Fig. 3. Correlation and agreement between NCS and BIOPAC estimate of RV, RR, and HR over the entire data.

The label shows a marker for each breathing style, including conscious normal, deep, fast and breath-hold (BH), as well as spontaneous breathing in relaxation and attention states. a–c Scatter plots of NCS vs. BIOPAC RV, RR, and HR, respectively, with denoted Pearson’s correlation coefficient, $r$, showing a high correlation between the two sensors. d–f$B\&A$ plots of NCS and BIOPAC showing the bias $m$ at the center (solid line) and the corresponding LoA (dotted lines) given by $m\pm 1.96\cdot \sigma$.