• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 합동 추계학술대회 논문집 정보 및 제어부문
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• pp.399-402
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• 2002

In this study, we constructed a four-channel impedance measurement system including a two-channel goniometer to analyze human arm movement. Impedances and joint angles were simultaneously measured for wrist and elbow movements. As the impedance changes resulting from wrist and elbow movements depended heavily on electrode placement, we determined the optimal electrode configurations for those movements by searching for high correlation coefficients, large impedance changes, and minimum interferences in ten subjects (age: 29+6). Our optimal electrode configurations showed very strong relationships between the wrist joint angle and forearm impedance (correlation coefficient = 0.95+0.04), and between the elbow joint angle and upper arm impedance (correlation coefficient = -0.98+0.02). Although the measured impedances changes of the wrist (1.1+1.5 ohm) and elbow (-5.0+2.9 ohm) varied among individuals, the reproducibilities of wrist and elbow impedance changes of five subjects were 5.8+1.8 % and 4.6+1.4 % for the optimal electrode pairs, respectively. We propose that this optimal electrode configuration would be useful for future studies involving the measurement of accurate arm movements by impedance method.

• 대한의용생체공학회:의공학회지
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• 제20권3호
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• pp.323-329
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• 1999

본 연구에서는 피부전기활동을 이용한 졸음 검출시 발생되는 동잡음 제거법을 제안하였다. 운전 조작시 발생하는 동잡음을 제거할 수 없는 기존의 핸들형 전극의 문제점을 해결하기 위하여 두 종류의 손목형 전극을 개발하였으며, 세 종류의 전극을 비교 실험한 결과, type I 전극을 개선한 손목형 전극 II가 동잡음 제거에 가장 효과적이었다. 가상 운전 실험을 통하여 동잡음 판별기준(IRI$\leq$10과 1.1$\leq$dNz)을 설정하고 이 기준을 동시에 만족하는 경우의 Nz값을 동잡음 발생이전의 Nz값으로서 치환하는 동잡음 제거 알고리즘을 개발하였다. 가상 및 도로 주행 실험결과 제안된 알고리즘은 동잡을 성공적으로 제거할 수 있었으며, 본 연구에서 제안된 알고리즘의 개선된 전극을 이용하여 구현된 시스템은 동일한 영향을 받지 않고 각성상태를 정확히 측정할 수 있음을 확인하였다.

• 대한의용생체공학회:의공학회지
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• 제25권2호
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• pp.151-156
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• 2004

편마비 환자에서 상지 기능을 효과적으로 회복시키기 위하여 근전도 유발 기능적 전기자극기 개발과 편마비 환자를 대상으로 손목, 수지신전 운동 시 가장 효과적으로 근수축을 감지 할 수 있는 위치와 전기 자극 시 가장 이상적인 손목, 수지 신전 운동이 일어나는 부위를 탐색하여 두 부과가 일치하는 이상적인 전극부착 위치를 설정하였다. 1) 전기자극 시스템으로 EMC 계측부, 정전류 회로부를 개발하고 프로그램으로는 근전도 유발 전기자극기와 Passive FES의 동작이 가능한 형태로 개발하였다 자극조건은 주파수 35 Hz, 펄스폭 150 ${\mu}\textrm{s}$, 비대칭적 이상성 파형을 선택하였다. 2) 상지 편마비 환자 15명을 대상으로 전완의 근위부 1/2부위를 12개의 영역으로 나눈 후 근위부의 외측으로부터 영역의 순서를 정하였다. 각 영역에서 환자의 손목을 신전 하였을 때 근전도 유발 자극기가 감지하는 활동전위의 진폭을 측정하였으며 가장 크게 감지된 영역은 4, 5 영역이었고, 전기자극을 시행하였을 때 손목과 수지부위가 신전 되는 모양이 이상적인 영역은 4, 5, 7, 8 영역이었다. 근전도 유발 전기자극을 시행하였을 때 근 수축을 감지하여 근전도 유발 전기자극이 일어나는 일련의 과정이 이상적인 영역은 해부학적으로 4, 5 영역이었다.

