• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.5
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• pp.482-485
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• 2016

In this work, a transcranial magnetic stimulation(TMS) experiment on animals is performed to stimulate the brain cortex of the mouse using modulated signals. The proposed TMS system is composed of the inverter, transformer, capacitor, variable inductor, and stimulation coil to generate 1.5 mT magnetic field in the brain cortex of the mouse. The stimulation signal is modulated to square wave where the carrier frequency is swept from 85 to 91 kHz to investigate the stimulation effect. The experimental result shows that when the carrier frequency of the stimulation signal is lower than 89 kHz, the reaction of the mouse does not change while the stimulation signal which has the carrier frequency higher than 89 kHz results in decreasing the threshold of the stimulus for the pressure.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2009.11a
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• pp.183-185
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• 2009

As imaging technology develops, magnetic resonance imaging (MRI) techniques have contributed to the understanding of brain function by providing anatomical structure of the brain and functional imaging related to information processing. Manganese-enhanced MRI (MEMRI) techniques can provide useful information about functions of the nervous system. However, systematic studies regarding information processing of pain have not been conducted. The purpose of this study was to detect brain activation during painful electrical stimulation using MEMRI with high spatial resolution. Male Sprague-Dawley rats (250-300 g) were divided into 3 groups: normal control, sham stimulation, and electric stimulation. Rats were anesthetized with 2.5% isoflurane for surgery. Polyethylene catheter (PE-10) was placed in the external carotid artery to administrate mannitol and MnCl2. The blood brain barrier (BBB) was broken by 20% D-mannitol under anesthesia mixed with urethane and a-chloralose. The hind limb was electrically stimulated with a 2Hz (10V) frequency while MnCl2 was infused. Brain activation induced by electrical stimulation was detected using a 4.7 T MRI. Remarkable signal enhancement was observed in the primary sensory that corresponds to sensory tactile stimulation at the hind limb region. These results suggest that signal enhancement is related to functional activation following electrical stimulation of the peripheral receptive field.

• Progress in Medical Physics
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• v.15 no.3
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• pp.128-133
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• 2004

The fMRI response of the somatosensory cortex was investigated with vibrotactile stimulation. Three different frequencies of 8, 15, or 25 Hz were applied in order to mainly focus on the hemodynamic response of Meissner corpuscles sensitive to frequencies of 5-40 Hz. A closed-system, pneumatically-driven, rubber diaphragm was fabricated that overcame many of the limitations of existing vibrotactile devices and produced robust sensory cortex activation in an fMRI experiment. Increasing frequency vs. activation area was analyzed in terms of signal percent change and number of pixels. Our preliminary results indicated that the distribution of the signal percentage change widened and more activated pixels were obtained with higher frequencies.

• Annals of Clinical Neurophysiology
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• v.1 no.2
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• pp.106-111
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• 1999

Backgroud : The generators of N37 and P37 of posterior tibial nerve somatosensory evoked potential(PTSEP) have not been exactly known. Recently, some reports suggested that P37 and N37 might have different generator. We conducted a study to know the generators of P37 and N37 of PTSEP using gating mechanism. Methods : We evaluated subcortical and cortical somatosensoy evoked potentials(SEPs) in response to posterior tibial nerve stimulation in 3 experimental conditions of foot movement and compared them with PTSEPs in full relaxation of foot. The experimental conditions were: (a) active flexion-extention of stimulated foot, (b) isometric contraction of the stimulated foot, (c) passive flexion-extention of the stimulate foot. We analyzed the latencies and amplitudes of following potentials; P30, N37, P37, and N50. Results : The amplitude of P30 potential did not change during at any paradigms. The amplitudes of P37 and N50 were significantly attenuated in all condition. However, the amplitude of N37 showed no significant change during at any paradigms. Conclusions : These results suggest that the generators of P37 and N37 of PTSEP be different in cortex.

• Journal of Veterinary Clinics
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• v.17 no.2
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• pp.388-394
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• 2000

