Whi-Young Kim

3 Stage 2 Switch Application for Transcranial Magnetic Stimulation

Transcranial magnetic stimulation utilizes the method of controlling applied time and changing pulse by output pulse through power density control for diagnosis purposes. Transcranial magnetic stimulation can also be used in cases where diagnosis and treatment are difficult since output pulse shape can be changed. As intensity, pulse range, and pulse shape of the stimulation pulse must be changed according to lesion, the existing sine wave-shaped stimulation treatment pulse poses limitations in achieving various treatments and diagnosis. This study actualized a new method of transcranial magnetic stimulation that applies a 3 Stage 2 Switch( power semiconductor 2EA) for controlling pulse repetition rate by achieving numerous switching control of stimulation coil. Intensity, pulse range, and pulse shape of output can be freely changed to transform various treatment pulses in order to overcome limitations in stimulation treatment presented by the previous sine wave pulse shape. The method of freely changing pulse range by using 3 Stage 2 Switch discharge method is proposed. Pulse shape, composed of various pulse ranges, was created by grafting PFN (Pulsed Forming Network) through AVR AT80S8535 one-chip microprocessor technology, and application in transcranial magnetic stimulation was achieved to study the output characteristics of stimulation treatment pulse according to delaying time of the trigger signal applied in section switch.

Chopper Application for Magnetic Stimulation

Since the hypothalamus immediately reacts to a nerve by processing all the information from the human body and the external stimulus being conducted, it performs a significant role in internal secretion; thus, a diverse and rapid stimulus pulse is required. By detecting Zero Detector accurately via the application of AVR on-Chip (ATMEL) using commercial electricity, chopping generates a stimulus pulse to the brain using an IGBT gate to designate a new magnetic stimulation following treatment and diagnosis. To simplify and generate a diverse range of stimuli for the brain, chopping can be used as a free magnetic stimulator. Then, commercial frequency (60㎐) is chopped precisely at the first level of the leakage transformer to deliver an appropriate stimulus pulse towards the hypothalamus when necessary. Discharge becomes stable, and the chopping frequency and duty-ratio provide variety after authorizing a high-pressure chopping voltage at the second level of the magnetic stimulator. These methods have several aims. The first is to apply a variable stimulus pulse via accurate switching frequency control by a voltaic pulse or a pulse repetition rate, according to the diagnostic purpose for a given hypothalamus. Consequently, the efficiency tends to increase. This experiment was conducted at a maximum of 210 W, a magnetic induced amplitude of 0.1~2.5 Tesla, a pulse duration of 200~350 ㎲, magnetic inducement of 5 ㎐, stimulus frequency of 0.1~60 ㎐, and a duration of stimulus train of 1~10 sec.

Changes in Poly ADP Ribose Polymerase Immune Response Cells of Cerebral Ischaemia Induced Rat by Transcranial Magnetic Stimulation of Alternating Current Approach

This study examined effect of a transcranial magnetic stimulation device with a commercial-frequency approach on the neuronal cell death caused ischemia. For a simple transcranial magnetic stimulation device, the experiment was conducted on an ischemia induced rat by transcranial magnetic stimulation of a commercialfrequency approach, controlling the firing angle using a Triac power device. The transcranial magnetic stimulation device was controlled at a voltage of 220 V 60 Hz and the trigger of the Triac gate was varied from 45° up to 135°. Cerebral ischemia was caused by ligating the common carotid artery of male SD rats and reperfusion was performed again to blood after 5 minutes. Protein Expression was examined by Western blotting and the immune response cells reacting to the antibodies of Poly ADP ribose polymerase in the cerebral nerve cells. As a result, for the immune response cells of Poly ADP ribose polymerase related to necrosis, the transcranial magnetic stimulation device suppressed necrosis and had a protective effect on nerve cells. The effect was greatest within 12 hours after ischemia. Therefore, it is believed that in the case of brain damage caused by ischemia, the function of brain cells can be restored and the impairment can be improved by the application of transcranial magnetic stimulation.

The Characteristics on the Change of Cerebral Cortex using Alternating Current Power Application for Transcranial Magnetic Stimulation

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° to 135°. 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, 250~300 μs, 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.

Treatment Pulse Application for Magnetic Stimulation

Treatment and diagnosis can be made in difficult areas simply by changing the output pulse form of the magnetic stimulation device. However, there is a limitation in the range of treatments and diagnoses of a conventional sinusoidal stimulation treatment pulse because the intensity, width, and form of the pulse must be changed according to the lesion type. This paper reports a multidischarge method, where the stimulation coils were driven in sequence via multiple switching control. The limitation of the existing simple sinusoidal pulse form could be overcome by changing the intensity, width, and form of the pulse. In this study, a new sequential discharge method was proposed to freely alter the pulse width. The output characteristics of the stimulation treatment pulse were examined according to the trigger signal delay applied to the switch at each stage by applying a range of superposition pulses to the magnetic simulation device, which is widely used in industry and medicine.

