• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.11
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• pp.2040-2050
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• 2007

In this study, we present a novel method for estimating the information of MU(motor unit) which is the basic element of human muscle by using surface EMG. Some of the method developed in this field could only estimate the numbers of MU that is activated. However, in our study the MU-simulator based on the line source model was designed to estimate the MU information including the numbers of MU and muscle fiber, conduction velocity, MU diameter, fiber diameter, and end plate position. The SMUAP(single motor unit action potential) detector was designed and CMAP(compound muscle action potential) by electrical stimulus was recorded. With these data, the MU-simulator can estimate the MU information by varying muscle paramater settings through MSE(mean square error) method. Our results shows that the proposed method can be comparable with the method of anatomical studies. Moreover, our system can be utilized to build a tool for diagnosis and treatment assessment of neuromuscular patients.

• The Korean Journal of Pain
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• v.20 no.2
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• pp.208-212
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• 2007

Although Churg-Strauss syndrome (CSS) is a rare disease that is generally associated with vasculitis, nerve involvement is also common in cases of CSS. A 48-year old man was diagnosed with a herniated disc at L4-5 and an annular tear at L5-S1 after complaining of pain and numbness in the left lower leg. Peripheral edema was observed during physical examination and the patient was diagnosed with CSS after a biopsy was conducted. In addition, electromyography and nerve conduction velocity revealed the presence of multiplex mononeuropathy, which indicated the pain and numbness was due to peripheral neuropathy caused by CSS. The symptoms were relieved after oral administration of prednisolone. This case indicates that when symptoms of peripheral neuropathy do not match the radiographic evidence other causes, such as CSS, must be considered.

• Clinics in Shoulder and Elbow
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• v.21 no.4
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• pp.252-255
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• 2018

A 51-year-old male who is right-handed visited the outpatient for right fingers-drop. The patient's fingers, including thumb, were not extended on metacarpophalangeal joint. The active motion of the right wrist was available. The electromyography and nerve conduction velocity study were consistent with the posterior interosseous neuropathy. Further evaluation was done with the magnetic resonance imaging for finding the space-occupying lesion or any possible soft tissue lesion around the radial nerve pathway. On magnetic resonance imaging, the ganglion cyst, which was about 1.8 cm in diameter, was observed on the proximal part of the superficial layer of the supinator muscle (Arcade of Frohse). The surgical excision was done on the base of ganglion cyst at the base of stalk of cyst which looked to be connected with proximal radioulnar joint capsule. The palsy had completely resolved when the patient was observed on the outpatient department a month after the operation.

• PNF and Movement
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• v.19 no.1
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• pp.97-104
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• 2021

Purpose: The human body can experience a variety of injuries. As a result, it may be difficult to directly treat the damaged area. In such a case, indirect treatment is required. Indirect treatment is typically PNF treatment. Morphological changes in muscle have been confirmed through several previous studies; however, few studies have analyzed neurological changes. Therefore, the purpose of this study was to determine how irradiation during resistance exercise using a diagonal pattern effects neurological excitability. Methods: Electromyography was performed on 13 healthy adults. A compound muscle action potential (CMAP) was obtained through a median motor nerve conduction velocity test, which was conducted before and after performing the irradiation exercise and general exercise. Results: Compared to baseline measurements, there was no significant difference in the latency of the irradiation exercise and general exercise. The amplitude of the CMAP measured after the irradiation exercise was significantly higher than after general exercise. Conclusion: Neurological excitability was high in irradiation during resistance exercise using a diagonal pattern. When clinically direct treatment is difficult, it is thought that irradiation can be used indirectly as a technique to induce nerve excitability.

• Solar Energy
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• v.10 no.1
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• pp.5-13
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• 1990

In the present investigation, experiments and numerical analysis during melting process of a phase change material were performed to research heat transfer phenomena generated by means of conduction and natural convection in the vertical tube at inward melting. The phase change material used in the experiments is 99 percent pure n-Docosane paraffin($C_{22}H_{46}$). In the results, it is found that the velocity of phase change interface at the top of tube is faster than at the bottom of tube because of the effect of natural convection, and the distribution of velocity at the liquid region is little affected by the initial temperature of phase change material. The velocity of phase change interface is slower as the initial temperature of phase change material is lower, and the effect of natural convection is larger as the aspect ratio of tube is larger. In tendency of heat transfer phenomena, the experimental results were well corresponded with numerical results. But there were a little disagrements between the results of experiment and numerical analysis because of the assumption of the constant volumetric expansion coefficient in numerical analysis.

• Journal of Life Science
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• v.30 no.3
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• pp.250-259
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• 2020

Diabetes is a well-known risk factor for dementia and cognitive impairment. Diabetic polyneuropathy (DPN) is the most prevalent microvascular complication in type 2 diabetes mellitus (T2DM) patients. The purpose of this study was to evaluate the relation between diabetic peripheral polyneuropathy and cognitive factors in T2DM patients. Retrospective chart review of type 2 diabetic patients with results of a nerve conduction study (NCS) and a neurocognitive study. A total of 19 patients were included. DPN was defined using data from a nerve conduction study: a score of less than 24 in the Korean version of the Mini-Mental State Examination (K-MMSE) was considered as an indicator of cognitive impairment (CI). The mean age of the 19 patients was 71.6±5.0 years. The mean duration of diabetes was 8.4±9.1 years, and the mean HbA1c level was 8.1±1.8%. DPN was present in 7 of the 19 patients. Based on the K-MMSE score, CI was diagnosed in eight patients. The mean K-MMSE scores and the prevalence of CI was not different between the groups with and without DPN. There was no significant difference in DPN prevalence between the groups with and without CI. Education was significantly correlated with cognitive factors. Only the digit span-forward among the cognitive factors showed a significant negative correlation with nerve conduction velocity. In conclusion, the longer education period was associated with higher cognitive function and no significant correlation was observed between diabetic peripheral neuropathy and cognitive dysfunction in type 2 diabetic patients. Further prospective research is needed in the future.

