• 동의생리병리학회지
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• 제25권1호
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• pp.138-143
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• 2011

In spite of abundant clinical resources of stroke patients, the objective and logical data analyses or diagnostic systems were not established in oriental medicine. As a part of researches for standardization and objectification of differentiation of syndromes for stroke, in this present study, we tried to develop the statistical diagnostic tool discriminating the 4 subtypes of syndrome differentiation using the essential indices considering the sex. Discriminant analysis was carried out using clinical data collected from 1,448 stroke patients who was identically diagnosed for the syndrome differentiation subtypes diagnosed by two clinical experts with more than 3 year experiences. Empirical discriminant model(V) for different sex was constructed using 61 significant symptoms and sign indices selected by stepwise selection. We comparison. We make comparison a between discriminant model(V) and discriminant model(IV) using 33 significant symptoms and sign indices selected by stepwise selection. Development of statistical diagnostic tool discriminating 4 subtypes by sex : The discriminant model with the 24 significant indices in women and the 19 significant indices in men was developed for discriminating the 4 subtypes of syndrome differentiation including phlegm-dampness, qi-deficiency, yin-deficiency and fire-heat. Diagnostic accuracy and prediction rate of syndrome differentiation by sex : The overall diagnostic accuracy and prediction rate of 4 syndrome differentiation subtypes using 24 symptom and sign indices was 74.63%(403/540) and 68.46%(89/130) in women, 19 symptom and sign indices was 72.05%(446/619) and 70.44%(112/159) in men. These results are almost same as those of that the overall diagnostic accuracy(73.68%) and prediction rate(70.59%) are analyzed by the discriminant model(IV) using 33 symptom and sign indices selected by stepwise selection. Considering sex, the statistical discriminant model(V) with significant 24 symptom and sign indices in women and 19 symptom and sign indices in men, instead of 33 indices would be used in the field of oriental medicine contributing to the objectification of syndrome differentiation with parsimony rule.

• 한국산학기술학회논문지
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• 제19권11호
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• pp.126-136
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• 2018

본 연구는 머신러닝을 활용하여 급성 뇌졸중 퇴원 환자의 중증도 보정 사망 예측 모형 개발을 목적으로 시행하였다. 전국 단위의 퇴원손상심층조사 2006~2015년 자료 중 한국표준질병사인분류(Korean standard classification of disease-KCD 7)에 따라 뇌졸중 코드 I60-I63에 해당하는 대상자를 추출하여 분석하였다. 동반질환 중증도 보정 도구로는 Charlson comorbidity index(CCI), Elixhauser comorbidity index(ECI), Clinical classification software(CCS)의 3가지 도구를 사용하였고 중증도 보정 모형 예측 개발은 로지스틱회귀분석, 의사결정나무, 신경망, 서포트 벡터 머신 기법을 활용하여 비교해 보았다. 뇌졸중 환자의 동반질환으로는 ECI에서는 합병증을 동반하지 않은 고혈압(hypertension, uncomplicated)이 43.8%로, CCS에서는 본태성고혈압(essential hypertension)이 43.9%로 다른 질환에 비해 가장 월등하게 높은 것으로 나타났다. 동반질환 중중도 보정 도구를 비교해 본 결과 CCI, ECI, CCS 중 CCS가 가장 높은 AUC값으로 분석되어 가장 우수한 중증도 보정 도구인 것으로 확인되었다. 또한 CCS, 주진단, 성, 연령, 입원경로, 수술유무 변수를 포함한 중증도 보정 모형 개발 AUC값은 로지스틱 회귀분석의 경우 0.808, 의사결정나무 0.785, 신경망 0.809, 서포트 벡터 머신 0.830로 분석되어 가장 우수한 예측력을 보인 것은 서포트 벡터머신 기법인 것으로 최종 확인되었고 이러한 결과는 추후 보건의료정책 수립에 활용될 수 있을 것이다.

• 대한한의학회지
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• 제27권1호
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• pp.118-129
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• 2006

Objectives : A human being is classified into 4 constitutions(Taeyangin, Soyangin, Taeumin, and Souemin) and each constitution has the different incidence, treatment and prevention of disease in Sasang Constutional Medicine[SCM], The purpose of this study is to find relative risk(RR)s of each risk factors including Sasang Constitution[SC] for incidence of ischemic stroke. Methods : In 344-case patients with ischemic stroke and 1446 healthy control subjects without ischemic stroke, we evaluated sex, age. height, weight, BMI, ECG abnormality, hypertension, diabetes mellitus, blood lipid level and SC. These data were statistically analysed to investigate the relations between risk factors and the incidence of ischemic stroke by chi-square test. And then significant factors were analysed to get each adjusted odds ratio[OR] by binary logistic regression analysis. Results : ECG abnormality, hypertension, diabetes mellitus, HDL(high density lipoprotein) cholesterol, and SC were significantly related to the incidence of ischemic stroke, while age, sex and BMI were adjusted in a binary logistic regression analysis. Especially in SC, the incidence of ischemic stoke in Tae-eumin and Soyangin were higher than that in Soeumin (Tae-eumin OR=11.68[95% CI: 6.26-21.80], Soyangin OR=4.64[95% CI: 2.66-8.10]). Conclusions : These results suggested that SC may be one of important risk factors for ischemic stroke and it should be a useful data for prediction of incidence of ischemic stroke.

