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ABSTRACT: Previous studies on gray matter concentration changes in patients with juvenile myoclonic epilepsy (JME) are inconsistent.
To investigate cortical abnormality in JME differently, we measured the cortical thickness in 19 JME patients and 18 normal
controls. Results showed that the cortical thicknesses of superior/middle/medial frontal gyri, and superior/middle/ inferior
temporal gyri were decreased in JME patients. Moreover, cortical thicknesses of precentral gyrus and medial orbital gyrus
of right hemispheres were negatively correlated with disease duration. These findings suggest that JME brains have cortical
gray matter atrophy in the frontal and temporal lobes.
Journal of Neurology 04/2012; 255(4):561-566. · 3.47 Impact Factor
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ABSTRACT: The aim of this study was to retrospectively assess the diagnostic performance of multidetector CT (MDCT) for the diagnosis of acute cholangitis using a new scoring method.
Of 80 patients with suspected biliary disease who underwent biphasic CT and endoscopic retrograde cholangiography, 39 were diagnosed as having acute cholangitis (Group 1) and 41 patients were classified as suspected biliary disease (Group 2). 100 age-matched patients without evidence of biliary disease were selected randomly as a control group (Group 3). Each patient's axial scan was scored by two independent radiologists for the extent of transient hepatic attenuation difference, the presence of biliary dilatation and identification of a biliary obstructive lesion. The difference in the scores among the three groups was evaluated and the optimal cut-off score for the diagnosis of acute cholangitis was determined. Interobserver agreement was also evaluated.
The total scores (mean ± standard deviation) for Groups 1, 2 and 3 were 7.0 ± 2.0, 4.4 ± 2.4 and 0.9 ± 1.2, respectively, for Reviewer 1 and 7.2 ± 2.7 and 0.7 ± 1.1, respectively, for Reviewer 2. Significant differences were found for the subscores and the total scores among the three groups (p < 0.001). Using a cut-off score of ≥ 5, the sensitivity and specificity for diagnosing acute cholangitis were 84.6% and 83.7%, respectively, for Reviewer 1 and 89.7% and 83.7%, respectively, for Reviewer 2. Agreement for the subscores between readers was good to excellent (κ = 0.74-0.86).
Based on dynamic MDCT and the described CT scoring method, the diagnosis of acute choangitis can be made with high sensitivity and specificity.
The British journal of radiology 07/2011; 85(1014):770-7. · 2.11 Impact Factor
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ABSTRACT: The shoulder can control the range of motion of upper-limb. However, proprioception declines of shoulder of patients with
stroke have affected the control of upper-limb motion. The motor learning regulates body movement posture by integrating the
proprioception feedback (muscle force, joint position, etc.) as well as exteroceptive feedback (vision, audition). Proprioception
feedback plays important role in the motor learning. Virtual reality (VR) is able to provide an environment which manipulates
visual feedback of movement of stroke patients. In this study, we developed a system that can provide the continuous matching
angle task with manipulating visual feedback using virtual reality for shoulder proprioception training of patients with stroke.
Nineteen patients with stroke (age: 58.16 ± 12.27 years, onset: 40.16 ± 49.76 months, males: 17, females: 2) were recruited
for this experiment. Participants performed the angle matching task and continuous matching angle task. In the results, error
angle of angle matching task were not different between the first half of angle matching task and the second half of angle
matching task (p = 0.202). Accumulated error angle of continuous matching angle task were more reduced in the second half
of continuous matching angle task than in the first half of continuous matching angle task (p = 0.002). These results are
similar to the result from a study assessing balance training using vision cue deprivation. It can be explained that manipulated
visual feedback using virtual reality affects the proprioception of shoulder of patients with stroke. As conclusion, we found
that visual feedback manipulation using virtual reality could provide an effective proprioception feedback for proprioception
training of shoulder of patients with stroke.
KeywordsVirtual reality-Shoulder-proprioception-Visual feedback
12/2009: pages 722-724;
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ABSTRACT: The purpose of this research was to effectively estimate the physical activity energy expenditure considering acceleration and ECG using the developed holter that is contained a tri-axial accelerometer. For this research, we developed the specific device that can measure three channels' ECG and three axes' accelerations simultaneously. The every experiment was processed by the designed protocol in laboratory environment, and each subject performed the protocol wearing our device and portable gas analyzer together. Three signals of acceleration were processed using the integration method, and the meaningful parameter was extracted through the frequency analysis of heart rate. Before the regression analysis, significant parameters were selected by correlation analysis, and then the estimating equation of physical activity energy expenditure was found out through the linear multiple regression analysis.
