Probe Site Specific Skin Tone Assessment and Perfusion Alteration for Assessment of Pulse Oximeter Accuracy: A Pilot Study.

Pulse oximeters are essential medical devices that estimate oxygen saturation. Researchers have shown that some pulse oximeters overestimate oxygen saturation, particularly for patients with darker skin tones and/or low perfusion. This overestimation worsens as oxygen saturation decreases. One of the main challenges with ensuring pulse oximeter accuracy is assessing the influence of skin tone and perfusion. Skin tone can be assessed quantitatively using the Individual Typology Angle (ITA). Here we show that finger ITA is considerably different from forehead ITA (a site commonly used for skin tone assessment) in almost half of the eighteen healthy volunteers studied. We also demonstrate a two minute hand submersion protocol to alter peripheral perfusion. Future work should use measurement site specific ITA, and compare performance in in vivo settings of low perfusion with those of assessments using functional testers.Clinical relevance- This study demonstrates the importance of site specific skin tone assessment and recommends in vivo perfusion assessment.