Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of Biomedical Engineering Research
Journal Basic Information
Journal DOI :
The Korea Society of Medical and Biological Engineering
Editor in Chief :
Volume & Issues
Volume 17, Issue 4 - Dec 1996
Volume 17, Issue 3 - Sep 1996
Volume 17, Issue 2 - Jun 1996
Volume 17, Issue 1 - Mar 1996
Selecting the target year
Human Postural Balance Control by Visual Stimulation
Journal of Biomedical Engineering Research, volume 17, issue 4, 1996, Pages 417~426
In this paper, we report the effects of visual stimulation patterns in the postural balance control. We used the motor-driven cloth panel and HMD(Head Mounted Display) to evaluate the effect of visual stimulation patterns in the postural balance control. We also investigated the usefulness of HMD in the postural balance rehabilitation training system from the view of reducing the scale of experimental system. Our results showed that a vertical-strip visual pattern was more effective than the others in the postural balance control. It was also indicated that HMD might be applied to clinical use as a new postural balance training system.
A Study on the Image Enhancement of Port Films using Edge-Adaptive Kalmsn filter
Journal of Biomedical Engineering Research, volume 17, issue 4, 1996, Pages 427~432
The primary purpose of port filming is to verify the treatment volume under treatment. Although the image quality with the megavoltage x-ray beam is poorer than with the diagnostic or the simulator film. This paper proposes an edge-adaptive Kalman filter for the image enhancement of port films. Suggested filtering procedure preserves edge information and eliminates edge noise and inside and outside treatment area preserving treatment boundary.
A Study on the Classification of Ultrasonic Liver Images Using Multi Texture Vectors and a Statistical Classifier
Journal of Biomedical Engineering Research, volume 17, issue 4, 1996, Pages 433~442
Since one texture property(i.e coarseness, orientation, regularity, granularity) for ultrasound liver ages was not sufficient enough to classify the characteristics of livers, we used multi texture vectors tracted from ultrasound liver images and a statistical classifier. Multi texture vectors are selected among the feature vectors of the normal liver, fat liver and cirrhosis images which have a good separability in those ultrasound liver images. The statistical classifier uses multi texture vectors as input vectors and classifies ultrasound liver images for each multi texture vector by the Bayes decision rule. Then the decision of the liver disease is made by choosing the maximum value from the averages of a posteriori probability for each multi texture vector In our simulation, we obtained higtler correct ratio than that of other methods using single feature vector, for the test set the correct ratio is 94% in the normal liver, 84% in the fat liver and 86% in the cirrhosis liver.
Quantification of Cerebral Perfusion Reserves using Deadtime Correction of Gamma Camera and Norma1ized Difference Ratio Image in Brain SPECT
Journal of Biomedical Engineering Research, volume 17, issue 4, 1996, Pages 443~448
Sequential brain SPECT imaging has been used to assess the cerebral perfusion reserve(CPR) in cerebrovascular diseases(UD). We have realized parametric images of CPR using deadtime correction of gamma camera and normalized difference ratio. For the anatomical localization of CPR, the parametric images were registered to the contours of the cerebral regions using optimal threshold method, which showed to reflect the CPR more reliably and distinctively than the simple subtraction. We conclude that the quantitative estimation of CPR using normalized difference ratio image could be useflll for the diagnosis and prognostic assessment of CVD.
Development of a High-Resolution Electrocardiography for the Detection of Late Potentials
Journal of Biomedical Engineering Research, volume 17, issue 4, 1996, Pages 449~458
Most of the conventional electrocardiowaphs foil to detect signals other than P-QRS-T due to the limited SNR and bandwidth. High-resolution electrocardiography(HRECG) provides better SNR and wider bandwidth for the detection of micro-potentials with higher frequency components such as vontricular late potentials(LP). We have developed a HRECG using uncorrected XYZ lead for the detection of LPs. The overall gain of the amplifier is 4000 and the bandwidth is 0.5-300Hz without using 60Hz notch filter. Three 16-bit A/D converters sample X, Y, and Z signals simultaneously with a sampling frequency of 2000Hz. Sampled data are transmitted to a PC via a DMA-controlled, optically-coupled serial communication channel. In order to further reduce the noise, we implemented a signal averaging algorithm that averaged many instances of aligned beats. The beat alignment was carried out through the use of a template matching technique that finds a location maximizing cross-correlation with a given beat tem- plate. Beat alignment error was reduced to
0.25ms. FIR high-pass filter with cut-off frequency of 40Hz was applied to remove the low frequency components of the averaged X, Y, and Z signals. QRS onset and end point were determined from the vector magnitude of the sigrlaIL and some parameters needed to detect the existence of LP were estimated. The entire system was designed for the easy application of the future research topics including the optimal lead system, filter design, new parameter extraction, etc. In the developed HRECG, without signal averaging, the noise level was less than 5
. With signal averaging of at least 100 beats, the noise level was reduced to 0.5
, which is low enough to detect LPs. The developed HRECG will provide a new advanced functionality to interpretive ECG analyzers.
