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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 23, Issue 6 - Dec 2002
Volume 23, Issue 5 - Nov 2002
Volume 23, Issue 4 - Aug 2002
Volume 23, Issue 3 - Jun 2002
Volume 23, Issue 2 - Apr 2002
Volume 23, Issue 1 - Feb 2002
Volume 24, Issue 6 - 00 2002
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Three-Dimensional Kinematic Model of the Human Knee Joint during Gait
Mun, Joung-Hwan ; Seichi Takeuchi ;
Journal of Biomedical Engineering Research, volume 23, issue 3, 2002, Pages 171~179
It is well known that the geometry of the articular surface plays a major role in the kinematic and kinetic analysis to understand human knee joint function during motion. The functionality of the knee joint cannot be accurately modeled without considering the effects of sliding and lolling motions. We Present a 3-D human knee joint model considering sliding and rotting motion and major ligaments. We employ more realistic articular geometry using two cam profiles obtained from the extrusion of the sagittal Plain view of the representative Computerized Tomography image of the knee joint compared to the previously reported model. Our model shows good agreement with the already reported experimental results on Prediction of the lines of force through the human joint during gait. The contact point between femur and tibia moves toward the Posterior direction as the knee undergoes flexion, reflecting the coupling of anterior and Posterior motion with flexion/extension. The anterior/posterior displacement of the contact Point on the tibia plateau during one gait cycle is about 16 mm. for the lateral condyle and 25 mm. for the medial condyle using the employed model Also. the femur motion on the tibia undergoes lateral/medial movement about 7 mm. and 10 mm. during one gait cycle for the lateral condyle and medial condyle. respectively. The developed computational model maybe Potentially employed to identify the joint degeneration.
Analysis for the Flow and Wall Shear Stress with the Diameter Ratios of an Abdominal Aortic Aneurysm in a Pulsatile Flow
Journal of Biomedical Engineering Research, volume 23, issue 3, 2002, Pages 181~187
The objective of the present study was to two-dimensionally investigate the characteristics of flow and wall shear stress under pulsatile flow in the aneurysm which is a local dilatation of the blood vessel for pulsatile flow. The numerical simulation using the commercial software were carried out for the diameter ratios(ratio of maximum diameter of aneurysm to the diameter of blood vessel) ranging from 1.5 to 2.5 and Womersley number, 15.47. It was shown that a recirculating flow at the bulge was developed and disappeared for one Period and the strength of vortex increased with the diameter ratio Especially. at time of 3.19s. the very weak recirculating flow was developed at the left upper sites of the aneurysm. The maximum values of the wall shear stress increased in Proportion to the diameter ratio. However. the Position of a maximum wall shear stress was the distal end of the aneurysm(z = 35mm) regardless of the diameter ratios.
Synergistic Effect of Oxygen Pressure and Sonophoresis for Skin Permeability
Journal of Biomedical Engineering Research, volume 23, issue 3, 2002, Pages 189~196
Transdermal drug delivery offers an alternative method to the conventional oral and injection delivery method. Its advantages include its ability to deliver drugs directly into systemic circulation. However, there have been restrictions in its application to deliver drugs because of the skin's barrier function. In this study, we try to combine a Sonophoresis and oxygen Pressure method in order to increase the Permeability of the skin. we used water as the compound and by utilizing the skin impedance method. we measured the hydration Permeability of skin Ultrasound was applied using a sonicator(Solcare-U1000. Solco, Korea) operating at a frequency of 1MHz. oxygen Pressure was applied using a compressor(Oxyjet-Pointer, Nora Bode. Germany) operating at a pressure of 2Bar/cm2. Experiment was performed in vivo for 42 People. We divided the subjects into four smaller groups. A different transdermal drug delivery method was applied for each group on the back of their hand. We measured the skin impedance variations on the hand. during a 20-minute time Period. The control group did not show any significant increase or variation of skin impedance to water. In comparison to the control group(Passive diffusion) the hydration Permeability of the ultrasound group and the oxygen Pressure group was approximately 25 and 30 times higher consecutively. Futhermore, the hydration permeability of the combination of ultrasound and oxygen Pressure group was about 70-fold higher in comparison to the control group(passive diffusion) . The results reveal that a combination of ultrasound and oxygen Pressure will significantly enhance transdermal water transport compared when only one of them is used.