Computers in Cardiology, 2009; 10/2009
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ABSTRACT: Oscillometric method is the method for the blood pressure measurement using mean arterial pressure (MAP). In the conventional method, the cuff pressure at the largest pulse is determined as MAP. However, it is difficult to find the largest oscillometric pulse from patients who have the cardiovascular disease or the elder subjects. Therefore, we studied a new method to determine the MAP by analyzing the changes of the morphology of oscillometric pulse different from above method. The new method was applied to the cuff pressure recorded by 11 healthy subjects. Two observers trained by BHS program measured the blood pressure using the auscultatory method to determine the reference MAP. The mean difference and standard deviation of the MAP determined by the algorithm proposed by this study were 1.45 mmHg and 3.47 mmHg respectively.
Computers in Cardiology, 2009; 10/2009
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ABSTRACT: Blood pressure measuring method using PPG signal is the one of many non-invasive blood pressure methods. In this study, we have studied a new method that estimates the blood pressure using wrist cuff and wrist PPG (photoplethysmograph) signal. During the deflation of the wrist cuff pressure, the PPG pulse appears at certain point that is similar to Korotkoff sound. After the pulse appeared, the morphology of PPG pulses was changed into the certain shape. So, we use these points to estimate the blood pressure. For validation, the reference SBP and DBP are measured by auscultatory method at the left upper arm. Subjects were 13 non cardiac disease of man in their twenties. The result of this study, the mean difference of SBP and DBP, between auscultatory method and PPG analysis is 2.08 ± 5.07 mmHg and 1.38 ± 7.86 mmHg respectively.
Computers in Cardiology, 2009; 10/2009
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ABSTRACT: To investigate the potential of our newly developed three-dimensional immersive virtual reality (VR) program modeled on a real street crossing as an assessment tool for extrapersonal neglect in stroke patients.
Thirty-two patients with right-hemispheric stroke (neglect group, 16; non-neglect group, 16) were enrolled. The deviation angle, reaction time, left-to-right reaction time ratio, visual and auditory cue rates, and failure rate were evaluated during missions to keep a virtual avatar safe from a traffic accident in the VR program. The line bisection test and letter cancellation test were also evaluated.
The deviation angle, left-to-right reaction time ratio, left visual and auditory cue rates and left failure rate in the VR program showed significant differences between the two groups (P < 0.05). Depending on the direction of approach of the virtual car, the left parameters were significantly higher than the right parameters in the neglect group (P < 0.05). In the neglect group, the line bisection test correlated significantly with the deviation angle (P < 0.05). None of the other virtual reality parameters significantly correlated with the paper and pencil tests.
Post-stroke neglect in the extrapersonal space can be easily and safely detected and measured using our three-dimensional immersive virtual street crossing program.
Acta Neurologica Scandinavica 10/2009; 121(3):171-7. · 2.47 Impact Factor
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ABSTRACT: We report multidetector row CT images of multiple gastrointestinal tumours in a patient with Type 1 neurofibromatosis who presented with haemoperitoneum. The use of CT demonstrated multiple, variably sized, ovoid, relatively well-enhancing masses in the intramural or subserosal location of the jejunum. The largest mass that showed a haemorrhagic necrosis caused haemoperitoneum. These imaging features are unique and differ from previous imaging features that have been reported in the radiological literature.
The British journal of radiology 08/2009; 82(979):e133-6. · 2.11 Impact Factor
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ABSTRACT: The most common form of splenic anomaly with a concurrent short pancreas is polysplenia, which has been described in various studies in the radiological literature. However, splenic duplication has never been reported. We report here a case of splenic duplication associated with a short pancreas and pre-duodenal portal vein. This extremely rare case of splenic anomaly shows unique multidetector CT findings that are distinguishable from a splenic lobulation or cleft.
