Response of 10 pulse oximeters to an In vitro test system

Abstract

Pulse oximeters are often used in situations in which severe hypoxaemia may occur. We have developed an in vitro system to test the accuracy of pulse oximeter calibration. The probe of10 different oximeters was attached to a model finger in an in vitro blood circuit, and pulse oximeter readings (Spo2) were compared with multi-wavelength in vitro oximeter readings (So2 over a range of So2 values from 50 to 100%. The oximeters tested varied widely in their accuracy and linearity. We conclude that the system can test the accuracy, reproducibility and linearity of response of pulse oximeter readings at low oxyhaemoglobin saturations. © 1992 British Journal Anaesthesia.