• 제목/요약/키워드: stimulus-duration

검색결과 76건 처리시간 0.021초

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

  • 김영삼;유윤조;오인균;김명동
    • 동의생리병리학회지
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    • 제21권2호
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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.

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

  • 이현숙
    • 한국의학물리학회지:의학물리
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    • 제17권3호
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    • pp.159-166
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    • 2006
  • 기능성 자기공명영상을 이용하여 진동자극에 대한 감각피질의 비선형성에 대하여 연구하였다. 진동자극은 25 Hz의 주파수로 5개의 각기 다른 진동 자극 기간, 2초, 4초, 8초, 12초 그리고 16초와 함께 20초의 무자극 주기와 pseudo-random순서로 구성되었다. 감각피질에 대한 자극 기간의 변화에 따른 선형성을 이해하기 위하여 두 다른 방법(시스템의 선형성 조사법과 gamma-variate 함수를 적용하여 impulse response함수를 구하는 방법)을 사용하여 혈류반응 함수를 분석하였는데, 그 결과는 거의 비슷하였다. 감각피질에서의 BOLD 반응은 8초보다 작은 자극 기간 동안에는 비선형이고 8초 이상일 때는 선형성을 보였다. 자극 기간의 함수로 Impulse response 함수의 진폭, 면적, 피크까지의 시간, FWHM을 계산하였고 진폭과 면적의 크기는 자극 기간이 증가할 때 감소함을 보여줌으로써 자극 기간 8초에서 BOLD 반응이 비선형성에서 선형성으로 변함을 뒷받침해 주었다.

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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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    • 제19권2호
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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.

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

  • 우상효;김태완;이정현;박희준;문연관;원철호;이승하;박일용;조진호
    • 센서학회지
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    • 제17권1호
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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
    • 한국운동역학회지
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    • 제30권4호
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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.

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

  • 임종수;김순희;송영화
    • 대한물리치료과학회지
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    • 제6권4호
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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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신경모델링을 이용한 인공와우 전기자극 패턴 연구 (Study on Electric Stimulus Pattern in Cochlear Implant Using a Computer Model)

  • 양혜진;우지환
    • 전자공학회논문지
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    • 제49권12호
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    • pp.249-255
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    • 2012
  • 청각 신경의 정상적 기능 회복을 위해 사용하는 인공와우는 인체 조직에 손상을 주는 단상파 방식의 펄스 대신 전하량 균형을 이루는 이상파 방식의 전기적 펄스를 사용한다. 본 논문에서는, Hodgkin-Huxley 신경 모델에 기반하여 다양한 전기적 펄스 방식의 자극이 신경 반응에 미치는 영향에 대하여 연구하였다. 전기적 펄스의 펄스 폭, 펄스간 간격 등을 변화시키면서, 청각신경의 역치, 반응 범위, 반응 시간 등을 측정하였다. 이러한 결과는 인공와우 시스템의 효과적인 자극 방식을 디자인 하는데, 활용 될 수 있으리라 기대된다.

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

  • 김윤홍;이승호;여수정;최일환;김영곤;임사비나
    • 대한한의학회지
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    • 제29권3호
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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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    • 제21권5호
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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.

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

  • 황도근
    • 한국자기학회지
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    • 제24권1호
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    • pp.28-33
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    • 2014
  • 최대 0.27 T 세기와 0.102 ms 펄스시간을 가지는 자기장 자극시스템을 이용하여 손에 인가한 후에 생혈액 분석을 통해 말초혈관에 흐르는 적혈구의 형태학적 변화를 조사하였다. 펄스자기장 자극 전 피실험자의 적혈구는 10여개 이상씩 서로 붙어있는 연전형성(連錢形成, rouleau formation)이 일어나서 적혈구의 움직임이 느려졌으나, 손에 10분간 자기장 인가한 후에 연전형성이 되었던 적혈구가 대부분 떨어져서 독립적인 움직임을 보이면서 운동이 활발해졌다. 또한 왼쪽 손에 펄스자기장을 10분 자극한 후에 자극받지 않은 오른쪽 손에서 채혈했을 때에도 연전현상이 똑같이 개선되었다. 이는 혈류흐름에 의해 체내에 모든 적혈구의 연전현상이 개선된 것으로 판단할 수 있다.