Controlled Oxygen Desaturation Study of the Neonatal Wireless Transmission System

The aim of the controlled desaturation study is to show that the NeWTS device can safely measure blood oxygen content in comparison to the "gold-standard" method of measuring blood oxygen levels (SaO2). To assess this, blood oxygen levels will be measured while the amount of oxygen participants breathe is gradually reduced.

Healthy adults will start breathing oxygen at the same levels as in room air (21% oxygen) and this will be gradually reduced. The measurements from the NeWTS device will be compared to the value taken directly from the blood via an arterial line (SaO2). The SaO2 is measured by obtaining multiple blood samples from an artery in the body.

As described in EN ISO 80601-2-61:2026 a minimum of 24 participants will be recruited with an average of 20 (±4), range 16-30 data points per participant.

The investigators will include a distribution of data pairs, with total pairs split across each desaturation decade between 70 % to 100 % saturations, with approximately 33 %, but no less than 25 %, in each decade.

90 % or greater of participants shall provide at least one useable data pair with an SaO2 below 85 %.

At least 75 % of participants shall also have provided at least one useable data pair with an SaO2 between 70 % to 80 %.

The number of data pairs for a given SaO2 decile (i.e. 70 % to 80 %, 80 % to 90 % and 90 % to 100 %) will be derived approximately equally from participants across skin pigment categories, ensuring that >25 % of data points come from light, medium and dark participants by MST and ITA.

Inclusion criteria

• Be aged 18-55 years

• Willing and have capacity to provide written informed consent
• Healthy adult volunteers classified as ASA 1
• Non-smoker (this does not exclude vaping)
• Willing and able to comply with study procedures and duration

Exclusion criteria

• History of Bleomycin treatment at any time
• Smokers or individuals exposed to high levels of carbon monoxide
• Compromised circulation, injury, or physical malfunction of the sensor sites which would limit the ability to test sites needed for the study
• Morbidly obese (defined as BMI >39.5) or significantly underweight (BMI <18)
• Pregnancy
• Participants who can conceive a pregnancy or carry a child (including women, trans men and non-binary people) will be required to demonstrate a negative pregnancy test
• Unwillingness or inability to remove coloured nail polish or nail attachments from test digits (relevant for reference pulse oximeter) or to have medical monitoring attached
• Known health conditions or medications disclosed on Health Assessment Form which mean that participant is not healthy
• Allergy to lidocaine
• Known allergy to adhesives used in medical dressings or tapes or materials used to adhere NeWTS components.
• Enrolment in any other clinical investigation/trial that is deemed would compromise the validity of the data or safety of the patient (at the discretion of the local PI)
• Sunburn/spray tan or other pigments on hands