Starting Current Application for Magnetic Stimulation

A power supply for magnetic-stimulation devices was designed via a control algorithm that involved a start current application based on a resonant converter. In this study, a new power supply for magnetic-stimulation devices was designed by controlling the pulse repetition frequency and pulse width. The power density could be controlled using the start-current-compensation and ZCS (zero-current switching) resonant converter. The results revealed a high-repetition-frequency, high-power magnetic-stimulation device. It was found that the stimulation coil current pulse width and that pulse repetition frequency could be controlled within the range of 200-450 µS and 200-900 pps, respectively. The magnetic-stimulation device in this study consisted of a stimulation coil device and a power supply system. The maximum power of the stimulation coil from one discharge was 130 W, which was increased to 260 W using an additional reciprocating discharge. The output voltage was kept stable in a sinusoidal waveform regardless of the load fluctuations by forming voltage and current control using a deadbeat controller without increasing the current rating at the starting time. This paper describes this magnetic-stimulation device to which the start current was applied.

Full Wave Cockroft Walton Application for Transcranial Magnetic Stimulation

A high-voltage power supply has been built for activation of the brain via stimulation using a Full Wave Cockroft-Walton Circuit (FWCW). A resonant half-bridge inverter was applied (with half plus/half minus DC voltage) through a bidirectional power transistor to a magnetic stimulation device with the capability of producing a variety of pulse forms. The energy obtained from the previous stage runs the transformer and FW-CW, and the current pulse coming from the pulse-forming circuit is transmitted to a stimulation coil device. In addition, the residual energy in each circuit will again generate stimulation pulses through the transformer. In particular, the bidirectional device modifies the control mode of the stimulation coil to which the current that exceeds the rated current is applied, consequently controlling the output voltage as a constant current mode. Since a serial resonant half-bridge has less switching loss and is able to reduce parasitic capacitance, a device, which can simultaneously change the charging voltage of the energy-storage condenser and the pulse repetition rate, could be implemented. Image processing of the brain activity was implemented using a graphical user interface (GUI) through a data mining technique (data mining) after measuring the vital signs separated from the frequencies of EEG and ECG spectra obtained from the pulse stimulation using a 90S8535 chip (AMTEL Corporation).

TRANSCRANIAL MAGNETIC STIMULATION WITH APPLIED MULTISTEP DIRECT CURRENT GRAFTING

The controlling method for high-voltage pulse form or pulse parameter is extremely important in high speed switching technique. Function generation can repeatedly make various forms and widths of pulse waves such as low-voltage sine wave, square wave, and sawtooth wave. Waveform control is not easy when voltage exceeds a certain amount of kVs. Pulse forming network (PFN) or pulse forming line (PFL) has been used so far along with trigger gap, rail gap, semiconductor switch, ignitron, cyratron, and autocompression switch, which are used as switching device. For PFN, multistep LC circuit is introduced to widen the pulse width, and for PFL, a method to lengthen the charging line is adopted. These methods are difficult to control because a large number of devices are used, and the devices are getting bigger in terms of size. In order to compensate this weakness, the researchers of this study made self-stimulating pulse forms with various pulse widths by actively engrafting the low-voltage two-step or four-step circuits with the AVR one-chip microprocessor technology, which is widely used for two-step or four-step electric network recently with low price.

AT90s8535D CHIP APPLICATION FOR HEART RATE VARIABILITY DIAGNOSTIC SYSTEMS

By using wireless mobile communications and mobile information terminals, Internet and the linking of computers and information technology to human bodies effectively, mobile computing can play an important role in modern technology that can be used by anybody anytime, anywhere, and can reconsider new technology with physiological measurements and reconstruct it creatively. In particular, mobile computing can intervene in the process of inducing biometric changes before diseased symptoms develop into diseases in an aging society. Nevertheless, there are difficulties, such as data, treatment by many parameters, ambiguity of data standardization and difficulty of the simultaneous collection of data etc. Therefore, in this study, a system was embodied by excluding time limiting factors using mobile computing and selecting the mobile neural dynamic coding method based on bioelectric signals. As a result of the experiment, it could be a model for biomedical Signal Mobile Analysis Devices and mobile biometric measuring devices, whose self-measurement can be made possible by an academic approach. Furthermore, it became the research foundation of the atypical characteristics of the formation of bioelectrical signals based on mobile applications and could be modeled in the structure circuit form of a biosignal.

Processor Application for the Magnetic Stimulation in the Cerebellum of Rat with Ischemia and its Effect on the c-Fos

Instead of relying on traditional medical electrotherapy, we seek to determine a more positive approach to early ischemic brain injury by researching the effect of applying a magnetic stimulation device in an SD mouse’s brain to stop apoptosis, where a 64-Bit-EISC Processor Core delivers transcranial magnetic stimulation (TMS). We determined the change of the post-ischemic stimulatory effects on the Bax, caspase-3, and immune-reactive perikarya over time by stimulating the mouse’s brain. c-Fos and Cox-2 were used to find a crucial determining factor regarding inflammation-related cytotoxicity. The cerebral ischemia caused a biochemical change in the brain tissue and increased the neuronal genes within a few minutes. The genes showed that these very fast reactions involve an early gene. Next, we found an approach that is more favorable than electrotherapy for the apoptosis that is caused by early ischemic brain injury by researching the c-Fos protein that changes largebrain neurons; this was achieved after we stimulated the ischemic mouse brain using a two-tank LLC resonant converter as part of the TMS experimental equipment.