Open Access e-Journal Cardiometry No.16 May 2020

Figure 4. Filtering of the ECG signal wide-band electrical noise
Table 2.
Evaluation of the high-frequency noise filtering quality
№
Type of reject filter
implementation
RMSD, mV
( q )
S i
The polynomial reject filter
Newton
Butterworth
RMSD, mV
RMSD, mV
NAC, dB RMSD, mV
( q )
S i
( q )
( q )
n i
n i
NAC, dB
1 The first RF output, n=2. 178,719 15,100 -0,0295 178,719 15,100 -0,0295
2 The second RF output, n=4 without n=2. 178,548 15,307 -0,0367 178,886 15,246 -0,0241
3 Cascade n=2 and n=4. 178,380 15,373 -0,0430 178,716 15,322 -0,0305
4
With general transfer function of
cascade n=6.
178,386 15,373 -0,0422 178,723 15,322 -0,0302
electrode M2202A generates the lowest value only in
5 of 12. Figure 7 gives a diagram Tukey showing an
accuracy of the low-frequency noise separation generated
by different electrodes in multi-lead ECG signal
recording.
Systematizing the results of multi-lead ECG signal
recording processing, we can note that despite a minor
variability in the RMSD values in the filtered signals of
the same ECG signal lead, taken with different electrodes,
a high variability is demonstrated in RMSD
values of the separated noises. The high variability
in RMSD noise values let us conclude that electrodes
H92SG, H99SG, MSGLT-05MGRT and M2202A,
to varying degrees, generate low-frequency noises
Issue 16. May 2020 | Cardiometry | 93