ECG 신호에서 불응기를 이용한 R-파 검출 방법

김정홍(Jeong-Hong Kim),김재수(Jea-Soo Kim),김진섭(Jin-Sub Kim) 한국컴퓨터정보학회 2013 韓國컴퓨터情報學會論文誌 Vol.18 No.1

심전도 신호에서 R-파는 다른 특징 점을 구하는데 중요한 역할을 할 뿐만 아니라 심장에 대한 많은 의학적인 정보를 가지고 있다. 지금까지의 연구는 심전도 신호 형태에 대한 분석을 통하여 R-파를 검출하였으나, R-파와 비슷한 형태의 P-파가 나타날 경우 정확한 R-파 검출이 어려웠다. 본 논문에서는 세포막이 흥분 후에 탈분극과 재 분극 기간인 불응기와 불응기내 파형의 첨도 형태를 이용하여 R-파를 검출하는 방식을 제시하였다. MIT-BIH 부정맥 데이터베이스에 있는 심전도 신호 대한 실험을 통하여 R-파와 유사한 형태의 P-파를 가진 105번과 108번 레코드뿐만 아니라 다른 레코드에서도 기존의 방식보다 비교적 우수한 검출율을 확인하였다. The accurate detection of R-wave is important for other feature extraction in ECG, and R-wave has a lot of medical information about heart. Numerous R-wave detection algorithms have been studied on the ECG signal shape analysis, but it was difficult to find accurate R-wave when the shape of R-wave is similar to the shape of P-wave. This paper presents an R-wave detection method based on the refractory period that is the period of depolarization and repolarization of the cell membrane after excitation. And we also use the shape of kurtosis in the refractory period. The proposed method is validated using the ECG records of the MIT-BIH arrhythmia database. Experimental results show that the proposed method significantly outperforms other method in case of 105 and 108 record that have R-wave similar to P-wave, as well as other records.

IoT 환경에서 최적 R파 검출 및 최소 특징점 추출을 통한 향상된 PVC 분류방법

조익성,우동식 (사)디지털산업정보학회 2017 디지털산업정보학회논문지 Vol.13 No.4

Previous works for detecting arrhythmia have mostly used nonlinear method such as artificial neural network, fuzzy theory, support vector machine to increase classification accuracy. Most methods require higher computational cost and larger processing time. Therefore it is necessary to design efficient algorithm that classifies PVC(premature ventricular contraction) and decreases computational cost by accurately detecting minimal feature point based on only R peak through optimal R wave. We propose an optimal R wave detection and PVC classification method through extracting minimal feature point in IoT environment. For this purpose, we detected R wave through optimal threshold value and extracted RR interval and R peak pattern from noise-free ECG signal through the preprocessing method. Also, we classified PVC in realtime through RR interval and R peak pattern. The performance of R wave detection and PVC classification is evaluated by using record of MIT-BIH arrhythmia database. The achieved scores indicate the average of 99.758% in R wave detection and the rate of 93.94% in PVC classification.

PVC Classification Algorithm Through Efficient R Wave Detection

( Ik Sung Cho ),( Hyeog Soong Kwon ) 한국센서학회 2013 센서학회지 Vol.22 No.5

Premature ventricular contractions are the most common of all arrhythmias and may cause more serious situation like ventricular fibrillation and ventricular tachycardia in some patients. Therefore, the detection of this arrhythmia becomes crucial in the early diagnosis and the prevention of possible life threatening cardiac diseases. Most methods for detecting arrhythmia require pp interval, or the diversity of P wave morphology, but they are difficult to detect the p wave signal because of various noise types. Thus, it is necessary to use noisefree R wave. So, the new approach for the detection of PVC is presented based on the rhythm analysis and the beat matching in this paper. For this purpose, we removed baseline wandering of low frequency band and made summed signals that are composed of two high frequency bands including the frequency component of QRS complex using the wavelet filter. And then we designed R wave detection algorithm using the adaptive threshold and window through RR interval. Also, we developed algorithm to classify PVC using RR interval. The performance of R wave and PVC detection is evaluated by using MIT-BIH arrhythmia database. The achieved scores indicate average detection rate of 99.76%, sensitivity of 99.30% and specificity of 98.66%; accuracy respectively for R wave and PVC detection.

