• Journal of Magnetics
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• v.19 no.2
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• pp.161-169
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• 2014

The aim of this study is to investigate the efficacy of pulsed electromagnetic field (PEMF) on the alleviation of lumbar myalgia. This is a randomized, real-sham, double blind pilot study. 38 patients were divided into the PEMF group and the Sham group, each of which was composed of 19 patients (1 patient dropped out in the Sham group) of randomized allocation. The PEMF group was treated by using the PEMF device and the Sham group by using a sham device on the lumbar muscle and acupuncture points, three times a week for a total of two weeks. Evaluations of Visual Analogue Scale for bothersomeness (VASB), Visual Analogue Scale for pain intensity (VASP), Oswestry Disability Index (ODI), 36-Item Short Form Health Survey Instrument (SF-36), EuroQol-5Dimension (EQ-5D), Beck's Depression Inventory (BDI) and Roland-Morris Disability Questionnaire (RMDQ), etc. before and 1 week after treatment were carried out. The primary outcome measure was the VASB, measured 1 week after the end of the pulsed electromagnetic therapy. VASB scores for the PEMF group changed by $-2.06{\pm}2.12$ from the baseline, and that for the Sham group changed by $-0.52{\pm}0.82$ (p < 0.05). VASP scores for the PEMF group were reduced by $-2.10{\pm}2.12$ from the base line, and that for the Sham group was reduced by $-0.53{\pm}1.50$ (p < 0.05). PEMF group showed significant improvements in all VASB, VASP, ODI, SF-36, EQ-5D, BDI and RMDQ scores, while the Sham group showed significant improvements in all scores, except the VASP score. However, the VASB, VASP and RMDQ scores of the PEMF group were much lower than those of the Sham group. The two groups showed no significant difference in ODI, SF-36, EQ-5D and BDI. This study demonstrates the effectiveness of PEMF treatment for alleviating lumbar myalgia.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.29 no.2
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• pp.123-131
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• 2007

Introduction: Distraction osteogenesis is widely used as for bone lengthening in patients with maxillofacial deformity and alveolar bone atrophy. One of the major problems in distraction osteogenesis is long consolidation period for 2-3 months, in which the devices have to be fixed on the bone to prevent relapse. It results in scar formation on the face, disturbance of mastication and speech. This study was performed to evaluate the stimulating effect of pulsed electromagnetic field on the early bone consolidation in distraction osteogenesis. Materials and methods: Total 10 rabbit were used (5 for control group, 5 for experimental group). A vertical osteotomy in the mandibular body was performed and the distraction device was fixed. After 5 days distraction was done 1mm per a day for 7 days. A pulsed electromagnetic field (38 Gauss, 60 Hz) was applied for 8 hours per day and it continued for 5 days immediately after distraction in the experimental group. Both groups were sacrificed after 2 weeks. Histological specimens with H&E and Masson Trichrome staining were made and histomorphometrically analysed with image analyser. Results: The device for distraction osteogenesis was displaced in one animal for each group, therefore, only four animals in both groups were evaluated. In both groups, a new bone formation was observed in the distracted area after 2 weeks. The bone formation was enhanced in the experimental groups ($31.76{\pm}8.68%$) compared with control group ($9.94{\pm}3.23%$), its difference was statistically significant (p<0.001). Conclusion: This study suggests that electrical stimulation with electromagnectic field may be effective in the early bone formation after distraction osteogenesis. Further studies with large number of animals are needed before clinical application.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.2109-2109
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• 2011

High power microwave sources operating in relativistic regions, high current reletivistic electron beams are obtained by using cold cathodes with the help of explosive emission. For these relativistic devices, the pulsed power and magnetic field systems are very large and heavy. The phase velocity of electromagnetic mode should be showed down close to the beam velocity, ensuring enough beam coupling with electromagnetic modes. By using the annular electron beam, a weakly relativistic oversized bwo consisting of rectangularly corrugated cylindrical waveguide is demonstrated.

• Nuclear Engineering and Technology
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• v.48 no.1
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• pp.189-199
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• 2016

Fast neutrons with a broad energy spectrum, with which it is possible to evaluate nuclear data for various research fields such as medical applications and the development of fusion reactors, can be generated by irradiating proton beams on target materials such as beryllium. To generate short-pulse proton beam, we adopted a deflector and slit system. In a simple deflector with slit system, most of the proton beam is blocked by the slit, especially when the beam pulse width is short. Therefore, the available beam current is very low, which results in low neutron flux. In this study, we proposed beam modulation using a buncher cavity to increase the available beam current. The ideal field pattern for the buncher cavity is sawtooth. To make the field pattern similar to a sawtooth waveform, a multiharmonic buncher was adopted. The design process for the multiharmonic buncher includes a beam dynamics calculation and three-dimensional electromagnetic simulation. In addition to the system design for pulsed proton generation, a test bench with a microwave ion source is under preparation to test the performance of the system. The design study results concerning the pulsed proton beam generation and the test bench preparation with some preliminary test results are presented in this paper.

• Proceedings of the Korean Magnestics Society Conference
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• 2008.12a
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• pp.251.1-251.1
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• 2008

• 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 Society for Nondestructive Testing
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• v.31 no.6
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• pp.609-615
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• 2011

Excitation and propagation of electromagnetic field of a cylindrical coil above an arbitrary number of conductive plates for pulsed eddy current testing(PECT) are very complex problems due to their complicated physical properties. In this paper, analytical modeling of PECT is established by Fourier series based on truncated region eigenfunction expansion(TREE) method for a single air-cored coil above stratified conductive structures(SCS) to investigate their integrity. From the presented expression of PECT, the coil impedance due to SCS is calculated based on analytical approach using the generalized reflection coefficient in series form. Then the multilayered structures manufactured by non-ferromagnetic (STS301L) and ferromagnetic materials (SS400) are investigated by the developed PECT model. Good prediction of analytical model of PECT not only contributes to the development of an efficient solver but also can be applied to optimize the conditions of experimental setup in PECT.

• 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.

• The Korean Journal of Pain
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• v.29 no.1
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• pp.3-11
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• 2016

A nerve block is an effective tool for diagnostic and therapeutic methods. If a diagnostic nerve block is successful for pain relief and the subsequent therapeutic nerve block is effective for only a limited duration, the next step that should be considered is a nerve ablation or modulation. The nerve ablation causes iatrogenic neural degeneration aiming only for sensory or sympathetic denervation without motor deficits. Nerve ablation produces the interruption of axonal continuity, degeneration of nerve fibers distal to the lesion (Wallerian degeneration), and the eventual death of axotomized neurons. The nerve ablation methods currently available for resection/removal of innervation are performed by either chemical or thermal ablation. Meanwhile, the nerve modulation method for interruption of innervation is performed using an electromagnetic field of pulsed radiofrequency. According to Sunderland's classification, it is first and foremost suggested that current neural ablations produce third degree peripheral nerve injury (PNI) to the myelin, axon, and endoneurium without any disruption of the fascicular arrangement, perineurium, and epineurium. The merit of Sunderland's third degree PNI is to produce a reversible injury. However, its shortcoming is the recurrence of pain and the necessity of repeated ablative procedures. The molecular mechanisms related to axonal regeneration after injury include cross-talk between axons and glial cells, neurotrophic factors, extracellular matrix molecules, and their receptors. It is essential to establish a safe, long-standing denervation method without any complications in future practices based on the mechanisms of nerve degeneration as well as following regeneration.

• 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.