• The Journal of the Korea Contents Association
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• v.9 no.12
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• pp.691-698
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• 2009

The purpose of this study was to examine the effect of neuromuscular electrical stimulation(LFES) during hindlimb suspension on weight and function of rat hindlimb muscles. Sprague-Dawley rats(body weight 300-350g) were randomly assigned to five groups: a HLS(n=5) that were hindlimb suspended for 14 days, a WB(n=5) that kept as control, a ES14 that were hind limb suspended for 14days with pre-application of LFES for 14 days, ES11 that were hindlimb suspended for 14 days with pre-application of LFES for 11 days, a LFES 7 that were hindlimb suspended for 14 days with pre-application of LFES for 7 days. Gastrocnemius muscle weight, stride length were significantly decreased and toe out angle were significantly increased in HLS and ES7 groups, whereas muscle weight, stride length, toe out angle were maintained in ES14, ES11. this indicated that LFES for 14 days, LFES for 11 days could prevent muscle atrophy and retain function.

• Progress in Medical Physics
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• v.17 no.4
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• pp.260-267
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• 2006

A retinal ganglion cell's receptive field is defined as that region on the retinal surface In which a light stimulus will produce a response. A retinal ganglion cell peers out at a small patch of the visual scene through its receptive field and encodes local features with action potentials that pass through the optic nerve to higher centers. Therefore, defining the receptive field of a retinal ganglion cell is essential to understand the electrical characteristics of a ganglion cell. Distribution of receptive fields over retinal surface provides us an Insight how the retinal ganglion cell processes the visual scene. In this paper, we provide the details how to reconstruct the receptive field of a retinal ganglion cell. We recorded the ganglion cell's action potential with multielectrode array when the random checkerboard stimulus was applied. After classifying the retinal waveform Into ON-cell, OFF-cell, ON/OFF-cell, we reconstructed the receptive field of retinal ganglion cell with Matlab. Here, we show the receptive fields of ON-cell and OFF-cell.

• The Zoological Society Korea : Newsletter
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• v.16 no.1
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• pp.17-50
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• 1999

시상하부에 극히 적은 수로 존재하는 신경분비세포인 성선자극호르몬-방출호르몬(gonadotropin-releasing hormone; GnRH) 뉴런은인간을 포함한 포유동물의 생식과 발생 과정에 있어 중요한 역할을 담당하고 있다. GnRH 뉴런은 배아 발생과정 중에 후판에서 유래하여 시상하부의 여러 영역으로 이동하며, 생후와 사춘기를 거치면서 분화를 계속한다. GnRH 뉴런에서 합성, 분비되는 10개의 아미노산으로 이루어진 작은 신경호르몬인 GnRH는 맥동적으로 분비되어 뇌하수체 성선자극 세포막에 존재하는 GnRH 수용체와 결합한 후 일련의 신호전달과정을 거쳐 성선자극호르몬의 합성과 분비를 제어하게 된다. GnRH의 합성과 분비는 글루탐산, 노르에피네프린, GABA와 같은 각종 신경입력과 스테로이드 호르몬에 의한 액성 피드백 신호에 의해 조절되나 이들의 GnRH 유전자 발현에 미치는 영향은 최근에 연구되고 있는 실정이다. GnRH 뉴런의 분화와 발생에는 다양한 신경영양인자들이 영향을 미치나 그 분자생물학적 기작은 아직 밝혀져 있지 않다. 본 논단에서는 신경호르몬인 GnRH와 그 수용체에 관하여 최근 연구성과를 중심으로 살펴보고자 한다.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.5
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• pp.58-65
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• 2015

This paper presents the design of an implantable stimulation IC intended for neural prosthetic devices using $0.18-{\mu}m$ standard CMOS technology. The proposed single-channel biphasic current stimulator prototype is designed to deliver up to 1 mA of current to the tissue-equivalent $10-k{\Omega}$ load using 12.8-V supply voltage. To utilize only low-voltage standard CMOS transistors in the design, transistor stacking with dynamic gate biasing technique is used for reliable operation at high-voltage. In addition, active charge balancing circuit is used to maintain zero net charge at the stimulation site over the complete stimulation cycle. The area of the total stimulator IC consisting of DAC, current stimulation output driver, level-shifters, digital logic, and active charge balancer is $0.13mm^2$ and is suitable to be applied for multi-channel neural prosthetic devices.

