• Title/Summary/Keyword: stimulus-duration

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Study on Relation of Stimulated Duration and Depth of Electroacupuncture with Sex and Weight In Rats (흰쥐의 성별과 체중에 따른 족삼리(足三里) 전침자극의 시간과 심도(深度)의 변화가 수장수송능(小腸輸送能)에 미치는 영향)

  • Kim, Young-Sam;Yu, Yun-Cho;Oh, Inn-Kun;Kim, Myung-Dong
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.21 no.2
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    • pp.444-452
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    • 2007
  • Acupuncture treatment cures disease by regulating the functional excessiveness or deficiency which occurs in the meridian and visceral organs, and by letting stagnated Qi and Blood flow through the whole body and then controlling Qi. Whether or not to have Qi feeling is the main factor needed to manifest the efficacy of acupuncture. So it needs the very stimulus to make Qi felt rather than the simple stimulus. In order to have Qi feeling, it needs to acupuncture a patient according to patient's thinness or fatness, constitution, richness or poverty and age. And also it needs to vary the way to acupuncture a patient according to meridian, kinds of pulse, degrees of disease, new or old diseases, seasons with a disease and local areas of disease. In order to ascertain that it is important for the quality and quantity of acupuncture stimulus and the state of feeling acupuncture to get the efficacy of acupuncture, the experiment was planned to confirm whether the form and Qi of subject has different result according to the stimulated duration and depth. On the basis of the report that acupuncture on derma, when using electroacupuncture at Zusanli(ST 36) which denotes small intestinal motility, is more efficient than full depth acupuncture, I got the following result, after I observed whether the stimulated duration and depth give different efficacy according to the sex and weights of rat in experiment. The increased effects of small intestinal motility by electroacupuncture on Zusanli(ST 36) appeared after stimulating full depth for thirty minutes without distinction of sex and weights. This significant change was observed only in the female experimental group when I distinguished the sex. The small interstinal motility in rats by electroacupuncture at zusanli(ST 36) decreased in the 10 minutes' stimulated group and 30 minutes' stimulated group by duration on the one hand, and derma-deep stimulated group and full depth stimulated group by the depth of stimulus on the other hand, as the weights increased. This result shows that the duration and depth of acupuncture depends on the differences of acupuncture points, sex of the experimental animals, ages, and, weights. And the further study on the experimental and clinical differences and sextual differences need to be continued on.

Nonlinearity in the Somatosensory Cortex Response to Vibrotactile Stimulator in fMRI (기능성 자기공명영상에서 진동자극에 대한 감각피질의 비선형성)

  • Lee, Hyun-Sook
    • Progress in Medical Physics
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    • v.17 no.3
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    • pp.159-166
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    • 2006
  • The nonlinearity of hemodynamic response in the somatosensory cortex was investigated with vibrotactile stimulation. The stimuli consisted of a train of 25 Hz, each tasting five different duration periods, 2 s, 4 s, 8 s 12 s, or 16 s with 20 sec periods of no vibration in a pseudo-random order. In order to understand the linearity on the change of stimulus duration for somatosensory cortex, two different tests- checking the linearity of system and finding the impulse response function from gamma-variate function were applied to analyze the hemodynamic response functions. They have produced nearly same results. The BOLD response in the somatosensory cortex Is nonlinear for stimuli of less than 8 seconds, but nearly linear for stimuli greater than 8 seconds. The amplitude, area, TTP, and FWHM as functions of the stimulus duration were calculated and showed a significant downward trend with Increasing stimulus duration for the amplitude and the area. It supports the ranges of nonlinearity are less than 8 seconds.

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Effect of Stimulus Waveform of Biphasic Current Pulse on Retinal Ganglion Cell Responses in Retinal Degeneration (rd1) mice

  • Ahn, Kun No;Ahn, Jeong Yeol;Kim, Jae-Hyung;Cho, Kyoungrok;Koo, Kyo-In;Senok, Solomon S.;Goo, Yong Sook
    • The Korean Journal of Physiology and Pharmacology
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    • v.19 no.2
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    • pp.167-175
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    • 2015
  • A retinal prosthesis is being developed for the restoration of vision in patients with retinitis pigmentosa (RP) and age-related macular degeneration (AMD). Determining optimal electrical stimulation parameters for the prosthesis is one of the most important elements for the development of a viable retinal prosthesis. Here, we investigated the effects of different charge-balanced biphasic pulses with regard to their effectiveness in evoking retinal ganglion cell (RGC) responses. Retinal degeneration (rd1) mice were used (n=17). From the ex-vivo retinal preparation, retinal patches were placed ganglion cell layer down onto an $8{\times}8$ multielectrode array (MEA) and RGC responses were recorded while applying electrical stimuli. For asymmetric pulses, 1st phase of the pulse is the same with symmetric pulse but the amplitude of 2nd phase of the pulse is less than $10{\mu}A$ and charge balanced condition is satisfied by lengthening the duration of the pulse. For intensities (or duration) modulation, duration (or amplitude) of the pulse was fixed to $500{\mu}s$($30{\mu}A$), changing the intensities (or duration) from 2 to $60{\mu}A$(60 to $1000{\mu}s$). RGCs were classified as response-positive when PSTH showed multiple (3~4) peaks within 400 ms post stimulus and the number of spikes was at least 30% more than that for the immediate pre-stimulus 400 ms period. RGC responses were well modulated both with anodic and cathodic phase-1st biphasic pulses. Cathodic phase-1st pulses produced significantly better modulation of RGC activity than anodic phase-1st pulses regardless of symmetry of the pulse.