Design and Evaluation of a parallel EMG Signal Identifier using Trsnsputers
Journal of Biomedical Engineering Research, volume 17, issue 4, 1996, Pages 459~468
This paper considers the problem of realising a parallel EMG identifier used in FES (functional electrical stimulation) system on a fixed dimension transputer array. This involves using an identifiestion algorithm in the wavelet transform domain. This algorithm have suggested by the authors in a previous paper(6). The transputer serial links permit higtlly varied and economic network-type connections and the structure enables rapid topological reconfiguration. Analysing the results Showed that the Speed-UPS ranged from 1.82 to 3.44 With 2-4 transputers for corresponding model order, and from 1.82 to 3.97 with increasing the model orders when two and four transputers are used respectively.
Digital Scan Converter Algorithm for Ultrsound Sector Scanner
Journal of Biomedical Engineering Research, volume 17, issue 4, 1996, Pages 469~478
In the conventional digital ultrasound scanner, the reflected signal is sampled either in polar coordinates of R-
method, or in Cartesian coordinates of uniform ladder algorithm (ULA). The R-
scan method necessitates a coordinate transform process which makes hardware complex in comparison with ULA scan mrthoA In spite of this complexity, R-
method has a good resolution in ultrasonographic (US) image, since scan direction of the US imaging is a radial direction. In this paper, a new digital scan converter is proposed, which is named the radius uniform ladder algorithm (RULA). The RULA has the rome scan direction as the US scanning in the radial direction and as the display space in the
direction. In tllis new approach, sampled points we uniformly distributed in each horizontal line i.n well as in each radial ray so that the data are displayed in the Cartesian coordinates by the 1-D interpolation process. The propped algorithm has an uniform resolution in the periphery and the center field in comparison with equi-angle ULA and equi-interval ULA. To extend the scan angle, concentric square raster sampling (CSRS) is adopted with reduction of discontinuities on the junctions between horizontal scan and vertical scan. The discontinuities are reduced by using the hmction filtering along the
Crosslinking Ratio Analysis of Type I Atelocollagen
Ahn, Soo-Jin ; Kim, Yo-Sook ; Seo, Hwal ;
Journal of Biomedical Engineering Research, volume 17, issue 4, 1996, Pages 479~490
To utilize collagen as an implantable biomateriall the mcct widely used bovine skin origin Type I collagen was investigated Pepsin treated, Type I atelocollagen was extracted and crosslinked by the ultraviolet(W) ray with wavelength of 254nm or by various concentrations of glutaraldehyde to produce collagen membranes. The crosslink rates of the specimens were observed by a polarized light microscope, a scanning electron microscope, and a Fourier transform infrared (FT-lR) spectrometer. The followings are concluded 1. The collagen membranes produced by both 2.5% glutaraldehyde solution and 254nm UV ray irra- diation demonstrated similar morphologies on polarized light microscopic and scanning electron microscopic views. 2. The chemical structures of the crosslinked membranes by glutaraldehyde over 2.5% in concentrations revealed similar intensities to that of the UV ray irradiated one in FT-lR investigation. 3. To obtain optimal croulink in bovine stalin origin Type I atelocollagen, 2.5% glutaraldehyde solution or UV ray irradiation with 254nm wavelength is acceptable.
Development of Surgical Two-wavelegth Nd:YAG Laser
Journal of Biomedical Engineering Research, volume 17, issue 4, 1996, Pages 491~498
The development of a compact two-wavelength Nd:YAG laser for dental and ENT applications is presented. The Nd:YAG resonator generates either 1.06
m or 1.32
m. The wavelength selection is made at the control panel. The Nd:YAG laser parameters at 1.06
m are ; the maximum pulse duration of 150
s, repetition rates of I-100Hz, and the maximum average power of 25W. At 1.32
m, the pulse duration is the same where the repetition rates and the maximum average power are I-30Hz and lOW respectively. High voltage power supply consists of a simmer module and two identical high voltage DC converters. In order to make a complete medical laser system, an optical fiber delivery unit, foot pedal and water spray handpiece are also developed. The wavelength selection is reliable since no movement of optical or mechanical components is required. The high voltage power supply is compact, easy to be maintained and applicable for other laser systems due to its modular design.
Design and Evaluation of Blood flow Measurement Using Self-mixing type Semiconductor Laser
Kim, Duck-Young ; Lee, Jin ; Kim, Se-Dong ; Ko, Han-Woo ; Kim, Sung-Hwan ;
Journal of Biomedical Engineering Research, volume 17, issue 4, 1996, Pages 499~506
Blood flow velocimeter is an essential device to measure the blood flow in skin tissue. In this study, we developed a high-speed LDV(laser Doppler Velocimeter) that has real time processing capability using a DSP(digital signal processing) chip and is able to continuously measure information about blood-flow based on a noninvasive method using self-mixing type laser diode. This LDV system has a simpler structure than any other typical blood flow velocimeter and is composed of new self-mixing probe, stabilizer circuits DSP board, and interf'ace boule We measured velocity of speaker-unit by operational frequencies to identify Doppler effect of this system, performed clinical experiment on bare finger tip and compared it with a commercial euipment BPM403A(USA).
