2.Electrophysiology of Hypothalamic Neuroendocrine Cells.
Pan Dong RYU ; Seong Kyu HAN ; Kyung Yoon KAM ; Wonee CHONG
Journal of Korean Society of Endocrinology 2000;15(6):672-683
No Abstract Available.
Electrophysiology*
;
Neuroendocrine Cells*
3.Photopic Electroretinogram in Adult Diabetics.
Hong Kyun KIM ; Jung Yoon KWON ; Sang Ha KIM
Journal of the Korean Ophthalmological Society 1999;40(1):121-127
In cross sectional fashion we recoreded the cone response in 98 adult diabetics and 20 normal controls according to the recommendation by the International Society for Clinical Electrophysiology of Vision. The photopic oscillatory potentials were extracted from the cone response by highpass filtering. The clear media and attached retina were criteria for inclusion in this study. The data were statistically analyzed expecting that this procedure may provide a feature that could have some clinical significance. The analysis of variance demonstrated that the summed amplitude of the oscillatory potentials, and second oscillatory potential amplitude were the most sensitive parameters to the diabetic retina. A timing delay in the first oscillatory potential wavelet, and a reduction in the second oscillatory potential amplitude and the summed amplitude of oscillatory potentials were the commonest abnormalities. Hence, the second oscillatory potential amplitude and the summed amplitude of oscillatory potentials may be the most valuable indicator among the photopic electroretinogram parameters representing a quantitative measure of overall retinal dysfunction.
Adult*
;
Electrophysiology
;
Humans
;
Retina
;
Retinaldehyde
4.Multi-channel in vivo recording technique: microdrive array fabrication and electrode implantation in mice.
Xiao-Yu MA ; Yi-Yao ZHANG ; Li-Na WANG ; Long-Nian LIN
Acta Physiologica Sinica 2013;65(6):637-646
Here we describe and illustrate our methods for multi-channel in vivo recording in mice, including the fabrication of the microdrive array and the surgical procedure for implanting electrodes. The multi-channel microdrive is fabricated from printed circuit board base, screws, nuts and clamping screws. Rotation of the screw drives both the nut and the attached electrodes to move forward simultaneously. Each full turn of the screw corresponds to 280 µm in depth penetration. The recording electrodes are self-made tetrodes consisting 4 wires (13 µm in diameter). The major steps of headstage fabrication include: tetrode making, microdrive construction, headstage assembling and tetrode plating. The finished headstage is suitable for multi-channel recording in freely moving rodents with the modest weight and the adjustable number of recording electrodes. Additionally, the recording site is allowed to be manipulated after implantation at any time. In the latter part of this paper, we introduce the procedure of the implant surgery to record in bilateral hippocampus in mice. Using these headstages, we simultaneously recorded population activity in bilateral CA1 in freely behaving mice.
Animals
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Electrodes, Implanted
;
Electrophysiology
;
instrumentation
;
Hippocampus
;
Mice
5.Cerebellar Control of Saccades.
Jae Hwan CHOI ; Kwang Dong CHOI
Korean Journal of Clinical Neurophysiology 2013;15(2):37-41
Saccades are rapid eye movements that shift the line of sight between successive points of fixation. The cerebellum calibrates saccadic amplitude (dorsal vermis and fastigial nucleus) and the saccadic pulse-step match (flocculus) for optimal visuo-ocular motor behavior. Based on electrophysiology and the pharmacological inactivation studies, early activity in one fastigial nucleus could be important for accelerating the eyes at the beginning of a saccade, and the later activity in the other fastigial nucleus could be critical for stopping the eye on target, which is controlled by inhibitory projection from the dorsal vermis. The cerebellum could monitor a corollary discharge of the saccadic command and terminate the eye movement when it is calculated to be on target. The fastigial nucleus and dorsal vermis also participate in the adaptive control of saccadic accuracy.
Cerebellum
;
Electrophysiology
;
Eye Movements
;
Saccades*
;
Sleep, REM
6.CAI Program of Potasium Courseware.
Journal of Korean Society of Medical Informatics 1996;2(1):75-85
Computer-Assisted Instruction(CAI) improved the possibility of individualized learning by enhancing the learning efficacy related to the apptitude, competency, speed and perceptual style of each learner. The reason that I introduced the computer in teaching and learning process is based on the assumption that individual differences can be minimized by applying CAI. This has special meaning because in the current teaching and learning system we can not consider the individual differences of learners. Considering the importance of developing individualized learning program, the course of electrophysiology and pathology of K that requires typical memorization and repetition is made as a purpose to increase the efficacy of learning and thus improve the quality of nursing curriculum.