Relationship between electrical stimulus strength and contraction force from the inside of small intestine (전기 자극 강도에 따른 소장 내부에서의 수축력 관계)

  • Woo, S.H.;Kim, T.W.;Lee, J.H.;Park, H.J.;Moon, Y.K.;Won, C.H.;Lee, S.H.;Park, I.Y.;Cho, Jin-Ho
    • Journal of Sensor Science and Technology
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    • v.17 no.1
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    • pp.1-8
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    • 2008
  • Recently, capsule endoscope was developed to observe small intestine in human body. However, the capsule does not have any locomotive ability, which reduces the benefit of the capsule endoscope. Many researches have done to give locomotion to the capsule, still it consumes too much power to generate the motion by small battery. One of the moving method is electrical stimulus that consumes less power than many methods. The electrical stimulus method causes contraction in the small intestine, and it moves the capsule. Some of papers showed it is possible to guide the capsule by electrical stimulus, however the relationship between electrical stimulus at the mucous and contraction force in the small intestine is not reported, yet. In this paper, the mucous in the small intestine was stimulated, and measured the contraction force in the small intestine is shown. The result shows, the relationship between electrical stimulus parameters (voltage, duration) and contraction force. Also, equation between electrical stimulus parameters and contraction force is roughly induced.

Effect of Auditory Stimulus using White Nosie on Dynamic Balance in Patients with Chronic Stroke during Walking

  • Lim, Hee Sung;Ryu, Jiseon;Ryu, Sihyun
    • Korean Journal of Applied Biomechanics
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    • v.30 no.4
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    • pp.301-309
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    • 2020
  • Objective: This study aimed to investigate the effect of white noise on dynamic balance in patients with stroke during walking. Method: Nineteen patients with chronic stroke (age: 61.2±9.8 years, height: 164.4±7.4 cm, weight: 61.1±9.4 kg, paretic side (R/L): 11/8, duration: 11.6±4.9 years) were included as study participants. Auditory stimulus used white noise, and all participants listened for 40 minutes mixing six types of natural sounds with random sounds. The dynamic balancing ability was evaluated while all participants walked before and after listening to white noise. The variables were the center of pressure (CoP), the center of mass (CoM), CoP-CoM inclined angle. Results: There is a significant increase in the antero-posterior (A-P) CoP range, A-P inclination angle, and gait speed on the paretic and non-paretic sides following white noise intervention (p<.05). Conclusion: Our findings confirmed the positive effect of using white noise as auditory stimulus through a more objective and quantitative assessment using CoP-CoM inclination angle as an evaluation indicator for assessing dynamic balance in patients with chronic stroke. The A-P and M-L inclination angle can be employed as a useful indicator for evaluating other exercise programs and intervention methods for functional enhancement of patients with chronic stroke in terms of their effects on dynamic balance and effectiveness.

A Study on the Functional Electrical Stimulation (기능적 전기 자극에 대한 고찰)

  • Lim, Jong-Soo;Kim, Soon-Hee;Song, Young-Wha
    • Journal of Korean Physical Therapy Science
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    • v.6 no.4
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    • pp.187-199
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    • 1999
  • Functional Electrical Stimulation (FES) is used for muscle reeducation, reduction of spasticity, delay of atrophy, and muscle strengthening. FES stronger stimulation than other forms of electrical stimulation. The efficacy of FES in improving function has been substantiated in the literature. Treatment programs employing FES - activation of muscular tissue through the intact peripheral nervous system - can be broken into five major categories, according to the goal of treatment. These broad areas would include the use of FES to: (1) a direct excitation onto the alpha motoneuron, through peripheral stimulation of the Ia myotatic sensory system and ascending afferent information, which will be integrated at conscious and subconscious level of the CNS. (2) The quality of a stimulated muscle contraction is determined by combination of many parameters, including stimulus amplitude, pulse duration, stimulus frequency, and duty cycle. (3) A unit that has a pulse duration between 200 and $400{\mu}sec$ will be more than adequate for FES applications. (4) The neuromuscular plasticity is critically important to return of function using muscle re-education and facilitation applications. (5) Prior to using FES as an electrical orthosis, the patient should build up endurance in the muscles to be stimu1ated during the gait cycle.

