• Proceedings of the IEEK Conference
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(5)
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• pp.129-132
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• 2002

In this paper, we describe a millimeter-wave radiation system developed for stimulating acupuncture points, and an analyzing system developed for monitoring the change of physiological signals after the stimulation such as ECG, skin temperature, skin potential and skin resistance. The systems are to be used to investigate the treatment efficacy and biological effects of the millimeter-wave, and eventually, can be used to study the acupuncture meridian system theory in the traditional Korean medicine.

• KSBB Journal
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• 제27권5호
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• pp.273-280
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• 2012

Graphene is a one-atom-thick sheet composed of carbon atoms only. It has a two-dimensional honeycomb structure with $sp^2$ orbital bonding, which presents some unique properties. Due to large Young's modulus, good electrical conductivity, ability to immobilize several kinds of small molecules and proteins, and biocompatibility of graphene, it has attracted interests inits ability to enhance cell growth and differentiation, followed by recent several studies. We reviewed about the osteogenic differentiation of mesenchymal stem cells, and neurogenic differentiation of neuron stem cells, and the ectodermal and mesodermal differentiation of induced pluripotent stem cells using graphene. Graphene has not only enhanced the adhesion and proliferation of mesenchymal stem cells, but also led to the faster differentiation even without any other exogenous signals. Nonetheless, graphene has some cytotoxicities in its amount-response manner, which is critical to regenerative medicine. The cytotoxicities of graphene were compared with those of grapheneoxide and carbon nanotubes.

• Journal of Biomedical Engineering Research
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• 제17권2호
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• pp.209-214
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• 1996

The display of biological signals in raster scan monitors often involves a multirate sampling operation which consists of decimation .and interpolation. All electroencephalouaphic (EEG) samples of 10 to 30 seconds (2, 500 to 7, 500 samples at 250[Hz] sampling frequency) must be displayed in the computer screen to keep the aspect ratio of the paper polygraph output. Since the current afrorclable display technology Plots at most 2, 000 Pixels Per row, sDme signal samples need to be discarde4 This Paper studies methods to perform this operation characterizing them from the signal processing viewpoint and compares the display quality among several decimation techniques. Experimental results show that a nonlinear operation such as the peak detection method could be preferable to the canonical linear filtering to reduce aliasing.

• Proceedings of the KOSOMBE Conference
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• 대한의용생체공학회 1997년도 추계학술대회
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• pp.27-30
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• 1997

The purpose of this study is to estimate human sensibility quantitatively under color and music stimulation and to examine the correlation between visual and auditory emotion. We measured biological signals such as EEG, ECG, skin conductance and the number of respiration in order to compare color with music sensibilities. Our result showed that red, yellow and violet color provoked active and exciting senses dominatively as dance, rock and blues music. While blue, cyan and pink color were involved in tranquil and resting emotions deeply as classic and ballade music. Our quantitative estimations of human sensibilites are useful in the design of manufactured goods.

• Proceedings of the KOSOMBE Conference
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• 대한의용생체공학회 1998년도 추계학술대회
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• pp.187-188
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• 1998

A low cost, low power, portable cardiac event recorder as a tether-free biological signal processor was developed. Dual channel ECG signals are sampled at 128Hz in 12 bits resolution. Sampled data are continuously recorded in a circular buffer. If event button is pressed, 2 minutes data before and after the event are recorded in 512 Kbyte SRAM. Total 11 events can be recorded. Data can be transferred to PC through RS-232 protocol. It operates for two months by a half AA size 3.6V Lithium battery. The system size is $55\times55\times13[mm^3]$.

• Journal of the Korean Society of Visualization
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• 제7권2호
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• pp.56-63
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• 2010

In this work, a dielectrophoresis-based particle-separation device is developed which is to be used to continuously separate particles in microchannels. We fabricated the particle-separation device with combining the benefits of electrode-based DEP and insulator-based DEP. The DEP forces are generated by an array of electrodes located in both sidewalls of a main channel. According to the magnitude and frequency of electrical signals, particles with different dielectric properties experience different DEP forces, and therefore, continuously move along different streamlines in the main flow channel without need of pre-focusing process. Based on this mechanism, we examined the performance of the device by controlling the trajectory of polystyrene particles. This device is applicable to the investigation of dielectric properties of biological cells as well as the continuous separation of biological cells.

• BMB Reports
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• 제51권1호
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• pp.3-4
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• 2018

Parkinson's disease (PD) is a debilitating disorder resulting from loss of dopamine neurons. In dopamine deficient state, the basal ganglia increases inhibitory synaptic outputs to the thalamus. This increased inhibition by the basal ganglia output is known to reduce firing rate of thalamic neurons that relay motor signals to the motor cortex. This 'rate model' suggests that the reduced excitability of thalamic neurons is the key for inducing motor abnormalities in PD patients. We reveal that in response to inhibition, thalamic neurons generate rebound firing at the end of inhibition. This rebound firing increases motor cortical activity and induces muscular responses that triggers Parkinsonian motor dysfunction. Genetic and optogenetic intervention of the rebound firing prevent motor dysfunction in a mouse model of PD. Our results suggest that inhibitory synaptic mechanism mediates motor dysfunction by generating rebound excitability in the thalamocortical pathway.

• Genomics & Informatics
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• 제11권4호
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• pp.224-229
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• 2013

Receptor for advanced glycation endproducts (RAGE) is a multi-ligand receptor that is able to bind several different ligands, including advanced glycation endproducts, high-mobility group protein (B)1 (HMGB1), S-100 calcium-binding protein, amyloid-${\beta}$-protein, Mac-1, and phosphatidylserine. Its interaction is engaged in critical cellular processes, such as inflammation, proliferation, apoptosis, autophagy, and migration, and dysregulation of RAGE and its ligands leads to the development of numerous human diseases. In this review, we summarize the signaling pathways regulated by RAGE and its ligands identified up to date and demonstrate the effects of hyper-activation of RAGE signals on human diseases, focused mainly on renal disorders. Finally, we propose that RAGE and its ligands are the potential targets for the diagnosis, monitoring, and treatment of numerous renal diseases.

• Proceedings of the KOSOMBE Conference
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• 대한의용생체공학회 1996년도 춘계학술대회
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• pp.311-314
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• 1996

The display of biological signals in monitors often involves a multirate sampling operation which consists of decimation and intenolation. All electroencephalographic (EEG) samples of 10 to 30 seconds must be displayed in the computer screen to keep the aspect ratio of the paper polygraph output. Since the current affordable display technology plots at most 2,000 pixels per row, some samples need to be discarded. This paper studies methods to perform this operation characterizing them from the signal processing viewpoint and compares the display quality among several decimations. Experimental results show that a nonlinear operation such as the peak detection could be preferable than the canonical linear filtering to reduce aliasing.

• Proceedings of the KOSOMBE Conference
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• 대한의용생체공학회 1996년도 춘계학술대회
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• pp.10-13
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• 1996

We have developed the digital polysomnograph system to enhance the manual sleep study. This system is composed of host PC and target board. The host computer is IBM-PC Pentium 133 MHz and the target board is PC31 (processor type: TMS320C31). These two Processors communicate with each other by dualport RAM. Target board acquire 16 channel sleep signals from the Polysomnographic system (GRASS model 78, USA) and digitize them. We used high resolution monitor$(1600{\times}1280)$ to simulate the paper-recording quality of polysomnographic signal. We also implemented the GUI based polysomnographic staging program on the windows environment. Clinicians can score the sleep stage, and edit and mark the event efficiently. Finally it can support making patient database.