Hand Perfusion and Pulse Oximetry Performance

Inclusion Criteria: * Healthy adult men and women of all races and ethnic backgrounds recruited from faculty and staff of the Mayo Medical Center and from Rochester, MN and surrounding communities. * Equal number of male and female participants to address potential sex differences in physiology. * We will intentionally recruit subjects with dark skin because of the issues surrounding accuracy of pulse oximetry and skin tone. * Non-smokers * BMIs between 18-30 kg·m-2. * Female subjects will be non-pregnant. * Free of cardiopulmonary diseases or other conditions and/or taking medications that might affect pulse oximeter-based estimates of arterial saturation. * All inclusion and exclusion criteria are at the discretion of the Principal Investigator. * At least 8 of the subjects will have Fitzpatrick Skin Type of IV to VI. Exclusion Criteria: • Children under the age of 18 will not be studied. We will exclude children less than 18 years of age because they are unable to give consent, and because these studies are non-therapeutic.