In a controlled laboratory study of 36 subjects, leading researchers at the University of California San Francisco found that dark skin can result in decreased accuracy of pulse oximeters, especially in combination with low oxygen saturations. In the study, the NONIN PureSAT oximetry with clip sensor was not affected by skin pigmentation compared to competitive products tested. The NONIN PureSAT oximeter with clip sensor had excellent accuracy and the lowest bias throughout the oxygen saturation levels and for all skin pigmentations. Of particular note, the authors state “clinically important bias should be considered when monitoring patients with saturation below 80%, especially those with darkly pigmented skin”. In this most challenging environment of low saturation (SaO2 70% to 80%) and dark skin pigmentation, the bias for NONIN PureSAT oximetry with the clip sensor was minimal at -0.6 ± 1.2 and the accuracy was excellent. This is in contrast to the competitor’s results with a mean bias of 2.6 ± 2.6 and 2.6 ± 3.0 in the same subgroup.