관상동맥질환을 진단하기 위한 R파와 T파의 크기에 대한 연구

임현균,유권규,김진목,김인선,강찬석,박용기,Lim, Hyun-Kyoon,Yu, Kwon-Kyu,Kim, Jin-Mok,Kim, In-Seon,Kang, Chan-Seok,Park, Yong-Ki 한국초전도학회 2008 Progress in superconductivity Vol.10 No.1

Multi-channel magnetocardiography (MCG) has been proposed to detect ischemic heart disease because its sensitivity is quite high comparing with other conventional diagnostic tools. Especially, current map and magnetic field map of MCG provide crucial information on whether myocardiac muscles maintain the normal conduction pathway. In addition, MCG parameters derived from repolarization are useful to detect coronary artery disease. Recently, there was a study reporting that R- and T- wave amplitude are highly correlated with ischemic heart disease. In this study, we studied R- and T-wave amplitude and their ratio as well as MCG parameters. MCG data from 20 young, 20 age-matched controls, and 20 myocardial infarction (MI) patients were analyzed. As a result, MCG parameters showed significant change in MI patients comparing to those of controls. R- and T-wave amplitude of MI patients showed a feature of severe ischemic heart disease even though it was difficult to find consistent values. Further study is needed to reveal the relations between small T-wave amplitude and coronary artery disease.

헬스케어 환경에서 복잡도를 고려한 R파 검출과 이진 부호화 기반의 부정맥 분류방법

조익성,윤정오,Cho, Iksung,Yoon, Jungoh 디지털산업정보학회 2016 디지털산업정보학회논문지 Vol.12 No.4

Previous works for detecting arrhythmia have mostly used nonlinear method to increase classification accuracy. Most methods require accurate detection of ECG signal, higher computational cost and larger processing time. But it is difficult to analyze the ECG signal because of various noise types. Also in the healthcare system based IOT that must continuously monitor people's situation, it is necessary to process ECG signal in realtime. Therefore it is necessary to design efficient algorithm that classifies different arrhythmia in realtime and decreases computational cost by extrating minimal feature. In this paper, we propose R wave detection considering complexity and arrhythmia classification based on binary coding. For this purpose, we detected R wave through SOM and then RR interval from noise-free ECG signal through the preprocessing method. Also, we classified arrhythmia in realtime by converting threshold variability of feature to binary code. R wave detection and PVC, PAC, Normal classification is evaluated by using 39 record of MIT-BIH arrhythmia database. The achieved scores indicate the average of 99.41%, 97.18%, 94.14%, 99.83% in R wave, PVC, PAC, Normal.

심전도 신호에서 R파 왜곡에 따른 적응적 특이심박 검출

이승민(SeungMin Lee),류춘하(ChunHa Ryu),박길흠(Kil-Houm Park) 대한전자공학회 2014 전자공학회논문지 Vol.51 No.9

부정맥 심전도 신호에서 특이 파형 검출

박길흠(Kil-Houm Park),김진섭(Jin-Sub Kim),류춘하(Chunha Ryu),최병재(Byung-Jae Choi),김정준(Jungjoon Kim) 한국지능시스템학회 2013 한국지능시스템학회논문지 Vol.23 No.4

본 논문에서는 불응기(Refractory Period)에 기반한 부정맥 심전도 신호의 특이 파형 검출 알고리즘을 제안한다. 부정맥 심전도 신호는 대부분 평균 10% 정도의 특이 파형을 갖는다. 따라서 장시간 심전도 신호를 관찰 및 분석해야 하는 의료진에게 심전도 신호 샘플의 90%이상이 축소된 특이 파형만을 제공함으로써 시간과 비용 측면에서 매우 큰 효과를 볼 수 있다. 제안 알고리즘은 R-파의 특징과 가변 불응기를 이용하여 R-peak를 검출한다. 검출된 R-peak에 대해 특이 파형에 포함되지 않은 R-peak들의 전위 및 첨도의 평균과 표준편차를 이용하여 특이 파형을 검출한다. 제안한 알고리즘을 MIT-BIH 부정맥 데이터베이스의 모든 레코드에 적용한 결과 평균 90% 이상의 압축률을 보였다. In this paper, unusual waveform detection algorithm based on Refractory Period in arrhythmia ECG signal is proposed. Most of arrhythmia ECG signals consist of unusual waveforms with average 10% rate. Thus tremendous benefit can be obtained in terms of time and cost by providing unusual waveform samples reduced more than 90% to medical staffs who have to monitor and analyze for a long time. The proposed algorithm detects the R-peak using the features of R wave and variable refractory period. For the detected R-peak, unusual waveforms are found using means and standard deviation of electric potential and kurtosis of the R-peaks which are not included in unusual waveform. The proposed algorithm was applied to all records of the MIT-BIH arrhythmia database and showed more than average 90% of compression ratio.

