• Title/Summary/Keyword: Stimulation rate

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Micro-bioreactor for Physical stimulation of endothelial cells using micro-bead impact by gravitational force (미세입자의 중력을 이용한 세포 자극기 개발에 관한 연구)

  • Kim, Young-Hun;Kim, Tae-Jin;Jung, Hyo-Il
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.1690-1691
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    • 2008
  • Micro cell stimulation device is interested in many researchers because it has several advantages such as saving time and reagents. We introduce new micro-bioreactor using micro bead and conduct cell stimulation experiments to verify effective time because cell have operated by cell-cycle (G1, S, G2, and M phase). Micro-bioreactor was made by soft lithography and CAPE (calf pulmonary artery endothelial cell) was cultured in PDMS (polydimethylsiloxane) micro device for 12 hour and cell starvation process was performed for 24 hours. Micro glass beads were rolled only by slating device every hour during 15 hour because of minimizing other stimulation force like flow and pressure. The result represents that cells under exposed under micro bead stimulation show higher growth rate than normal condition and earlier and later stimulation time are more effective.

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The development of a high efficient transcranial magnetic stimulation adopted real time-charging-discharging circuit

  • Kim, Whi-Young;Park, Sung-Joon
    • Journal of IKEEE
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    • v.14 no.2
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    • pp.9-15
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    • 2010
  • In this study, we have been proposed the new type of a transcranial magnetic stimulation adopted a variable voltage capacitor with Cockcroft-Walton circuit and constant-frequency current resonant half-bridge inverter. This a transcranial magnetic stimulation has some merits compared with the conventional one. First, it doesn't require the high voltage transformer. And second, it has less switching losses, compact size and capability in adjusting the transcranial magnetic stimulation output energy precisely. In this paper, we have performed the output characteristics of a transcranial magnetic stimulation system which is well known as magnetic stimulation. The tested results are described as a function of pulse repetition rate and switching numbers of the half-bridge inverter.

The Effect of Electroacupuncture on the Heart Rate Variability of Stroke Patients under Mental Arithmetic Stress

  • Oh, Jae-Gun;Kwon, So-Yeon;Yun, Henja;Sung, Kang-Keyng
    • The Journal of Korean Medicine
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    • v.33 no.4
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    • pp.50-59
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    • 2012
  • Objectives: This study aimed to compare the effects of high frequency electroacupuncture, low frequency electroacupuncture and manual acupuncture on the autonomic nervous system in stroke patients by using a heart rate variability measuring device. Methods: Thirty-nine participants were recruited and each participated in the high frequency electroacupuncture group, low frequency electroacupuncture group, manual acupuncture group and non-acupuncture group. Some participants received needle insertion with 100 Hz stimulation, with 2Hz stimulation and manual stimulation under mental arithmetic stress during 2 sections. Other participants maintained in the supine position without acupuncture under mental arithmetic stress during the 2 sections. Acupuncture needles were directly inserted perpendicularly to the right Liv 3 acupoint followed by delivery of electric pulses to these points for 8 minutes. Heart rate variability was measured 8 minutes before and 16 minutes after acupuncture stimulation by a heart rate variability measuring system. Results: We found a significant elevated HF total power between 1 section and 2 section and between 1 section and 4 section in the non-acupuncture group, between 3 section and 4 section in the 100Hz electroacupuncture group, and between 1 section and 2 section in the manual acupuncture group and with no change in the 2Hz electroacupuncture group. We also found a significant VLF total power between 2 section and 3 section in the 2Hz electroacupuncture group and between 1 section and 4 section and between 2 section and 4 section in the 100Hz electroacupuncture group. All four groups showed no significant differences in other parameters including heart rate mean, low-frequency power, and the ratio of low-frequency power to high-frequency power. Conclusions: This study may be a basis for research about effects of acupuncture and electroacupuncture because the parameters measured, heart rate variability, showed differences according to acupuncture.

The Effect of Auricular Acupuncture on the Pulse Rate (이침 요법이 맥박의 변화에 미치는 영향)

  • Jang, Jun-hyouk;Kim, Ji-young
    • Journal of Acupuncture Research
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    • v.20 no.1
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    • pp.97-103
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    • 2003
  • Objective : Auricular acupuncture is a method of treatment that involves needling the ear in order to produce relief of symptoms. This concept was first developed by P.Nogier, french doctor and referred to as somatotopic representation. Many authors have commented the fact that the vagus nerve supplies the external auditory and the concha. The aim of this randomised, single blind study was to investigate whether auricular acupuncture of the ear produced changes in the pulse rate, an indicator of vagal tone. Methods: 10 healthy man volunteers were divided into normal and epinephrine stimulation group. Then each group was divided into vagus area acupuncture and control area acupuncture group again. Epinephrine stimulation group was injected by epinephrine 0.3cc twice, first. All of them were needled in either the vagus area or control area of the ear, and pulse rate changes were measured by patient monitor over 1 hour. Results : In the epinephrine stimulation group, there was significant differences in the pulse rate change between vagus area acupuncture and control area acupuncture group. After injection of epinephrine, the basal pulse rate was increased 1.3~1.4 times in the control group. However, in the vagus area acupuncture group the basal pulse rate was increased only 1.1~1.2 times.

