Accuracy of Smartwatches in Measuring Oxygen Levels in Patients With Pulmonary Hypertension: A Pilot Study
NCT ID: NCT07311135
Last Updated: 2025-12-30
Study Results
The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.
Basic Information
Get a concise snapshot of the trial, including recruitment status, study phase, enrollment targets, and key timeline milestones.
RECRUITING
20 participants
OBSERVATIONAL
2025-12-17
2026-12-31
Brief Summary
Review the sponsor-provided synopsis that highlights what the study is about and why it is being conducted.
* 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.
Detailed Description
Dive into the extended narrative that explains the scientific background, objectives, and procedures in greater depth.
Patient recruitment:
Patients will be recruited prospectively from the Scottish Pulmonary Vascular Unit at the Golden Jubilee National Hospital, Glasgow, Scotland.
Patients attending outpatient clinic will be screened for eligibility. Additionally, a study poster will be displayed in the clinic waiting area. If eligible, they will be asked if they would like to learn about the study. After discussing the study overview in person, the patient will be offered the patient information sheet to take away with them and advised that if they are interested in taking part or have any further questions about the study, they can either reply using the opt in form provided or by phoning the study team. Those patients who opt in to the trial will be contacted to provide them with a date to attend for a study visit.
On the day of the study visit, prior to commencing any study activities, participants will see a different doctor from the research team who will clarify their full understanding of the study and will give them the opportunity to complete the written study consent form.
Procedure:
During a study visit, participants will have an arterial line inserted into their radial artery by an experienced intensive care unit doctor to allow easy access to arterial blood sampling. Each paired sample will include: smartwatch oxygen saturations, arterial oxygen saturations, finger probe pulse oximeter measurements taken at the same time. Paired samples will be taken at baseline (while the patient is in a seated, rested state), post-exercise in the recovery period after a six-minute walk test and in simulated high altitude during a hypoxic challenge.
The six minute walk test will comprise shuttles of 25 metres continuously for 6 minutes. 10 paired samples will be taken during the recovery period after a six-minute walk test. The hypoxic challenge will be undertaken by asking the patient to breathe through a 40% Venturi mask driven by 100% nitrogen at a flow rate of 10L/min which will deliver an inhaled oxygen level of 15%. If SpO2 falls below 85% for over 30 seconds the test will be stopped and if required, inhaled oxygen will be delivered to correct hypoxia. The participant will breathe the air/nitrogen mixture for 20 minutes unless the procedure is aborted due to hypoxia prior to that. 10 paired samples will be taken during the hypoxic challenge test. Following completion the arterial line will be removed and pressure will be applied until any bleeding stops. Participants will be monitored for 30 minutes prior to them leaving.
Data collection/management:
Each study participant will be assigned a study number which will be used on all study documentation to avoid using patient identifiable information. All data will be stored on an NHS password encrypted computer. Data will be collected on pseudonymised data capture sheets with a study ID number and all research measurements will be transferred to an Excel spreadsheet for analysis.
Sample size:
The study is a cross sectional study of validity requiring one study visit per participant. Regarding sample size, this is a pilot study to gain initial estimates of the mean bias and limits of agreement of smartwatch measurements compared to the gold standard arterial oxygen levels. The planned sample size of 20 is not based on a sample size calculation, and is considered sufficient to obtain initial estimates, and to allow planning of larger studies if required. We will aim to recruit 20 patients and will recruit up to a maximum of 25 in total if required in the case of incomplete data sets.
Statistical analysis:
The bias of smartwatches and standard pulse oximeter oxygen saturation measurements relative to the gold standard, arterial blood gas, will be compared using Bland-Altman analysis.
Plan for missing data:
In the event that an arterial sample cannot be analysed, the smartwatch and fingerprobe pulse oximeter samples will still be noted and compared. We will aim to obtain 10 complete paired samples per patient after exercise and also 10 full sets during the hypoxic challenge. We will aim to recruit 20 patients but will recruit up to 25 patients as required to achieve complete data sets. In the event that a smartwatch reading is not obtained during a paired sample, this will be documented as 'no measurement obtained'. This will still represent a complete paired sample as inability to obtain a measurement is useful to note as an outcome. In the event that the fingerprobe pulse oximeter is unable to obtain a reading the data will be documented as 'no measurement obtained' but will not require any increased requirement for recruitment as long as smartwatch and arterial gas measurements have been acquired as a paired sample.
