncture system which used solenoid coil for magnetizing acupuncture needle. The system could generate the meridian electric potential (MEP) similar to the potential by manual acupuncture. Thus, we tried to confirm the therapeutic effect that is caused by the MEP generation. Methods : To confirm the MEP, we stimulated the magnetic acupuncture with at 2Hz, $92.7{\pm}2mT$, PEMFs (Pulsed Electro-Magnetic Fields) at ST37 and measured the evoked potential between ST36 and ST41. Also, we conducted a fatigue recovery test using isokinetic exercise in order to identify the therapeutic effect on musculoskeletal disorders. We chose LR9 as a stimulation point. To observe the state of fatigue, we measured the EMG and analyzed median frequency and peak torque for 20minutes. Results : We observed that MEP which incurred from magnetic acupuncture was higher than he reported MEP induced by manual acupuncture. Moreover, its modes were divided into two types by the direction of magnetic flux. When generating magnetic flux in the direction of acupoint, the positive peak voltage of the MEP was generated. In contrast, negative peak voltage of the MEP was generated whenever meganetic flux generated in the outward direction. As a result of fatigue recovery, the median frequency (MF) of the magnetic acupuncture group were recovered faster than that of the non-stimulation group. However, the peak torques of both groups were not restored until after 20 minutes. Conclusions : We confirmed that the magnetic acupuncture system can lead to the MEP similar to manual acupuncture. Moreover, the MEP had a therapeutic effect on the musculoskeletal disorders.

Effects of electromagnetic stimulation on neurogenesis and neuronal proliferation in rat hippocampal slice culture (실험 쥐 해마조직배양에서 전자기 자극이 신경조직발생 및 증식에 미치는 영향)

  • Kim, Deok-Soo;Choi, Eung Sang;Chae, Soo Ahn
    • Korean Journal of Pediatrics
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    • v.49 no.5
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    • pp.558-564
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    • 2006
  • Purpose : Transcranial electromagnetic stimulation(TMS) is a noninvasive method which stimulates the central nervous system through pulsed magnetic fields without direct effect on the neurons. Although the neurobiologic mechanisms of magnetic stimulation are unknown, the effects on the brain are variable according to the diverse stimulation protocols. This study aims to observe the effect of the magnetic stimulation with two different stimulation methods on the cultured hippocampal slices. Methods : We obtained brains from 8-days-old Spague-Dawley rats and dissected the hippocampal tissue under the microscope. Then we chopped the tissue into 450 µm thickness slices and cultured the hippocampal tissue by Stoppini's method. We divided the inserts, which contained five healthy cultured hippocampal slices respectively, into magnetic stimulation groups and a control group. To compare the different effects according to the frequency of magnetic stimulation, stimulation was done every three days from five days in vitro at 0.67 Hz in the low stimulation group and at 50 Hz in the high stimulation group. After N-methyl-D-aspartate exposure to the hippocampal slices at 14 days in vitro, magnetic stimulation was done every three days in one and was not done in another group. To evaluate the neuronal activity after magnetic stimulation, the $NeuN/{\beta}$-actin ratio was calculated after western blotting in each group. Results : The expression of NeuN in the magnetic stimulation group was stronger than that of the control group, especially in the high frequency stimulation group. After N-methyl-D-aspartate exposure to hippocampal slices, the expression of NeuN in the magnetic stimulation group was similar to that of the control group, whereas the expression in the magnetic non-stimulation group was lower than that of the control group. Conclusion : We suggest that magnetic stimulation increases the neuronal activity in cultured hippocamal slices, in proportion to the stimulating frequency, and has a neuroprotective effect on neuronal damage.