Coherence as a measure of noise in the ECG
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Coherence as a measure of noise in the ECG. / Struijk, Johmmes J.; Graff, Claus; Kanters, Jørgen K.; Xue, Joel Q.; Jensen, Ask Schou; Schmidt, Samuel.
In: Computing in Cardiology, Vol. 41, 01.01.2014, p. 37-40.Research output: Contribution to journal › Conference article › Research › peer-review
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TY - GEN
T1 - Coherence as a measure of noise in the ECG
AU - Struijk, Johmmes J.
AU - Graff, Claus
AU - Kanters, Jørgen K.
AU - Xue, Joel Q.
AU - Jensen, Ask Schou
AU - Schmidt, Samuel
PY - 2014/1/1
Y1 - 2014/1/1
N2 - The 12-lead ECG can be described as the projection of a time-varying dipole on the lead vectors. This dipole-source assumption implies that the different leads must show a high coherence and that deviations from values close to unity may indicate the presence of noise. We evaluated the average coherence in the band of 5 Hz to 45 Hz in 309 ECGs and compared the coherence measure with an automatic out-of-band noise evaluation, quantified at a scale from 0 (clean) to 10 (very noisy). The generalized magnitude squared coherence (GMSC), which is a global measure of the linear relationships among the leads, was used. A high coherence (GMSC> 0. 95) was always associated with very low noise (level 0 or 1) and 0.9<GMSC<0.95 was associated with levels 0-2. For noise levels > 2 the GMSC was <0.87 in all cases. There were no cases of high noise level and a high coherence, however, in 32% of the cases with noise level 0 or 1 the GMSC was <0.8. For low-noise ECGs the GMSC is close to unity, with a good correlation between noise level and GMSC for normal ECGs. However, a low coherence also seems to be associated with abnormalities in the ECG, which will be subject for further study.
AB - The 12-lead ECG can be described as the projection of a time-varying dipole on the lead vectors. This dipole-source assumption implies that the different leads must show a high coherence and that deviations from values close to unity may indicate the presence of noise. We evaluated the average coherence in the band of 5 Hz to 45 Hz in 309 ECGs and compared the coherence measure with an automatic out-of-band noise evaluation, quantified at a scale from 0 (clean) to 10 (very noisy). The generalized magnitude squared coherence (GMSC), which is a global measure of the linear relationships among the leads, was used. A high coherence (GMSC> 0. 95) was always associated with very low noise (level 0 or 1) and 0.9<GMSC<0.95 was associated with levels 0-2. For noise levels > 2 the GMSC was <0.87 in all cases. There were no cases of high noise level and a high coherence, however, in 32% of the cases with noise level 0 or 1 the GMSC was <0.8. For low-noise ECGs the GMSC is close to unity, with a good correlation between noise level and GMSC for normal ECGs. However, a low coherence also seems to be associated with abnormalities in the ECG, which will be subject for further study.
UR - http://www.scopus.com/inward/record.url?scp=84931299783&partnerID=8YFLogxK
M3 - Conference article
AN - SCOPUS:84931299783
VL - 41
SP - 37
EP - 40
JO - Computing in Cardiology
JF - Computing in Cardiology
SN - 0276-6574
T2 - 41st Computing in Cardiology Conference, CinC 2014
Y2 - 7 September 2014 through 10 September 2014
ER -
ID: 204298447