Conditions
See the medical conditions and disease areas that this research is targeting or investigating.
Keywords
Explore important study keywords that can help with search, categorization, and topic discovery.
Study Design
Understand how the trial is structured, including allocation methods, masking strategies, primary purpose, and other design elements.
OTHER
CROSS_SECTIONAL
Study Groups
Review each arm or cohort in the study, along with the interventions and objectives associated with them.
Adult patients with pulmonary hypertension
Pre-capillary pulmonary hypertension, able to complete a six-minute walk test
No interventions assigned to this group
Eligibility Criteria
Check the participation requirements, including inclusion and exclusion rules, age limits, and whether healthy volunteers are accepted.
Inclusion Criteria
* 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.
Exclusion Criteria
* 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
* Patients with bleeding disorders
* Patients on anticoagulation
* Except in circumstances where anticoagulation is given solely for historical perceived long term survival benefit for pulmonary arterial hypertension. This patient group could be given the option to come off their anticoagulation for 1 week prior to the study visit if they wished to take part in the study. It could then be restarted the day following the study visit providing there were no bleeding complications related to the arterial line.
18 Years
ALL
No
Sponsors
Meet the organizations funding or collaborating on the study and learn about their roles.
Golden Jubilee National Hospital
OTHER_GOV
Responsible Party
Identify the individual or organization who holds primary responsibility for the study information submitted to regulators.
Principal Investigators
Learn about the lead researchers overseeing the trial and their institutional affiliations.
Martin Johnson, BA, MBChB(Hons), MD, FRCP
Role: PRINCIPAL_INVESTIGATOR
Golden Jubilee National Hospital
Locations
Explore where the study is taking place and check the recruitment status at each participating site.
Golden Jubilee National Hospital
Glasgow, Glasgow, United Kingdom
Countries
Review the countries where the study has at least one active or historical site.
Central Contacts
Reach out to these primary contacts for questions about participation or study logistics.
Martin Johnson, BA, MBChB(Hons), MD, FRCP
Role: CONTACT
Phone: (0044) 0141 951 5497
Email: [email protected]
Jamie Ingram, MBChB, BMSc, PGCert
Role: CONTACT
Phone: (0044) 0141 951 5497
Email: [email protected]
Facility Contacts
Find local site contact details for specific facilities participating in the trial.
Martin Johnson, BA, MBChB(Hons), MD, FRCP
Role: primary
Jamie Ingram, MBChB, BMSc, PGCert
Role: backup
References
Explore related publications, articles, or registry entries linked to this study.
Spaccarotella C, Polimeni A, Mancuso C, Pelaia G, Esposito G, Indolfi C. Assessment of Non-Invasive Measurements of Oxygen Saturation and Heart Rate with an Apple Smartwatch: Comparison with a Standard Pulse Oximeter. J Clin Med. 2022 Mar 8;11(6):1467. doi: 10.3390/jcm11061467.
Pipek LZ, Nascimento RFV, Acencio MMP, Teixeira LR. Comparison of SpO2 and heart rate values on Apple Watch and conventional commercial oximeters devices in patients with lung disease. Sci Rep. 2021 Sep 23;11(1):18901. doi: 10.1038/s41598-021-98453-3.
Arslan B, Sener K, Guven R, Kapci M, Korkut S, Sutasir MN, Tekindal MA. Accuracy of the Apple Watch in measuring oxygen saturation: comparison with pulse oximetry and ABG. Ir J Med Sci. 2024 Feb;193(1):477-483. doi: 10.1007/s11845-023-03456-w. Epub 2023 Jul 13.
Related Links
Access external resources that provide additional context or updates about the study.
US FDA Pulse oximeter premarket notification submissions- Guidance for Industry and Food and Drug Administration Staff. 2013
US FDA Pulse oximeter premarket notification submissions- Guidance for Industry and Food and Drug Administration Staff. 2025 DRAFT Document
Other Identifiers
Review additional registry numbers or institutional identifiers associated with this trial.
25/CARD/03
Identifier Type: -
Identifier Source: org_study_id