• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.359-359
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• 2002

Brain Stimulator processes both visual and audible stimulus and send them human sensory organ. The stimulus was accepted by our sensory organ effect upon human mental function. In this study, we examine the actual effect of commercial brain stimulator using tMRI system.

• Journal of Biomedical Engineering Research
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• v.28 no.5
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• pp.657-664
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• 2007

Stroke patients need regular medical treatments and rehabilitation training from their doctors. However, severe aftereffects caused by stroke allow them minimum activities, which make it difficult for them to visit doctor. Recently, electric brain stimulation treatment has been found to be better way compared to conventional ones and many are interested in using this method for the treatment of stroke. In this study, we have developed a remote medical treatment system using wireless electric brain stimulator that can help the stroke patients to get a treatment without visiting their doctors. The developed remote medical treatment system connects the doctors to the brain stimulator implanted in the patients via the internet and ZigBee communication built in the brain stimulator. Also, the system receives personal information of the connected patients and cumulates the total records of electric stimulation therapy in a database. Doctors can easily access the information for better treatment planning with the help of graphical visualization tools and management software. The developed remote medical treatment system can be applied to the electric stimulation treatments for other brain diseases with a minor change.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.3
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• pp.514-517
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• 2008

Ubiquitous healthcare (U-healthcare) system is one of potential applications of embedded system. Conventional U-healthcare systems are used in health monitoring or chronic disease care based on measuring and transmission of various vital signs. However, future U-healthcare system can be of benefit to more people such as stroke patients which have limited activity by providing them proper medical care as well as continuous monitoring. Recently, an electric brain stimulation treatments have been found to be a better way compared to conventional ones and many are interested in using the method toward the treatment of stroke. In this study, we proposed a remote medical treatment system using ZigBee-based wireless electric brain stimulator that can help them to get a treatment without visiting their doctors. The developed remote medical treatment system connects the doctors to the brain stimulator implanted in the patients via the internet and ZigBee communication built in the brain stimulator. Also, the system receive personal information of the connected patients and cumulate the total records of electric stimulation therapy in a database. Doctors can easily access the information for better treatment planning with the help of graphical visualization tools and management software. The developed remote medical treatment system can extend their coverage to outdoors being networked with hand-held devices through ZigBee.

• Journal of the Optical Society of Korea
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• v.16 no.2
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• pp.145-150
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• 2012

We present a display-based visual stimulator for psychophysical and electrophysiological visual sensitivity measurements. The stimulator offers various psychophysical visual stimuli and transfers the signals from external devices along with the stimulation signals to an electrophysiological recorder. As an experimental demonstration, we perform a visual sensitivity experiment in the mesopic vision range by using the display-based stimulator. The intensity of the steady-state visual evoked potential is observed to correlate with the luminance of the flickering visual stimulation. For the psychophysically determined detection thresholds, we determine the mesopic luminance, showing agreement with the perceived brightness within the uncertainty of the luminance measurement.

• Proceedings of the KSMRM Conference
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• 2002.11a
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• pp.131-131
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• 2002

목적： 인간의 뇌는 감각기관이 지속적으로 시각적, 청각적 자극을 받음으로 인해 영향을 받는다. 현재 이러한 이론을 실용화하여 몇 가지 상업적인 뇌 자극장치가 개발되어 시판 중이다 본 실험에서는 시중에 판매 중인 뇌 자극장치를 이용하여 실험을 하여 실제 인간의 뇌에 영향을 주는 지를 확인한다.

• The Journal of the Korea Contents Association
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• v.9 no.11
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• pp.289-296
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• 2009

In this study, I presented power control unit with potential use in the magnetic stimulation of biological systems. The effect of the magnetic stimulation depends on the geometry and orientation of the induced electric field as well as on the current pulse waveform delivered by the stimulator coil. TMS is achieved from the outside of the head using pulses of electromagnetic field that induce an electric field in the brain. There are numerous possibities in the applications TMS, such as diagnosis and therapy through the brain stimulation. These factors are very important to define the equipment requirements and characteristics in that the topology of the power supply and the size and geometry of the coil. The proposed solution is the generation of current pulses with variable amplitude and duration, according to a user defined input. Another solution is the topology that uses elements to store and transfer energy from the power source to the load. In addition to proposed topology, an adequate control strategy and right set of the power circuit parameters made possible to obtain unipolar waves and bipolar waves.

