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 1991 Issue 11
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체내의 유익한 정보를 검출하기 위해서는 생리학적으로 부작용이 얼고 정확한 정보를 신속히 걸출하여야만 한다. 이를 위해서는 무침습적으로 측정하거나 무침습적이지 못할 경우, 침습을 최소화하기 위한 센서의 소형화가 불가피하다. 최근 집적회로 공정 기술인 미세 가공 기술을 응용하여 소형화될 뿐 아니라 고도의 기능을 가진 센서가 연구되고 있다. 또한 센서에 집적회로와 액류에이터를 일체화한 집적화 센서도 연구되고 있다. 여기서는 현재 사용되고 있는 미세 가공 기술들 중 식각 기술과 식각 중지 기술, 접합 기술에 관해 언급하였다. 그리고, 이러한 기술을 이용하여 제작된 마이크로 센서(Micro Sensor)에 관해 간략히 살펴본다.
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In the field of prosthesis arm control, tile pattern classification of the EMG signal is a required basis process and also the estimation of force from col looted EMG data is another necessary duty. But unfortunately, what we've got is not real force but an EMG signal which contains the information of force. This is the reason why he estimate the force from the EMG data. In this paper, when we handle the EMG signal to estimate the force, spatial prewhitening process is applied from which the spatial correlation between the channels are removed. And after the orthogonal transformation, which is used in the force estimation process the transformed signal is inputed into the probabilistic model for pattern classification. To verify the different results of the multiple channels, SNR(signal to noire ratio) function is introduced.
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The object of speech processor for cochlear implants is to deliver speech information to the central nerve system. In this study we have presented the method which simulate speech processing and coding strategy for cochlear implants and simulated two different processing methods to the 12 adults with normal ears. The formant sinusoidal coding was better than the formant pulse coding In the consonant perception test and learning effects.(p < 0.05)
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본 논문에서는 저주파의 envelope와 고주파의 neural oscillation 신호의 곱으로 이루어진 EEG 신호의 envelope를 추출을 하기 위하여 multiplicative homomorphic 시스템을 사용하였다. 이 방법은 다른 방법에 비하여 처리 과정이 간단하여 계산량이 감소되어 실시간 envelope 추출의 가능성을 보였으며, 또 neural oscillation signal의 주파수가 변하여도 정확한 envelope 추출할 수 있는 우수한 적응력을 보였다.
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In order to cluster the Input pattern neatly, some neural network modified from Kohonen's self organizing feature map is introduced and Korean phoneme recognition experiments are performed using the modified self organizing feature map(MSOFM) and the auditory model.
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There exists a transform trellis code that is optimal for stationary Gaussian sources and the squared-error distortion measure at all rates. In this paper, we train an asymptotically optimal version of such a code to obtain one which is matched better to the statistics of real world data. The training algorithm uses the M-algorithm to search the trellis codebook and the LBG-algorithm to update the trellis codebook. To adapt the codebook for the varying input data. we use two gain-adaptive methods. The gain-adaptive scheme 1, which normalizes input block data by its gain factor, is applied to images at rate 0.5 bits/pixel. When each block is encoded at the same rate, the nonstationarity among the block variances leads to a variation in the resulting distortion from one block to another. To alleviate the non-uniformity among the encoded image, we design four clusters from the block power, in which each cluster has its own trellis codebook and different rates. The rate of each cluster is assigned through requiring a constant distortion per-letter. This gain-adaptive scheme 2 produces good visual and measurable quality at low rates.
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The discrete cosine transform (DCT)-based progressive and hierarchical coding schemes developed by the International Standardization Organization (ISO) Joint Photographic Experts Groups (JPEG) are implemented and evaluated for the application of medical image communication. For a series of head sections of magnetic resonance images, a compression ratio of about 10 is obtained by the algorithm without noticeable image degradation.
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Many techniques have been used for medial image compression. Its first requirement is "Errorless" or, "Completely Reversible". Under this condition, we have increased the performance of compression using Space Filling Curve. This method converts source image in direction of Hilbert's curve path in order to ate average length longer thar in traditoinal horizental normal path. After that, we have applied RLC and reduced statistical redundancy by Huffman Coding. By this method, we have obtained more efficient results of RLC.
