• Title/Summary/Keyword: RR 간격

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Adaptive Detection of Unusual Heartbeat According to R-wave Distortion on ECG Signal (심전도 신호에서 R파 왜곡에 따른 적응적 특이심박 검출)

  • Lee, SeungMin;Ryu, ChunHa;Park, Kil-Houm
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.9
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    • pp.200-207
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    • 2014
  • Arrhythmia electrocardiogram signal contains a specific unusual heartbeat with abnormal morphology. Because unusual heartbeat is useful for diagnosis and classification of various diseases, such as arrhythmia, detection of unusual heartbeat from the arrhythmic ECG signal is very important. Amplitude and kurtosis at R-peak point and RR interval are characteristics of ECG signal on R-wave. In this paper, we provide a method for detecting unusual heartbeat based on these. Through the value of the attribute deviates more from the average value if unusual heartbeat is more certainly, the proposed method detects unusual heartbeat in order using the mean and standard deviation. From 15 ECG signals of MIT-BIH arrhythmia database which has R-wave distortion, we compare the result of conventional method which uses the fixed threshold value and the result of proposed method. Throughout the experiment, the sensitivity is significantly increased to 97% from 50% using the proposed method.

Efficient QRS Detection and PVC(Premature Ventricular Contraction) Classification based on Profiling Method (효율적인 QRS 검출과 프로파일링 기법을 통한 심실조기수축(PVC) 분류)

  • Cho, Ik-Sung;Kwon, Hyeog-Soong
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.3
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    • pp.705-711
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    • 2013
  • QRS detection of ECG is the most popular and easy way to detect cardiac-disease. But it is difficult to analyze the ECG signal because of various noise types. Also in the healthcare system that must continuously monitor people's situation, it is necessary to process ECG signal in realtime. In other words, the design of algorithm that exactly detects QRS wave using minimal computation and classifies PVC by analyzing the persons's physical condition and/or environment is needed. Thus, efficient QRS detection and PVC classification based on profiling method is presented in this paper. For this purpose, we detected QRS through the preprocessing method using morphological filter, adaptive threshold, and window. Also, we applied profiling method to classify each patient's normal cardiac behavior through hash function. The performance of R wave detection, normal beat and PVC classification is evaluated by using MIT-BIH arrhythmia database. The achieved scores indicate the average of 99.77% in R wave detection and the rate of 0.65% in normal beat classification error and 93.29% in PVC classification.

Evaluation of the Odor with Aging (연령증가에 따른 향의 평가)

  • 강인형;민병찬;전광진;김철중
    • Science of Emotion and Sensibility
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    • v.5 no.2
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    • pp.1-9
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    • 2002
  • It is already known that olfactory susceptibility differ with races and sex. Moreover, with aging both detection and identification about olfactory information were impaired. For researches about evaluation of the odor with aging, although the subject used, from infants to elderly, was various, the kinds of odor used were restricted to simple alcohol and acetic acid. Also, the evaluation methods were mainly used olfactory test. From over respects , this research was done as follows. Subjects were 19 to 72 years (n=50) whose sense-of-smell functions are normal. They were taken as stability and closed eye state. The odor stimuli were used 100% natural odor of six kinds of Basil, Lavender, Lemon, Jasmine, Ylangylang oil and Skatole , during 60 seconds using olfactometer. ECG, GSR and subjective evaluation were measured, and examined their relevance. Twenty and 40 ages group evaluated Lemon and 60 ages group did Lavender affirmatively. Correlation was seen among RRI, HR, GSR and subjective evaluation for 40 ages group, and it turns out that it is the group which a mature olfactory function most. These results are fully applied not only to development of the classified cosmetics for the age group but to development of the artificial smell and taste.

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Parasympathetic Modulation Plays a Key Role in Initiation of Paroxysmal Atrial Fibrillation

