Electrocardiogram (ECG) Hsiao-Lung Chan Dept Electrical Engineering Chang Gung University

Transcription

1 Electrocardiogram (ECG) Hsiao-Lung Chan Dept Electrical Engineering Chang Gung University

2 ECG measurements Patient Monitors First Electrocardiograph (ECG) by William Einthoven in 1903 Portable ECG system ECG Holter Embedded ECG ECG chip ECG 2

3 Heart anatomy and electrical conduction ECG 3

4 Pacing rate of cardiac cells John G. Webster, Bioinstrumentation, John Wiley & Sons, ECG 4

5 Formation of ECG ECG 5

6 Deporalization of atrial muscles Atrial reporalization Ventrical depolarization Ventrical repolarization R. Rangayyan, Biomedical Signal Analysis, John Wiely & Sons, 2002.

7 12-lead ECG Precordial leads: V 1 -V 6 Einthoven leads: I, II & III Goldberger augmented leads: V R, V L & V F ECG 7

8 ECG 8

9 Limb leads and augmented leads ECG 9

10 Bipolar limb leads in frontal plane Precordial leads in transversal plane ECG 10

11 Precordial leads (chest leads) Referenced to Wilson central terminal ECG 11

12 Vectorcardiogram (VCG) ECG 12

13 ECG features P wave : Atrial depolarization QRS complex : Ventricular depolarization T wave : Ventricular repolarization R-R : Heart period P-Q : Conduction delay in the atria Q-T : Ventricular repolarization time ECG 13

14 Power spectrum of P, QRS complex, and T wave ECG 14

15 Noise and artifacts in the ECG Baseline wander Electrode motion artifacts Electromyographic noise ECG 15

16 Pan-Tompkins QRS detection ECG Band-pass Filter 32 d 1 dt 2 32 n 1 Adaptive threshold ECG 16

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18 Heart rate variability (HRV, 心率變異度 ) Parasympathetic modulation Sympathetic modulation 心率變異度 ECG 18

19 Sinus rhythm Normal sinus rhythm Respiratory sinus arrhythmia ECG 19

20 Respiratory sinus arrhythmia ECG 20

21 Premature beat A supraventricular premature beat with a small, negative P wave A premature ventricular beat followed by a compensatory pause ECG 21

22 Ectopic beats with different origins Bigeminy Trigeminy Interpolated ventricular premature beat ECG 22

23 Atrial and ventricular tachyarrhythmias Atrial flutter Atrial fibrillation Ventricular flutter Ventricular fibrillation

24 Atrial flutter ( 心房撲動 ) Atrial fibrillation ( 心房顫動 ) J. Malmivuo, Bioelectromagnetism, Oxfold University Press, ECG 24

25 Atria fibrillation Atrial fibrillation Sinus rhythm Blood that remains in the atria becomes "sluggish Allows blood clots to form, Risk of stroke Atria activity analysis ECG 25

26 Detecting VT and VF by TCI Thaker et al, IEEE Trans. Biomed. Eng ECG 26

27 Threshold crossing interval (TCI) TCI ( N 1) 1000 T 2 T1 T 2 T3 T3 T 4 ECG 27

28 Detecting VT and VF by TCI ECG 28

29 Lempel-Ziv complexity (複雜度) ECG 29

30 Detecting Ventricular Tachycardia and Fibrillation by Complexity Measure (Xu-Sheng Zhang, et al, 1999) window length 3 s 5 s 7 s ECG 30

31 Sudden cardiac death Major risks for coronary artery disease Myocardial infarction Induced lethal cardiac arrhythmia by myocardial ischemia Major causes of sudden deaths in congestive heat failure Life threatening cardiac arrhythmia Ventricular tachycardia Ventricular fibrillation ECG 31

32 Myocardial Infarction Normal QRS complex QRS complex after myocardial infarction Infarcted area Lead avf ST-segment elevation upon arrival at emergency room after 10 days after 6 months ECG 32

33 Stress test: Diagnosis and prognosis of coronary artery disease (CAD) ST-segment depression due to myocardia ischemia 33

34 ST-Segment Elevation for Heart Attack Detection Robert Fischell on medical inventing,

35 ST segment elevation, a sign of a heart attack

36 ST segment elevations related to blockages

37 Implantable medical device

38 Acute myocardial infarction from implanted copper stents

39 AngelMed Guardian System

40 Reference Leif Sörnmo, Pablo Laguna, Bioelectrical Signal Processing in Cardiac and Neurological Applications, Academic Press, John Enderle, Susan Blanchard, Joseph Bronzino, Introduction to Biomedical Engineering, Academic Press, John G. Webster, Medical Instrumentation, application and design, 3 rd Ed., Houghton Mifflin, Joseph J. Carr, John M. Brown, Introduction to Biomedical Equipment Technology, Pearson Education, 2000.