RecruitingDevice studyControlled Desaturation Study for Perin Health Patch ValidationThis study aims to test the accuracy of the Perin Health Patch (PHP), a non-invasive, chest-worn device that measures blood oxygen levels, by comparing its readings to a standard pulse oximeter device. The PHP device uses light sensors to measure blood oxygen saturation (SpO2), similar to how standard pulse oximeters work, and could allow for continuous remote monitoring at home. Participants in this study will breathe low-oxygen air through a mask to simulate different oxygen levels in a controlled environment. The goal is to see if the PHP device can accurately measure blood oxygen levels under different conditions and meet safety standards set by the FDA and international guidelines.