A Basic Study on the Differential Diagnostic System of Laryngeal Diseases using Hierarchical Neural Networks
Journal of Biomedical Engineering Research, volume 23, issue 3, 2002, Pages 197~205
The objectives of this Paper is to implement a diagnostic classifier of differential laryngeal diseases from acoustic signals acquired in a noisy room. For this Purpose, the voice signals of the vowel /a/ were collected from Patients in a soundproof chamber and got mixed with noise. Then, the acoustic Parameters were analyzed, and hierarchical neural networks were applied to the data classification. The classifier had a structure of five-step hierarchical neural networks. The first neural network classified the group into normal and benign or malign laryngeal disease cases. The second network classified the group into normal or benign laryngeal disease cases The following network distinguished polyp. nodule. Palsy from the benign laryngeal cases. Glottic cancer cases were discriminated into T1, T2. T3, T4 by the fourth and fifth networks All the neural networks were based on multilayer perceptron model which classified non-linear Patterns effectively and learned by an error back-propagation algorithm. We chose some acoustic Parameters for classification by investigating the distribution of laryngeal diseases and Pilot classification results of those Parameters derived from MDVP. The classifier was tested by using the chosen parameters to find the optimum ones. Then the networks were improved by including such Pre-Processing steps as linear and z-score transformation. Results showed that 90% of T1, 100% of T2-4 were correctly distinguished. On the other hand. 88.23% of vocal Polyps, 100% of normal cases. vocal nodules. and vocal cord Paralysis were classified from the data collected in a noisy room.
Quantitative Analysis of Postural Balance Training using Virtual Bicycle System
Journal of Biomedical Engineering Research, volume 23, issue 3, 2002, Pages 207~216
This Paper describes a quantitative analysis of Postural balance training using virtual bicycle system. We have used a virtual bicycle system that combines virtual reality technology with a bicycle . In this experiment, 20 normal adults were tested to investigate the influencing factors on Postural balance. Several factors including cycling time. cycling velocity. number of times of Path deviation, center of Pressure(COP) . and weight shift were extracted and evaluated to quantify the extent of control. Also, To improve the effect of balance training, we investigated the usefulness of visual feedback information by weight shift The results showed that the system was effective Postural balance rehabilitation training device and. in addition. the analysis method might have a wider applicability to the rehabilitation field.
Experimental Verification of Implantable Middle Ear System using the Differential Electromagnetic Type Transducer
Journal of Biomedical Engineering Research, volume 23, issue 3, 2002, Pages 217~225
The implantable middle ear(IME) system, which has good sound quality. superior sound intelligibility and wide frequency characteristics. can resolve the sound distortion and ringing effect by sound feedback at high gain operation those are the major problems of conventional hearing aid. In this paper, we have manufactured the IME system using differential electromagnetic transducer(DET) and verified the performance of the system by carrying out vibration and animal implanting experiment. The DET was manufactured using micro-machining technology and vibration experiment of the transducer was performed to inspect whether the transducer could vibrate in accordance with the applied sound signal or not. And the result of the loaded experiment using temporal bone sampled from cadaver showed that the transducer can drive the middle ear bone and transmit the signal to inner ear After the internal unit of IME system was implanted in a dog. the auditory brainstem response (ABR) test was carried out. The result of the test indicated the Proper behavior of the IME system in the living body From the results of the experiments, it is verified that the manufactured system ewll work well when it is applied to human and a basis of clinical experiment of IME system to real human hearing impaired was be arranged.