콘크리트 넓은 보의 상태평가를 위한 초음파 속도의 통계학적 분포에 대한 연구

윤영근 ( Young-geun Yoon ),이인복 ( In-bok Lee ),사민형 ( Min-hyung Sa ),오태근 ( Tae Keun Oh ) 한국안전학회 2017 한국안전학회지 Vol.32 No.2

The ultrasonic pulse velocities of pressure, shear, and Rayleigh waves ( P-, S-, and R- waves) have been used for the condition evaluation of various concrete structures, but the statistical distribution according to the wave type has not been studied clearly in view of data reliability and validity. Therefore, this study analyzed the statistical distribution of P-, S-, R-wave velocities in concrete wide beams of 800 × 3100 mm (width x length) with a thickness of 300 mm. In addition, we investigated an experimental consistency by the Kolmogorov-Smirnov goodness-of-fit test. The experimental data showed that the R-, S- and P- wave velocities in order have better statistical stability and reliability for in situ evaluation because R- and S-waves are less sensitive to confinement and boundary conditions. Also, good correlations between wave velocities and strength and modulus of elasticity were found, which indicate them as appropriate techniques for estimating the mechanical properties.

S/R 밸브에서 격막의 곡률반경과 재료가 밸브 개구시간에 미치는 영향

전흥균(Heung-Kyun CHEON),황재군(Jae-Gun HWANG),조태석(Tae-Seok CHO),권영두(Young-Doo KWON),권순범(Soon-Bum KWON) 대한기계학회 2007 대한기계학회 춘추학술대회 Vol.2007 No.5

When the pressure at the weak spot established at a certain part of a high pressure vessel or piping system exceeds a design pressure, this weak spot is burst, and the pressurized gas emitted through the weak spot will cause a compression wave system. In this connection, in the present study, an experimental study by using a conventional shock tube facility is performed to estimate the effects of the material of diaphragm, curvature radius and thickness of materials on the valve opening time in diaphragm. Pressure sensor having 500㎑ in natural frequency is installed at 35㎜ downstream of the rupture diaphragm to measure the static pressure history of propagating and being accumulated compression wave. 4 kinds of materials are used as diaphragm that is aluminium, copper, stainless steel and zinc. The diaphragm radii of curvature R are ∞, 120㎜ and 60, respectively. And the depth for 90° groove is 0.04㎜. It is found that the smaller the tensile strength and elongation of the rupture diaphragm is, the smaller the radius of curvature of the rupture diaphragm is, and for the same conditions the thinner the thickness of the rupture diaphragm is, the shorter the valve opening time becomes. Also, the tensile strength, elongation and the radius of curvature of the rupture diaphragm for the same conditions are smaller, the maximum pressure rise caused by the coalescences of the compression wave is smaller. Finally the pressure ratio is higher, the valve opening time is shortened and gradient of pressure increment is more steepen.

D-P-S-I-R 기법을 이용한 대한민국 폭염 취약성 분석

이형주(Hyeong Joo Lee),장현빈(Hyeon Bin Jang),한재형(Jae Hyeong Han),정건희(Gunhui Chung) 한국방재학회 2024 한국방재학회논문집 Vol.24 No.4

최근 지구온난화로 인해 여름철 폭염일수의 빈도가 증가함에 따라 온열질환자의 수도 증가하는 추세이다. 질병관리청의 온열질환자 신고현황 연보에 따르면 2011~2023년 온열질환자의 수는 약 21,000명으로 나타났고, 2018년을 기준으로 ‘재난 및 안전관리 기본법’을 개정해 폭염을 자연재난에 포함 시키며 인해 폭염 예방에 관심이 대두되고 있다. 이에 본 연구에는 폭염 취약성 분석을 위해 D-P-S-I-R (Driver force–Pressure–State–Impact–Response)기법을 활용하였다. 2011년부터 2020년까지 10년 단위 대한민국 행정구역 별 기온, 습도, 온열질환자, 무더위 쉼터 등 데이터를 수집하여 D-P-S-I-R 기법을 이용해 취약성 분석을 실시하였고, 최종적으로 전국 폭염 취약성 지수를 도출했다. 폭염 취약성 결과를 통해 취약한 지역에 대해 선제적인 대비가 가능하고, 효과적으로 폭염에 대응할 수 있는 시스템을 구축 할 수 있을 것으로 기대된다. The increasing frequency of summer heat waves due to global warming has led to a rise in the number of patients with heat-related illnesses. According to the annual report on heat patients by the Korea Centers for Disease Control and Prevention, about 21,000 cases were reported between 2011 and 2023. In 2018, the “Framework Act on Disaster and Safety Management” was revised to classify heat waves as natural disasters, highlighting the need for preventing measures. Therefore, this study employed the driver force–pressure–state–impact–response (D-P-S-I-R) technique to analyze heat wave vulnerability from 2011 to 2020. Using data on temperature, humidity, heat-related patients, and heat shelters, a national heat wave vulnerability index was developed. The results aim to facilitate preemptive preparation for vulnerable areas and establish an effective response system for managing heat waves.