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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of Biomedical Engineering Research
Journal Basic Information
Journal DOI :
The Korea Society of Medical and Biological Engineering
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Volume & Issues
Volume 16, Issue 4 - Dec 1995
Volume 16, Issue 3 - Sep 1995
Volume 16, Issue 2 - Jun 1995
Volume 16, Issue 1 - Mar 1995
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Synthesis and Physical Properties of Biocompatible and Biodegradable Chitin Derivatives Vl. -Biodegradation of
-Chitin and Its Derivatives by Lysozyme-
Journal of Biomedical Engineering Research, volume 16, issue 3, 1995, Pages 257~264
-chitin derivatives were synthesized by reacting
-chitin with chloropropane, propyleneoxide and chloropropane diol to form propyl chitin (PPC), hydroxypropyl chitin (HPC) and dihydroxypropyl chitin (DHPC), respectively. Cast films from
-chitin derivatives solutions degraded by Iyrozyme in pseudo-extrra cellular fluid (PECF) solutions, at pH1.2, pH6.7 and pH8.2. Chitin derivatives rapidly degraded compared with virgin
-chitin within the first week. DHPC showed the best biodegradation among these derivatives.
The Magnetic Nerve Stimulator Using a Switching Mode Power Supply
Lee, Su-Yeol ; Lee, Seong-Geun ; Lee, Jeong-Han ;
Journal of Biomedical Engineering Research, volume 16, issue 3, 1995, Pages 265~270
An implementation scheme of the magnetic nerve stimulator using a switching mode power supply is proposed. By using a switching mode power supply rather than a conventional linear power supply for chArging high voltage cApacitors, the weight and size of the magnetic net've stimulator can be considerably reduced. Maximum output voltage of the developed magnetic nerve stimulator using the switching mode power supply is 3,000 volts and switching time is about 100 msec Experimental results of human nerve stimulations using the developed stimulator are presented.
Implementation of Real Time 3 channel Transmission System Using ECG Data Compression Algorithm by Max-Min Slope Update
Journal of Biomedical Engineering Research, volume 16, issue 3, 1995, Pages 271~278
An ECG data compression algorithM using max-min slope update is proposed and a real time 3 channel ECG transmission system is implemented using the proposed algorithm. In order to effectively compress ECG data, we compare a threshold value with the max-min slope difference (MMSD) which is updated at each sample values. If this MMSD value is smaller than the threshold value, then the data is compressed. Conversely, when the MMSD value is larger than threshold value, the data is transmitted after storing the value and the length between the data which is beyond previous threshold level. As a result, it can accurately compress both the region of QRS, P, and T wave that has fast-changing and the region of the base line that slope is changing slow. Therefore, it Is possible to enhance the compression rate and the percent roms difference. In addition, because of the simplicity, this algorithm is more suitable for real-time implementation.
A Spatial Average Method Using 2nd Order Sampling in Ultrasonic Doppler System
Journal of Biomedical Engineering Research, volume 16, issue 3, 1995, Pages 279~288
Ultrasonic Doppler systems for the purpose of estimating blood flow velocity, blood flow volume, and flow imaging are commonly used due to advantages of non-invasive and real time observation. Specially, the technical developments of color flow mapping (2-D Doppler) systems have made a relatively rapid progress. However, the 2-D Doppler systems have several problems, such as the range ambiguity, low signal to noise ratio, and slow frame rate. The slow frame rate problem is resolved by using the spatial average which is a method to acquire more data samples for mean frequency estimation. In this paper, spatial average method using the 2nd order sampling instead of quadrature sampling is proposed. The experimental results show that the proposed methods have good performance and easy application to the color flow mapping system.
A New Method of Estimating Coronary Artery Diameter Using Direction Codes
Jeon, Chun-Gi ; Gang, Gwang-Nam ; Lee, Tae-Won ;
Journal of Biomedical Engineering Research, volume 16, issue 3, 1995, Pages 289~300
The conventionally used method requires centerline of vessels to estimate the vessel diameter. Two methods of estimating the centerline of vessels are reported : One is manually observer-defined method. This potentially contributes to inter-and intra-observer variability. And the other is to auto- matically detect the centerline of vessels. But this is very complicated method. In this paper, we propose a new method of estimating vessel diameter using direction codes and position informs:ion without detecting centerline. Since this method detects the vessel boundary and direction code at d same time, it simplifies the procedure and reduces execution time in estimating the vessel diameter. Compared to a method that automatically estimates the vessel diAmeter uslng centerline, our method provides improved accuracy in image with poor contrast, branching or obstructed vessels. Also, this provides a good compression of boundary description, because each direction code element can be coded with 3 bits only, instead of the 4 bytes required for the storage of the coordinates of each border pixel. Our experiments demonstrate the usefulness of the technique using direction code for quantitative analysis of coronary angiography Experimental results Justify the validity of the proposed method.
