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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 31, Issue 6 - Dec 2010
Volume 31, Issue 5 - Oct 2010
Volume 31, Issue 4 - Sep 2010
Volume 31, Issue 3 - Jun 2010
Volume 31, Issue 2 - Apr 2010
Volume 31, Issue 1 - Feb 2010
Selecting the target year
In vivo Evaluation of Flow Estimation Methods for 3D Color Doppler Imaging
Yoo, Yang-Mo ;
Journal of Biomedical Engineering Research, volume 31, issue 3, 2010, Pages 177~186
In 3D ultrasound color Doppler imaging (CDI), 8-16 pulse transmissions (ensembles) per each scanline are used for effective clutter rejection and flow estimation, but it yields a low volume acquisition rate. In this paper, we have evaluated three flow estimation methods: autoregression (AR), eigendecomposition (ED), and autocorrelation combined with adaptive clutter rejection (AC-ACR) for a small ensemble size (E=4). The performance of AR, ED and AC-ACR methods was compared using 2D and 3D in vivo data acquired under different clutter conditions (common carotid artery, kidney and liver). To evaluate the effectiveness of three methods, receiver operating characteristic (ROC) curves were generated. For 2D kidney in vivo data, the AC-ACR method outperforms the AR and ED methods in terms of the area under the ROC curve (AUC) (0.852 vs. 0.793 and 0.813, respectively). Similarly, the AC-ACR method shows higher AUC values for 2D liver in vivo data compared to the AR and ED methods (0.855 vs. 0.807 and 0.823, respectively). For the common carotid artery data, the AR provides higher AUC values, but it suffers from biased estimates. For 3D in vivo data acquired from a kidney transplant patient, the AC-ACR with E=4 provides an AUC value of 0.799. These in vivo experiment results indicate that the AC-ACR method can provide more robust flow estimates compared to the AR and ED methods with a small ensemble size.
Design and Experiment of a Micro Electronic System for Prediction of Alveolar-Gas Partial Pressures
Kim, Da-Jung ; Chang, Keun-Shik ; Kim, Sa-Ji ; Park, Hye-Yun ; Suh, Gee-Young ;
Journal of Biomedical Engineering Research, volume 31, issue 3, 2010, Pages 187~193
In this study we have designed and fabricated an inexpensive micro electronic system that we call Alvitek. It can indirectly but accurately predict and display the partial pressures of alveolar oxygen and carbon dioxide for the patients in the ICU of a hospital. Alvitek consists of both hardware part and software part. Performance of the system is tested by animal experiment with pigs for various
and RR(Respiratory Rate) values under the mechanical ventilation. The predicted alveolar gas partial pressures are cprpared with the approximate alveolar oxygen partial pressures easily calculated by the physician’s bedside formula. As a result, we have concluded that the relative error of A-
calculated by the bedside formula grows seriously for lower
values. The present prediction method of Alvitek is henceforth believed very meaningful to the physicians. The system hardware and software are described in the text.
A Simpler Method to Estimate the Elastic Constant of Collagen-like Microfibril Using Voigt-Reuss Bounds
Yoon, Young-June ; Bae, Cheol-Soo ;
Journal of Biomedical Engineering Research, volume 31, issue 3, 2010, Pages 194~198
The effective Young’s modulus of a microfibril surrounded by water may be simply calculated by using the upper (Voigt) and lower (Reuss) bounds, which is one way to estimate the Young’s modulus in composite materials. The Steered Molecular Dynamics (SMD) has been used for estimating the Young’s modulus of a microfibril surrounded by water. In this paper, the result estimated by the upper (Voigt) and lower (Reuss) bounds shows 9.2% to 21.8% discrepancy from the result estimated by SMD, but introducing “efficiency of reinforcement parameter” removes the discrepancy and shows good agreement with the result estimated by SMD. We found the best fit for the Young’s modulus against the size of the gap between microfibrils. Also the steps using these bounds are much simpler than SMD.
Effects of Screw Configuration on Biomechanical Stability during Extra-articular Complex Fracture Fixation of the Distal Femur Treated with Locking Compression Plate
Kwon, Gyeong-Je ; Jo, Myoung-Lae ; Oh, Jong-Keon ; Lee, Sung-Jae ;
Journal of Biomedical Engineering Research, volume 31, issue 3, 2010, Pages 199~209
The locking compression plates-distal femur(LCP-DF) are being widely used for surgical management of the extra-articular complex fractures of the distal femur. They feature locking mechanism between the screws and the screw holes of the plate to provide stronger fixation force with less number of screws than conventional compression bone plate. However, their biomechanical efficacies are not fully understood, especially regarding the number of the screws inserted and their optimal configurations. In this study, we investigated effects of various screw configurations in the shaft and the condylar regions of the femur in relation to structural stability of LCP-DF system. For this purpose, a baseline 3-D finite element (FE) model of the femur was constructed from CT-scan images of a normal healthy male and was validated. The extra-articular complex fracture of the distal femur was made with a 4-cm defect. Surgical reduction with LCP-DF and bone screws were added laterally. To simulate various cases of post-op screw configurations, screws were inserted in the shaft (3~5 screws) and the condylar (4~6 screws) regions. Particular attention was paid at the shaft region where screws were inserted either in clustered or evenly-spaced fashion. Tied-contact conditions were assigned at the bone screws-plate whereas general contact condition was assumed at the interfaces between LCP-DF and bone screws. Axial compressive load of 1,610N(2.3 BW) was applied on the femoral head to reflect joint reaction force. An average of 5% increase in stiffness was found with increase in screw numbers (from 4 to 6) in the condylar region, as compared to negligible increase (less than 1%) at the shaft regardless of the number of screws inserted or its distribution, whether clustered or evenly-spaced. At the condylar region, screw insertion at the holes near the fracture interface and posterior locations contributed greater increase in stiffness (9~13%) than any other locations. Our results suggested that the screw insertion at the condylar region can be more effective than at the shaft during surgical treatment of fracture of the distal femur with LCP-DF. In addition, screw insertion at the holes close to the fracture interface should be accompanied to ensure better fracture healing.
A Response to Postural Response to Sine Curve Vestibular Electric Stimulation during Standing
Lee, Ah-Reum ; Yu, Mi ; Kim, Jin-Ho ; Kim, Dong-Wook ; Kim, Jung-Ja ;
Journal of Biomedical Engineering Research, volume 31, issue 3, 2010, Pages 210~216
This study is vestibular electric stimulation applied between the mastoids during quiet standing elicits postural sway. The aim of this study was to characterize the postural sway response to continuous sinusoidal vestibular electric stimulation across various stimulus frequencies and amplitudes. Binaural bipolar sinusoidal vestibular electric stimulation was applied to the skin overlying the mastoid processes of 10 subjects while they stood on a force plate. The position of the center of pressure(COP) and signals at the feet are obtained on an force plate, while the head and whole body center of mass(COM) was measured with motion analysis system. The stimulus conditions included eight frequencies (1/64, 1/32, 1/16, 1/8, 1/4, 1/2, 1, and 2Hz) and six peak amplitudes (0.1, 0.25, 0.5, 0.7, 1 and 2mA). Each subject experienced one trial at each amplitude-frequency pair. The stimuli elicited sway in lateral plane in all subjects, as evidenced by changes in the stimulus frequency. Our results demonstrate that the vestibular system is sensitive to vestibular electric stimulation intensity changes and responds by altering the magnitude of the response accordingly.
Analysis on the Assist Characteristics for the Knee Extension Motion of Lower Limb Orthosis Using Muscular Stiffness Force Feedback
Kim, K. ; Kang, S.R. ; Jeong, G.Y. ; Joo, S.J. ; Kim, N.G. ; Kwon, T.K. ;
Journal of Biomedical Engineering Research, volume 31, issue 3, 2010, Pages 217~226
The lower limb orthosis with a pneumatic rubber actuator, which is intended for the assistance and the enhancement of muscular activities of lower limbs was developed in this study. Compared to other knee extension assistive devices being developed by other researchers, our device is designed especially for the elderly people and intended only for slight assistance so that the subjects can keep their muscular strength. For the effectiveness of system, muscular activities of major muscles in lower limbs during sit-to-stand (STS) and squat motion were measured and analyzed. Subjects were performed the STS and squat motion with and without lower limb orthosis. We made comparison muscular activities between with and without lower limb orthosis. Lower limb orthosis was controlled using muscular stiffness force feedback that is controlled by muscular activities of the measured muscle from force sensor. For analysis of muscular activities, electromyography of the subjects was measured during STS and squat motion, and these were measured using MP 150(BIOPAC Systems, Inc.). Muscles of interest were rectus femoris(RF), vastus lateralis(VL), vastus medialis(VM) and vastus intermedius(VI) muscles in lower limbs of the right side. A biodex dynamometer was used to measure the maximal concentric isokinetic strength of the knee extensors of wearing and not wearing orthosis on right side. The test were performed using the concentric isokinetic mode of test with the velocity set at 60°/s for muscles around the knee joints. The experimental result showed that muscular activities in lower limbs wearing orthosis using muscular stiffness force of a vastus medialis muscle was reduced and knee extension torque of an knee joint wearing lower limb orthosis was increased. With this, we confirmed the effectiveness of the developed lower limb orthosis.