• Tuberculosis and Respiratory Diseases
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• v.40 no.6
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• pp.683-693
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• 1993

Background: During movement the major inputs to nervous system come from firstly the muscle and joint to maintain posture and motion and secondly the chemoreceptors and baroreceptors to adjust the cardiovascular and respiratory function. Their complex relationships are generally studied for many years but the direct relation between the joint and respiratory system is not studied thoroughly until now. So this experiment was performed to determine whether the natural movement of knee joint can cause the enhancement of respiratory function by observation of the changes of respiratory rate, phrenic nerve activity and inspiratory neuron activity during the stimulation of knee joint in cat anesthetized with $\alpha$-chloralose. Method: Twenty six male adult cats were used and the extracelluar recording using bipolar platinum electrode and carbon filament electrode was done to record the changes in the activities of phrenic nerve and inspiratory neuron movement of knee joint, injection of chemicals into the joint cavity and electrical stimulation of articular nerve were done. Results: The 60 Hz. could not but 120 Hz. flexion-extension movement of knee joint increased respiratory rate(R.R.), tidal neural activity(TNA) and minute neural activity(MNA). Intra-articular injection of lactate could not increase R.R. but significantly increase TNA and MNA which represented the enhanced respiratory function. Injection of potassium chloride showed similar effects with the case of lactate but the duration of effect was shorter. The electrical stimulation of medial articular nerve with IV strength which could activate only group I and II afferents showed increased TNA and MNA during stimulation but 20 V stimulation which could activate all the afferents increased all the respiratory parameters. The changes of inspiratory neuron activity by knee joint stimulation was similar to that of phrenic nerve. Conclusion: The respiratory center could be directly stimulated by the activation of group I and II articular afferents and it seemed that the magnitude of the respiratory center enhancement is proportional to the amount of sensory information from the knee joint. These facts might suggest that the respiratory function could be enhanced even by the normal movement of knee joint.

• Journal of Yeungnam Medical Science
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• v.17 no.2
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• pp.129-136
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• 2000

Background and Purpose: This study was undertaken to compare the sensitivity of the Repetitive Nerve Stimulation Test (RNST) between the upper and lower extremity muscles in myasthenia gravis(MG) patients. Material and Methods: The study population consisted of 20 normal persons(control group) and 10 MG patients(MG group). Using Stalberg's method. RNST was systemically performed in orbicularis oculi muscle. upper extremity muscles(flexor carpi ulnaris. abductor digiti quinti), and lower extremity muscles(tibialis anterior. extensor digitorum brevis. vastus medialis). Results: There were statistical differences of decremental response($mean{\pm}SD$) in orbicularis oculi and upper extremity muscles between the control and MG groups(p<0.05 or p<0.01). However, there was no statistical difference of decremental response($mean{\pm}SD$) to RNST in lower extremity muscles between the control and MG groups. There were highersensitivity in orbicularis oculi and upper extremity muscles than lower extremity muscles. Although positive reponse were detected in the lower extremity muscles, the positive response rates of lower extremity muscles were lower than o.oculi and upper extremity muscles. Conclusions: When the response rates of RNST in facial and upper extremity muscles are normal, may not be required RNST in lower extremity muscles.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.11
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• pp.4418-4426
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• 2010

Muscle fatigue often induces deterioration of postural balance and muscle contraction, such as strength or maximal voluntary contraction(MVC). This study was to investigate the effects of transcutaneous electrical stimulation(TENS) applied to the fatigued muscles on postural imbalance and decline in muscle strength following fatigue of triceps surae. For the 4 months from March, 2010, twenty healthy subjects without vestibular disease and visual disturbance were recruited and induced muscle fatigue of triceps surea performed by repeated voluntary contraction. TENS was applied to gastocnemius immediately after development of muscle fatigue. Postural sway length, velocity and MVC were recorded under these conditions: pre-fatigue, post-fatigue, and TENS application to fatigued muscle during post-fatigue. Muscle fatigue increased postural imbalance as expressed by sway length and velocity and decreased muscle contraction(p<.05), while TENS improved the postural imbalance and MVC following muscle fatigue during stance(p<.05). The results suggested that fatigue on plantar flexor is associated with postural balance and muscle contraction, and TENS application to fatigued muscle was effective in improving postural imbalance and decline in muscle strength following muscle fatigue. TENS will be an effective method in exercise, working environment and daily life.

• The Korean Journal of Physiology
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• v.22 no.1
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• pp.101-109
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• 1988