The Design of High Precision Pre-amplifier for EEG Signal Measurement
Journal of Biomedical Engineering Research, volume 16, issue 3, 1995, Pages 301~308
A high-precision pre-amplifier is designed for general use in EEG measurement system. It consists of signal generator, signal amplifier with a impedance converter, shield driver, body driver, differential amplifier, and isolation amplifier. The combination of minimum use of inaccurate passive components and the appropriate matching of each monolithic amplifiers results in good noise behavior, low leakage current, high CMRR, high input impedance, and high IMRR. The performance of EEG pre-amplifier has been verified by showing the typical EEG pattevn of a nomad person through the clinical experiments.
Development of inside-out probes for both Nuclear Magnetic Resonance Imaging and Nuclear Magnetic Resonance Spectroscopy
Lee, Dong-Hun ; Go, Rak-Gil ; Jeong, Eun-Gi ;
Journal of Biomedical Engineering Research, volume 16, issue 3, 1995, Pages 309~316
RF (radio-frequency) probes of Nuclear Magnetic Resonance are one of the important factors and should be designed and built properly depending upon the geometry of the samples and the information. In general there are two kinds of rf probes : one encircles the sample while the other is placed on the surface of the sample. However, in case that the samples on human internal organs have a tube shape, the two kinds of rf probes, as specified above, are usually unsuitable for the internal imaging due to the degradation of signal-to-noise ratios (SNR's). In this case a probe should be positioned as close to the area as possible by putting the probe in the tubelike sample to improve filling factor In the present study inside-out probes have been constructed in the three different shapes such as an anti-solenoidal, a saddle and a dual surface types. RF-field distributions have also been calculated depending upon the geometrical changes of anti-solenoid probes. Moreover, the performance of the inside-out probes has been checked by measuring SNR's of the images acquired. The inside-out probes constructed in this study produced better SWR's and rf-field uniformity in the area close to the probes in comparing with any other commercial probes. There is a high feasibility that the constructed probes in the present study are applicable to the diagnosis of human bodies.
Real Time Implementittion of Time Varying Nonstationary Signal Identifier and Its Application to Muscle Fatigue Monitoring
Journal of Biomedical Engineering Research, volume 16, issue 3, 1995, Pages 317~324
A need exists for the accurate identification of time series models having time varying parameters, as is important in the case of real time identification of nonstationary EMG signal. Thls paper describes real time identification and muscle fatigue monitoring method of nonstationary EMG signal. The method is composed of the efficient identifier which estimates the autoregressive parameters of nonstationary EMG signal model, and its real time implementation by using T805 parallel processing computer. The method is verified through experiment with real EMG signals which are obtained from surface electrode. As a result, the proposed method provides a new approach for real time Implementation of muscle fatigue monitoring and the execution time is 0.894ms/sample for 1024Hz EMG signal.
Residual Strain Effect on Circumferential Strain on Arterial Cross-Section
Journal of Biomedical Engineering Research, volume 16, issue 3, 1995, Pages 325~330
The distribution of circumferential strain of arterial cross-section Is highest at intima and lowest at adventitia. However, the circumferential strain is theoretically severe at Intima because there is strain concentration. The theoretical degree of the intimal strain can not be explained in physiological condition even though artery is physiologically normal. Physiological adaptation may be undertaken to strain concentration. However, it is not clear, yet. Residual strain of artery is eagerly studied. There is experimental evidence that residual strain exists in artery. When ring of artery is longitudinally cut, it is opened. Assumption is made that intimal strain concentration is reduced with the considel'ation of residual strain. This study experimentally attempts to quantify the effect of residual strain on circumferential strain which is determined under the assumption of zero strain with zero pressure
Biodegradable Inorganic-Organic Composite Artificial Bone Substitute -in vitro biocompatibility evaluation by cell culture-
An, Su-Jin ; Kim, Yo-Suk ; Lee, Chun-Gi ; Seo, Hwal ;
Journal of Biomedical Engineering Research, volume 16, issue 3, 1995, Pages 331~336
A composite material was produced as an artificial bone substitute which is gradually degrAded and replaced by the regenerated natural bones after implantation. To detect the effect of the material on the cell's activity, the composite specimens were placed in MEMs and incubated at
for one week. Human uterus cervical cancer origin HeLa 3 cells and mouse subcutaneous origin L929 cells were cul- tured in the specimen dissolved MEMs for 5 days to investigate cytotoxicity via cell growth rates.
solution was added to the media, to label the HeLa 53 cells, and the released amount of
was measured by a
-counter. On the cell growth investigation, no significant cytotoxic phenomena were revealed in both HeLa S3 and L929 cell cultures. On the released 51CR from the incubated HeLa 53 cells, no significant cell degeneration was observed from the composite embedded MEMs.
