• Journal of Magnetics
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• v.17 no.1
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• pp.27-32
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• 2012

Transcranial magnetic stimulation requires an electric field composed of dozens of V/m to achieve stimulation. The stimulation system is composed of a stimulation coil to form the electric field by charging and discharging a capacitor in order to save energy, thus requiring high-pressure kV. In particular, it is charged and discharged in capacitor to discharge through stimulation coil within a short period of time (hundreds of seconds) to generate current of numerous kA. A pulse-type magnetic field is formed, and eddy currents within the human body are triggered to achieve stimulation. Numerous pulse forms must be generated to initiate eddy currents for stimulating nerves. This study achieved high internal pressure, a high number of repetitions, and rapid switching of elements, and it implemented numerous control techniques via introduction of the half-bridge parallel load method. In addition it applied a quick, accurate, high-efficiency charge/discharge method for transcranial magnetic stimulation to substitute an inexpensive, readily available, commercial frequency condenser for a previously used, expensive, high-frequency condenser. Furthermore, the pulse repetition rate was altered to control energy density, and grafts compact, one-chip processor with simulation to stably control circuit motion and conduct research on motion and output characteristics.

• The Journal of the Korea Contents Association
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• v.10 no.4
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• pp.257-264
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• 2010

Though existent a transcranial magnetic stimulation makes various treatment and diagnostic sine waveform of fixed stimulation pulse, there is limitation. In this research, because strength, pulse width, pulse pattern required in treatment and diagnostic introduce other Cockroft-Walton circuit and half bridge inverter frequency and voltage variable become new device propose wish to. Have more advantages than existing device. First, do not have high voltage transformer. Second, switching loss can be less, and control output energy precisely. Three, stimulation strengths, pulse width, pulse pattern are various. As a result, sought special quality and an experiment that is improved applying inverter and cockroft - Walton circuit is half bridge inverter that do not use transformer.

• The Journal of Korean Physical Therapy
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• v.21 no.4
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• pp.73-79
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• 2009

Purpose: Recently, neurostimulation studies involving manipulation of cortical excitability of the human brain have been increasingly attempted. We investigated whether transcranial direct current stimulation (tDCS) applied to the underlying cerebral cortex, directly induces cortical activation during fMRI scanning. Methods: We recently recruited five healthy subjects without a neurological or psychiatric history and who were right-handed, as verified by the modified Edinburg Handedness Inventory. fMRI was done while constant anodal tDCS was delivered to the underlying SM1 area?? immediately after the pre-stimulation for eighteen minutes. Results: Group analysis yielded an averaged map that showed that the SM1 area and the superior parietal cortex in the ipsilateral hemisphere were activated. The voxel size and peak intensity were, respectively, 82 and 5.22 in the SM1, and 85 and 5.77 in the superior parietal cortex. Conclusion: Cortical activation can be induced by constant anodal tDCS of the underlying motor cortex. This suggests that tDCS may be an effective therapeutic device for enhancing? physical motor function by modulating neural excitability of the motor cortex.

• The Journal of Korean Physical Therapy
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• v.23 no.6
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• pp.49-53
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• 2011

Purpose: The purpose of this study is to investigate whether dual-hemisphere transcranial direct current stimulation (tDCS) could induce more cortical activity, compared to single-hemisphere, using functional MRI (fMRI). Methods: One right-handed healthy subject was recruited. Three phases of dual-hemisphere tDCS (i.e. anodal tDCS over the left-dominant primary sensoriomotor cortex (SM1) and cathodal tDCS over the right-non dominant SM(1) were consecutively delivered on to a subject, during fMRI scanning. The voxel count and the intensity index in the averaged cortical map were analyzed among the three tDCS phases. Results: Our result showed that cortical activation was observed on all the three phases of the dual-hemisphere tDCS. Voxel count and intensity index were as following; 912 and 4.07 in the first phase, 1102 and 3.90 in the second phase, 1031 and 3.80 in the third phase. Conclusion: This study demonstrated that application of the dual-hemisphere tDCS could induce cortical activity and maintain to recruit cortical neurons. Our findings suggested that application of dual-hemisphere tDCS could produce efficiency of the ongoing tDCS effect to facilitate cortical excitability.

• Journal of Magnetics
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• v.19 no.2
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• pp.197-204
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• 2014

A transcranial magnetic stimulation device is a complicated appliance that employs a switching power device designed for discharging and charging a capacitor to more than 1 kV. For a simple transcranial magnetic stimulation device, this study used commercial power and controlled the firing angle using a Triac power device. AC 220V 60 Hz, the power device was used directly on the tanscranial magnetic stimulation device. The power supply device does not require a current limiting resistance in the rectifying device, energy storage capacitor or discharge circuit. To control the output power of the tanscranial magnetic stimulation device, the pulse repetition rate was regulated at 60 Hz. The change trigger of the Triac gate could be varied from $45^{\circ}$ to $135^{\circ}$. The AVR 182 (Zero Cross Detector) Chip and AVR one chip microprocessor could control the gate signal of the Triac precisely. The stimulation frequency of 50 Hz could be implemented when the initial charging voltage Vi was 1,000 V. The amplitude, pulse duration, frequency stimulation, train duration and power consumption was 0.1-2.2T, $250{\sim}300{\mu}s$, 0.1-60 Hz, 1-100 Sec and < 1 kW, respectively. Based on the results of this study, TMS can be an effective method of treating dysfunction and improving function of brain cells in brain damage caused by ischemia.