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A new approach to texture classification for ultrasound liver diagnosis using run difference matrix was developed. The run difference matrix consists of the gray level difference along with distance. From this run difference matrix, we defined several parameters such as LDE, LDEL, NUF, SMO, SMG, SHP etc. and three vectors namely DOD, DGD and DAD. Each parameter value calculated in fatty cirrhotic, chronic hepatitic and normal liver mage was plotted in two dimensional plane. We compared our results with run length method. There are several advantages of run difference matrix method over the run lengths. 1) It is more sensitive to small difference of gray level distribution. 2) The parameters provide more statistically significant value. Images were classified with the extracted parameters to each diseases using neural networks. In preliminary clinical exprements, this approach showed satisfying results.
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This paper describes a design of transducer for non-invasively detecting pressure radial pulse wave in aterial system and a recording system that for the studing the aterial pulse diagnosis of korean traditional medicine. The mechanism of transducer is composed of sensing mechanism, pressure sensor, conditioning amplifier. The variation of radial pulse pressure in the sensing mechanism is converted to the electric signal by piezo-resistive pressure sensor and it converted to the digital signal after preprocessing via A/D converter. The converted signals inputed to the computer as data files and then it display to the monitor for waveform watching and this datas can be used as the aterial pulse diagnosis data. This system effectively detect non-differential radial pulse wave and we conside that if analizing the recorded radial pulse wave, compared each other, it can be helpful in quantify radial pulse wave diagonosis of the Korean traditional medicine.
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Choi, Jin-Wook;Lee, Kyu-Bak;Koh, Young-Hwan;Kim, Hwoa-Ryoung;Jung, Dae-Young;Kim, Cheol-Sang;Park, Jae-Hyoung;Min, Byoung-Goo 70
좌심실보조기의 임상응용범위를 넓히기 위해서 개심술을 하지 않고 좌심실보조기를 적용할 수 있도록 캐뉼라형 좌심실보조기를 이용한 보조순환 실험을 하였다. 좌심실 보조기는 모터의 회전력이 PVC 벨로우즈를 수측, 팽창시키는 전기유압식으로 구동되며 환자는 양쪽 대퇴동맥을 통하여 보조순환을 받도록 되어 있다. 두차례의 동물실험을 통하여 대퇴동맥을 통한 보조 순환방식의 가능성 및 그 효과에 대해서 관찰하였다. 첫 실험은 12kg 개를 이용하여 셀딩거 방법으로 뮬린형 카테터를 디퇴동맥으로 삽입히여, 캐뉼라형 보조순환방법의 가능성을 확인하였고, 두번째 동물실험에서는 내경 4.8 mm의 PVC 카테터를 이용하여 좌심방에 유입카테터를 연결하고 대동맥에 유출카테터를 연결하여 보조순환에 의한 대동맥압의 변화와 혈류량의 변화를 관찰하였다. 보조순환동안 개의 동맥압을 100mmHg로 유지할 수 있었으며, 좌심실내압이 감소하는 것을 관찰할 수 있었다. -
Digital FHR monitoring system based on the personal computer combined wi th the digital signal processing (DSP) board was implemented. The DSP board acquires and digitally processes ultrasound fetal Doppler signal for digital rectification, envelope detection, autocorrealtion function calculation and its peak position detection. The personal computer interfaced with the DSP board is in charge of graphic display, hardcopy, data taransmission and on-line analysis of fetal heart rate change including on-line warning system, base-line estmation, acceleration, deceleration and variability. The advantages of PC-DSP based system can be summarized as follows: 1) Minimum hardware realization. 2) Increased flexibility. 3) Total care system.
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A method in order to restore the body movement by means of Functional Electrical Stimulation (FES) was considered. Multichannel EMG signals from a normal subject during the rolling-over motion were measured and analyzed. The results of the experiment indicated the synergetic role of the muscles during the desired motion.
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As the ensemble averaged dZ/dt signal during exercise is smoothed, it is difficult to find the distinctive marks. The cross correlation function was made use of estmating these marks. LVET was calculated based on the calculated parameters of the characteristic points. For the accuracy validation, LVET calculated by hand, by the ensemble average and the cross correl at ion were compared.