Automated radiation field edge detection in portal image using optimal threshold value
Journal of Biomedical Engineering Research, volume 16, issue 3, 1995, Pages 337~344
Because of the high energy of the treatment beam, contrast of portal films is very poor. Many image processing techniques have been applied to the portal images but a significant drawback is the loss of definition on the edges of the treatment field. Analysis of this problem shows that it may be remedied by separating the treatment field from the background prior to enhancement and uslng only the pixels within the field boundary in the enhancement procedure. A new edge extraction algorithm for accurate extraction of the radiation field boundary from portal Images has been developed for contrast enhancement of portal images. In this paper, portal image segmentation algorithm based on Sobel filtration, labelling processes and morphological thinning has been presented. This algorithm could automatically search the optimal threshold value which is sensitive to the variation of the type and quality of portal images.
A Study on Speech Recognition using Vocal Tract Area Function
Journal of Biomedical Engineering Research, volume 16, issue 3, 1995, Pages 345~352
The LPC cepstrum coefficients, which are an acoustic features of speech signal, have been widely used as the feature parameter for various speech recognition systems and showed good performance. The vocal tract area function is a kind of articulatory feature, which is related with the physiological mechanism of speech production. This paper proposes the vocal tract area function as an alternative feature parameter for speech recognition. The linear predictive analysis using Burg algorithm and the vector quantization are performed. Then, recognition experiments for 5 Korean vowels and 10 digits are executed using the conventional LPC cepstrum coefficients and the vocal tract area function. The recognitions using the area function showed the slightly better results than those using the conventional LPC cepstrum coefficients.
Development of Respiratory Monitoring System by Inductive Plethysmography
Kim, Deok-Won ; Yeon, Dong-Su ; Kim, Su-Chan ;
Journal of Biomedical Engineering Research, volume 16, issue 3, 1995, Pages 353~358
The impedance pneumography which is widely used in monitoring respiration is simple to use and noninvasive, but it is sensitive to motion artifacts and insensitive to detect obstructive apnea. A 3-channel respiratory inductive plethysmography (RIP) developed in this study detects inductance change of the inductance band induced by cross-sectional area change of thorax or abdomen as one breathes. It was confirmed that RIP was less sensitive to various motion artifacts but more sensitive to detection of obstructive apnea than impedance pneumography.
Quantitative Evaluation Technique for Healing Fractured Bones Using Ultrasound
Journal of Biomedical Engineering Research, volume 16, issue 3, 1995, Pages 359~366
The parameter, B/A, quantifies nonlinearity of the pressure-density relationship of propagation medium. This study investigated quantitative evaluation technique for healing fractured bones using this ultrasonic nonlinear parameter, B/A, obtained by the second harmonic amplitude method. A series of fundamental experiments were performed on cylinder phantoms made of aluminium, which demonstrated potential capability of nonlinear parameter B/A in the diagnosis of healing fractured bones using ultrasound.
Release of Ampicillin-Na from fibrin glue and its adhesive strength as a tissue adhesive
Journal of Biomedical Engineering Research, volume 16, issue 3, 1995, Pages 367~375
Ampicillin sodium (AMP-Na) was loaded Into fibrin glue (FG) in two different ways and was tried to achieve sustained release from FG. One was loading of AMP-Na in a simple mixing and the other was loading of bovine serum albumin (BSA) microspheres which contained ANP-Na. In case of simple mixing, the release control of AWP-Na from FG was tried by variation of FBNG concentration, but failed. However, the loading of BSA mlcrosphere containing ANP-Na into FG showed sustained re- lease of AMP-Na, especially when microsphere was crosslinked with glutaraldehyde (tO.9 : 33hr). The maximum adhesive strength of FG showed at concentration of FBWG and thrombin, 5.0 % and 25-50 NIHU/ml, respectively. The concentration of Factor Xlll (0-500 U/1g of FBNG) did not affect the adhesive strength of FG. The optimal incubation time was 60 min. The AMP-Na or BSA microsphere which was loaded into FG had no significant effect on the adhesive strength of FG.