Figure 5.

Short-term acquisitions: (a–c) Correlation of PPG AVNN with ECG AVNN; (d–f) Boxplots of PPG AVNN and ECG AVNN; (g–i) Correlation of PPG LF/HF ratio with ECG LF/HF ratio; (j–l) Boxplots of PPG LF/HF ratio and ECG LF/HF ratio.