Are there differences in the respiratory and cardiac components of the PPG signal when monitoring respiration rate and pulse at different measurement sites in spontaneously breathing subjects?
Combined PPG monitoring of respiration and pulse is feasible, though signal components vary significantly depending on the measurement site.
Combined PPG respiration and pulse monitoring is possible, but there are significant differences between the respiratory and cardiac components of the PPG signal at different sites.
Nilsson et al. (2007) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: