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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
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Volume & Issues
Volume 33, Issue 4 - Dec 2012
Volume 33, Issue 3 - Sep 2012
Volume 33, Issue 2 - Jun 2012
Volume 33, Issue 1 - Mar 2012
Selecting the target year
Survival Prediction of Rats with Hemorrhagic Shocks Using Support Vector Machine
Jang, K.H. ; Choi, J.L. ; Yoo, T.K. ; Kwon, M.K. ; Kim, D.W. ;
Journal of Biomedical Engineering Research, volume 33, issue 1, 2012, Pages 1~7
DOI : 10.9718/JBER.2012.33.1.001
Hemorrhagic shock is a common cause of death in emergency rooms. Early diagnosis of hemorrhagic shock makes it possible for physicians to treat patients successfully. Therefore, the purpose of this study was to select an optimal survival prediction model using physiological parameters for the two analyzed periods: two and five minutes before and after the bleeding end. We obtained heart rates, mean arterial pressures, respiration rates and temperatures from 45 rats. These physiological parameters were used for the training and testing data sets of survival prediction models using an artificial neural network (ANN) and support vector machine (SVM). We applied a 5-fold cross validation method to avoid over-fitting and to select the optimal survival prediction model. In conclusion, SVM model showed slightly better accuracy than ANN model for survival prediction during the entire analysis period.
Obesity Estimation of Abdominal Fat by Using Computed Tomography : Influence of Breathing Motion on The Fat Measurement
Seoung, Youl-Hun ;
Journal of Biomedical Engineering Research, volume 33, issue 1, 2012, Pages 8~14
DOI : 10.9718/JBER.2012.33.1.008
The purpose of this study was to evaluate how much effect to accuracy when measuring abdominal fat by Computed Tomography (CT) under different respiration movements. The study volunteer composed of 66 normal adults (
years, 33 males, 33 females). We measured their obesity by using Broca index, body mass index (BMI) and CT and have investigated the correlation. The CT scanning for the obesity measurement have done in two ways, one was done in stopping breath after exhaling and the other was holding a breath after inhaling. The results showed no statistically significant difference among the three measuring techniques. And, the error in two ways of inhaling and exhaling was showed 24.2% of volunteers. The two ways of respiration movements made different result in visceral fat area (P = 0.044), subcutaneous fat area (P = 0.636) and abdominal obesity value (P = 0.012). This study demonstrates that the two ways of respiration movements when scanning CT makes change in accuracy in visceral fat area, and in abdominal obesity quantitative measure. Therefore, our study suggests that CT should take twice in two ways while a patient stops breath after exhaling and holds a breath after inhaling when measuring abdominal obesity using CT equipments.
Classification of Mental States Based on Spatiospectral Patterns of Brain Electrical Activity
Hwang, Han-Jeong ; Lim, Jeong-Hwan ; Im, Chang-Hwan ;
Journal of Biomedical Engineering Research, volume 33, issue 1, 2012, Pages 15~24
DOI : 10.9718/JBER.2012.33.1.015
Classification of human thought is an emerging research field that may allow us to understand human brain functions and further develop advanced brain-computer interface (BCI) systems. In the present study, we introduce a new approach to classify various mental states from noninvasive electrophysiological recordings of human brain activity. We utilized the full spatial and spectral information contained in the electroencephalography (EEG) signals recorded while a subject is performing a specific mental task. For this, the EEG data were converted into a 2D spatiospectral pattern map, of which each element was filled with 1, 0, and -1 reflecting the degrees of event-related synchronization (ERS) and event-related desynchronization (ERD). We evaluated the similarity between a current (input) 2D pattern map and the template pattern maps (database), by taking the inner-product of pattern matrices. Then, the current 2D pattern map was assigned to a class that demonstrated the highest similarity value. For the verification of our approach, eight participants took part in the present study; their EEG data were recorded while they performed four different cognitive imagery tasks. Consistent ERS/ERD patterns were observed more frequently between trials in the same class than those in different classes, indicating that these spatiospectral pattern maps could be used to classify different mental states. The classification accuracy was evaluated for each participant from both the proposed approach and a conventional mental state classification method based on the inter-hemispheric spectral power asymmetry, using the leave-one-out cross-validation (LOOCV). An average accuracy of 68.13% (
) was attained for the proposed method; whereas an average accuracy of 57% (
) was attained for the conventional method (significance was assessed by the one-tail paired
< 0.01), showing that the proposed simple classification approach might be one of the promising methods in discriminating various mental states.
Development of Processing System for Audio-vision System Based on Auditory Input
Kim, Jung-Hun ; Kim, Deok-Kyu ; Won, Chul-Ho ; Lee, Jong-Min ; Lee, Hee-Jung ; Lee, Na-Hee ; Yoon, Su-Young ;
Journal of Biomedical Engineering Research, volume 33, issue 1, 2012, Pages 25~31
DOI : 10.9718/JBER.2012.33.1.025
The audio vision system was developed for visually impaired people and usability was verified. In this study ten normal volunteers were included in the subject group and their mean age was 28.8 years old. Male and female ratio was 7:3. The usability of audio vision system was verified by as follows. First, volunteers learned distance of obstacles and up-down discrimination. After learning of audio vision system, indoor and outdoor walking examination was performed. The test was scored by ability of up-down and lateral discrimination, distance recognition and walking without collision. Each parameter was scored by 1 to 5. The results were 93.5 +- SD(ranges, 86 to 100) of 100. In this study, we could convert visual information to auditory information by audio-vision system and verified possibility of applying to daily life for visually impaired people.
