증례 : Milian`s Syndrome 을 동반한 Arsphemine 약물성간장염의 1 예

오동열 ( Tong Yal Oh ) 대한내과학회 1965 대한내과학회지 Vol.8 No.8

도전율 및 유전율이 다른 병소의 검출을 위한 320-채널 다주파수 Trans-Admittance Scanner(TAS)

오동인,이민형,김희진,우응제,Oh, Tong-In,Lee, Min-Hyoung,Kim, Hee-Jin,Woo, Eung-Je 대한의용생체공학회 2007 의공학회지 Vol.28 No.1

In order to collect information on local distribution of conductivity and permittivity underneath a scan probe, we developed a multi-frequency trans-admittance scanner (TAS). Applying a sinusoidal voltage with variable frequency on a chosen distal part of a human body, we measure exit currents from 320 grounded electrodes placed on a chosen surface of the subject. The electrodes are packaged inside a small and light scan probe. The system includes one voltage source and 17 digital ammeters. Front-end of each ammeter is a current-to-voltage converter with virtual grounding of a chosen electrode. The rest of the ammeter is a voltmeter performing digital phase-sensitive demodulation. Using resistor loads, we calibrate the system including the scan probe to compensate frequency-dependent variability of current measurements and also inter-channel variability among multiple. We found that SNR of each ammeter is about 85dB and the minimal measurable current is 5nA. Using saline phantoms with objects made from TX-151, we verified the performance of the lesion estimation algorithm. The error rate of the depth estimation was about 19.7%. For the size estimate, the error rate was about 15.3%. The results suggest improvement in lesion estimation algorithm based on multi-frequency trans-admittance data.

다주파수 임피던스 단층촬영 시스템

오동인,조성필,김상민,구환,우응제,Oh, Tong-In,Cho, Seong-Phil,Kim, Sang-Min,Koo, Hwan,Woo, Eung-Je 대한의용생체공학회 2007 의공학회지 Vol.28 No.1

We have developed a multi-channel, multi-frequency EIT system with operating frequency of 10Hz to 500KHz. The number of digital voltmeters using phase-sensitive demodulation can be varied from 8 to 64 and we found that 16 and 32-channels are most practical. This paper describes the design, implementation, and construction of 16 and 32-channel systems. The performance of the system was thoroughly tested and we found that CMRR of the developed voltmeter is about 85dB with $100{\Omega}$ unbalancing series resistor. The SNR is greater than 99.6dB and the output impedance of the constant current source is $1{\Omega}W$ at least for all frequencies. Imaging experiments using a banana with frequency-dependent conductivity and permittivity show that frequency-difference imaging is possible using the developed system. Future works of animal and human experiments are discussed.

공간주파수응답의 기저대역 확장에 의한 초음파영상의 개선

송대건,오동인,김현,전계석,Song, Dae-Geon,Oh, Tong-In,Kim, Hyun,Jun, Kye-Suk 한국음향학회 2003 韓國音響學會誌 Vol.22 No.5

항공전자산업이나 반도체 산업분야에서 제품에 대한 품질관리와 안정성 확보 및 생산공정의 경비절감이라는 차원에서 초음파현미경이 사용되고 있다. 기존의 초음파현미경은 음향렌즈의 단일 특성주파수에서만 영상을 획득함으로써 깊이방향의 영상분해능이 결정되어졌다. 본 연구에서는 음향렌즈의 대역폭 내에서 동작주파수를 변화시키면서 K/sub z/방향성분의 지연을 일으켜 K/sub z/ 방향의 대역폭을 증가시키므로 깊이 분해능이 향상됨을 보였다. 실험에서는 내부의 홀을 갖는 시료와 깊은 홈을 갖는 시료에 대해 다중주파수 (4.4 ㎒∼5.6㎒)를 적용한 결과, 영상강도의 변화가 단일 주파수인 경우 10%이내로 변화하였으나 다중주파수의 경우 50%로 나타났다 한편 결함의 깊이가 다른 고체 내부의 결함에 대한초음파 영상의 복원시, 진폭의 경우에는 단일 주파수를 사용한 경우 결함의 형태는 나타났으나 깊이 정보는 알 수 없었고 다중 주파수를 사용한 경우 깊이에 따라 다른 영상 강도를 나타내며 출력되었다. 따라서 초음파 현미경에서 다중주파수를 사용할 경우, 깊이방향으로 더 좋은 영상분해능을 얻을 수 있음을 알 수 있다. In this paper, we have studied the enhancement of the acoustic image by combining bases of support for SFR (Spatial Frequency Response) taken at multi-frequencies. The scanning acoustic microscope system have been constructed using the quadrature detector that is able to measure the amplitude and phase of the reflected signal simultaneously. Both real and quadrature components of reflected signal have been acquired at 4.4 ㎒ to 5.6 ㎒ reliably and accurately. In this experimental result, better depth resolution can be obtained by numerically combining images taken at several different frequencies. Image intensity have been better about 3.4 times at multi-frequency than one at a single frequency.

