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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
Editor in Chief :
Volume & Issues
Volume 27, Issue 6 - Dec 2006
Volume 27, Issue 5 - Oct 2006
Volume 27, Issue 4 - Aug 2006
Volume 27, Issue 3 - Jun 2006
Volume 27, Issue 2 - Apr 2006
Volume 27, Issue 1 - Feb 2006
Selecting the target year
Ex Vivo MR Diffusion Coefficient Measurement of Human Gastric Tissue
Mun Chi-Woong ; Choi, Ki-Sueng ; Nana Roger ; Hu, Xiaoping P. ; Yang, Young-Il ; Chang Hee-Kyung ; Eun, Choong-Ki ;
Journal of Biomedical Engineering Research, volume 27, issue 5, 2006, Pages 203~209
The aim of this study is to investigate the feasibility of ex vivo MR diffusion tensor imaging technique in order to observe the diffusion-contrast characteristics of human gastric tissues. On normal and pathologic gastric tissues, which have been fixed in a polycarbonate plastic tube filled with 10% formalin solution, laboratory made 3D diffusion tensor Turbo FLASH pulse sequence was used to obtain high resolution MR images with voxel size of
field of view in conjunction with an acquisition matrix of
. Diffusion weighted- gradient pulses were employed with b values of 0 and
in 6 orientations. The sequence was implemented on a clinical 3.0-T MRI scanner(Siemens, Erlangen, Germany) with a home-made quadrature-typed birdcage Tx/Rx rf coil for small specimen. Diffusion tensor values in each pixel were calculated using linear algebra and singular value decomposition(SVD) algorithm. Apparent diffusion coefficient(ADC) and fractional anisotropy(FA) map were also obtained from diffusion tensor data to compare pixel intensities between normal and abnormal gastric tissues. The processing software was developed by authors using Visual C++(Microsoft, WA, U.S.A.) and mathematical/statistical library of GNUwin32(Free Software Foundation). This study shows that 3D diffusion tensor Turbo FLASH sequence is useful to resolve fine micro-structures of gastric tissue and both ADC and FA values in normal gastric tissue are higher than those in abnormal tissue. Authors expect that this study also represents another possibility of gastric carcinoma detection by visualizing diffusion characteristics of proton spins in the gastric tissues.
A Biomechanical Analysis of an Interspinous Distraction Device for Treatment of Lumbar Spinal Stenosis
Lee Hui-Sung ; Chen Wen Ming ; Song Dong-Ryul ; Kwon Soon-Young ; Lee Kwon-Yong ; Lee Sung-Jae ;
Journal of Biomedical Engineering Research, volume 27, issue 5, 2006, Pages 210~217
Many types of interspinous distraction devices (IDDs) have been recently developed as an alternative surgical treatment to laminectomy and fusion with pedicle screws for the treatment of the lumbar spinal stenosis (LSS). They are intended to keep the lumbar spine in a slightly flexed posture to relieve pain caused by narrowing of the spinal canal and vertebral foramen. However, their biomechanical efficacies are not well known. In this study, we evaluated the kinematic behaviors and changes in intradiscal pressure (IDP) of the porcine lumbar spine implanted with IDD. For kinematics analysis, five porcine lumbar spines (L2-L6) were used and the IDD was inserted at L4-L5. Three markers (
) were attached on each vertebra to define a rigid body motion for stereophotogrammetric assessment of the spinal motion in 3-D. A moment of 7.5Nm in flexion-extension, lateral bending, and axial rotation were imparted with a compressive force of 700N. Then, IDD was implanted at L3-L4. IDPs were measured using pressure transducer under compression (700N) and additional extension moment (700N+7.5Nm). In kinematic behaviors, insertion of IDD resulted in statistically significant decrease 42.8% at the implanted level in extension. There were considerable changes in ROM at the adjacent levels, but statistically insignificant. In other motions, there were no significant changes in ROM as well regardless of levels. IDPs at the surgical level (L3-L4) under compression and extension moment decreased by 12.9% and 18.8% respectively after surgery (p<0.05). At the superiorly adjacent levels, IDPs increased by 19.4% and 12.9% under compression and extension, respectively (p<0.05). Corresponding changes at the inferiorly adjacent levels were 29.4% and 6.9%, but they were statistically insignificant (p>0.05). The magnitude of pressure changes due to IDD, both at the operated and adjacent levels, were far less than the previously reported values with conventional fusion techniques. Our experimental results demonstrated the IDDs can be very effective in limiting the extension motion that may cause narrowing of the spinal canal and vertebral foramens while maintaining kinematic behaviors and disc pressures at the adjacent levels.