• Korean Journal of Radiology
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• 제24권4호
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• pp.338-348
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• 2023

Objective: Patients with a history of ischemic stroke are at risk for a second ischemic stroke. This study aimed to investigate the relationship between carotid plaque enhancement on perfluorobutane microbubble contrast-enhanced ultrasonography (CEUS) and future recurrent stroke, and to determine whether plaque enhancement can contribute to risk assessment for recurrent stroke compared with the Essen Stroke Risk Score (ESRS). Materials and Methods: This prospective study screened 151 patients with recent ischemic stroke and carotid atherosclerotic plaques at our hospital between August 2020 and December 2020. A total of 149 eligible patients underwent carotid CEUS, and 130 patients who were followed up for 15-27 months or until stroke recurrence were analyzed. Plaque enhancement on CEUS was investigated as a possible risk factor for stroke recurrence and as a possible adjunct to ESRS. Results: During follow-up, 25 patients (19.2%) experienced recurrent stroke. Patients with plaque enhancement on CEUS had an increased risk of stroke recurrence events (22/73, 30.1%) compared to those without plaque enhancement (3/57, 5.3%), with an adjusted hazard ratio (HR) of 38.264 (95% confidence interval [CI]:14.975-97.767; P < 0.001) according to a multivariable Cox proportional hazards model analysis, indicating that the presence of carotid plaque enhancement was a significant independent predictor of recurrent stroke. When plaque enhancement was added to the ESRS, the HR for stroke recurrence in the high-risk group compared to that in the low-risk group (2.188; 95% CI, 0.025-3.388) was greater than that of the ESRS alone (1.706; 95% CI, 0.810-9.014). A net of 32.0% of the recurrence group was reclassified upward appropriately by the addition of plaque enhancement to the ESRS. Conclusion: Carotid plaque enhancement was a significant and independent predictor of stroke recurrence in patients with ischemic stroke. Furthermore, the addition of plaque enhancement improved the risk stratification capability of the ESRS.

• 재활복지공학회논문지
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• 제11권2호
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• pp.91-98
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• 2017

연구배경 및 목적: 수정된 바델지수(MBI)는 지역사회 재활세팅 및 재활 병원에서 흔히 사용되어지는 기본적인 일상생활 평가 도구이다. 선행 연구들에 의하면 노인 혹은 뇌졸중 환자들의 운전 능력과 일상생활활동의 수준은 유의미한 상관성이 있음을 보고된 바 있다. 그러나, 뇌졸중 환자의 운전능력을 예측함에 있어 임상에서 흔히 사용되는 일상생활 활동 기본 평가인 수정된 바델지수의 유용성을 밝힌 연구는 미비하다. 본 연구에서는 한국형 수정된 바델 지수(K-MBI)룰 활용하여 뇌졸중 환자의 운전 가능성을 알아봄으로서 운전 수행 능력을 예측함에 있어 한국형 수정된 바델 지수의 임상적 유용성을 알아보고자 하였다. 연구방법: 서울 소재 재활병원에서 재활치료를 받고 있는 뇌졸중 환자 48명이 연구에 참여하였다. 모든 연구 대상자에게 K-MBI 검사를 통해 기본적인 일상생활 활동 수준을 측정하였고 가상현실 운전시뮬레이터를 이용하여 운전 수행능력을 측정하였다. 운전 시뮬레이터상의 운전 수행 검사의 합격/불합격에 따른 K-MBI 점수의 예측 타당도를 ROC curve를 이용하여 검증하였다. 결과: 뇌졸중 이후 운전재활을 권고할 만한 기본적인 일상생활 활동 수준은 K-MBI 점수가 최소 86.5점인 경우가 적절한 것으로 나타났다. 결론: 본 연구는 뇌졸중 환자의 운전 재활을 권고하는 시기를 예측함에 있어 유용한 기초 자료가 될 것으로 판단된다.

• 한국자동차공학회논문집
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• 제3권2호
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• pp.130-135
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• 1995

In this paper, the numerical simulation of the method of characteristics for a two-stroke SI engine was carried out, and the scavenging efficiency and the performance of single engine with two types of exhaust system, that is, a pipe exhaust system and a tuned exhaust system, were predicted and compared. The conculusions are obtained as follows. (1) The method of characteristics of hometropic flow considering the friction and the variation of area is useful to predict the scavenging efficiency and the performance of the two-stroke engine. (2) The shape of exhaust system effects directly on the scavenging and the trapping efficiency. (3) A tuned exhaust system consisted of the diffuser and the convergent nozzle makes the plugging pulse and therefore enhances the scavenging and the trapping efficiency. (4) It may be possible to design the optimum exhaust system by using the plugging pulse.