나노웹 섬유형 전극 인터페이스와 KHU Mark2 EIT 시스템을 이용한 생체신호 동기 도전율 영상법

김태의,김현지,위헌,오동인,우응제,Kim, Tae-Eui,Kim, Hyun-Ji,Wi, Hun,Oh, Tong-In,Woo, Eung-Je 대한의용생체공학회 2012 의공학회지 Vol.33 No.1

Electrical impedance tomography(EIT) can produce functional images with conductivity distributions associated with physiological events such as cardiac and respiratory cycles. EIT has been proposed as a clinical imaging tool for the detection of stroke and breast cancer, pulmonary function monitoring, cardiac imaging and other clinical applications. However EIT still suffers from technical challenges such as the electrode interface, hardware limitations, lack of animal or human trials, and interpretation of conductivity variations in reconstructed images. We improved the KHU Mark2 EIT system by introducing an EIT electrode interface consisting of nano-web fabric electrodes and by adding a synchronized biosignal measurement system for gated conductivity imaging. ECG and respiration signals are collected to analyze the relationship between the changes in conductivity images and cardiac activity or respiration. The biosignal measurement system provides a trigger to the EIT system to commence imaging and the EIT system produces an output trigger. This EIT acquisition time trigger signal will also allow us to operate the EIT system synchronously with other clinical devices. This type of biosignal gated conductivity imaging enables capture of fast cardiac events and may also improve images and the signal-to-noise ratio (SNR) by using signal averaging methods at the same point in cardiac or respiration cycles. As an example we monitored the beat by beat cardiac-related change of conductivity in the EIT images obtained at a common state over multiple respiration cycles. We showed that the gated conductivity imaging method reveals cardiac perfusion changes in the heart region of the EIT images on a canine animal model. These changes appear to have the expected timing relationship to the ECG and ventilator settings that were used to control respiration. As EIT is radiation free and displays high timing resolution its ability to reveal perfusion changes may be of use in intensive care units for continuous monitoring of cardiopulmonary function.

A Study on an Apparatus for the Metal Material Thickness Measurement in High Temperature by Magnetostrictive Ultrasonic Method

Ji Yeon Shin(신지연),Ting Ting Zhang(장팅팅),Tong In Oh(오동인),Soo Woon Park(박수운),Yong Cheol Kim(김용철),Seung Bong Lee(이승봉),Kwang Sik Yoon(윤광식),Kil Mo Koo(구길모) 대한전자공학회 2020 대한전자공학회 학술대회 Vol.2020 No.8

In vary high temperature conditions a metal material thickness measurement is of importance in the phenomena associated with the nuclear accident, in connection with the demonstration experiments of In-vessel phenomenon. In this case a hemispherical thickness measuring apparatus and method using a magnatostrictive ultrasonic wave that can be suggested to measure for this thickness change in real time as the ultrasonic wave apparatus is secured.

韓國農民의 生理的 年齡에 關한 硏究

吳東烈 中央醫學社 1940 中央醫學 Vol.9 No.3

852 middle class farmers, male and female, aged from 20 to 79, who inhabit in three different districts of Korea, were subjected to this experiment. This study was designed to verify the biological changes of human beings due to aging by measuring 18 kinds of physiological functions-physical structures and strengths, motor and sensory functions, cardio-pulmonary functions, basal metabolism, etc. Based upon 10 kinds of functions out of the 18 tested which have close relations with aging, such as, number of missing teeth, basal metabolism, frequency of tapping, grasping power, lifting power, expiratory force breath holding time, diastolic blood pressure, visual acuity for near and auditory function; the author reached the following conclusions by means of evaluating the scores in percentil of each group of the subjects. 1. As for the reduction due to aging in the scores of functional tests, audio-visual acuities were definitely low in those 30's and the rest of the functions except basal metabolism showed remarkable changes in those in their 40's. 2. In comparison with the average scores of the physiological functions of each corresponding age group, these scores decreased remarkably in those in their 40's and 60's in both sexes. 3. The average scores of physiological functions were higher in males under the age of fifty, and they were higher in females thereafter.

Streptomycin으로 因한 아나휘락시 쇽크死의 1例

吳東烈 中央醫學社 1940 中央醫學 Vol.9 No.2

A case of anaphylactic shock death followed by streptomycin injection is presented A 52 year-old farmer with far advanced pulmonary tuberculosis had developed a sudden shock and respiratory paralysis within five minutes after a streptomycin injection, and the cardiac arrest had occurred in twenty minutes after the incident. In spite of an artificial respiration and resuscitation with open cardiac massage, the patient failed to survive not more than four and a half hours. The toxicity of the streptomycin, which consists of 1) the 8th cranial nerve damage, 2) toxic nephritis, 3) histamine like reaction, 4) hypersensitivity and anaphylactic reaction and 5) neuro-muscular blocking action has been reviewed. The necessity of sensitivity test and close evaluation of allergy history before the administration of streptomycin is advocated.

體表面積 및 年齡이 換氣機能에 미치는 影響에 대하여

吳東烈 대한의학협회 1965 대한의학협회지 Vol.8 No.8