  • Lee, Won-Jae;Shin, Dong-Gu;Hong, Geu-Ru;Park, Jong-Sun;Kim, Young-Jo
    • Journal of Yeungnam Medical Science
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    • v.24 no.2
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    • pp.216-231
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    • 2007
  • Background : An acceleration or deceleration of the heart rate (HR), which reflects autonomic effects, is observed before the onset of paroxysmal atrial fibrillation (PAF). The purpose of this study was to assess the discrepancy in the autonomic interactions before the onset of PAF for different patterns of change in the HR. Materials and Methods : From 105 Holter tapes with the PAF recorded, 55 episodes (42 patients, 34 men, $58{\pm}12$ years) of PAF (>5 min), preceded by a sinus rhythm for more than 1 hour, were selected and submitted to time-domain and frequency-domain HR variability analyses. Fifty-five episodes were divided into 2 groups: group A PAF (n=30) with acceleration of the HR during the last 2 minutes before the PAF and group B (n=25) with deceleration of the HR. Results : A significant linear decrease in the mean R-R interval was observed in group A ($924{\pm}30$ to $835{\pm}28ms$, $P$=0.001) and an increase from $831{\pm}32$ to $866{\pm}31ms$ in group B PAF episodes ($P$=0.046). In the frequency-domain analyses, the LF/HF ratio exhibited a progressive linear increase before the PAF in group A ($P$=0.005). The HF normalized units (HFnu) and natural logarithm-transformed HF ($In$HF) values decreased from $30.8{\pm}4.0$ to $16.1{\pm}1.8$ ($P$=0.003) and $4.49{\pm}0.25$ to $4.07{\pm}0.22$ ($P$=0.001), respectively. Contrary to the results in group A, a significant increase in the HF components (HFnu and $In$HF) (from $22.6{\pm}3.2$ to $30.2{\pm}4.0$, $P$=0.005, and $4.27{\pm}0.27$ to 4.75 0.33, $P$=0.001, respectively) and a resultant decrease in the LF/HF ratio were observed in group B PAF episodes. No significant changes were observed in the LF components in either PAF group. Conclusion : Autonomic stimuli leading to an acceleration or deceleration of the HR before the onset of AF are due to parasympathetic modulation. Parasympathetic modulation plays a key role in the initiation of PAF.

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Clinical Response to Etoposide Plus Carboplatin and Topotecan Chemotherapy in Small Cell Lung Cancer (소세포폐암에 대한 Etoposide와 Carboplatin 병합요법과 Topotecan 화학요법의 효과)

  • Park, Kyung Hwa;Cho, Gye Jung;Ju, Jin Young;Son, Chang Young;Wi, Jeong Ook;Kim, Kyu Sik;Kim, Yu Il;Lim, Sung Chul;Kim, Young Chul;Park, Kyung Ok
    • Tuberculosis and Respiratory Diseases
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    • v.54 no.4
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    • pp.415-428
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    • 2003
  • Background : This study assessed the efficacy and toxicity of etoposide and carboplatin(EC) combination regimen as a first line therapy for small cell lung cancer(SCLC), and determined the efficacy and toxicity of topotecan for relapsed SCLC. Methods : One hundred and ten patients with previously untreated SCLC received etoposide($100mg/m^2$ i.v., day 1 to 3) and carboplatin($300mg/m^2$ i.v., day 1) combination chemotherapy every 3 weeks. For patients with relapsed SCLC after EC therapy, topotecan($1.5mg/m^2$) was administered for 5 consecutive days every 3 weeks. Response rate, survival and toxicity profiles were assessed. Response was recorded as CR(complete remission), PR(partial remission), SD(stable disease) and PD(progressive disease). Results : One hundred and one patients were assessed for response to EC. Overall response rate to EC was 57.4%(CR 15.8%, PR 41.6%) with a time to progression of 10.3 months(median). The toxicity was tolerable and there was no treatment-related death. Twenty one relapsed SCLC patients were treated with topotecan. Of those who relapsed within 3 months of EC(refractory relapse, RR), 15.4%(2/13) showed PR, while of those who relapsed after 3 months(sensitive relapse, SR), 25%(2/8) exhibited PR. Grade 4 neutropenia was noted in 9.5% and 14.3% showed thrombocytopenia(G4). Conclusion : The EC regimen showed a moderate response rate for SCLC with minimal toxicity. The use of topotecan for relapsed SCLC warrants further investigation.

