Combined photoplethysmographic monitoring of respiration rate and pulse: a comparison between different measurement sites in spontaneously breathing subjects

Abstract

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.

Using pulse oximetry to account for high and low frequency physiological artifacts in the BOLD signal

“…This analysis confirms that the PO signal reflects both cardiac and respiration components of blood oxygenation modulation (see also Nilsson et al, 2007). Using spectral filtering, it was possible to isolate these components, which appeared to be shifted from the time of the mechanical events that cause them.…”

“…When aligned to the R component of the The cardiac signal from the ECG (dark gray) covers a broad range of frequencies ranging from 0.5 to 3.5 Hz. The pulse oximetry (PO) signal (black) also has a peak corresponding to 15 events per minute, as well as a peak at approximately 60 events per minute (see also Nilsson et al, 2007). A minor high frequency peak can be found at about 2.25 Hz as well.…”

“…We begin by confirming that PO captures both the low and high frequency fluctuations induced from respiration and cardiac events respectively (Nilsson et al, 2007). These filtered components are then used to produce physiological noise models of both cardiac and respiration artifacts (Glover et al, 2000;Birn et al, 2006Birn et al, , 2008Chang and Glover, 2009a,b;Chang et al, 2009) and compared against similar models generated using the independently recorded measures of heart rate (ECG) and breathing (pneumatic belt).…”

Design rationale and performance evaluation of Wavelet Health Wristband: bench-top validation of a wrist-worn physiological signal recorder (Preprint)

“…Previously, several investigators reported accurate estimation of vitals using PPG signal collected from the finger in comparison with ECG in healthy [58][59][60] and disease settings [61][62][63]. Investigations by Maeda et al [55] showed relatively high signal strength can be obtained over from the wrist but lacked signal to noise ratio assessments which is essential to estimating accurate biometrics.…”

Finger and forehead PPG signal comparison for respiratory rate estimation based on pulse amplitude variability

“…Light-transmission configuration can be used in the finger but not in the forehead, where lightreflection is the only possible configuration. This affects to the PPG morphology, obtaining a smoother waveform when the signal is recorded in the forehead [6]. These characteristics in combination with the differences in arterial routes can generate differences in the estimated respiratory rate depending on the sensor location.…”