Shaft Kick Point and Stiffness due to the Difference in Performance Analysis
Oh, H.Y. ; Yu, M. ; Kim, S.H. ; Jang, J.H. ; Kim, N.G. ; Kim, D.W. ;
Journal of Biomedical Engineering Research, volume 31, issue 3, 2010, Pages 227~233
This study analyzed performance according to kick point and stiffness of Soft-
shaft. This research team developed soft-
as a new fusion sports with similar motions with golf and it can be learned safely for all age groups in 2002. The head of Soft-
club is made of zinc alloy and has a mesh or a grid structure, and shaft uses carbon graphite to reduce the total weight of the club. To improve carry distance and to assure consistency of a ball during Soft-
swing, this study manufactured shaft with various kick points (low, middle and high) and stiffness (stiff, regular, lady, morelady) and analyzed a swing motion with characteristics of each shaft presented in a dynamic condition such as a ball's speed, a head's torsion angle and a ball's deviation with ProAnalyst program through a high-speed camera taking pictures using a swing machine robot system(Robo-7). From all of the results, this study determined an appropriate shaft of Soft-
Development of Diagnosis Protocol for Micro-spike Biopsy Using Paraffin-based Tissue Collecting tool
Jeong, Hyo-Young ; Koo, Kyo-In ; Lee, Sang-Min ; Park, Ho-Soo ; Hong, Suk-Jun ; Bang, Seoung-Min ; Song, Si-Young ; Cho, Dong-Il ;
Journal of Biomedical Engineering Research, volume 31, issue 3, 2010, Pages 234~239
We have developed and reported several micro-spikes for minimally invasive biopsy. This paper presents a diagnosis protocol for micro-spike biopsy using paraffin-based tissue collecting tool. Using the proposed tissue collecting tool, which has a negative micro-spike structure in a porous chamber, the biopsied tissue in a micro-spike is effectively detached. The proposed diagnosis protocol prevents the loss of tissues in a paraffin embedding and sectioning process. Hence, it is compatible with conventional histopathology without additional reagents and processes. The gastro-intestinal tissue of a pig is biopsied in an in vivo environment, and then it is detached from a micro-spike using the paraffin-based tissue collecting tool. A histopathological photomicrograph of the detached tissue is acquired with the proposed diagnosis protocol. The acquired image offers clinical quality. This result shows that the paraffin-based tissue collecting tool is applicable to the medical practice.
Measurement and Comparison of Finger Tapping Movement in Patients with Idiopathic Parkinson's Disease and Normal Subjects using Gyrosensor
Kim, Ji-Won ; Kwon, Yu-Ri ; Lee, Jae-Ho ; Eom, Gwang-Moon ; Kwon, Do-Young ; Koh, Seong-Beom ; Park, Byung-Kyu ; Hong, Jung-Hwa ;
Journal of Biomedical Engineering Research, volume 31, issue 3, 2010, Pages 240~244
The purpose of this study is to compare finger tapping (FT) movement of patients with Parkinson's disease (PD) with normal subjects. A gyrosensor system was used for the measurement of FT movement, because it provides angular velocity free from the gravitational artifact and it can be used during clinical FT test listed in unified PD rating scale (UPDRS). Forty PD patients (age: 65.7
11.1 yrs, H&Y stage:2.3
0.5), 14 age-matched elderly subjects (65
3.9 yrs) and 17 healthy young subjects (24
2.1yrs) participated in this study. Angular velocity of finger tapping movement was measured in both right and left index finger. As quantitative measures, root-mean-squared (RMS) angular velocity, RMS angle, peak power and total power were used. ANOVA showed that all measures were significantly different among three groups (p<0.001) in all quantitative measures. Post-hoc test revealed that all quantitative measures except peak power in patients with PD were significantly smaller than in both healthy elderly and young subjects (p<0.01). This suggests that the measures developed in this study can distinguish patients with PD from normal subjects.
Premotor-time of the Ankle Muscle during Bilateral Contraction in the Elderly
Kim, Ji-Won ; Kwon, Yu-Ri ; Shin, Jae-Nam ; Eom, Gwang-Moon ; Kim, Chul-Seung ; Park, Byung-Kyu ; Hong, Jung-Hwa ;
Journal of Biomedical Engineering Research, volume 31, issue 3, 2010, Pages 245~250
The purpose of this study is to investigate the effects of sex and age and their interactions in premotor-time (PMT) of ankle muscle. Forty-eight elderly subjects (aged 65-90 years) and thirty young subjects (aged 19-27 years) participated in this study. Subject were instructed to perform maximal, voluntary, isometric, bilateral contraction of ankle muscle in reaction to auditory stimulus to determine PMT. As analysis variables, PMT, intrasubject variability of PMT and asymmetry of PMT between dominant and nondominant legs were used. As statistical analysis, two-way ANOVA was performed to assess the main effects of age group and sex and also their interactions. All variables showed significant age effects (p<0.01). However, no sex effect and interaction existed in all variables in both dominant and nondomiant legs. Theses results suggest that the PMT of ankle muscle is related to the age-related deterioration in postural control, however, not related to the sex-difference of fall incidence in the elderly population.
Development of Integrated Computer Interface for Power Wheelchair User
Kim, Chang-Geol ; Song, Byung-Seop ;
Journal of Biomedical Engineering Research, volume 31, issue 3, 2010, Pages 251~257
This paper reports a noble instrument that helps physically disabled people to access computers. There have been numerous attempts to develop such a methodology, but most of them require an additional space for workstation often including access program installation. The additional space also needs to be carefully designed to consider each specific disabled area. This study aims to develop a system that removes the spacial limitation by putting the integrated computer interface using the wheelchair controller. The implementation of the computer workstation is performed by utilizing an USB interface. The developed equipment will take an important role to support various social lives for the users and eventually to improve their quality of life.