The study will be conducted in hospitalised patients who undergo spot-check monitoring of vital signs as part of their routine care.

In an additional spot-check measurement procedure, the study will measure oxygen saturations through different Philips SpO2 finger sensors. Patients will wear a nasal cannula linked to a CO2 measuring device at the same time. The data from both devices will be used to design and improve algorithms for measurement of respiratory rate with the saturation probe and the Philips FAST pulse oximeter system. The study will include 50 adult patients and 25 pediatric patients.

Inclusion Criteria:

• Adult subjects (aged 18 years or older) willing and able to understand and provide written informed consent
• Paediatric subjects aged 16 years and older willing and able to understand and provide written informed consent
• Paediatric subjects aged approx. 4-16 years and their legal guardians, willing and able to understand and provide written informed consent/assent
• Subject weight within intended use of at least one SpO2 sensor under test at time of enrolment (M1191T: adult patients >50kg, M1196T: adult patients >40kg, M1192A: paediatric patients 15-50kg)
• Willing and able to wear study devices during study procedures
• Subject undergoing regular spot-check measurements as per the site's standard of care

Exclusion Criteria:

• Palliative patients
• Critically ill patients with severe physiological instability (NEWS ≥9)
• Injury/wounds or physical malformation of sensor application site (i.e. fingers, toes, hands, feet)
• Subjects with severe contact allergies to standard adhesives, latex or other materials found in pulse oximetry sensors (self-reported)
• Unwillingness or inability to remove coloured nail polish or artificial nails from application site
• Nail fungus on application site
• Severe dermatitis or hyperkeratosis (e.g. ichthyosis) at sensor application site