Proceedings of the KOSOMBE Conference (대한의용생체공학회:학술대회논문집)
The Korean Society of Medical and Biological Engineering
- 기타
Domain
- Health Sciences > Medical Devices for Reconstruction/Rehabilitation/Well-being
Volume 1993 Issue 11
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In this paper the morphological characteristic parameters according to the Lee's physical constitution theory are suggested using the X-ray computed tomography. The Lee's physical constitution theory is classify into 4 physical constitutional types by the relative degree of visceral function: those are macro-negative(strong liver- weak lung), micro-negative(strong kidney- weak spleen), micro-positive(strong spleen- weak kidney) and macro-positive(string lung- weak liver). The morphological characteristic parameters are the following. The AA-line is the distance between Rt. & Lt. acupuncture point keug-cheun. The BB-line is the length of lung. The CC-line is the longest width of thorax. The DD-line is the vertical distance between the CC-line and the EE-line. The EE-line is the distance between the Rt. and Lt. anterior superior iliac spines. As the results macro-negative(strong liver-weak lung) has the longest CC-line and the short BB-line. Micro-negative(strong kidney-weak spleen) has the longest EE-line and the short CC-line. Micro-positive(strong spleen-weak kidney) has the longest DD-line and the short BB-line. And macro-positive(strong lung-weak kidney) has the longest BB-line and the short EE-line.
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정자의 형태 분석은 운동 분석과 더불어 불임의 원인 규명 및 진단에 중요한 정보를 제공한다. 본 연구에서는 Diff-Quick 염색된 정자의 영상에 대해, 제안된 Image segmentation 방법을 적용해 정자 형태 특성을 검출해 내는 알고리즘을 구현했다. 비디오 신호로 보내진 정자 영상을 디지탈화하고, 정확한 테두리를 찾은 뒤, 정자 머리 부분의 형태 정보를 추출한 후, 그 특성을 나타내는 parameter 들을 추정하였다.
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In MR functional imaging, it is shown that the signal change during photic activation is composed of two terms, i.e. the inflow effect and the susceptibility effect. Relatively the inflow effect affects the data obtained by CGE on the condition of short
$T_E$ (15ms) and large$\alpha$ (90degree). The susceptibility effect, however, mainly contributes to the data on the condition of large$T_E$ (35ms) and small$\alpha$ (30degree). In this apper, we will discriminate the susceptibility effect for the intermingled data affected both flow effect and susceptibility effect. Finally susceptibility only functional imaging is proposed by using TRFGE. -
Information about retinal blood vessels can be used in grading disease severity or as part of the process of automated diagnosis of diseases with ocular menifestations. In this paper, we address the problem of detecting retinal blood vessels and optic disk (papilla) in Eye-fundus images. We introduce an algorithm for feature extraction based on Fuzzy festering(FCM). The results ore compared to those obtained with other methods. The automatic detection of retinal blood vessels and optic disk in the Eye-fundus images could help physicians in diagnosing ocular diseases.
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A new low-power, high-order optimization scheme to design surface gradient coils (SGC) is proposed for magnetic resonance imaging (MRI). Although previous SGCs have been designed and constructed just to get strong linear gradients, this paper proposes more systematic ways of SGC design by minimizing electrical power consumption in the gradient coil and by removing unnecessary high-order field distortions in the imaging region. By assuming continuous current flow on the coil surface which may be or may not be planar, power consumption in the coil is minimized. According to the simulation results, the SGC designed by using the proposed scheme seems to produce much more uniform linear gradient field using less electrical power compared to the previously proposed SGCs.