• The Journal of Korean Physical Therapy
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• 제6권1호
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• pp.85-93
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• 1994

The purposes of this study were 1) to examine the effects of microcurrent electrical neuromuscular stimulation 2) to compare surface electrode with needle electrode at somatic acupuncture points on experimental pain threshold measured at the distal end of the radius 3) to determine the changes in effect over time. A total of sixty healthy adult male and female subjects were assigned randomly to one of two experimental group or to a control group. Group 1(n=20) received MENS(Microcurrent Electrical Neuromuscular Stimulation) with surface electrode. Group 2(n=20) received HENS with needle electrode. Group 3(n=20) received no MENS. It measured experimental pain threshold at the wrist on pretreatment, 0 min after treatment. 15 min after treatment, 30 min after treatment in two experimental group. The results were as follows: 1. Experimental pain thresholds were higher in males than females(P<0.01). 2. Only the experimental group exhibited a significant increased in pain threshold after MENS treatment(P<0.05). 3. Surface electrode group increased significant pain threshold 0 min, 15 min after treatment, but greatly decrease 30 min after treatment. 4. Needle electrode group increased significant pain threshold 0 min, 15 min after treatment, but decrease 30 min after treatment. The results suggest that MENS applied to appropriate somatic acupuncture point can increase pain threshold. Further research is needed to assess the effects of greatly variety intensity of MENS of pain sufferes.

• 센서학회지
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• 제18권5호
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• pp.359-364
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• 2009

This paper presents flexible electrocardiography(ECG) sensors using micro electro mechanical systems(MEMS) and flexible printed circuit(FPC) technology. By using FPC technology, ECG sensors which consisted of an outer hook-shaped electrode and an inner circular-shaped electrode were fabricated on the polyimide substrate. Thereafter, the bipolar ECG sensor was miniaturized using MEMS technology. The ECG measurement capability was examined by attaching the sensor to the human chest and wrist. Performance of the proposed sensors was then compared with ECG measured by commercial Ag/AgCl electrodes. It was verified that ECG could be measured using proposed sensors at only single body.

• Journal of Acupuncture Research
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• 제21권6호
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• pp.249-257
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• 2004

Objective : Radial nerve palsy is characterized by palsy or paralysis of extensors of the wrist and digits, as well as the forearm supinators. Very proximal lesions also may affect the triceps. Numbness occurs on the dorsoradial aspect of the hand and the dorsal aspect of the radial 3 and 1/2 digits. We observed 7 patients with radial nerve palsy, the results are as follows. Methods & Results : All patients were treated by the same method and treatment was performed by acupuncture and Neuromuscular Electrical Stimulation. the electrode were placed unilaterally on the motor points of forearm. As the result, symptoms are improved remarkably. Conclusions : Patients were treated for 5.4 weeks, 14.7 times(average). The grade was that 6 cases were good and 1 case was excellent.

• 대한의용생체공학회:의공학회지
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• 제23권5호
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• pp.413-418
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• 2002

본 연구에서는 변기에 앉아 있을 때 체성분을 효과적으로 측정할 수 있는 체임피던스 측정기(Bioelectrical Impedance Analyzer, BIA)를 개발하고, 이 시스템으로 정확한 체성분 값을 구할 수 있는 방정식을 도출하였다. 이를 위해 설계한 하드웨어고 건강한 한국인 남·여 181명의 체임피던스 값을 변기에 적합한 전극 부착 위치(손목, 허벅지)에서 획득였다. 같은 피험자를 대상으로 기존의 한국인에게 적용시 정확도의 문제를 내포하는 수중체중법의 Siri 방정식을 modified-Siri 방정식으로 적용함으로서 한국인의 제지방량 표준값을 산출하였다. 이 표준값을 기준으로 임피던스 지수, 체중, 성별로 한국인의 제지방을 예측하는 추정식을 얻었다. 제지방량의 추정값과 표준값 사이의 상관계수(r)는 0.977로 높은 관련성을 나타냈으며, SEE(Standard Error of Estimation)은 2.47kg으로 낮은 오차를 나타냈다(p<0.05). 이는 기존의 전극 부착위치인 손목과 발목을 같은 피험자에 적용하여 체임피던스에 의한 제지방량 추정식을 세울 때, 추정값과 표준값 사이의 상관계수(r = 0.978) 및 SEE(2.43kg)와 큰 차이가 없는 것으로 나타났다. 또한. 이중교차검증(Double Cross Validation)을 통해 실험에 참가하지 않은 피검자에 대한 적용 가능성도 유효한 것으로 나타나 본 논문에서 설계한 체임피던스 분석기와 추정식은 한국인의 제지방량을 산출하는데 적합한 것으로 평가되었다.

