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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of Biomedical Engineering Research
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Journal DOI :
The Korea Society of Medical and Biological Engineering
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Volume & Issues
Volume 9, Issue 2 - Dec 1988
Volume 9, Issue 1 - Jun 1988
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Korean Vowel Recognition using Peripheral Auditory Model
Yun, Tae-Seong ; Baek, Seung-Hwa ; Park, Sang-Hui ;
Journal of Biomedical Engineering Research, volume 9, issue 1, 1988, Pages 1~10
In this study, the recognition experiments for Korean vowel are performed using peripheral auditory model. In addition, for the purpose of objective comparison, the recognition experiments are performed by extracting LPC cepstrum coefficients for the same speech data. The results are as follows. 1) The time and the frequency responses of the auditory model show that important features of input signal are involved in the responses of inner ear and auditory nerve. 2) The recognition results for Korean vowel show that the recognition rate by auditory model output is higher than the recognition rate by LPC cepstrum coefficients. 3) The adaptation phenomenon of auditory nerve provides useful characteristics for the discrimination of vowel signal.
A Study of on the Optimal Vaccinaton using Pontryagin's Minimum Principle
Jeong, Hyeong-Hwan ; Ju, Su-Won ; Lee, Gwang-U ;
Journal of Biomedical Engineering Research, volume 9, issue 1, 1988, Pages 11~16
The optimum control theory has been applied to the problem of finding the most economic use of active and passive immunization controls. Application of Pontryagin's Minimum Principle to this case, involving functions of delayed control has been demonstrated and a procedure has been developed for the numerical solution of the resulting control problem. Using the numerical procedure, optimum control strategies have been obtained for different values of reported case cost.
Neural Network Modelling and Computer Simulation of the Local Circuits of the Outer Plexiform Layer in a Vertebrate Retina
Journal of Biomedical Engineering Research, volume 9, issue 1, 1988, Pages 17~24
This paper describes a neural network modelling of a vertebrate retina using a discrete-time and discrete-space approach based on neuro-anatomical data, and the computer simulations of the model which approximate the frog/amphibian negro-physiological data. It then compares them and describes how such a model can be beneficially used for confirming the hypothesis of a given neural system and further predict yet unknown experimental data.
Functional Exploration of Vestibulo-Ocular Reflex by a Caloric Stimulation
Nam-Gyun Kim ; Bu- ;
Journal of Biomedical Engineering Research, volume 9, issue 1, 1988, Pages 25~30
In this paper, we proposed the bidirectional mono-thermic test for the functional exploration of the vestibules by considering a temeprature variation in the semicirular canals constant for a short time and an inclination of the semicircular canal plan relative to the vertical. Through the proposed test we showed the evidence of an eventual asymmetry between the responses of right and left vestibules. In view of clinical practice, the proposed test has the advantages of saving the test time, of using only one temperature for the ear irrigation and of making only head movements to the given angle for the stimulation.
Topographic Brain Map of Multi-Channel EEG by Spectrum Analysis Method
Journal of Biomedical Engineering Research, volume 9, issue 1, 1988, Pages 31~36
A personal computer-based brain map is described which will display a gray scale maps showing the distribution of signals derived from the electrical activity of the brain such as EEG or EP This topographic brain mapping system has a flexibility which describe the electrode number and placement mapping onto any shaped space and generate a brain maps by incoorporated the data acquisition and processing software with conventional EEG machine.
Synthesis and Physical Properties of Biodegradable Polymers -Poly (glycine-co-lactic acid) and Poly (glycine-co-glycolic acid)-
Journal of Biomedical Engineering Research, volume 9, issue 1, 1988, Pages 37~46
Synthetic biodegradable polymers are of great interest for biomedical applications such as surgical sutures and drug delivery systems. The copolymers of
matrices having the required permeability for drugs. Poly (glycine.co-lactic acid) and poly (glycine-co-glycolic acid) have been synthesized by ring-opening polymerization. Morpholine-2, 5-diane, lactide, and glycolid have been used as starting materials for polydepsipeptides. The synthesized monomers and copoylmers have been identified by NMR and FT-lR spectrophotometer. The thermal properties and glass transition temperatures (
) of the copolymers have been measured by differential scanning calorimetry. The
values of poly (glycine-co-lactic acid) and poly (glycine co.glycolic acid) are increased with increasing mole fraction of morpholine-2, 5-dione in the copolymers.
