The goal of this study is to learn how accurate smartwatches are at measuring oxygen levels in patients with a condition called pulmonary hypertension. The main questions it aims to answer are:
* How accurate the smartwatches are at measuring oxygen levels when the patient is sitting at rest * How accurate are smartwatches at measuring oxygen levels after exercise * How accurate are smartwatches at measuring oxygen levels after breathing a lower level of oxygen through a mask.
Researchers will compare oxygen levels measured through a smartwatch with those checked through a finger probe oxygen monitor and also from a blood sample checked from the artery in the wrist to see if smartwatch oxygen measurements are similar.
Participants will:
-Attend the hospital once, just for a few hours to collect all the required data.
Aged 18-years old and above.
Diagnosed with pulmonary hypertension by right heart catheterisation showing a baseline mean pulmonary artery pressure > 20mmHg, PVR >2 Woods Units.
Able to perform a six-minute walk test (6MWT)
Able to give written informed consent.
Peripheral arterial disease
Tattoos or skin markings which cover the dorsal wrist.
Resting SpO2 <88%
Severe concurrent medical condition that would prevent participation in study procedures or with life expectancy <3 months