Biomedical Engineering Reference
In-Depth Information
The STC (Eq.
2.14
) will filter out any T peak being falsely detected, since QRS
complex is always sharper than T wave. If Eq. (
2.14
) is satisfied, then Eq. (
2.15
)is
searched to find a positive R peak. While both equations are satisfied at a sample
position say k, it is concluded that a positive R peak exists. This is verified by a slope
sign reversal within next 70-ms interval from current sample of reference k, con-
firming occurrence of an S peak. Hence, the correct position of R peak is determined
by finding the index with highest amplitude within next 50 samples from k.ForQS
peaks (i.e., for negative QRS polarization), Eq. (
2.14
) will be only satisfied, but not
Eq. (
2.15
) within current 96-ms window. In this case, it is concluded that a positive R
peak does not exist and search for QS peak is initiated. The index with minimum
amplitude within the current window of 96 ms is taken as the QS peak. Once the R
peak (or QS peak) is determined, the next R-peak search is initiated at 400 samples
upside the data array, assuming that the minimum R-R interval is 400 ms. If
Eq. (
2.14
) is not satisfied throughout the entire 96-ms window formed around p
max
Table 2.5 S
e
and P+ figures for Ptb-db using amplitude span detection
Patient file ID in Physionet
Lead I
Lead II
Lead aVR
Lead aVF
Lead V1
Lead V5
S
e
P+
S
e
P+
S
e
P+
S
e
P+
S
e
P+
S
e
P+
P237/s0465 (N)
100
100
100
100
100
100
100
100
100
100
100
100
P242/s0471 (N)
100
100
100
100
100
100
100
100
100
100
100
100
P248/s0481 (N)
100
100
100
100
100
100
100
100
100
100
100
100
P249/s0484 (M)
100
100
100
100
100
100
100
100
100
100
100
100
P267/s0504 (N)
100
100
100
100
100
100
100
100
100
100
100
100
P270/s0507 (Ant-Lat)
100
100
100
100
100
100
100
100
100
100
100
100
P269/s0508 (N)
100
100
100
100
100
100
100
100
100
100
100
100
P093/s0375(MI-Inf)
100
100
100
100
100
100
100
100
100
100
100
100
P093/s0378 (MI-Inf)
100
100
100
100
100
100
100
100
100
100
100
100
P002/0015 (MI-Ant)
100
100
100
100
100
100
100
100
100
100
100
100
P005/0021 (MI-Ant)
100
100
100
100
100
100
100
100
100
100
100
100
P001/0010 (Inf-Lat)
100
100
100
100
100
100
100
100
100
100
100
100
Narration
N
Normal;
MI
Myocardial
infarction;
Ant
Anterio;
Inf
Inferio;
Lat
Latera;
M Myocarditis
Table 2.6 S
e
and P+ figures
for mit-db using amplitude
span detection
Patient file ID from Physionet with lead no.
R
e
P+
102 (v2)
100
100
103 (v2)
100
100
108 (v1)
96.15
100
109 (v1)
97.37
100
111 (v1)
100
100
114 (ML-II)
100
100
115 (v1)
100
100
123 (v5)
100
100
124 (v4)
100
100
201 (v1)
100
100
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