• Journal of Magnetics
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• v.19 no.2
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• pp.170-173
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• 2014

The purpose of the present study was to investigate the effect of repetitive transcranial magnetic stimulation (rTMS) in conjunction with task oriented training, on cortical excitability and upper extremity function recovery in stroke patients. This study was conducted with 31 subjects who were diagnosed as a hemiparesis by stroke. Participants in the experimental (16 members) and control groups (15 members) received rTMS and sham rTMS, respectively, during a 10 minutes session, five days per week for four weeks, followed by task oriented training during a 30 minutes session, five days per week for four weeks. Motor cortex excitability was performed by motor evoked potential and upper limb function was evaluated by motor function test. Both groups showed a significant increment in motor function test and amplitude, latency in motor evoked potential compared to pre-intervention (p < 0.05). A significant difference in post-training gains for the motor function test, amplitude in motor evoked potential was observed between the experimental group and the control group (p < 0.05). The findings of the current study demonstrated that incorporating rTMS in task oriented training may be beneficial in improving the effects of stroke on upper extremity function recovery.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.4 no.1
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• pp.31-37
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• 1974

The author has studied roentgenographic images of temporomandibular articulation using various conventional roentgenographies. The roentgenographic images have obtained by application of the contrast media on the glenoid fossa and condylar head in a human dry skull. Comparing the various roentgenograms by Modified Transcranial projection, A-P T.M. articulation projection, Reverse Towne projection, Mayer projection and Bregma-Menton projection. The author has drawn following results. 1. The sharp radiogaphic details were obtained by all technics used except the Bregma-Menton projection, which seemed to be impractical to the study of T.M.J. because of to be shortened the image of condylar head. 2. The best image of the condyle-fossa relationship was appeared by Modified Transcranial projection and better image was acquired by Orbito-Ramus projection, but there were all inferior in Reverse Towne projection, Mayer projection and Bregma-Menton projection. 3. In all of the above techniques, the radiographic images of condylar head were clear and were appeared to be the convex type in Modified Transcranial projection, the angled type in Orbito-Ramus and Reverse Towne projection, the flat type in Mayer projection and the distorted angled type in Bregma-Menton projection. 4. The radiographic image of condylar head was shortened in Bregma-Menton projection only and was magnified somewhat in other projection.

• Journal of Magnetics
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• v.20 no.2
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• pp.133-137
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• 2015

This study was conducted to determine the effects of repetitive transcranial magnetic stimulation (rTMS) integrated mirror therapy on the gait of post-stroke patients. Thirty patients who were six months post-stroke were assigned to either the experimental group (n = 15) or the control group (n = 15). Stroke patients in the experimental group underwent rTMS and mirror therapy for the lower limbs, while those in the control group underwent rTMS and sham therapy. Participants in both groups received therapy five days per week for four weeks. A significant difference in post-training gains for the single support phase, step length, stride length and velocity was observed between the experimental group and the control group (p < 0.05). The experimental group showed a significant increment in the single support phase, step length, stride length, swing phase, velocity, cadence, double support phase and step width as compared to pre-intervention (p < 0.05). The control group showed a significant increment in step length, velocity, cadence and step width compared to preintervention (p < 0.05). Further investigation of the availability and feasibility of rTMS integrated mirror therapy for post-stroke patients as a therapeutic approach for gait rehabilitation is warranted.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.11 no.1
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• pp.300-318
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• 1998

Background : The vasoreactivity of cerebral artery is currently the subject of increasing interest. Transcranial Doppler Sonography(TCD) is an accurate method of monitoring the blood flow velocities of the cerebral artery. We wished to assess the vasoreactivity between age-matched normal and cerebral infarction group. Method : We performed TCD findings in 40 normals and 20 cb-inf. subjects who arrived at hospital during 48 hours after attack. The former were devided into twenties normal group and fifties normal group. Result : 1. Fibrinogen levels showed significant changes between age-matched normal and cb-inf. group. 2. $V^{MEAN}$ of the both side Carotid Siphon during rest state increased significantly in cb-inf. group as compared with the age-matched normal group. 3. $V^{MEAN}and\;V^{MAX}$ of the both side carotid siphon during breath-hold state increased significantly in cb-inf. group as compared with the age-matched normal group. 4. Vasoreactivity of cerebral artery increased significantly in cb-inf. group as compared with the age-matched normal group. 5. $V^{MEAN}and\;V^{MAX}$ of the both side Radial artery during heat-stimuration state increased significantly in cb-inf. group as compared with the age-matched normal group. 6. Vasoreactivity of Radial artery increased significantly in cb-inf. group as compared with the age-matched normal group.

• Korean Journal of Clinical Laboratory Science
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• v.42 no.3
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• pp.155-160
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• 2010

Transcranial Doppler ultrasonography (TCD) allows measurement of blood flow velocity to be made from the basal intracerebral vessels. Blood flow velocity in TCD is highly affected not only by blood vessel diameter, blood flow volume, blood viscosity, but also age and sex. Therefore, the study is focused on the correlation between TCD measurement index and sex/age. Subjects were 214 (male 147, famale 67) who had TCD for headache and stroke evaluations at Dongguk University Ilsan Hospital neurology department from December 2009 to April 2010. Sex did not show significant differences with mean flow velocity (MFV), peak systolic flow velocity (PSFV), end diastolic flow velocity (EDFV), pulsatility index (PI) and resistance index (RI) in middle cerebral artery (MCA). Although age also did not show significant differences with MFV and PSFV, EDFV has statistically decreased with age, and PI and RI has statistically increased with age. In addition, age showed significant correlation with MFV, EDFV, PI and RI, but not with PSFV. Therefore, TCD is definitely correlated with age and sex, so that those influencial factors must be considered when being tested.