Analysis of Signal Transfer Characteristics of Implantable Middle Ear System using Acoustic Model
Journal of Biomedical Engineering Research, volume 23, issue 3, 2002, Pages 227~233
The IME(implantable middle ear) system is Promising due to its ability to free from sound feedback and Produce a good sound quality and intelligibility with low distortion even if it is operated with high gain for severe hearing impaired. The differential electromagnetic vibration transducer. which was developed for using in IME system and has two small magnets attached the same Pole facing in the coil. is not influenced by environmental external magnetic field. Besides, it has high vibration efficiency and good frequency response characteristics. In this Paper, using acoustic model of the transducer and ear model of normal Person. the signal transfer characteristics of the IME system are analyzed and investigated From the differences of the characteristics between normal ear and the IME system, it is Possible that design of the IME system that have the signal transfer characteristics similar to normal person's ear.
Development and Evaluation of an Automated Stainer for Mycobacterium Tuberculosis
Journal of Biomedical Engineering Research, volume 23, issue 3, 2002, Pages 235~241
The detection of tubercle bacilli (TB) from sputum smear is one of the fast and inexpensive methods for diagnosis of tuberculosis. For this method. sputum smears are usually flexed by heating and stained by acid-fast staining method, and then examined under an optical microscope. Two Procedures are commonly used fur TB staining. One is hot staining and the other is cold staining method. The Ziehl-Neelsen method which is a hot staining method is widely used in Korea because its stained color is more vivid However, the conventional automated stainer has to fix the sputum smear on a slide manually and the stain is not so vivid because it has not heating function. In an effort to save labor and minimize variations in manual staining Procedure. we developed an automated stainer with heating function. The entire staining process is fully automated. from fixation to final washing and drying. With the automated methods, five slides can be flexed and stained in 21 minutes at consistent high quality We compared the concordance rate between the two methods for 91 sputum samples to validate the stain quality of the developed automated stainer. As the results, the concordant rate between the two methods was 95% and there was no significant difference (p>0.05)
An Experimental Study of the Synthetic Sinc Wave in Ultrasonic Imaging
Journal of Biomedical Engineering Research, volume 23, issue 3, 2002, Pages 243~251
Synthetic zinc wave employs Pulsed plane wave as transmit beam with linear time delay curve. The received echoes in different transmit directions at different transmit times are superposed at imaging Points with Proper time delay compensation using synthetic focusing scheme. This scheme. which uses full aperture in transmit, obtains a high SNR image, and also features high lateral resolution by using two way dynamic focusing at all imaging depths. In this Paper, we consider the Problems in realization of synthetic zinc wave. Also. we have applied the scheme to obtain phantom and in-vivo images using a linear array of 5 MHz. In phantom test. experimental images show high resolution over a more extended imaging depth than conventional fixed Point transmit and receive dynamic focusing schemes In-vivo images show that the resolution could not overcome conventional focusing systems because of motion blurring and(or) aberration of tissue. but the frame rate tan be increased by a factor of more than 5 compared to conventional focusing schemes. with competitive resolution at all imaging depths .
Development of Adaptive Spatial Filter to Improve Noise Characteristics of PET Images
Journal of Biomedical Engineering Research, volume 23, issue 3, 2002, Pages 253~261
A spatially adaptive falter was formulated to imrove PET image qualify and the Performance of the filter was evaluated using simulation and phantom and human PET studies. In the proposed filter. if a pixel was identified as the edge Pixel, the Pixel value was Preserved. Otherwise a Pixel was replaced by the mean of the pixel values weighted by 2:7: 2. A Pixel was identified as the edge Pixel. if it satisfies the following conditions : the number of ADs (absolute difference between center and neighborhood pixels) which is smaller than THl ((
, NPM : mean of 6 neighborhood pixels excluding minimum and maximum) is 8-k and the number of ADs which is lager than TH2 (
) is k. where k : 2, 3, …, 6. The results of this study demonstrate the superior performance of the Proposed titter compared to Gaussian fitter, weight median filter and subset averaged median filter. The proposed tittering method is simple but effective in increasing uniformity and contrast with minimal degradation of spatial resolution of PET images and thus. is expected to Provide improved diagnositc quality PET images .