Evaluation of the Melanin-Adjusted Blood Oxygen Sensor (MABOS) in ICU Settings

Inclusion Criteria:

* Age ranges from 18 to 85 years.
* Individuals admitted to one of UNC Hospital's intensive care units (Medical Intensive Care Unit or Cardiovascular and Thoracic Intensive Care Unit).
* Individuals with a medical condition necessitating a minimum of two arterial blood gas measurements within a 24-hour period.
* Participant, or Legally Authorized Representative (LAR) must be able to read, write, and speak English fluently.

Exclusion Criteria:

* History of active (clinically significant) skin disorders that make skin vulnerable to contact with conventional electronic devices.
* History of allergic response to silicones, adhesives (such as 3M Tegaderm), or acetone.
* Broken, damaged or irritated skin or rashes near the sensor application sites.
* Presence of tattoos on the fingers, hands, or forearms.
* History of a genetic condition or skin disorder that variably impacts the amount of melanin pigmentation (e.g., Vitiligo).
* Pregnant or lactating individuals
* Individuals given methylene blue within the last 24 hours or Hydroxocobalamin within the last 2 weeks.
* Individuals experiencing carbon monoxide poisoning.
* History of conditions that may affect ABG readings (e.g., lipemic specimens).
* History of hematological conditions affecting red blood cell morphology (e.g., sickle cell disease)
* Patients on Venoarterial extracorporeal membrane oxygenation (VA-ECMO), durable left ventricular assist device (LVAD), or Impella.