Synthesis and Physical Properties of Hydrophilic Biomedical Polymers -Poly (N-substituted Acrylamide) and its Copolymer-
Journal of Biomedical Engineering Research, volume 9, issue 1, 1988, Pages 47~60
N-n-Propylacrylamide has been synthesized from acrylamide and n-propyl bromide. N -n Propylacrylamide was copolymerized with acrylamide at
in tetrahydrofuran using
-azobisisbutyronitrile as initiator. The synthesized monomer and copolymers have been identified by NMR and FT-lR spectrophotometer. The swelling properties of the crosslinked homopolymers were investigated at different temperatures. Three types of hydration layer around the back-bone structure of gels were determined. The thermal properties of copolymers were also measured by differential scanning calorimeter and thermogravimetry. As the amounts of N-n-propylacrylamide are increased, the enthalpic changes associated with endothermic transition and glass transition of the copolymers are decreased. As the amount of N-n-propylacrylamide is increased, the thermal stability is increased. The activation energies of thermal decomposition and dehydration for the poly (acrylamide-co-N -n-propylacrylamide) have been evaluated by Freeman and Carroll's method. As the amounts of N-n- propylacrylamide are increased, the activation energies of thermal decomposition and dehydration are increased.
Local Contrast Enhancement of X-ray Chest Image using Adaptive Algorithm
Journal of Biomedical Engineering Research, volume 9, issue 1, 1988, Pages 61~66
Because the amount of radiation emerging from the thorax behind the lungs is often literally thousands of times that exiting behind the mediastinum, the dynamic range of X-ray chest image is very large. In order to solve the dynamic range problem, we propose a signal adaptive algorithm which enhances the local contrast and contracts the enhancement of quantum noise by local mean/valiance estimator.
Synthesis of Poly(hydroxypropyl methacrylate-co-N-vinylpyrrolidone) hydrogel and its Application to the Contact Lens
Journal of Biomedical Engineering Research, volume 9, issue 1, 1988, Pages 67~72
Poly (HPMA/NVP) hydrogel was synthesized according to the composition and the con- centration of the crosslinking agent. The swelling degree of the P(HPMA/NVP) hydrogel decreased with increasing of P(HPMA) composition and crosslinking agent. The glass transi- tion and softening temperatures of the P(HPMA/NVP) increased with increasing of P(HPMA) composition. The composition of P(HPMA/NVP) : 70/30 and the concentration of the crosslin- king agent of 0.5 wt % gave the optimum condition in the application to the contact lens. There were also adequate in the mechanical, refractive properties and in vivo test in the P(HPMA/ NVP): 70/30 system.
Formation of Polyelectrolyte Complex Hydrogel and its Application to Drug Delivery System
Cho, Chong-Su ; Kim, Seun-Ung ; Kim, Hack-Joo ;
Journal of Biomedical Engineering Research, volume 9, issue 1, 1988, Pages 73~78
The polymer electrolyte complex hydrogels consisting of poly (methacrylic acid) and poly (4-vinylpyrridine) were formed and 5-flurouracil and pilocarpine drugs were loaded on their hydrogels. Cumulative 5-FU released from PEC hydrogel was affected by the degree of loading and release rate of 5-FU was followed by the monolithic type. Cumulative pilocarpine released from PEC hydrogel increased by ionic interaction between cationic pilocarpine and anionic PMA. Release rate showed the zero order after burst effect.
Design of Pipeline Processor for ECG Feature Extraction
Journal of Biomedical Engineering Research, volume 9, issue 1, 1988, Pages 79~86
This paper describes the design of a hardware systenl for ECG feature extraction based on pipeline processor consistinsf of three microcomputers. ECG data is acquisited by 12 bit A/D converter with hardware QRS triggered detector. Four diagnostic parameters parameters-heart rate, morPhology, axis, and 57 segment-are used for the classification and the diagnosis of arrhythmia. The functions of the main CPU were distributed and processed with three microcomputers. Therefore the effective data process and the real time process using microcomputer can be obtained. The interconnection structure consisting of two common memory units is designed to decrease the delay time caused by data transfer between processors and designed by which the delay time can be taken Loye of one clock period.
A Study on the Improvement a Lateral Resolution of the Ultrasound Imaging System
Journal of Biomedical Engineering Research, volume 9, issue 1, 1988, Pages 87~92
In this paper, a new focusing method, to be called the pipelined sampled delay focusing (PSDF), is implemented. This method improves the lateral resolution in ultrasound imaging system. In PSDF, the analog belay lines are no longer necessary because sampling sum process can replace the conventional delay sum process. Also, the method offers continuous dynamic focusing on the resolution pixel basis, and eliminates the constraint that the maximum delay time is less than the sampling interval. Second order sampling is adopted in order to extend the sampling interval.