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A Study about Sasang Constitutional difference on Autonomous Function after Acupuncture stimulation (침자극 후 사상체질별 자율신경활동의 변화에 대한 연구)

  • Kwak, Chang-Kyu;Sohn, Eun-Hae;Lee, Eui-Ju;Koh, Byung-Hee;Song, Il-Byung;Hwang, Wook
    • Journal of Sasang Constitutional Medicine
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    • v.16 no.3
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    • pp.76-84
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    • 2004
  • 1. Objectives This paper is intended to find out Sasang Constitutional difference on Autonomous Function after Acupuncture stimulation in healthy subjects. 2. Methods of Research Nineteen healthy volunteers(Soyangin 6, Taeumin 7, Soeumin 6) had acupunctured perpendicularly into the Hapkok point(LI4) and the Taechung point(Liv3). Heart Rate Variability, Mean Heart Rate and Blood Pressure were checked 4 times(before and after Acupuncture stimulation) to evaluate Autonomous Function. 3. Results & Conclusions The conclusions were as follows 1. There was no statistically significant Sasang Constitutional difference on sympathetic activity and parasympathetic activity before Acupuncture stimulation. 2. Acupuncture stimulation caused a statistically significant increase in the parasympathetic activity in the whole subject. 3. After Acupuncture stimulation, there was a statistically significant increase in the parasympathetic activity in Soeumin and a tendency of increase in the parasympathetic activity in Soyangin. But there was a tendency of increase in the Sympathetic activity in Taeumin.

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Commercial frequency AC discharge magnetic stimulation operating characteristics (상용교류방전 자기자극장치의 동작특성)

  • Kim, Whi-Young
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.12
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    • pp.2685-2692
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    • 2009
  • We propose pulsed magnetic stimulation below 30W by the AC(60Hz) switching control of leakage transformer primary which has some advantage of cost and size compared to a typical pulsed power supply. Pulse repetition rate is adjusted from 5Hz to 60Hz to control magnetic stimulation output. In this magnetic stimulation, a low voltage open loop control for high voltage discharge circuit is employed to avoid the HV sampling or switching and high voltage leakage transformer is used to convert rectified low voltage pulse to high voltage one. A ZCS(Zero Cross Switch)circuit and a DSP & FPGA are used to control gate signal of SCR precisely. The pulse repetition rate is limited by 60Hz due to the frequency of AC line and a high leakage inductance. The maximum magnetic stimulation output was obtained about 33W at pulse repetition rate of 60Hz, total 40, 80, 120, $160^{\circ}$, SCR gate trigger angle $90^{\circ}$ and total output.

Effects of Transcutaneous Auricular Vagus Nerve Stimulation on the Activity of Autonomic Nervous System and Postprandial Blood Glucose Levels (경피적 귀 미주신경 자극이 자율신경계의 활동 및 식후 혈당 변화에 미치는 영향)

  • Hana, Lee;Hyun, Kim;Doyong, Kim;Minjoo, Lee;Seungkwan, Cho;Han Sung, Kim
    • Journal of Biomedical Engineering Research
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    • v.44 no.1
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    • pp.33-40
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    • 2023
  • Transcutaneous auricular vagus nerve stimulation (taVNS) is known to be effective in improving symptoms of numerous diseases such as depression and epilepsy by increasing vagus nerve activity through electrical stimulation. The purpose of this study is to investigate the effect of vagus nerve stimulation on the activity of autonomic nervous system and the changes in postprandial blood glucose levels. Seven healthy adults participated in a non-invasive transcutaneous auricular vagus nerve stimulation experiment. taVNS (25 Hz, 200 ㎲, biphasic pulse) was applied to the cymba concha (taVNS group) or the earlobe (Sham-taVNS group) of the left ear. As autonomic nervous system signals, skin conductance level, skin temperature, and heart rate were recorded during the application of taVNS. Postprandial blood glucose changes due to food intake were recorded at 5 min intervals for 25 minutes after taVNS or sham-taVNS. The taVNS showed a significantly lower skin conductance level than the shamtaVNS (p < 0.05). The increase rate of postprandial blood glucose was significantly lower in the taVNS than in the sham-taVNS (p < 0.05). These results showed that taVNS reduced the activity of the sympathetic nerve system and alleviated early rise in postprandial blood glucose. Although further studies in diabetic patients are needed, this study suggest that taVNS has a potential for clinical use to improve postprandial blood glucose.