• Proceedings of the KIEE Conference
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• 2006.04a
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• pp.33-35
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• 2006

We studied the prototypal developments of Plastic Cortex Stimulator (PCS) for stroke patients. The PC sends the stimulation parameters (amplitude, pulse width, cycle, etc.) to the transmitter ZigBee module through serial port. The receiver ZigBee module generates stimulation waveform. The generated output can be controlled by the PC program. Further study can be expanded to portable handset such as PDA using ZigBee. The wireless control of PCS with the handset can help the tele-rehabilitation.

• Journal of Korean Neurosurgical Society
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• v.54 no.4
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• pp.359-362
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• 2013

Chronic hypoventilation due to injury to the brain stem respiratory center or high cervical cord (above the C3 level) can result in dependence to prolonged mechanical ventilation with tracheostomy, frequent nosocomial pneumonia, and prolonged hospitalization. Diaphragm pacing through electrical stimulation of the phrenic nerve is an established treatment for central hypoventilation syndrome. We performed chronic phrenic nerve stimulation for diaphragm pacing with the spinal cord stimulator for pain control in a quadriplegic patient with central apnea due to complete spinal cord injury at the level of C2 from cervical epidural hematoma. After diaphragmatic pacing, the patient who was completely dependent on the mechanical ventilator could ambulate up to three hours every day without aid of mechanical ventilation during the 12 months of follow-up. Diaphragm pacing through unilateral phrenic nerve stimulation with spinal cord stimulator was feasible in an apneic patient with complete quadriplegia who was completely dependent on mechanical ventilation. Diaphragm pacing with the spinal cord stimulator is feasible and effective for the treatment of the central hypoventilation syndrome.

• Investigative Magnetic Resonance Imaging
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• v.1 no.1
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• pp.114-118
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• 1997

Purpose: Functional MR imaging is the method of demonstrating changes in regional cerebral blood flow produced by sensory, motor, and any other tasks. Functional MR of visual cortex is performed as a patient stares a photic stimulation, so adaptable photic stimulation is necessary. The purpose of this study is to evaluate whether the size of photic stimulator can affect the degree of visual cortex activation. Materials and Methods: Functional MR imaging was performed in 5 volunteers with normal visual acuity. Photic stimulator was made by 39 light-emitting diodes on a plate, operating at 8Hz. The sizes of photic stimulator were full field, half field and focal central field. The MR imager was Siemens 1.5-T Magnetom Vision system, using standard head coil. Functional MRI utilized EPI sequence (TR/TE= 1.0/51. Omsec, matrix $No.=98{\times}128$, slice thickness=8mm) with 3sets of 6 imaging during stimulation and 6 imaging during rest, all 36 scannings were obtained. Activation images were obtained using postprocessing software(statistical analysis by Z-score), and these images were combined with T-1 weighted anatomical images. The activated signals were quantified by numbering the activated pixels, and activation a index was obtained by dividing the pixel number of each stimulator size with the sum of the pixel number of 3 study using 3 kinds of stimulators. The correlation between the activation index and the stimulator size was analysed. Results: Mean increase of signal intensities on the activation area using full field photic stimulator was about 9.6%. The activation index was greatest on full field, second on half field and smallest on focal central field in 4. The index of half field was greater than that of full field in 1. The ranges of activation index were full field 43-73%(mean 55%), half field 22-40 %(mean 32%), and focal central field 5-24%(mean 13%). Conclusion: The degree of visual cortex activation increases with the size of photic stimulator.

• Journal of Radiation Industry
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• v.11 no.3
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• pp.139-144
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• 2017

To evaluation of clinical usefulness for B1+RMS limits, we compared image quality of Routine, Specific absorption rate (SAR) and Root mean square (RMS) protocol. 5 volunteers underwent Magnetic Resonance Imaging (MRI) scan of the brain using three different protocols. We draw Region of interest ROI in cortex, white matter, gray matter, putamen and thalamus of axial plan. Signal to noise ratio (SNR) were evaluated in each area and Contrast to noise ration (CNR) were evaluated between white matter and gray matter. Qualitative evaluation was used to score each ROI. B1+RMS is confirmed its usefulness compared to conventional SAR standard on the aspect of improvement of image quality, reduction of scan time and easy adjusting parameter.