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Jun, John-B.;Lee, H.C.;Yoon, H.J.;Yang, S.I.;Kim, Y.M.;Lee, I.S.;Kim, Y.T.;Kim, A.;Nam, J.H.;Mok, J.E. 40
Electronic fetal monitoring system is an easier ar d usual method in various prenatal and labor period fetal surveilence methods currently in use. But there haven't been enough cases of using the central monitoring system despite the fact that the bedside fetal monitoring system have already been widely in use in Korea as an essential medical equipment item. We have developed more efficient central fetal monitoring system based on the personal computer with the visual maternal monotoring device using infrared camera which processes the signals from existing bedside fetal monitoring systems such as H/P's 8040 series. And we have performed the clinical application on 41 pregnant women and the results were satisfactory. In conclusion, more efficient and familial fetal monitoring is possible with our PC based central fetal monitoring system which provides the medical personnel with the view of a selected pregnant woman on the same screen where the electronic waveforms and data are displayed. -
In this paper, the wall follwing method of a motorized wheelchair is discussed. The wall fellowing problem is characterized by maintaining a constant distance to the wall, which should be possible using a distance measuring sensor only. Ultrasonic sensors are cheap are fairly simple to use in this case. The main problem is the calculation of the distance and orientation of the wheelchair with respect the wall from the sensor data. This is solved by the method that sensor data is obtained from 3 ultrasonic sensors arranged at a same perpendicular pivot. The results show that a new method is very effiecient for a motorized wheelchair.
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The purpose of this research is to investigate the relationship between the blood flow and autonomic nervous system which regulates the circulation system. After the oral glucose tolerance test(GTT) the velocity changes of the blood flow were measured from the normal, hyperglycemia and diabetic neuropathy using the laser doppler. The FFT analyses showed that the spectrums were concentrated around the particular bands(0.02-0.166Hz, 0.8-1.1Hz) for the normal, while almost uniform distribution of the spectrums was observed for the abnormal. The blood glucose affects the compliance of the blood vessels and viscosity and finally causes the resistance problem in the blood vessels. An index PG was introduced, which was determined by the ratio of the change or the integral power spectrum in the range between 0.02 and 0.166Hz to change of the blood glucose before and after GTT. The index shows 1.0. 0.3 and 0.1 for the normal, hyperglycemia and diabetic neuropathy, respectively. As a conclusion, this spectrum analysis shows the potential of checking the progress or the diabetic, also car be used to evaluate the vasomotion which are regulated by the autonomic nervous system.
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신체의 특정부위에 정전류를 흘리고 이에 의한 전압의 차이를 이용하여 임피던스를 측정한 후 체내수분을 구하는 방법은 안전하고, 비침습적이며 신속하고, 조작하기 쉽다. 더우기 측정기구의 이동이 용이하므로 실험실 밖에서도 측정이 가능하고 환자의 협조가 별로 없어도 쉽게 측정할 수 장점이 있기 때문에 이를 임상에 적용시키기가 용이하다. 본 연구에서는 설계한 임피던스 측정기는 8bit원칩 마이크로프로세서를 이용하여 다중 채널 주파수 선택이 가능하며 데이터의 입출력 및 통신까지도 가능하도록 설계하였고 이 장치에 대한 실험으로 100명(남자71명, 여자 29명, 평균나이
$34.1{\pm}18.4$ 세, 1-78세)을 대상으로 체내 임피던스의 기초적인 자료를 구하고 이를 바탕으로 수술전후 환자의 체내수분 변화량을 측정하였다. 실험결과, 수술전후 금식 및 수액투여에 따른 체수분 변화를 관찰할 수 있었다. -
Localized NMR spectra were obtained from phantom by OSIRIS technique. The selected volume, which can be controlled by frequency and its bandwidth, was 0.125cc out of 25cc and free of contamination from outer volume. With this technique NMR spectrum of a living tissue can be obtained without biopsy. i.e. in vivo state in which the metabolism of tissue may be quite different from in in vitro state. It is expected of this technique to be useful in the study of metabolism of living tissue as well as in diagnosis of deseases.
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This preliminary study describes the self-mixing effect of laser diode for the measurement of tissue blood flow. A self-mixing effect of laser diode was detected by the single-mode laser diode and the moving target, and the Doppler shifted frequency was thanked linearly with the driving frequency of speaker. The measured Doppler shifted frequency was compared with the simulated data.