• The Journal of Korean Physical Therapy
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• 제6권1호
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• pp.171-183
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• 1994

Purphose. This present study examines the effect of brief, intense transcutaneous electrical nerve stimulation(BTENS) on sensory nerve conduction, electrical pain threshold, and two-point discrimination measured at the superficial radial nevre distribution in 20 healthy subjects. Subjects. Twenty volunteercs, (10 females and 10 males(age range : 20-38 years : $mean{\pm}SD\;:\;27.00{\pm}5.12$), only subjects without prior traumatological and pathological were eligible to participated in this study. Methods. Nerve conduction were determined for the right superficial radial nerve. Electrical pain threshold were determined for the right wrist ipsilateral to the site of BTENS. Small disc electrodes were attached to the surface of the skin stradding the end of the radius. Square wave electrical pulses were delivered from an isolated stimulator through a constant current device at a frequency of 2 Hz(5 ms pulse width). Two-point discrimination, measured on the sensory distribution of superficial radial nerve. BTENS was delivered using a Max-SD( Medical design co.) portable battery powered stimulator. A cicular Ag/AgCl electrode in contact with hypertonic saline gel was attached to the lateral(radial side) surface of the forearm. Results. No significant effects were observed between stimulation methods in the prestimulation cycle(multi-way ANOVA repeated measures : distal latency ; F1.14=0.332. amplitude ; F 0.80=0.445, pain threshold ; F0.06=0.940.2 point discrimination ; F1.50=0.236). Highly significant effects were observed time with the pretreatment and 6 posttreatment cycles(p<0.01). Mighty significants differences in nerve conduction and pain threshold were found using un multi-way ANOVA repeated measures among stimulation methods for each cycles(p<0.01). Conclusion and Discussion The authors concludes that both nerve conduction and pain threshold changes are associated with therapy (stimulation) level of BTENS.

• 대한의용생체공학회:의공학회지
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• 제13권2호
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• pp.133-140
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• 1992

Bioelectrical Impedance method for measuring human body composition is based upon the principle that the electrical conductivity of the fat-free mass (FFM) is far greater than that of the (at. Deter- mination o( impedance was nlade in 30 healthy and obese men aged $40.9{\pm}14.7$yr (mean${\pm}$SD) and 25 healthy and obese women aged $44.0{\pm}10.2$ yr. A commercial impedance body fat analyzer was used with a four electrode arrangement that introduced a painless constant current(ImA at 50 kHz) into the body. Linear relationships were found between impudence values and FFM(r=-0.786) and between weight and FFM(r=0.837). Signigicant increases in the correlation coefficients were ob served when the predicator Hta/z was regressed against FFM(r=0.912) where Ht Is height and Z Is impedance. A linear regression equation, FFM=0.586(Htf/z) +0.317(Weight) -1.674(r=0.977), was found. The correlation coefficient of % body fat between the impedance and infrared methods was 0.898. These data Indicate that the bioelectrical impedance technique is a reliable and valld approach for the estimation of human body composition. This method Is safe, noninvasivr, prouides rapld measure menu, requires little operator skill and subject cooperation, and Os portable. Finally measurement of percent body fat was made possible using both the regression equation and a developed impedance measuring device which measures impedance between wrist and ankle.

• 마이크로전자및패키징학회지
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• 제29권4호
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• pp.21-27
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• 2022

저렴한 전도성 흑연을 인쇄전자 공법으로 유연 압력 센서를 개발하였다. 유연 압력 센서는 의료, 게임, AI 등 미래 산업에 활용될 소재로 각광받고 있다. 유연 압력 센서용 인쇄전극을 다양한 전기-기계적 특성을 평가한 결과 최대인장률 20%, 30°의 인장/굽힘, 간이 맥박 시험에서 일정한 저항 변화율을 보였다. 이렇게 검증이 완료된 전극을 시뮬레이션하여 더 적합한 matrix 패턴을 설계하였다. Serpentine 패턴을 활용하여 matrix 패턴 제작과 인캡슐레이션을 동시에 진행할 수 있는 공정을 활용하였다. 인쇄된 흑연 전극의 한쪽 면에 접착력 증가를 위한 O₂ 플라즈마 표면처리하고, 90°회전시켜, 라미네이션 공정을 통해 2개의 전극을 하나로 제작하였다. 이렇게 제작된 matrix 패턴을 인체의 손목 맥박 위치에 부착하여 실측을 진행한 결과 남녀 상관없이 일정한 저항 변화율을 보였다.