Effect of Skin Pigmentation and Finger Choice on Accuracy of Oxygen Saturation Measurement in an IoT-based Pulse Oximeter

The pulse oximeters are widely used in hospitals and homes for measurement of blood
oxygen saturation level (SpO2) and heart rate (HR). Concern has been raised regarding a possible bias in obtaining pulse oximeter measurements from different fingertips and the potential effect of skin pigmentation (white, brown and dark). In this study, we obtained 600 SpO2 measure-ments from 20 volunteers using three UK NHS-approved commercial pulse oximeters alongside our custom-developed sensor and used the Munsell colour system (5YR and 7.5YR cards) to classify the participant skin pigmentation into three distinct categories (white, brown and dark). The statistical analysis using ANOVA post-hoc tests (Bonferroni correction), Bland-Altman plot and correlation test were then carried out to determine if there was a clinical significance in measuring SpO2 reading from the different fingertips and highlight if skin pigmentation affects the accuracy of SpO2 measurement. The results indicate that although the three commercial pulse oximeters had different mean and standard deviations, these differences had no clinical significance.