Curriculum
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Electrophysiology
;
Individuality
;
Learning
;
Nursing
;
Pathology
7.The Characteristics of Unipolar and Bipolar Electrograms at the Origin of Ventricular Tachycardia.
Hyoung Seob PARK ; Yoon Nyun KIM ; Chang Wook PARK ; Min Jung KIM ; Yun Kyeong CHO ; Sun Hyo PARK ; Young Soo LEE ; Dae Woo HYUN ; Seong Wook HAN ; Seung Ho HUR ; Kee Sik KIM ; Kwon Bae KIM
Korean Circulation Journal 2004;34(10):963-969
BACKGROUND AND OBJECTIVES: In radiofrequency catheter ablation (RFCA), it is an essential point to understand the characteristics of local electrograms at arrhythmic focus. However controversy exists as whether the unipolar or bipolar electrogram is superior in detecting arrhythmic focus. SUBJECTS AND METHODS: We evaluated the characteristics of unipolar and bipolar electrograms at ventricular tachycardia (VT) origin. Electroanatomical mapping and RFCA were performed in 6 patients with idiopathic VT. 22 sites were enrolled and 6 of them were successful sites. We analyzed the relationship between surface and local electrograms in accordance with success or failure. We also analyzed the morphology of local electrograms. RESULTS: At successful sites of RFCA, point of unipolar onset (22.86+/-10.82 msec vs 5.47+/-26.31 msec, p<0.05) and maximal negative slope (16.57+/-17.46 msec vs -4.00+/-22.77 msec, p<0.05) were recorded earlier than unsuccessful sites. R wave amplitude (0.11+/-0.19 mm vs 0.64+/-0.57 mm, p<0.05) and R/S ratio (0.02+/-0.30 vs 0.18+/-0.26, p<0.05) of unipolar electrograms were smaller at successful sites. R wave duration was shorter at successful sites (6.29+/-8.49 msec vs 11.33+/-6.26 msec) but there was no statistical significance. QRS duration of bipolar electrograms was longer at successful sites (66.14+/-17.93 msec vs 49.07+/-13.11 msec, p<0.05). CONCLUSION: In electranatomical mapping for VT, point of unipolar onset and maximal negative slope could predict local activation time more precisely Unipolar electrograms showed shorter R wave duration and smaller R/S ratio at successful sites of RFCA. We can estimate the focus of VT by using these chracteristics of unipolar and bipolar electrogram.
Catheter Ablation
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Electrophysiology
;
Humans
;
Tachycardia, Ventricular*
9.Measuring the electricity frequency properties of blood.
Hua HUANG ; Maoqing HU ; Huaiqing CHEN ; Zirun YUAN ; Shan TONG ; An LUO
Journal of Biomedical Engineering 2005;22(2):275-279
In order to understand the electricity frequency specialties of blood, we have developed a wide frequency electricity characteristic testing system and used it to test the amplitude frequency property and phase frequency property of the blood in different states and constituents at 1 Hz to 20 MHz. Further analysis on the results of tests helped us know some important properties of blood at even more microcosmic levels from a new angle. Meanwhile, some problems and considerations on the improvement of the electricity model of biotic tissue and blood were pointed out. (1) From 1 Hz to 5 KHz, the impedance of blood descended 99%. (2) Simple equivalent circuit of resistance and capacitance must be used in series equivalent but not in usual parallel connection equivalent. (3) Experiment indicated, equivalent circuits of blood need more analysis, because simple equivalent circuit of resistance and capacitance is liable to gross error. (4) When the three element model is used for measuring the resistance of inside liquid, capacitance of cell membrane and the resistance of outside liquid of blood, the three testing frequencies must be very similar.
Blood
;
Blood Physiological Phenomena
;
Electric Impedance
;
Electrophysiology
;
Humans
;
Models, Biological
10.Study of correlation dimension on EEG.
Hao YANG ; Liang FANG ; Wei HE
Journal of Biomedical Engineering 2004;21(1):81-84
The study of non-linear EEG is of great significance in clinical practice and research work. This paper has gone into the feasibility of calculating the correlation dimension and has developed some subjects with the characters of correlation dimension and the difference under four conditions: (1) passive eyes closed(PEC); (2) mental arithmetic with eyes closed(MAEC); (3) passive eyes open(PEO); (4) mental reasoning with eyes open (MRED). The results show it is feasible and meaningful to calculate correlation dimension and the correlation dimension can reflect the regular patterns of mental activity.
Algorithms
;
Brain
;
physiopathology
;
Brain Mapping
;
Electroencephalography
;
Electrophysiology
;
Humans
;
Nonlinear Dynamics