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We are developed out-patient order communication system using server/client architecture. We used Microsoft SQL server for relational database and Visual basic language for client. The configuration of system hardware is 486 DX servers and 200 node 486/SX PC and 10 base T network.
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Artificial Heart Valve is the one of the most important artificial organ which has been implanted to many patients. The most important problems related to the artificial heart valve prosthesis are thrombosis and hemolysis. Usual method to test against this problem in vivo experiment, which is complex and hard work. Nowadays the request for In vitro Artificial Heart Valve testing system is increasing. Several papers has announced us flow pattern of Artificial Heart Valve is highly correlated with thrombosis and hemolysis. They usually gel flow pattern by LDA, it is also hard work and has narrow measuring region. In this reason we have determined to develop PTV(Particle Tracking Velocimetry). By using High-speed camera and image processing technique, flow pattern could be relatively easily obtained. Parachute and Bileaflet Artificial Heart Valve designed by SNU were testified.
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Park, Seong-Keun;Won, Yong-Soon;Jung, Pil-Sup;Choi, Jin-Wook;Kim, In-Young;Lee, Kyu-Baek;Min, Byoung-Goo 89
In this article, we present and analyze the results of the three consecutive in vivo experiments of the LVAD to evaluate the function of the LVAD and the adverse effects on living animals. We applied the LVAD consecutively to three mongrel dogs and the circulation of the blood was assisted under the anesthesia. We used in general both the asynchronous mode and the synchronous mode to drive the LVAD. During the experiments we monitored the dogs with a polygraph to evaluate the function of the LVAD and the additional effects on the natural hearts. We also examined several clinical pathologic tests in order to see the effects of the LVAD to the red blood cells and the other internal organs. The dogs survived for two to there days. The LVAD assisted the circulatory system at the maximum assist flow rate of 3.0 1/min. Although the red blood cells of the dogs had mechanical damages by the LVAD to result in the hemolysis, the degree of the hemolysis was not so high and the damages caused by the hemolysis on the dogs were not serious. The myocardium of the first dog was gradually worsened and eventually failed. The damage of the myocardium was due to the asynchronous driving mode of the LVAD. The other organs did not have serious damages due to the application of the LVAD. The main purpose of this paper is to evaluate the results of the in vivo experiments of the LVAD and to find better ways to the application of the LVAD to human beings. -
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A monoleaflet polymer artificial heart valve which showed the remarkable improvement in pressure drop compared with other types of artificial valve was designed to decrease the deflection in vertical direction and the displacement or the valve tip in horizontal direction. Stress distribution change was studied as the location of the supporting members or the valve frame changed. And it was found that using the valve tip horizontal displacement the minimum valve thickness could be obtained in order to prevent the gap between the valve tip and the frame wall.
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Some cardio-vascular assist systems need more inexpensive artificial heart valves for short-term use. To meet with this need, we have developed a new polymer valve that is very simple to manufacture and of which its dimensions are easy to change, depending on its application. We have tested the hydrodynamic performance of the new polymer valve using a mock circulatory testing system and studied the flow through the valve using high-speed camera combined with image processing techniques. The results show that this valve is superior in its performances to the other valves (Bjork-Shiley mechanical valve and trileaflet polymer valve) and have no stagnation points. We also have tested the hemolytic potential of the valve. The valve is less hemolytic than the Bjork-shiley mechanical valve finally, we have applied this valve to a left ventricular assist device that we are developing.
