Integrated Vital Sign Measurement Platform

Eligibility Details: Inclusion Criteria: For volunteers with one or more vital signs presumed to be within normal physiological range, at rest: - Age ≥ 18 years - Willing to allow arm and finger size to be measured - Willing to allow measurement of skin color (optional)a - Willing to undergo exercise testing (optional); - Willing to allow an arterial blood gas draw (optional); For volunteers with one or more vital signs expected to be outside of normal physiological range, at rest: - Age≥18 years - Willing to allow arm and finger size to be measured - Willing to allow measurement of skin color (optional) Exclusion Criteria: For Volunteers Undergoing Heart Rate and Oxygen Saturation Measurement: - Nail paint or artificial nail on the index finger of the left hand - SpO2 less than 94% For Volunteers Undergoing Exercise Testing with Vital Signs within Normal Physiological Range, at rest: - Volunteers with vital signs outside of normal physiological range (ascertained during measurements conducted at study site before exercise testing) - Age 65 years or older - Consumption of food, alcohol or caffeine (coffee, tea or caffeinated soft-drinks) in a 3-hour period prior to testing - Uncomfortable clothing, or inappropriate footwear for exercise testing - Self-report of any of the following: - History of fall or fracture in the past year - History of arthritis - History of dizziness - History of neurological illness - History of chest pain or myocardial infarction - History of hypertension or diabetes mellitus - History of heart disease - History of stroke or transient ischemic attack - Active treatment for anemia, electrolyte imbalance, or hyperthyroidism - Physical disability that precludes safe and adequate testing - Mental impairment with limited ability to cooperate4 - Pregnancy (Volunteer will be excluded if either of the following is true: a) self-report of being pregnant; b) positive urine pregnancy test) For Volunteers undergoing an Arterial Blood Gas Draw with Vital Signs within Normal Physiological Range, at rest: - Self-reported history of a clotting disorder of the blood, or active treatment with medicines affecting blood clotting (e.g. Warfarin).