Heuristic selection of PPG filtering parameters

Determine whether band-pass filter cutoff frequencies and related preprocessing configurations used to process photoplethysmography signals for inter-beat interval and pulse rate variability estimation are typically selected heuristically rather than according to standardized guidelines across studies.

Background

The paper surveys prior work on photoplethysmography (PPG) preprocessing and highlights large variability in reported band-pass filter cutoff frequencies and limited justification for chosen parameters. This variability suggests a lack of consensus on optimal preprocessing practices for deriving inter-beat interval (IBI) and pulse rate variability (PRV) from PPG.

Building on this survey, the authors explicitly state a conjecture that researchers often choose filtering parameters heuristically rather than following standardized guidelines. Establishing whether this conjecture holds would inform efforts to develop consistent, validated preprocessing standards for PPG-based cardiac metrics.

References

This observation reinforces our conjecture that filtering parameters are often chosen heuristically rather than following standardized guidelines .

— Beyond Motion Artifacts: Optimizing PPG Preprocessing for Accurate Pulse Rate Variability Estimation (2510.06158 - Watanabe et al., 7 Oct 2025) in Section 2 (Background), Subsection 2.1 (Preprocessing and filtering strategies)