The British journal of radiology 04/2009; 82(975):e42-3. · 2.11 Impact Factor
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ABSTRACT: Most automatic sphygmomanometers use oscillometric method with a blood pressure cuff. Conventional oscillometric sphygmomanometer is simple to use and it needs no peripheral device. However, the method provides no guarantee of accuracy in all circumstance, because it is based on statistics. In this paper, we propose a new oscillometric method with two cuffs. A cuff is placed on upper arm as usual and another cuff is added on forearm. By adding one more blood pressure cuff, there are two different waveforms are shown and the different characteristics between both cuffs can be compared. The results of our experiments show that it is possible to measure blood pressure using dual-cuff oscillometric method.
Computers in Cardiology, 2008; 10/2008
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ABSTRACT: In non-invasive blood pressure (NIBP) measurement, most of the automatic devices use oscillometric method. There are two types of deflation in oscillometric method. One is the linear deflation and the other is the stepwise deflation method. In this study, we suggest the modified step deflation to reduce the measurement time while keeping the advantage of step deflation over linear deflation. With the control of the valve and real time signal processing, we implemented the blood pressure measurement system and new algorithm. We measure the amplitude of each systolic pulsation. For the validation of our suggested method, human observer assessed SBP / DBP according to EHS (European Hypertension Society) guideline. The mean differences between the suggested method and traditional auscultation method were 1.95 mmHg for SBP and -0.55 mmHg for DBP.
Computers in Cardiology, 2008; 10/2008
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ABSTRACT: The heartbeat class detection of the electrocardiogram is important in cardiac disease diagnosis. For detecting morphological QRS complex, conventional detection algorithm have been designed to detect P, QRS, T wave. However, the detection of the P and T wave is difficult because their amplitudes are relatively low, and occasionally they are included in noise. We applied two morphological feature extraction methods: higher-order statistics and Hermite basis functions. Moreover, we assumed that the QRS complexes of class N and S may have a morphological similarity, and those of class V and F may also have their own similarity. Therefore, we employed a hierarchical classification method using support vector machines, considering those similarities in the architecture. The results showed that our hierarchical classification method gives better performance than the conventional multiclass classification method. In addition, the Hermite basis functions gave more accurate results compared to the higher order statistics.
Computers in Cardiology, 2008; 10/2008
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ABSTRACT: In the NIBP (Non-Invasive Blood Pressure) measurement, we need well trained observer and there are differences in reading values between observers. We suggest new automated auscultation algorithms to select the proper epoch of K-sound for each heart beat. The sound for each epoch is converted into frequency domain and total power was calculated. We decided SBP(Systolic Blood Pressure) point when there was abrupt jump from the baseline. DBP (Diastolic blood pressure) was decided when there was the biggest drop in total power of successive beats. For the validation of our suggested method, human observer assessed SBP/DBP according to EHS (European Hypertension Society) recommendation. The mean differences between the automatic method and traditional auscultation method were 2.0 mmHg for SBP and 3.1 mmHg for DBP. We also took the paired t-test with the two results, and there was no statistically significant difference between these two methods.
Computers in Cardiology, 2008; 10/2008
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S Y Yoo,
J H Jang,
Y-W Shin,
D J Kim,
H-J Park,
W-J Moon,
E C Chung,
J-M Lee, I Y Kim,
S I Kim,
J S Kwon
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ABSTRACT: The aim was to investigate the white matter abnormalities of drug-naïve patients with obsessive-compulsive disorder (OCD) using diffusion tensor-imaging and the white matter changes in the patients after pharmacotherapy.
Thirteen drug-naïve OCD patients and 13 age- and sex-matched healthy comparison subjects were examined using diffusion tensor-imaging and structural magnetic resonance imaging. Measurements were made in OCD patients before and after 12 weeks of citalopram treatment.
Compared with controls, the drug-naïve OCD patients showed significant increases in fractional anisotropy (FA) in the corpus callosum, the internal capsule and white matter in the area superolateral to the right caudate. The increases in FA were mostly no longer observed in patients after 12 weeks of treatment compared with controls.
Our findings suggest that white matter alterations are associated with the pathophysiology of OCD, and the abnormalities may be partly reversible with pharmacotherapy.