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An in vitro experiment under laminar non-pulsatile blood flow and an acute canine ex vivo femoral A-V series shunt experiment were undertaken to investigate the effectiveness of saline perfusion through pores of porous tubes to prevent formation of mural thrombus. PS/SBR porous tubes were used for the in vitro experiment. Commercially obtained ePTFE porous tubes were etched by sodium naphthalenide, and the etched tubes were used for the ex vivo experiment. According to the results of the in vitro experiment, mural thrombus on the surface of the porous tribe could be prevented by the saline perfusion. Adhered blood cells decreased semi-logarithmically with increased perfusion rate (up to
$0.022\;ml/min-cm^2$ ) of isotonic saline solution. According to results of the ex vivo experiment, mural thrombus decreased with increased perfusion rate (upto$0.060\;ml/min-cm^2$ ). -
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Kim, Jin-Hee;Jeon, Seong-Min;Kim, Jong-Won;Chang, Jun-Keun;Ryu, Gyu-Ha;Yoon, D.H.;Min, Byoung-Goo 124
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In order to get the basic data for the study of the heat stimulation of burning moxa, the pattern of combustion temperature, which is one of the important factors of thermal characteristics, was measured by density of cone moxa along the time procedure. The following results have been obtained 1) The pattern of combustion temperature by moxa burning was classified into input period which means the infiltration of heat into the area and output period which means the radiation of heat from the area. The input period consists of preheating and heating periods, while the output period consists of heat retaining and cooling periods. 2) The pattern of combustion temperature showed the same type or curve, which was not influenced by the moxa weight. However, Its pattern gradient are varied by density. It is considered that the pattern of combution temperature is primarily influenced by the rate of combustion temperature, gradient temperature and duration of combustion.
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This paper describes a Chaos analyzer and its applications to characteristic analysis of ECG signals and the other signals. We can detect chaotic system among the various system by quantitative and qualitative analysis using the proposed system. And we also propose a new Possibility to recognize abnormal state of ECG signal using the chaotic characteristcs of signal.
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This paper propose a two pole phase compensated titer to remove baseline wandering and preserve ST-segment accuracy in real time environment. Bilinear transformed null phase filter(ideal filter), Standard FIR filter and Cubic spline filter are evalauated in the same condition. The proposed phase compensated filter shows better performance than standard filter in real ECG test and triangular pulse test.
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It is an important component of the diagnosis to research the morphological changes of EMG in pathological conditions. In order to provide an EMG signal resulting from a predetermined neuromuscular pathophysiology, we have initially developed a mathmatical model of electromyographic interference pattern(IP). It can be used to study the variation of the IP resulting from morphological and electrophysiological changes occurring in disease states, because the model computes the IP from the underlying fiber and muscle structure. We performed quantative analysis or the model output, focusing on IPs resulting from simulations of dystrophic fiber loss and the MU denervation and reinnervation typical of neuropathies. To discribe the characteristics of IPs associated with these pathologies, a set of frequency domain discriptors, activity, mobility, and complexity were used, as well as several measures of the spectral density function. These discriptors demonstrate distinct patterns of variation corresponding to morphological changes observed in disease states, and closely with results obtained from the classical method, turn/amp technique.
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Evoked potentials(EP) measured with scalp electrodes are often described as a deterministic process corrupted by uncorrelated electrical activities occuring in the brain and These electrical activities(ongoing EEG) refer to noise in EP recording. The Conventional method to determine the EP waveform requires long recording time. Unfortunately most of algorithm developed are too complicated for implementation in real time. Thus, conner EP recording devices use Ensemble average for real time processing. In this paper introduce EP recording hardware for processing advanced algorithm in real tlne. This hardware is composed of DSP chip(TMS320c25) and microcomputer.
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In this paper, computerized BEAM (brain electrical activity map) was implemented for objective and quantitative multichannel EEG analysis. BEAM is calculated by 4 point Interpolation method and number of elements are 5140. Representation methods of BEAH are two. One is dot density method which classify brain electrical potential 9 levels by dot density and the other is color method which classify brain electrical 12 levers by different colors. In this BEAM, instantaneous change and average energy distribution over any arbitrary time interval of brain electrical activity could be observed and analyzed easily.
