Armband Sensors Location Assessment for Left Arm-ECG Bipolar Leads Waveform Components Discovery Tendencies around the MUAC Line

Figures

• 

  Figure 1. Placement of mid upper-arm channel electrodes on the left arm during the WASTCArD arm-ECG mapping database recordings and derived radial arm axis rotation angles (30° stepwise) of six bipolar-leads around the mid upper-arm circumference (MUAC), as defined in Table 1.

• 

  Figure 2. Noise and signal windows in the SAECG 700 ms frame (locked with respect the SFP point at 320 ms of the frame) for QRS signal-to-noise ratio (SNR), P/QRS ratio (PqrsR) and T/QRS ratio (PqrsR) analysis.

• 

  Figure 3. Example subject case results of signal averaged ECG denoising process P-QRS-T frames (700s), of reference Chest Lead I ECG signal (blue) and bipolar arm-ECG signals (brown) for the six arm leads (Lead-1 to Lead-6) under study, after averaging 564 validated heart beats.

• 

  Figure 4. Bar charts presentation with amplified scale ranges (zoom-in) to facilitate depicting performance differentiation between the six arm leads mean and median value results (on the 30 subject cases) in Table 3: (a) for QRS SNR metric values, (b) for PqrsR (%) metric values and (c) for TqrsR (%) metric values.

• 

  Figure 5. Bar charts presentation with amplified scale ranges (zoom-in) to facilitate depicting performance differentiation between arm leads of the Se (%) and PPV (%) mean and median value results in Table 4.

• 

  Figure 6. Bar charts for results in Table 5: arm-leads (1–6) values of NTPqrs vs. number of valid QRS in the Chest Lead I (NVChestQRS): (a) Pearson correlation (p), and (b) trendline coefficient of determination (R2).

• 

  Figure 7. Scatter plot of 18 data pair/case points and associated trendline coefficient of determination (R2) of NTPqrs metric on arm leads (1–6) versus values of NVChestQRS on the Chest Lead-I.

• 

  Figure 8. Bar charts for results in Table 6: arm leads (1–6) HRV RMS metric values versus measured HRV RMS values in the Chest Lead I: (a) Pearson correlation (p), and (b) trendline (Figure 9) coefficient of determination (R2).

• 

  Figure 9. Scatter plot of 18 data pair/case points and associated trendline coefficient of determination (R2) of HRV RMS metric measured values (ms) on arm leads (1–6) versus measured values (ms) on the Chest Lead-I.

• 

  Figure 10. Bipolar arm-Lead axis angular range positions rough map for best recording of arm-ECG QRS-complex, T-wave and P-wave waveform components from an upper armband sensor (arm leads 1 to 6 are as derived from Ch8 to Ch10 and GND in Table 1).