P-wave Detection Using Wavelet Transform
Journal of Biomedical Engineering Research, volume 17, issue 4, 1996, Pages 507~514
The automated ECG diagnostic systems in hospital have a low P-wave detection capacity in case of some diseases like conduction block. The purpose of this study is to improve the P-wave detection ca- pacity using wavelet transform. The first procedure is to remove baseline drift by subtracting the median filtered signal from the original signal. The second procedure is to cancel ECG's QRS-T complex from median filtered signal to get P-wave candidate. Before we subtracted the templete from QRS-T complex, we estimated the best matching between templete and QRS-T complex to minimize the error. Then, wavelet transform was applied to confirm P-wave. In particular, haiti wavelet was used to magnify P-wave that consisted of low frequency components and to reject high frequency noise of QRS-T complex cancelled signal. Finally, p-wave was discriminated and confirmed by threshold value. By using this method, We can got the around 95.1% P-wave detection. It was compared with contextual information.
A Study on Characteristics of Unsteady Laminar Flows in Squaresectional
Park, G.M. ; Mo, Y.W. ; Cho, B.K. ;
Journal of Biomedical Engineering Research, volume 17, issue 4, 1996, Pages 515~524
The flow characteristics of developing unsteady laminar flow in a square-sectional
curved duct are experimentally investigated by using laser doppler velocimerty (LDV) system with data acquisition and processing system of rotating machinery resolver(RMR) and PHASE software. The major flow characteristics of developing laminar pulsating flows are presented by mean velocity profilel velocity distribution of secondary flow, wall shear stress distributions, entrance lengths according to dimensionless angular frequency(
), velocity amplitude ratio(
), and time-averaged Dean number(
). The velocity profiles and wall shear stress distribution of laminar pulsating flow with dimensionlessangular frequency show the flow characteristics of the quasi-steady laminar flow in a curved duct. The developing region of laminar pulsatile flows in a square-sectional
curved duct is extended to the curved duct angle of approximately
under the present experimental condition.
SSFP Interferometry (SSFPI) Technique Applied to functional MRI - A Fast and Direct Measurement of Magnetic Susceptibility Effect
Journal of Biomedical Engineering Research, volume 17, issue 4, 1996, Pages 525~534
We have developed a fast steady state free precession interferometry (SSFPI) technique which is useful for the fMRl (functional Magnetic Resonance Imaging). As is known, SSFP sequence with a suitable adjustment of Vadient (readeut) allows us to measure precession angle 6 which in tw relates to the field inhomogeneity. Combining the two pulses (known as FID and Echo) in FADE (Fast Acquisition Double Echo) sequence, for example, one can obtain the interference term which is directly related to the precession angle It has been known that a fast high resolution magnetic field mapping is possible by use of the modified FADE sequence or SSFPI, and we have attempted to use the SSFPI technique for the susceptibility-induced fMRl. When the method is applied to the susceptibility effect based functional magnetic resonance imaging (fMRl), it was found that the direct susceptibility effect measurement was possible without perturbations such as the backgrounds and inflow effect. In this paper, simulation results and experimental results obtained with 2.0 Tesla MRI system are presented.
Design of Vibrating Transducer for Implantable Middle Ear Hearing Aid
Journal of Biomedical Engineering Research, volume 17, issue 4, 1996, Pages 535~544
In this paper, we analyzed the coil-magnet type vibrating transducer for the implantable middle ear hearing aid which is appropriate for patient's hearing level, and an experimental transducer system is designed For the objective and quantitative analysis of the transducer, a theoretical equivalent model containing coil, magneto and inner ear is developed To perform effective evaluation of the transducer, a transforming ratio Tr is introduced and its range that is suitable for practical implantable middle ear hearing device is foun4 The result of applying physical parameters of ear system to the proposed analytical model shows that frequency response of the coil magrlet type vibrator is predominantly governed by resistive impedance of the coil rather than inertia effect of the magnet and the inner parameters. In addition, we realized an experimental middle ear hearing aid system to show the theoretical validity of designed system and this will provide the basis of the development for actually implantable system.
Morphological Feature Parameter Extraction from the Chromosome Image Using Reconstruction Algorithm
Journal of Biomedical Engineering Research, volume 17, issue 4, 1996, Pages 545~552
Researches on chromosome are very significant in cytogenetics since a gene of the chromosome controls revelation of the inheritance plasma The human chromosome analysis is widely used to diagnose genetic disease and various congenital anomalies. Many researches on automated chromosome karyotype analysis has been carried out, some of which produced commercial systems. However, there still remains much room for improving the accuracy of chromosome classification. In this paper, we propose an algorithm for reconstruction of the chromosDme image to improve the chromosome classification accuracy. Morphological feature parameters are extracted from the reconstructed chromosome images. The reconstruction method from chromosome image is the 32 direction line algorithm. We extract three morphological feature parameters, centromeric index(C.I.), relative length ratio(R.L.), and relative area ratio(R.A.), by preprocessing ten human chromosDme images. The experimental results show that proposed algorithm is better than that of other researchers'comparing by feature parameter errors.