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It has been shown that some of physiological systems have nonlinear dynamics. The evidences of these nonlinear behaviors make us analyze physiological systems in the new viewpoint. And, nonlinear dynamics can be represented by chaotic behaviors, which is studied by several methods - correlation dimension, return map, power spectrum analysis, etc. This study is on the analysis of nonlinear characteristics of ECG. Data have been acquired from the 20 children (10 - 13 years old). and 30 students (20 -24 years old). We have calculated parameters HR, PR, VAT, TD, TRD from data. and estimated correlation dimension, return map, power spectrum. Results show the nonlinear characteristics of ECG.
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matched filter는 신호와 잡음의 통계적 값을 알고 있을 때 신호대 잡음비를 최대로 하는 filter이다. 그런데, matched filter가 최적화 되려면 잡음이 white noise이어야한다. 그러나 ECG신호에 존재하는 잡음은 여러가지 성분이 공존하는 서로 연관되어있는 잡음이다. 따라서 whitening filter를 사용하여 잡음을 whitening시킨후에 matched filter를 통과 시켜야한다. 본 논문에서는 QRS complex를 검출하기 위한 matched filter에 있어서 LMS방법을 이용한 linear whitening filter와 neural network을 이용한 non-linear whitening filter의 특성을 비교하였다.
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We propose the vocal tract area function as the feature vector of speech recognition. Vocal tract area function is directly related to speech production. The vocal tract area function is not only showing mechanism of speech production but also can be used as an effective feature vector in speech, recognition in this study.
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A Study on the speech processing and coding strategy for cochlear implants have been developed to create a speech signal processing system which extracts stimulus parameter including formants, pitch, amplitude information. In this study we have presented the method which extracts characteristic information of speech signal and adapt patients with hearing handicap.
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We have developed a bioimpedance measurement system for impedance cardiography and pneumography. The system injects 50kHz,
$200mA_{p-p}$ curreng into the thorax and measures the voltage changes using body surface electrodes. We used the four-electrode method for tile measurement of cardiac singnals and two-electrode method for respiratory signals. We developed a Microsoft Windows program for the acquisition, display, storage, and processing of impedance signals. -
I developed a computer program that can be used in studying the human anatomy. The program not only displays anatomical images, but also it gives some questions about the name of organs in the human body and evaluates tile answers. The program helps students scrutinize the detailed human anatomy by providing a way of interactive zooming anatomical images. To make the program more useful, better anatomical images need to be collected, and a context-sensitive search-and-view facility should be equipped with.
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본 연구에서는 개인용 컴퓨터(PC), 모델(MODEM), 그리고 공중회선망(PSTN)을 이용하여 다수의 환자와 병원사이에 환자 정보 및 처방정보를 주고 받을 수 있는 시스템을 구성하였다. 시스템의 구성은 환자에게서 측정된 아나로그 신호를 Analog to Digital Converter에 의해 디지탈 신호로 변환 시킨후 공증회선망을 이용하여 의사 컴퓨터에 측정된 정보를 전해주고 의사의 처방등을 다시 공중회선망을 통해 서어비스받는 형식을 취했다. 본 논문에서는 크게 두가지 점에 초점을 두었다. 첫째로 아나로그신호인 심전도 (ECG:Electrocardiogram)를 컴퓨터에서 사용가능한 화일로 생성하고, 전송해서 치사의 모니터에 본래의 파형과 비교해 왜곡이 적은, 신호로 출력해 주는데 있고, 둘째는 거의 모든 메세지를 한글화 하였고, pull down menu 구동 방식을 채택하여 컴퓨터사용에 초보적인 사람들도 쉽게 사용할 수 있게 하였다.
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A technique for fast image reduction or expansion, in which the reduction(expansion) factor is either any integer or any rational number M/L Is represented. The multiresolution is modeled as an interpolation and filtering followed by a decimation. The model enables frequency domain analysts of the muitiresolution representations as well as convenient design of the Kernels(filters). Using any rin linear phase(Type I) filters a fine to coarse multiresolution structure can be generated.