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We studied the characteristics of the compound electrode and found that the compound electrode provides the four-electrode method in a compact form. We developed a new method of measuring the skin impedance using simple electrodes at low frequencies. At high frequencies where the effect of internal tissue impedance is not negligible, we used the compensation method using compound electrodes since they measure the voltage right under the skin. At 50 kHz, we measured the real part of the skin impedance of less than
$80\;{\Omega}$ on the thorax. -
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A three-dimensional finite element model of a ligamentous two motion segments (L4-S1) was developed to investigate its dynamic response. A number of parameters like the intradiscal pressure, forces in ligaments. and across facet joints in response to a sinusoidal axial compression force (-360 N to -440 N at 5 Hz) were predicted. The increase in the parameters varied from 12% to as high as 50% in comparison to response for a static load of 400 N. The predicted parameters also revealed a distortion and a phase shift in comparison to the applied sinusoidal signal. These changes may lead to degenerative changes seen clinically in persons exposed to a chronic vibration environment over time.
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Hypertension is a medical problem with no permanent cure. Extended hypertension can cause various cardio vascular diseases, cerebral vascular diseases, and circulatory system trouble. Medical treatment at present does not consider circadian variation of blood pressure in patients ; therefore, the problem of over-reduction of blood pressure through drugs sometimes occurs. This paper presents a prediction model of circadian variation or moon blood pressure employing the endocrine grand and the autonomic nervous system.
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Chung, Chan-Il;Chang, Jun-Keun;Kim, Gi-Joon;Choi, Jin-Wook;Kim, Cheol-Sang;Kim, Hee-Chan;Han, Dong-Chul;Min, Byoung-Goo 123
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Skin conductance level(SCL) was measured in 51 paralytic subjects. The measurements are made on the back of the second metacarpal according to the Zhang's method. Physical constitution is classified based on the Lee's physical constitution theory. The following tendencies were observed. In paralytic examinees, SCL of micro-positive physical constitution is generally higher than that of micro-negative and macro-negative physical constitution. And as Setting old, SCL is slightly decreased.
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This paper describes the ECG pattern recognition using the syntatic pattern recognition algorithm. The algorithm uses the BNF rule wi th the semantic evaluation which has the structural Information of the ECG. This algorithm is constructed with (1) removing the baseline drift by the Cubic spline function and exract the significant point by the line-approximation algorithm, (2) syntatic peak recognition algorithm with the extracted significant point, (3) produce the token which is used pattern recognition, (4) pattern recognition of the ECG by the syntatic pattern recognition algorithm, (5) extract the parameter with the pattern recognized ECG signal.
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혈중 산소 포화도는 생체의 중요한 정보로써 많은 학자들이 산소 포화도를 비추출방법으로 측정하기 위한 이론과 센서의 제작에 관해서 연구를 하고 있다. 혈액에서의 빗의 흡수(Absorption)와 산란(Scattering)에 관한 이론 연구가 Ishimaru, Takatani. Johnson 등의 학자들에 의해 진행되었고, Polanyi, Hehir, Johnson, Schmitt등에 의해서 센서 구조와 센서 제작에 관한 연구가 진행되고 있다. 산소 포화도를 직접 혈액을 추출하지 않고 비추출식으로 측정하게 된다면, 최근 우리나라에서도 인공 심장이 개발되고 있으므로 인공 심장의 제어에 필요한 정보로써 산소 포화도를 신속 정확하게 공급할 수 있어 인공 심장의 정확한 재어가 가능하다. 그리고 반도체 기술을 이용하여 소형화가 가능하므로 생체 적용성(Biocompatibility)이 우수하고 다기능을 가진 센서를 만들 수 있다. 본 논문에서는 비추출식으로 산소 포화도를 측정하기 위한 투과광 방식과 반사광 방식의 기본 이론 및 센서의 설계를 위한 기본 이론을 분석하였다. 그리고, 적색광의 사용가능성을 테스트하기 위한 모의 실험도 행하였다.
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In this study, we have developed 64 channel computerized cardiac mapping system using micro-computer for basic research of electrophysiology and electrical propagation in cardiac arrhythmias. The significant problems of this study are the simultaneous acquisition of large amount data at 64 sites, the need of accurate and rapid analysis, and the effective display of the analyzed data. To solve these problems, we made 64 channel signal pre-processing board in order to amplify and filter the raw signals. And the software for cardiac isochronous mapping which were presented immediately via computer-generated graphics has been developed. This system is expected to enable us to study pathophysiology of cardiac arrhythmia and to improve the results of diagnosis and surgical treatment for cardiac arrhythmia.