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Study on Electric Stimulus Pattern in Cochlear Implant Using a Computer Model (신경모델링을 이용한 인공와우 전기자극 패턴 연구)

  • Yang, Hyejin;Woo, Jihwan
    • Journal of the Institute of Electronics and Information Engineers
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    • v.49 no.12
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    • pp.249-255
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    • 2012
  • A cochlear implant system uses charge-balanced biphasic pulses that are known to reduce tissue damage than monophasic pulses. In this study, we investigated effect of pulse pattern on neural responses using a computer model, based on the Hodgkin-Huxley equation. Electric pulse phase, pulse duration, and phase gap have been systematically varied to characterize auditory nerve responses. The results show that neural responses, dynamic range and threshold are represented as a function of stimulus patterns and duration. The results could greatly extend to develop more efficient cochlear implant stimulation.

Study on Moxa density-related Changes in Warm Needle Temperature (온침(溫鍼)의 표준화를 위한 애주의 밀도에 따른 온도 측정 연구(硏究))

  • Kim, Yoon-Hong;Lee, Seung-Ho;Yeo, Su-Jung;Choi, Il-Hwan;Kim, Young-Kon;Lim, Sabina
    • The Journal of Korean Medicine
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    • v.29 no.3
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    • pp.11-20
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    • 2008
  • Objectives: Warm-needling is a method combining the effects of acupuncture with the effects of moxibustion. We need to standardize the characteristics of warm-needling in order to achieve consistency in its operational mechanisms and effects, which will improve clinical ability in the field of Eastern medicine. Methods: In this study, using the LabVIEW system on the warm-needling technique, we measured and compared partial temperature changes which varied according to the density of the moxa cone and the moxa cone's core peak temperature. Results& Conclusions: Examination of the warm-needle's partial temperature in relation to the cone density of the 0.8g moxa specimen suggests that a lower density of the moxa cone corresponds to a higher peak temperature and but with a shorter duration. During the effective stimulus time, the lower the density of the moxa cone, the shorter the duration of the effective stimulus time and the higher the mean temperature. Conversely, the higher the density of the moxa cone, the longer the effective stimulus time and lower the mean temperature.

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The advantage of topographic prominence-adopted filter for the detection of short-latency spikes of retinal ganglion cells

  • Ahn, Jungryul;Choi, Myoung-Hwan;Kim, Kwangsoo;Senok, Solomon S.;Cho, Dong-il Dan;Koo, Kyo-in;Goo, Yongsook
    • The Korean Journal of Physiology and Pharmacology
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    • v.21 no.5
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    • pp.555-563
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    • 2017
  • Electrical stimulation through retinal prosthesis elicits both short and long-latency retinal ganglion cell (RGC) spikes. Because the short-latency RGC spike is usually obscured by electrical stimulus artifact, it is very important to isolate spike from stimulus artifact. Previously, we showed that topographic prominence (TP) discriminator based algorithm is valid and useful for artifact subtraction. In this study, we compared the performance of forward backward (FB) filter only vs. TP-adopted FB filter for artifact subtraction. From the extracted retinae of rd1 mice, we recorded RGC spikes with $8{\times}8$ multielectrode array (MEA). The recorded signals were classified into four groups by distances between the stimulation and recording electrodes on MEA (200-400, 400-600, 600-800, $800-1000{\mu}m$). Fifty cathodic phase-$1^{st}$ biphasic current pulses (duration $500{\mu}s$, intensity 5, 10, 20, 30, 40, 50, $60{\mu}A$) were applied at every 1 sec. We compared false positive error and false negative error in FB filter and TP-adopted FB filter. By implementing TP-adopted FB filter, short-latency spike can be detected better regarding sensitivity and specificity for detecting spikes regardless of the strength of stimulus and the distance between stimulus and recording electrodes.

Change in Rouleau Formation of Red Blood Cells by Pulse Magnetic Field Stimulus in the Hand (펄스자기장 자극에 의한 손의 적혈구 형태학적 변화)

  • Hwang, Do Guwn
    • Journal of the Korean Magnetics Society
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    • v.24 no.1
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    • pp.28-33
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    • 2014
  • The change of rouleau formation of red blood cells in the hand stimulated by pulse magnetic field having a maximum intensity of 0.27 Tesla and pulse duration of 0.102 msec was investigated. Before pulse magnetic field stimulus, the red blood cells of test subject were adjoined over ten and the flow of cells was slowed. However after the stimulus in the hand during 10 minutes, the red blood cells adjoined over tens was spreaded out each other and its motion was fast. Also the red blood cells of left hand unstimulated by pulse magnetic field were spreaded out each other, even though the right hand was stimulated during 10 minute. It prove that the rouleau formation of red blood cells can be improve in the whole body in spite of stimulus in the hand because the blood is flowing a whole body.