Surface Immobilization of
onto Biodegradable Polymer for Tissue Regeneration
Lee, S.G. ; Lee, J.B. ; Yu, S.M. ; Park, J.C. ; Choi, J.B. ; Kim, J.K. ;
Journal of Biomedical Engineering Research, volume 27, issue 5, 2006, Pages 218~223
We examined the effects of
-glucan-reinforced PLGA film and scaffold on HDFs (human dermal fibroblast) attachment and proliferation. The PLGA films were prepared by simple solvent-casting method. The prepared films were grafted with
in various ratios after plasma treatment on surface. The surface of the film was characterized by contact angle measurement, scanning electron microscope (SEM), and Fourier-transform infrared spectrophotometer (FT-IR). The amount of
in the prepared film was indirectly determined by phenol-sulfuric acid method. The HDFs (Human dermal fibroblasts) were used to evaluate the cell attachment and proliferation on PLGA specimens before and after plasma/
treatment. The result showed that the plasma treated groups exhibited more mont of
might be grafted than the non plasma treated groups. Cell attachment was significantly enhanced in the plasma/
grafted group after 4 hours incubation (p<0.05) due to the improved hydrophilicity and cytoactivity effect of the
. The cell proliferation of plasma/
(2mg/ml) grafted group was the highest rate among the groups (p<0.05).
Dual Electrospinning to Manufacture Hybrid Nanofibrous Scaffold using Polyurethane and Poly(Ethylene Oxide)
Shin, Ji-Won ; Shin, Ho-Jun ; Heo, Su-Jin ; Kim, Ji-Hee ; Hwang, Young-Mi ; Kim, Dong-Hwa ; Shin, Jung-Woog ;
Journal of Biomedical Engineering Research, volume 27, issue 5, 2006, Pages 224~228
The object of this study is to investigate the potential of dual-electrospun polymer based structure for vascular tissue engineering, especially for the medium or small sue blood vessels. Polyurethane(PU), which is known to be biocompatible in this area, was electrospun with poly(ethylene oxide) (PEO). Concentration of PU was fixed at 20wt%, while that of PEO was set from 15 to 35wt%. Morphological features were observed by SEM image and measurement of porosity and cellular responses were tested before and after extracting PEO from the hybrid scaffolds by immersing the scaffolds into distilled water. The diameter of PEO fibers were ranged from 200nm to 500nm. The lower concentration of PEO tended to show beads. The porosity of the scaffolds after extracting PEO was highly increased with higher concentration of PEO as expected. Also, higher proliferation rate of smooth muscle cells was observed at higher concentration of PEO than at the lower concentration and without PEO. As conclusions, this dual electrospinning technique combined with PU and PEO is expected to overcome the current barrier of cell penetration by providing more space for cells to proliferation.
A Study of Testing Method for Diagnostic Ultrasonic Array Probe through Pattern Analysis of Acoustic-Fields with Probe Channel Division
Yoo, B.C. ; Choi, H.H. ; Noh, S.C. ; Min, H.K. ; Kwon, J.W. ;
Journal of Biomedical Engineering Research, volume 27, issue 5, 2006, Pages 229~236
The acoustic field analysis method is the superior calibration method for rectifying the ultrasonic probe sensitivity. This method also can be applied to evaluate the probe performance in clinical fields without numerical analysis and precise measurements. In this paper, we propose the method of acoustic field pattern analysis with probe channel division for the evaluation of diagnostic ultrasound probe characterization. In order to verify our purpose, we performed a set of experiments. We measured the acoustic-field pattern of the three inferiority probes by channel division to evaluate an acoustic field distribution and impulse response characteristics. By comparing the results of acoustic field measurement method with that of conventional method such as impulse response and live image test for linear array probes, it is demonstrated that the ultrasound field measurement method is more effective then conventional method in detection of defective elements.