MDM2, p53 and pRb Expression Prior to Definitive Chemoradiotherapy in Esophageal Carcinoma (식도암에서 MDM2, p53, pRb 발현과 동시적 항암화학방사선요법의 결과)

  • Yoon, Mee-Sun;Lee, Jae-Hyuk;Cho, Sang-Hee;Song, Ju-Young;Ahn, Sung-Ja;Chung, Ik-Joo;Chung, Woong-Ki;Nah, Byung-Sik;Nam, Taek-Keun
    • Radiation Oncology Journal
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    • v.25 no.4
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    • pp.193-200
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    • 2007
  • Purpose: This study evaluated the pretreatment expression patterns of MDM2, p53, and pRb proteins to determine if the expression patterns could predict the outcome of concurrent chemoradiotherapy (CCRT) for esophageal squamous cell carcinoma and aid in the decisions for the selection of treatment modalities. Materials and Methods: Fifty-one patients that were treated with definitive chemoradiotherapy for stage $I{\sim}IVa$ esophageal squamous cell carcinoma were selected for this study. Radiotherapy was administered with daily $1.8{\sim}2\;Gy$ fractions up to a median dose of 54 Gy for primary tumors, and with four cycles of cisplatin/5-fluorouracil chemotherapy that was administered every 4 weeks, the first two cycles of which were administered concurrently with radiotherapy. Expression of MDM2, p53, and pRb was investigated by immunohistochemical analysis using pretreatment biopsy specimens. Results: MDM2, p53, and pRb were detected with high immunoreactivity in 19.6%, 27.5%, and 66.7% of the patients, respectively. However, there was no significant correlation between expression of these factors and clinical outcome. By the use of multivariate analysis with nine covariates-age, tumor location, tumor length, stage, pathological response, clinical response, MDM2 expression, p53 expression, and pRb expression, only pathological response and stage were significant factors for cause-specific survival. Conclusion: Expression of MDM2, p53, and pRb was not found to be clinically significant for predicting outcomes after CCRT in this study. Further studies with a larger patient population and longer follow-up periods are needed to re-evaluate the expression pattern and to identify new predictors for CCRT response.

Assessment of Autonomic Function in Alzheimer's Disease and Mild Cognitive Impairment Using Heart Rate Variability (알츠하이머병과 경도인지장애에서 심박동 변이를 이용한 자율신경기능 평가)

  • Seo, Han;Kim, Hyun;Lee, Kang Joon
    • Korean Journal of Psychosomatic Medicine
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    • v.21 no.1
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    • pp.55-61
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    • 2013
  • Objectives : Alzheimer's disease(AD) and mild cognitive impairment(MCI) affect several nervous structures involved with the autonomic nervous system. Association between neuropsychiatric deficits and heart rate variability has been observed. But cardiac autonomic function in AD has been scarcely studied and the results reported are conflicting. We investigated autonomic function in normal control, MCI, AD using heart rate variability(HRV) technique. Methods : Time and frequency-domain variability of 5-min R-R interval series was comparatively evaluated in 26 normal control subjects, 22 MCI subjects and 34 AD subjects. Analysis of variance(ANOVA) was used to compare the differences across groups. Correlations between MMSE-KC and HRV components were performed using Pearson's correlation coefficient. Results : No significant difference was observed among the groups in time, frequency-domain analysis of HRV(p>0.05). HRV were not found to be significantly correlated with the degree of cognitive impairment. Conclusions : There were no differences in HRV with MCI, AD subjects when compared with normal controls. Further investigation is required to use HRV technique as noninvasive parameters of MCI and AD.

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An Experimental Study on Bond Strength of High-Strength Reinforcing Bars with High Relative Rib Area (높은 마디면적 고강도 철근의 부착강도에 관한 실험적 연구)

  • Hong Geon-Ho;Choi Dong-Uk;Choi Oan-Chul;Hong Gi-Suop
    • Journal of the Korea Concrete Institute
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    • v.17 no.3 s.87
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    • pp.375-384
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    • 2005
  • The effects of bar deformation properties on bond of steel reinforcing bars to concrete are experimentally studied to predict the bond strength. Based on the previous research about high relative rib area, bond strength between reinforcing bars and concrete can be improved by the control of rib height and spacing. But, the equations in Korean code provisions to estimate development and splice length do not include these specifications of reinforcing bars. So the purpose of this paper is to determine the effect of relative rib area to the bond strength. This paper describes 2 kinds of experimental researches. Thirty beam-end specimens were tested to investigate the effects of bar size and relative rib areas ranging from 0.112 to 0.162. And, twelve lap-splice beam specimens were tested to the same variables. Each test results are normalized and compared with the proposed equations of ACI 408 committee. The results show that bond strength is increased as bar size and the relative rib area(Rr) increase. The distribution of flexural cracks and failure aspect do not appear to be affected by $R_r$.