Effect of prenatal different auditory environment on learning ability and fearfulness in chicks

  • Zhao, Shuai;Xu, Chunzhu;Zhang, Runxiang;Li, Xiang;Li, Jianhong;Bao, Jun
    • Animal Bioscience
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    • v.35 no.9
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    • pp.1454-1460
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    • 2022
  • Objective: Early environmental enrichment in life can improve cognition in animals. The effect of prenatal auditory stimulation on learning ability and fear level in chick embryos remained unexplored. Therefore, this study investigated the effect of prenatal auditory stimulation on the learning ability and fear level of chicks. Methods: A total of 450 fertilized eggs were randomly divided into 5 groups, including control group (C), low-sound intensity music group (LM), low-sound intensity noise group (LN), high-sound intensity noise group (HN) and high-sound intensity music group (HM). From the 10th day of embryonic development until hatching, group LM and group LN received 65 to 75 dB of music and noise stimulation. Group HN and group HM received 85 to 95 dB of noise and music stimulation, and group C received no additional sound. At the end of incubation, the one-trial passive avoidance learning (PAL) task and tonic immobility (TI) tests were carried out, and the serum corticosterone (CORT) and serotonin (5-HT) concentrations were determined. Results: The results showed that compared with the group C, 65 to 75 dB of music and noise stimulation did not affect the PAL avoidance rate (p>0.05), duration of TI (p>0.05) and the concentration of CORT (p>0.05) and 5-HT (p>0.05) in chicks. However, 85 to 95 dB of music and noise stimulation could reduce duration of TI (p<0.05) and the concentration of CORT (p<0.05), but no significant effect was observed on the concentration of 5-HT (p>0.05) and PAL avoidance rate (p>0.05). Conclusion: Therefore, the prenatal auditory stimulation of 85 to 95 dB can effectively reduce the fear level of chicks while it does not affect the learning ability.

The Effect of Mental Stress Stimulation and Acupuncture at Shinmun(HT7) on Heart Rate Variability (정신적 스트레스와 신문(神門)(HT7) 자침(刺鍼)이 정상성인의 심박변이도(HRV)에 미치는 영향)

  • Kang, Mun-Su;Kim, Lak-Hyung
    • Journal of Oriental Neuropsychiatry
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    • v.20 no.1
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    • pp.165-176
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    • 2009
  • Objectives : The purpose of this study was to assess the effects of mental stress stimulation and acupucnture applied at HT7 point on heart rate variability (HRV) in normal subjects. Methods : Thirty seven healthy volunteers participated in this study. The volunteers were randomly allocated into two groups. Both groups performed a mental arithmetic stress test and stroop color-word test for 10 minute. Then, acupuncture needles were inserted on HT7 for the study group and on non-acupucnture point for the control group. HRV was recorded three times at test time and before and after acupuncture stimulation. Results : After giving mental stress stimulation to both groups, LF and LF!HF ratio were increased and HF was decreased significantly. After giving acupuncture to study group, LF and LF/HF ratio were decreased and HF was increased, but it was not significant. After giving acupuncture to control group, LF and LF/HF ratio were increased and HF was decreased, but it was not significant. Conclusions : This results show that mental arithmetic stress test and stroop color-word test contribute to activation of the sympathetic nervous system Acupuncture at HT7 could be relatively useful to decrease sympathetic activity and balance autonomic nervous system for those who are under stress.

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Comparison of Skin Stimulation Method and Topical Anesthetic Cream on Pain and Heart Rate Variability during Arteriovenous Fistula Puncture in Hemodialysis Patients (혈액투석 환자의 동정맥루 천자 시 피부자극법과 국소마취크림 도포에 따른 통증과 심박변이도 비교)

  • Kang, Hyo Young;Chae, Young Ran
    • Journal of Korean Biological Nursing Science
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    • v.21 no.3
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    • pp.207-216
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    • 2019
  • Purpose: The purpose of this was to compare effects of application of the skin stimulation method and topical anesthetic cream on pain, heart rate variability and satisfaction according to nursing intervention methods during arteriovenous fistula puncture in chronic renal failure hemodialysis patients. Methods: This study was a crossover design. Participants were 36 patients with chronic renal failure receiving hemodialysis treatment. Two forms of intervention were applied to participants, and then pain and heart rate variability were measured during the puncture. Results: There were no statistically significant differences according to each treatment in vein pain and artery pain. Also, there were no statistically significant differences according to each treatment in stress index, sympathetic activity (LF), parasympathetic activity (HF) and sympathetic activity/parasympathetic activity (LF/HF ratio). Satisfaction with application of skin stimulation method was statistically higher than that of topical anesthetic cream application. Conclusion: This suggests that application of the skin stimulation method complements disadvantages of topical anesthetic cream application and demonstrates possibility of application as a nursing intervention method which can be conveniently used by nurses in clinical practice.