Development of Flexible Ultrasound System for Elastography
Kim, D.I. ; Lee, S.Y. ; Cho, M.H. ;
Journal of Biomedical Engineering Research, volume 33, issue 1, 2012, Pages 32~38
DOI : 10.9718/JBER.2012.33.1.032
Recently, several ultrasound imaging techniques for tissue characterization have been developed. Among them, ultrasound elastography is regarded as the most promising modality and has been rapidly developed. One of ultrasound elastography techniques is shear modulus imaging. Normal and cancerous tissues show big difference of shear moduli and they have good image contrast. However shear wave elastography requires more complicated hardware and more computations for image reconstruction algorithm. Therefore new efficient techniques are being developed. In this paper, we have developed a very flexible ultrasound system for elastography experiments. The developed system has capabilities to acquire ultrasound RF data of all channels and generate arbitrary ultrasound pulse sequences. It has a huge amount of memories for RF data acquisition and a simple and flexible pulse generator. We have verified the performance of the system showing conventional B-mode images and preliminary results of elastography. The developed system will be used to verify our own reconstruction algorithm and to develop more efficient elastography techniques.
Gated Conductivity Imaging using KHU Mark2 EIT System with Nano-web Fabric Electrode Interface
Kim, Tae-Eui ; Kim, Hyun-Ji ; Wi, Hun ; Oh, Tong-In ; Woo, Eung-Je ;
Journal of Biomedical Engineering Research, volume 33, issue 1, 2012, Pages 39~46
DOI : 10.9718/JBER.2012.33.1.039
Electrical impedance tomography(EIT) can produce functional images with conductivity distributions associated with physiological events such as cardiac and respiratory cycles. EIT has been proposed as a clinical imaging tool for the detection of stroke and breast cancer, pulmonary function monitoring, cardiac imaging and other clinical applications. However EIT still suffers from technical challenges such as the electrode interface, hardware limitations, lack of animal or human trials, and interpretation of conductivity variations in reconstructed images. We improved the KHU Mark2 EIT system by introducing an EIT electrode interface consisting of nano-web fabric electrodes and by adding a synchronized biosignal measurement system for gated conductivity imaging. ECG and respiration signals are collected to analyze the relationship between the changes in conductivity images and cardiac activity or respiration. The biosignal measurement system provides a trigger to the EIT system to commence imaging and the EIT system produces an output trigger. This EIT acquisition time trigger signal will also allow us to operate the EIT system synchronously with other clinical devices. This type of biosignal gated conductivity imaging enables capture of fast cardiac events and may also improve images and the signal-to-noise ratio (SNR) by using signal averaging methods at the same point in cardiac or respiration cycles. As an example we monitored the beat by beat cardiac-related change of conductivity in the EIT images obtained at a common state over multiple respiration cycles. We showed that the gated conductivity imaging method reveals cardiac perfusion changes in the heart region of the EIT images on a canine animal model. These changes appear to have the expected timing relationship to the ECG and ventilator settings that were used to control respiration. As EIT is radiation free and displays high timing resolution its ability to reveal perfusion changes may be of use in intensive care units for continuous monitoring of cardiopulmonary function.
Effects of Medication and Deep Brain Stimulation on the Finger-tapping Speed and Amplitude of Parkinsonian Bradykinesia
Kim, Ji-Won ; Kwon, Yu-Ri ; Park, Sang-Hoon ; Eom, Gwang-Moon ; Koh, Seong-Beom ; Jang, Ji-Wan ; Lee, Hye-Mi ;
Journal of Biomedical Engineering Research, volume 33, issue 1, 2012, Pages 47~52
DOI : 10.9718/JBER.2012.33.1.047
The purpose of this study is to investigate whether medication and deep brain stimulation (DBS) have differential effects on the speed and amplitude of bradykinesia in patients with Parkinson's disease (PD). Five PD patients with implanted DBS electrodes (age:
, H&Y stage:
) participated in this study. FT (finger tapping) movement was measured using a gyrosensor system in four treatment conditions: Med (Medication)-off/DBS-off, Med-off/DBS-on, Med-on/DBS-off and Med-on/DBS-on. Quantitative measures representing average speed and amplitude of FT movement included root-mean-squared (RMS) angular velocity and RMS angle. One-way repeated measures ANOVA showed that RMS angular velocity of Med-on/DBS-on was significantly greater than those of Med-off/DBS-off and Med-off/DBS-on (p < 0.01) whereas RMS angle was not different among conditions (p = 0.06). Two way repeated measures ANOVA showed that only medication improved RMS angular velocity (p < 0.01), whereas both medication and DBS had no significant effect on RMS angle (p > 0.02). Effect size of RMS angular velocity was greater than that of RMS angle in both medication and DBS. This suggests that medication and DBS have differential effects on FT bradykinesia and velocity and amplitude impairments may be associated with different functional aspects in PD.