Performance Improvement of EMG-Pattern Recognition Using MFCC-HMM-GMM
Choi, Heung-Ho ; Kim, Jung-Ho ; Kwon, Jang-Woo ;
Journal of Biomedical Engineering Research, volume 27, issue 5, 2006, Pages 237~244
This study proposes an approach to the performance improvement of EMG(Electromyogram) pattern recognition. MFCC(Mel-Frequency Cepstral Coefficients)'s approach is molded after the characteristics of the human hearing organ. While it supplies the most typical feature in frequency domain, it should be reorganized to detect the features in EMG signal. And the dynamic aspects of EMG are important for a task, such as a continuous prosthetic control or various time length EMG signal recognition, which have not been successfully mastered by the most approaches. Thus, this paper proposes reorganized MFCC and HMM-GMM, which is adaptable for the dynamic features of the signal. Moreover, it requires an analysis on the most suitable system setting fur EMG pattern recognition. To meet the requirement, this study balanced the recognition-rate against the error-rates produced by the various settings when loaming based on the EMG data for each motion.
Development of the Gait Rehabilitation Equipment for Hemiplegic Patients after Stroke
Nam, T.W. ; Cho, J.M. ; Kim, S.H. ; Lim, J.H. ;
Journal of Biomedical Engineering Research, volume 27, issue 5, 2006, Pages 245~249
The aim of this study is to design and develop the gait rehabilitation equipment that judge patient's movement of his/her center of gravity using pressure sensors, and to aid hemiplegic patients to balance themselves using an automatic stepper that changes the patient's center of gravity. It is hard to bear the weight on the affected side for hemiplegic patients. The gait rehabilitation equipment detects the footing phase of hemiplegic patient during training and moves the unaffected footing side of the stepper up and moves the affected footing side down simultaneously so that the patient's center of gravity can shift from unaffected side to affected side. The gait rehabilitation system was developed and applied for hemiplegic patients during exercise. Eight hemiplegic patients and one normal adult were studied. The developed gait rehabilitation system could judge not only the normal adult's intention but also the patient's intention to move his/her center of gravity. Even though the most of hemiplegic patients exercised in automatic mode and a few hemiplegic patients exercised in manual mode, the developed gait rehabilitation system can aid the hemiplegic patients to train more easily.
A Study for Detecting a Gazing Point Based on Reference Points
Kim, S.I. ; Lim, J.H. ; Cho, J.M. ; Kim, S.H. ; Nam, T.W. ;
Journal of Biomedical Engineering Research, volume 27, issue 5, 2006, Pages 250~259
The information of eye movement is used in various fields such as psychology, ophthalmology, physiology, rehabilitation medicine, web design, HMI(human-machine interface), and so on. Various devices to detect the eye movement have been developed but they are too expensive. The general methods of eye movement tracking are EOG(electro-oculograph), Purkinje image tracker, scleral search coil technique, and video-oculograph(VOG). The purpose of this study is to embody the algorithm which tracks the location of the gazing point at a pupil. Two kinds of location data were compared to track the gazing point. One is the reference points(infrared LEDs) which is effected from the globe. Another is the center point of the pupil which is gained with a CCD camera. The reference point was captured with the CCD camera and infrared lights which were not recognized by human eyes. Both of images which were thrown and were not thrown an infrared light on the globe were captured and saved. The reflected reference points were detected with the brightness difference between the two saved images. In conclusion, the circumcenter theory of a triangle was used to look for the center of the pupil. The location of the gazing point was relatively indicated with the each center of the pupil and the reference point.
Development of An Intelligent Tilt Table for Paralytic Patients
Kim, S.H. ; Cho, J.M. ; Nam, T.W. ; Lim, J.H. ; Pack, S.I. ;
Journal of Biomedical Engineering Research, volume 27, issue 5, 2006, Pages 260~266
Due to damaged vertebrae nerves, serious disease and aging, patients who have to lie down for long period of time need to exercise to maintain up-right standing position and recover their paralytic leg. This study describes a development of an intellectual tilt table which can provide a patient with rehabilitating condition. This can be possible by measuring and displaying the hee bent angle and pressure for each foot during exercise in real time. It is expected that the patient's exercising effect can increase by monitoring these two values during exercise.