Acta Psychiatrica Scandinavica 10/2007; 116(3):211-9. · 4.22 Impact Factor
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ABSTRACT: The aim of this study is to investigate the possibility that human sleep EEGs can be characterized by a multifractal spectrum using wavelet transform modulus maxima (WTMM). We used sleep EEGs taken from healthy subjects during the four stages of sleep and REM sleep. Our findings showed that the dynamics in human sleep EEGs could be adequately described by a set of scales and characterized by multifractals. We performed multivariate discriminate analysis to evaluate the use of multifractal features for classification. The multivariate discriminate analysis using within-groups covariance matrices for all sleep stages yielded a total error rate of 41.8%. In conclusion, multifractal formalism, based on the WTMM, appears to be a good tool for characterizing dynamics in sleep EEGs
Neural Engineering, 2007. CNE '07. 3rd International IEEE/EMBS Conference on; 06/2007
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ABSTRACT: In this paper, we proposed the regression model which could estimate unspecified people's systolic blood pressure (SBP) conveniently and continuously and checked its accuracy through clinical experiments. The method for estimating each individual SBP by using only pulse transit time (PTT) has been studied, but it is difficult to estimate unspecified people's SBP with the method using only PTT. Thus we researched several physical characteristic parameters which might affect blood pressure (BP) with the standard that we can measure them easily and conveniently, chose valid physical characteristic parameters through a clinical testing and correlation analysis, and made the regression model using PTT and valid physical characteristic parameters for estimating unspecified people's SBP. Comparing the result of the proposed method with American National Standards Institute of the Association of the Advancement of Medical Instrument (ANSI/AAMI), we know that the proposed regression model gives an acceptable result
Engineering in Medicine and Biology Society, 2005. IEEE-EMBS 2005. 27th Annual International Conference of the; 02/2006
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ABSTRACT: In this paper, we proposed a feedback cancellation algorithm based on independent component analysis (ICA) for digital hearing aids. In conventional adaptive feedback cancelling systems, the normalized least mean squares (NLMS) algorithm used to reduce acoustic feedback in which hearing aids occurs, generally at high gains. But primary input signal depend on the acoustic feedback signal in higher-order statistics, proposed algorithm was better acoustic feedback cancelling performance than the conventional NLMS algorithm when the input signal has a Laplacian distribution with high-order processing in real-time simulation of TMS320C 6711 DSK
Engineering in Medicine and Biology Society, 2005. IEEE-EMBS 2005. 27th Annual International Conference of the; 02/2006
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ABSTRACT: Extrapulmonary small cell carcinoma is a rare neoplasm. It is an aggressive malignant tumour characterized by rapid local progression and early metastasis. We report a case of small cell carcinoma arising in the transverse colon in a 34-year-old man who presented with epigastric pain. On CT, a poorly enhancing bulky mass encircling the transverse colon with extensive regional lymph node metastases was observed. A segmental annular narrowing with thick interhaustral folds of the transverse colon was found by barium enema examination. This is the first report of barium study and CT findings of extrapulmonary small cell carcinoma of the colon.
British Journal of Radiology 04/2005; 78(927):255-6. · 1.31 Impact Factor
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ABSTRACT: In this paper, we proposed a feedback cancellation algorithm based on independent component analysis (ICA) for digital hearing aids. In conventional adaptive feedback cancelling systems, the normalized least mean squares (NLMS) algorithm used to reduce acoustic feedback in which hearing aids occurs, generally at high gains. But primary input signal depend on the acoustic feedback signal in higher-order statistics, proposed algorithm was better acoustic feedback cancelling performance than the conventional NLMS algorithm when the input signal has a Laplacian distribution with high-order processing in real-time simulation of TMS320C 6711 DSK.
Conference proceedings: ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference 02/2005; 3:2711-3.
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ABSTRACT: Bioelectrical impedance analysis (BIA) method has been commonly used for measuring human body composition, especially body fat rate. In this study, we developed PDA based body fat measurement system using BIA method. A regression model for predicting fat free mass (FFM) was developed. Sixty-three weighted stable subjects (53 men, 10 women) aged 20∼32 years old participated in this study. A regression model, FFM = 0.0005*height<sup>2</sup> - 0.0160*impedance + 0.3920*weight - 0.0684*age - 5.8141*sex + 25.984, was found. The correlation coefficient of body fat rate between our system and HTM1000plus(Bionet™) was 0.928. HTM1000plus was approved from KFDA (Korean Food & Drug Administration) and it was a commercial product. These results indicated that our system is a reliable for estimation of body fat rate.
Biomedical Engineering, 2003. IEEE EMBS Asian-Pacific Conference on; 11/2003