• 오토저널
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• 제9권1호
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• pp.69-76
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• 1987

This paper deals with the theoretical prediction and cyclic variation of combustion characteristics in a four stroke, single0cylinder, diesel engine. Theoretical calculations employed a simple empirical model of analysis of energy equation for the thermodynamic system of engine cylinder. The cyclic variation of combustion characteristics is investigated, in term of frequency distribution and standard deviation of peak characteristics, as obtained by combustion analyzer system. The results of theoretical prediction are shown to be in close agreement with the experimental data. The effect of fuel injection timing, engine speed, cooling water temperature, and the compression ratio on the cyclic variations of combustion characteristics were discussed.

• Physical Therapy Rehabilitation Science
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• 제5권1호
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• pp.1-8
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• 2016

Objective: The present study was to investigate the discrimination capacity of the Performance Oriented Mobility Assessment-Gait Scale (POMA-GS), for predicting falls in stroke survivors. Design: Retrospective cohort study. Methods: Data including the characteristics and number of falls of 52 chronic stroke patients from a rehabilitation center were collected. The number of falls each subject had experienced in the previous year were investigated through interviews. The subjects were divided into two groups depending on the number of falls: if falls occurred twice or more on the basis of the time of study after stroke, they were defined as the falls group and if there was no fall experience or one fall, they were defined as the non-falls group. The subjects were examined with the POMA-GS, and physical functions were examined using by the One Leg Stand Test (OLST), Sit to Stand Test (SST), 10-m Walk Test, Lower Extremity in Fugl-Meyer assessment (FM-LE), and Trunk Impairment Scale (TIS). The validity of POMA-GS for falls prediction was analyzed. Results: In the POMA-GS, which predicts falls in stroke survivors, the cut-off value was 8.5 (sensitivity 72%; specificity 65%) and the area under the curve was 0.75 (95% confidence interval: 0.60-0.90, p<0.007). There was a significant difference in the OLST, SST, FM-LE, and TIS between the subjects with POMA-GS >8.5 and the subjects with POMA-GS ${\leq}8.5$. Conclusions: The POMA-GS could be a useful tool in predicting falls in stroke survivors, as its discrimination capacity and predictive validity is proven satisfactory.

• 한국전문물리치료학회지
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• 제21권2호
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• pp.37-47
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• 2014

Falls are common after stroke and most frequently related to loss of balance while walking. Consequently, preventing falls is one of the goals of acute, rehabilitative, and chronic stroke care. The purpose of this study was to investigate the incidence and risk factors of falls and to determine how well the Falls Efficacy Scale (FES), Timed Up and Go test (TUG), and Berg Balance Scale (BBS) could distinguish between fallers and non-fallers among stroke patients during inpatient rehabilitation. One hundred and fifteen participants with at least 3 months post-stroke and able to walk at least 3 m with or without a mono cane participated in this study. Fifty-four (47%) participants reported falling, and 15 (27.8%) had a recurrent fall. Logistic regression analysis for predicting falls showed that left hemiplegia [odds ratio (OR)=4.68] and fear of falling (OR=5.99) were strong risk factors for falls. Fallers performed worse than non-fallers on the FES, TUG, and BBS (p<.05, p<.01, respectively). In the receiver operator characteristic curve analysis, the TUG demonstrated the best discriminating ability among the three assessment tools. The cut-off score was 22 seconds on the TUG for discriminating fallers from non-fallers (sensitivity=88.9%, specificity=45.9%) and 27 seconds for discriminating recurrent fallers from single fallers and non-fallers (sensitivity=71.4%, specificity=40.2%). Results suggest that there is a need for providing fall prevention and injury minimization programs for stroke patients who record over 22 seconds on the TUG.

• 한국추진공학회지
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• 제26권3호
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• pp.43-53
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• 2022

본 연구에서는 스플릿라인 TVC를 적용한 핀틀 추력조절 노즐에 대한 유동해석을 수행하고 추력성능을 예측하였다. 해석 결과로 도출된 추력계수를 시험결과와 비교하여 수치해석 결과를 검증하였으며, 동일한 수치해석 기법을 적용하여 주요 성능 변수인 운용고도, 핀틀 스트로크 위치, TVC 각도에 따른 1/10 크기의 노즐의 유동특성을 확인하였다. TVC 각도가 증가할수록 추력손실이 발생하였고, 핀틀 스트로크 위치에 따라 AF의 경향성이 달랐다. 해석결과를 기반으로 반응표면법을 적용하여 추력계수에 대한 관계식을 도출하였고, 해석 결과와 평균 1.2% 수준의 근소한 차이를 가지는 추력성능 모델을 생성하였다.