The Auto Regressive Parameter Estimation and Pattern Classification of EKS Signals for Automatic Diagnosis
Journal of Biomedical Engineering Research, volume 9, issue 1, 1988, Pages 93~100
The Auto Regressive Parameter Estimation and Pattern Classification of EKG Signal for Automatic Diagnosis. This paper presents the results from pattern discriminant analysis of an AR (auto regressive) model parameter group, which represents the HRV (heart rate variability) that is being considered as time series data. HRV data was extracted using the correct R-point of the EKG wave that was A/D converted from the I/O port both by hardware and software functions. Data number (N) and optimal (P), which were used for analysis, were determined by using Burg's maximum entropy method and Akaike's Information Criteria test. The representative values were extracted from the distribution of the results. In turn, these values were used as the index for determining the range o( pattern discriminant analysis. By carrying out pattern discriminant analysis, the performance of clustering was checked, creating the text pattern, where the clustering was optimum. The analysis results showed first that the HRV data were considered sufficient to ensure the stationarity of the data; next, that the patern discrimimant analysis was able to discriminate even though the optimal order of each syndrome was dissimilar.
Power Spectral Estimation of Background EEG with LMS PHD
Journal of Biomedical Engineering Research, volume 9, issue 1, 1988, Pages 101~108
In this paper the power spectrum of background EEG is estimated by the LMS PHD based on least mean square. At the power spectrum estimatiom, the stocastic process of background EEG is assumed to consist of the nonharmonic sinusoid and the white noise. In the LMS PHD the model parameters are obtained by the least mean square at optimal order which is obtained from the fact that the eigenvalue's fluctuation of autocorrelation matrix of the normal back-ground EEG is smaller at some order than at other order when the power spectrum of background EEG is esitmated by PHD. The optimal order of this model is the 6-th order when the eigenvalue's fluctuation of autocorrelation matrix of background EEG is considered. The estimation results are with compared the results from the Maximum Entropy Spectral Estimation and Pisarenko Harmonic Decomposition. From the comparison results. The LMS PHD is possible to estimate the power spectrum of background EEG.
Measurement of Cardiac Function using Impedance Cardiography
Journal of Biomedical Engineering Research, volume 9, issue 1, 1988, Pages 109~116
In this paper, principles of impedance tenchinque and relationship between stroke volume and impedance change were theoretically explained. An impedance cardiograph was designed and constructed. Its reproducibility was verified by experiment. Until now, the peak point of dZ/dt waveform, first derivative of impedance change(
Z) , has been detected by software technique requiring considerable time to process. However in this paper its peak point was found using hardware for saving processing time. Useful cardiac parameters such as stroke volume and contractility of cardiac muscle were measured noninvasively. The reproducibility of the instrument was measured to be better(less than 10%) than that of clinical standard method such as thermodilution (more than 30%). Hence impedance cardiography was found to be better techique for monitoring stroke volume and myocardial contractility for pre and post operation, and pharmacological studies.
잡음동기형 표본화 제어기에 의한 전력선 잡음의 적응제거
Ko, Han-Woo ; Kim, Won-Ky ; Lee, Gun-Ki ;
Journal of Biomedical Engineering Research, volume 9, issue 1, 1988, Pages 117~124
A new implementation of a noise tracking filter is prposed to eliminate time-varying 60 Hz noise and its harmonics and baselins wandering in biological signals. This technique was applied to ECG. Filter's notch frequency could track the power line frequency well and it showed much better characteristics than the conventional method.
MRI의 현황과 전망
Journal of Biomedical Engineering Research, volume 9, issue 1, 1988, Pages 125~130
In the conventional infrared imaging system, complex infrared lens systems are usually used for directing collimated narrow infrared beams into the high speed 2-dimensional optic scanner. In this paper, a simple reflective infrared optic system with a 2-dimensional optic scanner is proposed for the realization of medical infrared thermography system. It has been experimentally proven that the intfrared thermography system composed of the proposed optic system has the temperature resolution of
under the spatial resolution of lmrad, the image matrix size of
and tile imaging time of 4 seconds.
Journal of Biomedical Engineering Research, volume 9, issue 1, 1988, Pages 131~134
In this paper, MIIS (Medical Image Information System) has been designed and implemented using INGRES RDBMS, which is based on a client/server architecture. The implemented system allows users to register and retrieve patient information, medical images and diagnostic reports. It also provides the function to display these information on workstation windows simultaneously by using the designed menu-driven graphic user interface. The medical image compression/decompression techniques are implemented and integrated into the medical image database system for the efficient data storage and the fast access through the network.
일본ME학회 학술대회 참관기
Journal of Biomedical Engineering Research, volume 9, issue 1, 1988, Pages 135~138
In this paper, computerized BEAM was implemented for the space domain analysis of EEG. Trans-formation from temporal summation to two-dimensional mappings is formed by 4 nearest point inter-polaton method. Methods of representation of BEAM are two. One is dot density method which classify brain electrical potential 9 levels by dot density of gray levels and the other is colour method which classify brain electrical 12 levels by red-green colours. In this BEAM, instantaneous change and average energy distribution over any arbitrary time interval of brain electrical activity could be observed and analyzed easily. In the frequency domain, the distribution of energy spectrum of a special band can easily be distinguished normality and abnormality.