최근에 마취한 흰쥐에서 중뇌망상체를 전기적으로 자극하면 췌장의 외분비 기능이 증가하며 이러한 결과는 망상체의 자극으로 인하여 교감신경계의 활성도가 상승하기 때문이라는 보고가 있다. 한편 교감신경계의 활성도가 상승할 경우 교감신경계의 전달 물질인 catecholamine이 교감신경 종말 뿐만 아니라 부신수질에서도 유리된다고 알려져 있다. 그러므로 본 연구에서는 중뇌망상체의 자극으로 인하여 췌장의 외분비 기능이 증가함에 있어 교감신경계가 중요한 역할을 담당하는지를 확인하고, 이때 부신수질이 관여하는가를 알아보고자 하였다. 마취한 흰쥐에게 atropine (1mg/kg) 또는 reserpine (5mg/kg)을 투여하거나 또는 부신을 적출한 다음 중뇌망상체를 전기 자극하면서 췌장액을 채취하였다. 사용한 전기자극의 매개변수는 1.3V, 40Hz, 2msec이었다. atropine과 reserpine을 투여하면 마취한 흰쥐의 자발적 췌장액 분비량과 단백질 분비량은 모두 유의하게 감소하였으나 부신을 제거하면 췌장액 분비량에는 이렇다할 변동이 없는 반면에 단백질 분비량은 유의하게 감소하였다. 중뇌망상체를 전기자극하면 췌장액 분비량과 단백질 분비량 모두가 유의하게 증가하였다. 이러한 망상체의 자극효과는 atropine 전처치에 의하여 이렇다할 영향을 받지 않았으나 reserpine 전처치에 의하여 소실되었다. 그러나 부신을 적출하면 망상체 자극에 의한 췌장액 분비량의 증가는 유지되는 반면에 단백질 분비량의 증가는 소실되었다. 한편 미주신경을 절단한 흰쥐에서 중뇌망상체를 자극하는 동안에 경동맥의 수축기 및 이완기 혈압이 상승하였는데 이러한 망상체의 자극효과도 reserpine의 투여에 의하여 유의하게 감소되었다. 본 실험의 결과를 종합하여 보면 마취한 흰쥐에서 중뇌망상체의 자극은 교감신경계를 활성화시켜 췌장액 분비량과 단백질 분비량에 촉진적인 영향을 미치며, 이때 활성화된 교감신경계는 부분적으로 부신을 경유하게 췌장의 단백질 분비에 촉진적인 영향을 미치는 것으로 생각된다.

• Journal of Korea Multimedia Society
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• v.9 no.3
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• pp.360-368
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• 2006

Recently, performance of the mobile phone has increased dramatically. Due to this, it is possible to integrate various biotechnology. There are many ventures to integrate biotechnology with mobile phone, because of increasement interest of peoples well-being. The transcutaneous electrical nerve stimulation can Improve the circulation of blood and suppress a pain. To integrate the transcutaneous electrical nerve stimulation with mobile phone, it is necessity to make small, low power, and safe module. In this paper, the transcutaneous electrical nerve stimulation module is designed and implemented by small boost convertor. The value of tank capacitor, which is the total stimulus energy to human, can be chosen to insure safe condition. The confirm the of operation of designed module, a small micro-controller is used to make system and test the module. The implemented system is small and consumes a low enough power to be integrated with mobile phone.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1991.06a
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• pp.14-14
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• 1991

후두의 생리적 기능은 하기도를 보호하는 방어기능과 호흡기능 그리고 발성기능으로 대별할 수 있는데 이 가운데 계통발생적으로 가장 원시적이지만 중요한 기능은 하기도 방어기능으로 이는 다른 기능과 달리 전적으로 불수의적이고 반사적으로 이루어진다. 이 기능은 후두내 점막에 존재하는 촉각 수용체(tactile receptor)가 자극되면서 후두근육이 수축 반사를 일으켜 성문이 닫히는 성문폐쇄반사(glottic closure reflex)로서 다접합뇌간반사(polysynaptic brain stem response)이다. 현재까지 후두의 신경장애에서 그 부위나 정도 또는 신경재생 상태 등을 검사하는 방법으로 근전도검사가 주로 쓰여져 왔으나 그것이 주는 정보가 극히 제한되어 있다. 그러나 최근 청각뇌간유발반응과 같이 후두뇌간유발반응 이라 명명된 wave가 존재한다는 사실이 밝혀져 이에 대한 연구가 이루어지고 있어 이것이 임상에 쓰여질 수 있다면 현재 성문폐쇄반사의 소실이나 이상이 원인으로 사료되는 idiopathic laryngospasm, gastroesophageal reflux, spastic dysphonia, stuttering, sudden infant death syndrome과 같은 질환의 진단과 치료에 커다란 진전이 있을 것이다. 이에 저자들은 고양이 6마리를 이용하여 상후두신경을 전기적으로 자극하여 유발되는 반응을 far field recording을 이용 평균 가산법으로 그 wave를 측정하여 다음과 같은 결과를 얻었다. 1. 상후두신경자극(2㎃, stimuli frequency 3/s, Band filter 320-1000, 0.2 ㎳ duration)에 의한 반회신경에의 유발 반응을 기록하였고 그 잠복시간은 평균 8.2 ㎳ 였다. 2. 상후두신경을 자극하여 후두뇌간유발반응을 기록하였고 후두뇌간유발반응은 4개의 양 wave와 4개의 음 wave로 구성되었다. 3. 각 wave의 평균 잠복시간은 P1은 0.8㎳, P2는 2.3㎳, P3는 3.6㎳, P4는 4.3㎳였고 N1은 1.5㎳, N2 은 2.7㎳, N3는 3.9㎳, N4는 5.5㎳ 였다.