• Annals of Clinical Neurophysiology
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• v.13 no.1
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• pp.31-37
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• 2011

Background: Carpal tunnel syndrome (CTS) and tarsal tunnel syndrome (TTS) are thought to share a similar pathophysiology, compression of the median and plantar nerve by the carpal tunnel and flexor retinaculum. A few reports introduced the relationship between idiopathic CTS and TTS without definite evidence of coexistence. The current study was designed to analyze the electrophysiologic characteristics of combined idiopathic CTS and TTS by comparing with each idiopathic CTS or TTS. Methods: We retrospectively collected patients with combined idiopathic CTS and TTS (CTS-TTS group) from June 2001 to February 2009. Patients with each idiopathic CTS or TTS were collected as controls. Electrophysiologic data of median and plantar nerves were compared between CTS-TTS group and controls. Results: CTS-TTS group was composed of 31 patients. Control group of each CTS or TTS were 50 CTS and 49 TTS patients. In comparison of median nerve conduction study between CTS-TTS group and CTS control group, decreased compound muscle action potential amplitude (p<0.001), decreased median sensory nerve action potential amplitude (p<0.001) and sensory nerve conduction velocity at finger stimulation (p=0.013) were prominent in CTS-TTS group. Decreased medial plantar sensory nerve action potential amplitude (p=0.034) was indicated when CTS-TTS groups and TTS control group were compared. Conclusions: If the electrophysiology study of patients with CTS or TTS was suggestive of severe degree of nerve injury, concerns about the possibility of combined CTS and TTS would be helpful.

• Journal of Korean Tunnelling and Underground Space Association
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• v.16 no.1
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• pp.105-115
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• 2014

A numerical analysis on the smoke behavior and evacuee safety has been performed with computational fluid dynamics. The purpose of this study is to build computational processes for an evacuation and prevention of a fire disaster of a 3 km-length tunnel in Korea. To save computational cost, 1.5 km of the tunnel that can include a few cross-passing tunnels is considered. We are going to assess the fire safety in a road tunnel according to the smoke level, which consists of the smoke density and the height from the floor. The smoke density is obtained in detail from three-dimensional unsteady CFD analysis. To obtain proper temperature distributions on the tunnel wall, one-dimensional conduction equation is considered instead of an adiabatic wall boundary or a constant heat flux. The tunnel considered in this study equips the cross passing tunnels for evacuees every 250 m. The distance is critical in both safety and economy. The more cross passing tunnels, the more safe but the more expensive. Three different jet fan operations can be considered in this study; under- and over-critical velocities for normal traffic condition and 0-velocoty operation for the traffic congestion. The SE (smoke environment) level maps show a smoke environment and an evacuating behavior every moment.

• Annals of Clinical Neurophysiology
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• v.2 no.1
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• pp.21-26
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• 2000

Background: There has been few electrophysiologic studies in median proper palmar digital nerve(PPDN). Bar electrode may be a useful tool to evaluate the pathophysiologic state of the distal peripheral nerves. Objectives : To evaluate sensory nerve conduction velocities(NCVs) of median PPDNs in normal controls and carpal tunnel syndrome(CTS) patients by bar electrode, and clarify the usefulness of the bar electrode. Methods : We checked NCV of each median PPDN of thumb(D1), index(D2) and middle finger(D3) in normal controls(68 hands) and CTS patients(95 hands) by bar electrode. The each mean NCV of both groups were compared to find the correlation between them. Results : The mean NCV of each median PPDN in control group were $38.7{\pm}4.2$(D1), $32.0{\pm}4.6$(D2), $34.2{\pm}4.4$(D3) m/sec, and in CTS group were $35.3{\pm}8.9$(D1), $20.2{\pm}5.2$(D2), $20.2{\pm}5.1$(D3) m/sec orderly. There were significant differences between mean NCV of each finger in control group(p=0.0001), but not between each left and right finger(p>0.05). The differences between each mean NCV of control and CTS were significant in all 3 fingers(p=0.0014, 0.0000, 0.0000). Conclusion : Bar electrode is a useful tool to evaluate the pathophysiologic state of the median PPDNs in normal controls and CTS patients.

• Korean Journal of Clinical Laboratory Science
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• v.53 no.2
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• pp.151-157
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• 2021

Charcot-Marie-Tooth disease (CMT) is a slowly progressive hereditary degenerative disease and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an acquired immune-mediated disorder characterized by weakness and sensory deficits. The purpose of this study was to analyze and compare the electrophysiological characteristics observed in sensory nerve conduction studies (SNCS) of both diseases. A retrospective study of 65 patients with a diagnosis of CIDP (N=35) and CMT type I (N=30) was performed. This study analyzed No potentials ratio, distal compound nerve action potential (dCNAP) of various nerve types, and a correlation coefficient analysis of the sensory nerve conduction velocity (SNCV). As a result, I found that CMT 1 was more severe systemic demyelinating and axonal polyneuropathy better than CIDP (P<0.05). In a quantitative analysis of dCNAP and SNCV, especially sural nerve was the most severe nerve injury observed in both diseases. In correlation and scatter plot analysis, CMT 1 showed relatively high correlations compared to CIDP based on the correlation coefficient analysis (Fisher's Z test) of SNCV. The results of this study suggested that CMT 1 showed the slowness in SNCV, one of the characteristics of demyelinating polyneuropathy, and this slowing had a uniform pattern. In conclusion, electrophysiological characteristic of SNCS may be useful in the diagnosis and research between patients with CMT 1 and CIDP.