The Effect of Urokinase Infusion Regimens on Thrombolysis - a Numerical Study
Jeong, Woo-Won ; Jang, An-Sik ; Rhee, Kye-Han ;
Journal of Biomedical Engineering Research, volume 27, issue 5, 2006, Pages 267~273
Numerical analysis was performed on the enzyme transport and the flow fields in order to predict the effectiveness of urokinase injection regimens in clot dissolution. The species and momentum transport equations were numerically solved for the case of uniform perfusion of enzyme into a fibrin clot for an arterial thrombus and a deep vein thrombus models. In order to predict the thrombus lysis efficiency of continuous and forced intermittent injections, enzyme perfusion and clot lysis were simulated for the different injection velocities. Intermittent injection showed faster clot lysis compared to continuous perfusion, and lysis efficiency was increased as injection velocity increased.
Monitoring System for Oxygen Therapy Patients
Lee, Seung-Yup ; Kang, Jae-Min ; Shin, Il-Hyeung ; Lee, Jae-Ho ; Lee, Choon-Taek ; Kim, Hee-Chan ;
Journal of Biomedical Engineering Research, volume 27, issue 5, 2006, Pages 274~281
In this paper, we propose a ubiquitous
monitoring system for patients using oxygen therapy. For these patients, the ability to monitor oxygen saturation ubiquitously is very important fur accurate adjustment of ventilator's flow rate to match the patient's time-varying requirements with the shortest lag time possible. We have developed a portable device to measure
and transmit it to hospital in real-time or in store-and-forward mode through the integration of
technology and the code division multiple access (CDMA) cellular network. We also developed software for doctors to receive and manage the patients'
information. Performance of the developed system was evaluated as acceptable by assessing the accuracy of the measured oxygen saturation value and the stability of communication network. Test results in real clinical setting demonstrate that our system is feasible for immediate use in home oxygen therapy.
Developments of A Hearing Aid Algorithm with Emphasis on Adaptive Feedback Cancellation and Hardware Module
Jung, Sun-Yong ; Ji, Yun-Sang ; Kim, In-Young ; Park, Young-Cheol ; Kim, Nam-Gyun ; Lee, Sang-Min ;
Journal of Biomedical Engineering Research, volume 27, issue 5, 2006, Pages 282~290
We have developed a multi band digital hearing aid algorithm emphasizing feedback cancellation and a hardware module to evaluate the performance of our algorithm. The hearing aids should be able to compensate for individual hearing loss characteristics of hearing impaired person. Thus hearing aids need the function of multi-bands amplification and the capabilities of feedback cancellation that can remove howling caused by acoustic feedback. In this paper, we proposed a digital hearing aid algorithm which has multi-bands compensation using modified discrete cosine transform (MDCT) and can efficiently remove acoustic feedbacks. Moreover, we have developed digital hearing aid hardware module, which can evaluate hearing aid algorithms in real time operation. The developed algorithm and hardware module were verified through computer simulation and clinical tests. Through operational experiments, good performances in real time operation environment and an efficient howling cancellation were also observed. The developed hardware module can operate in stable condition and it is expected to become a good hardware platform for developing hearing aid algorithms.
A Hierarchical Microcalcification Detection Algorithm Using SVM in Korean Digital Mammography
Kwon, Ju-Won ; Kang, Ho-Kyung ; Ro, Yong-Man ; Kim, Sung-Min ;
Journal of Biomedical Engineering Research, volume 27, issue 5, 2006, Pages 291~299
A Computer-Aided Diagnosis system has been examined to reduce the effort of radiologist. In this paper, we propose the algorithm using Support Vector Machine(SVM) classifier to discriminate whether microcalcifications are malignant or benign tumors. The proposed method to detect microcalcifications is composed of two detection steps each of which uses SVM classifier. The coarse detection step finds out pixels considered high contrasts comparing with neighboring pixels. Then, Region of Interest(ROI) is generated based on microcalcification characteristics. The fine detection step determines whether the found ROIs are microcalcifications or not by merging potential regions using obtained ROIs and SVM classifier. The proposed method is specified on Korean mammogram database. The experimental result of the proposed algorithm presents robustness in detecting microcalcifications than the previous method using Artificial Neural Network as classifier even when using small training data.