Fig. 4
From: Pulse oximetry
Oxygen saturation measured with pulse oximetry (SpO2) using transmittance finger probe (diamond) and reflectance forehead probe (squares) during apnea and mask ventilation with 100% O2. The reflectance probe showed faster responses than the transmission probe at every measurement point. *P < 0.05 between the two groups. Reprinted with permission from Wiley [16]