이 실험은 소형견종에 대한 정상 SEPs의 범위를 알아내기 위해 실시되었다. 임상증 상이 정상인 28두를 대상으로 자극점에서 channel 1 까지의 Pl(LPI), channel 1까지의 Nl (LN1), 자극점에서 channel 2가지의 Pl(TP1), channel 2까지의 N1(TNI)의 절대잠복기와 LP1-TN1` 의 파간잠복기를 알아내기 위해서 실시하였다. 이번 실험에서 LPI, LNI, TPI, TNI의 절대잠복기 (absolute latency)의 평균값은 2.69$\pm$0.31 msec, 4.91$\pm$0.49m/sec, 4.64$\pm$0.39 msec, 5.21$\pm$0.42 msec 띠었다. LP1과 TN1 사이의 파간절대잠복기의 핑균값은 2.52$\pm$7.19 msec 이었다. 측정 치들을 속도로 변환하였을 경우 다음과 같았다. 측, LPI, LNI. Tfl, TNI 그리고 LP1-TN1 에서의 속도의 평균값은 각각 93.11$\pm$ 8.58 m/sec, 50.99$\pm$ 5.36m/sec. 80.18$\pm$ sec, 71.31$\pm$4.79m/sec그리고 49.50$\pm$3.58m/sec 이었고. 71.66m/sec, 37.79m/sec, 65.75m/ sec, 59.33 m/sec, 40.55m/sec 의 최저속도를 초과하였을 때 정상범위로 간주하였다. LPI, LNI, TPI,TN1까지의 절대잠복기와 자극전극에 시 측정전극가지의 거리 사이에는 상관관계가 있었다 LP1, LN1, TP1, TN1의 상관계수는 각각 0.621, 0.494. 0.577,0.618 이었다 요추에서 기록된 SEPs갈은 LP1의 상관계수가 LN1 보다 높았으며 흉추에서 기록된 SEPs값은 TN1의 상관계수가 TP1보다 높았다. LP1과 TN1의 파간잠복기와 channel 1과 2의 거리차이와의 상관계수는 0.571이다. 따라서 LPI, LNI. TPI, TNI그리고 LPI-TNI 들의 최저속도를 이용 하여 척수 손상 여부를 판단할 수 있다고 생각된다.

• Journal of the Korean Society of Physical Medicine
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• v.15 no.1
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• pp.25-32
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• 2020

PURPOSE: This study examined the efficacy of an interferential current (IFC) treatment on the improvement of pain, disability, and quality of life in stroke patients with lumbago. METHODS: A double-blind, randomized clinical trial was conducted on 40 stroke patients with lumbago. The patients were allocated randomly into two groups: the IFC treatment group (n= 20) and the placebo treatment group (n= 20). The IFC group received 30 minutes of IFC treatment on the lumbar region, while the placebo group received IFC treatment but without real electrical stimulation. The intervention was administered five days a week for four weeks. The primary outcomes of pain intensity were measured using a visual analogue scale. The secondary measurements included the Barthel Index, Oswestry Disability Index (ODI), and health-related quality of life (HRQoL). RESULTS: The measurements were conducted before and after the two-week intervention period. Compared to the placebo treatment group, the IFC treatment group showed significantly greater improvement in the pain intensity (p<.05), ODI (p<.05), and SF-36 (p<.05) at the end of the intervention. No significant differences in the Barthel Index were found between the two groups. CONCLUSION: These findings show that an IFC treatment can improve pain, functional ability, and quality of life, highlighting the benefits of somatosensory stimulation from IFC in stroke patients with lumbago.

• Biomedical Science Letters
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• v.11 no.3
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• pp.365-373
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• 2005

The aim of this study was to investigate the alterations in meningeal blood flow by stimulation of trigeminovascular system. An open cranial window was prepared on the right parietal bone of male Sprague-Dawley rats. Trigeminovascular system was stimulated by electrical stimulation of trigeminal ganglion (ETS), somatosensory (whisker) stimulation, or topical applications of capsaicin and neuropeptides including substance P and calcitonin gene-related peptide (CGRP). Neonatal capsaicin pretreatment was performed with subcutaneous administration of capsaicin (50 mg/kg) within the first 24 hours after birth. Changes in regional blood flow of dural artery (rDBF) and pial artery (rPBF) were continuously measured through the cranial window by laser-Doppler flowmetry. Both ETS and capsaicin caused a chain of alterations in rPBF and rDBF responses, i.e., an immediate transient decrease followed by rapid and marked increase in rPBF, which were significantly attenuated not only by pretreatments with L-733,060, a $NK_1$ receptor blocker, $CGRP_{8-37}$, a $CGRP_1$ receptor blocker, and 7-nitroindazole monosodium salt (7-NINA), a neuronal nitric oxide synthase inhibitor but also by neonatal capsaicin treatment. Exogenous neuropeptides including substance P and CGRP increased the meningeal blood flow, which was significantly attenuated not only by pretreatment with L-733,060 and $CGRP_{8-37}$, respectively, but also by pretreatment with 7-NINA. The rPBF response to whisker stimulation was significantly attenuated not only by trigeminovascular system injuries including nasociliary nerve denervation and neonatal capsaicin treatment but also by pretreatments with L-733,060, $CGRP_{8-37}$ and 7-NINA. These results suggest that the stimulation of trigeminovascular system causes prominent alterations in meningeal blood flow, and that neuropeptides as well as nitric oxide in the trigeminovascular system are importantly implicated in the regulation of meningeal blood flow.

• Physical Therapy Korea
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• v.27 no.3
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• pp.191-198
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• 2020

Background: Stroke patients experience multiple dysfunctions that include motor and sensory impairments. Therefore, new intervention methods require a gradational approach depending on functional levels of a stroke patient's activity and should include cognition treatment to allow for a patient's active participation in rehabilitation. Objects: This study investigates the effect of integrated revision of electrical sensory stimulation, which stimulates somatosensory and action observation training, which is synchronized cognition intervention method on stroke patients' functions. Methods: Twenty-one stroke patients were randomized into two groups. The two groups underwent twenty minutes of intervention five times a week for three weeks. This study used an electromyogram to evaluate symmetric muscle activation of lower extremities and muscle onset time when performing sit to stand before and after intervention. A weight-bearing ratio was used to evaluate the weight-bearing of the affected side in a sit to standing. To evaluate sit to stand performance ability, this study performed five timed sit to stand tests. Results: The two groups both showed statistically significant improvement in muscle onset time of lower extremity, static balance ability in a standing position, and sit to stand performance after the intervention (p < 0.05). In addition, the action observation and synchronized electrical sensory stimulation group showed significant improvement in symmetric muscle activation of lower extremities and weight-bearing ratio of the affected side (p < 0.05). Conclusion: action observation and synchronized electrical sensory stimulation (AOT with ESS) can have positive effects on a stroke patient's sit to stand performance, and the intervention method that provides integrated AOT with ESS can be used as new nervous system intervention program.

• Journal of Veterinary Clinics
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• v.19 no.3
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• pp.277-282
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• 2002

This study was designed to evaluate the effects of anesthetics on waveform of SEPs and to authorize possible anesthetic protocol for measurement of the somatosensory evoked potentials (SEPs). Thirteen anesthetic methods were used. The SEPs were recorded on two channels (between the 5th and 6th lumbar vertebra as the channel 1 and between the 11th and 12th thoracic vertebra as the channel 2) following stimulation of posterior tibial nerve. ID analyze SEPs wave, latency and conduction velocity were measured. Among thirteen anesthetic methods, standard SEPs waveforms were observed in dogs anesthetized with following six methods: Acepromazine + Thiepfntal Na + Isoflurane, Acepronazine + Propofol + Isoflurane, Diazepam + Xylazine, Xylazine + Ketamine, Acepromazine + Propofol infusion and Propofol infusion. Above six methods could be used with sufficient anesthetic depth. The differences of latency and conduction velocity among six groups were minimal compared to general waveform of SEPs. These results indicate that the six anesthetic methods can be used for recording SEPs in the dog. In particular, Diazepam + Xylazine and XylaBine + Ketamine as injectable anesthesia are considered more convenient than other four methods in veterinary medicine.

• Journal of Korean Neurosurgical Society
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• v.29 no.8
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• pp.985-994
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• 2000

Objective : There are some advantages of trigeminal evoked potential(TEP) recording compared to other somatosensory evoked potential(SSEP) recordings. The trigeminal sensory pathway has a pure sensory nerve branch, a broader receptive field in cerebral cortex, and a shorter pathway. Despite these advantages, there is little agreement as to what constitutes a normal response and what wave forms truly characterize the intraoperative TEP. This study presents the normative data of TEP recorded on the epidural surface of the rat with a platinum ball electrode. Materials & Methods : Under general anesthesia with urethane, the adult Sprague-Dawley male rats(300-350g) were given electrical stimulation with two stainless steel electrodes which were inserted into the subcutaneous layer of the area around whiskers. A reference electrode was positioned in the temporalis muscle ipsilateral to the recording site. Results : TEPs were recorded in the Par I area of somatosensory cortex and recorded most apparently on the point of 2mm posterior from the bregma and 6mm lateral from the midline. The typical wave form consisted of 5 peaks (N1-P1-N2-P2-N3 according to emerging order, upward negativity). Each latency to corresponding peaks was not influenced by the different intensities of stimulation, especially from 1 to 5mA. Average latencies of 5 peaks were in the following order ; 7.7, 11.1, 15, 22.3, 29.4ms. There was also no significant difference between latencies before and after administration of muscle relaxant(pancuronium). For the electrophysiological localization of recorded waves, the action potential of a single unit was recorded with glass microelectrode(filled with 2M NaCl, $3-5M{\Omega}$) in the thalamus of rat. A sharp wave was recorded in the VPM nucleus, in which the latency was shorter than that of N1. This suggests that all 5 peaks were generated by neural activities in the suprathalamic pathway. Conclusion : In terms of recording near-field potentials, our data also suggests that TEP in the rat may be superior to other SSEPs. In overall, these results may afford normative data for the studies of supratentorial lesions such as hydrocephalus or cerebral ischemia which can have an influence on near-field potentials.