Respiration From Pleth Validation

Inclusion Criteria: 1. Adult Participants (defined as aged 18 years or older): Willing and able to understand and provide written informed consent 2. UK Pediatric subjects: * Aged 16 years and older willing and able to understand and provide written informed consent * Aged 4-15 years and their legal guardians willing and able to understand and provide written informed consent/assent 3. US Pediatric Participants: aged 4 to 17 years and their parent/legal guardian are willing and able to understand and provide written informed assent/consent 4. Participant weight is within intended use of at least one SpO2 sensor under test as time of enrollment. * M1191T, adult participants \> 50 kg * M1192A, pediatric participants 15-50 kg * Nasal Alar Sensor, adult and pediatric participants ≥ 15 kg * M1194A, adult and pediatric participants \> 40 kg 5. Willing and able to wear study devices for the entirety of study procedures 6. Undergoing regular spot-check measurements as per the site's standard of care Exclusion Criteria: 1. Palliative patients 2. Patients with tremors, cardiac pacemakers, or known atrial fibrillation 3. Patients receiving oxygen supplementation at the time of study participation 4. Critically ill patients with severe physiological instability 5. Pregnant and/or lactating patients (self-reported) 6. Injury, wounds, and/or physical malformation of any sensor application site (e.g., fingers, nose, ear) 7. Self-reported severe contact allergies to standard adhesives, latex, and/or other materials found in pulse oximetry sensors 8. Unwillingness or inability to remove colored nail polish or artificial nails from the application site 9. Unwillingness or inability to remove foreign objects, such as nose and/or ear jewelry from sensor application sites 10. Nail fungus on application site 11. Severe dermatitis or hyperkeratosis (e.g. ichthyosis) at sensor application site