Investigation of Skin Pigmentation Effect on Performance of Masimo Pulse Oximetry (INSPIRE)

Inclusion Criteria: * Subject is 18 years of age or older. * Subject is receiving care in an intensive care unit. * Subject with an arterial catheter in place. * Subject is experiencing hypoxemia as defined by 1) need for supplement oxygen or 2) peripheral oxygenation ≤ 94% on room air Exclusion Criteria: * Subjects in whom pulse oximetry cannot be reliably performed on both the third and fourth digit on the hand ipsilateral to the arterial line, precluding application of the sensor (e.g., amputation and deformity). * Subjects with a skin condition affecting the digits, where the sensor is applied, which would preclude sensor placement as standard of care (e.g., psoriasis, eczema, angioma, scar tissue, burn, fungal infection, substantial skin breakdown, etc.). * Subjects with distinct geographic variances in skin pigmentation (e.g., vitiligo) on the digit where the sensor is applied, which would preclude sensor placement as standard of care. * Subjects with nail polish or acrylic nails on the digits where sensor needs to be applied. * Subjects with known allergic reactions to adhesive tapes. * Subjects with arterial catheter placed in a lower extremity. * Subjects not suitable for the investigation at the discretion of the investigator or the clinical team.