Healthy VollunteerPulseOxNCT07884500
Temporal Dynamics of Peripheral SpO₂ During Reoxygenation
A study testing Voluntary Apnea in people with Healthy Vollunteer and Apnea, run by Cliniques universitaires Saint-Luc- Université Catholique de Louvain at 1 site in Belgium.
Trial summary
Pulse oximeters estimate arterial oxyhaemoglobin saturation (SaO₂) from photoplethysmographic signals recorded at peripheral sites (usually the fingertip), thus measuring the peripheral oxygen saturation (SpO₂). Read more about this study
- Who is it for?
- Ages 18 to 60 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy Vollunteer, Apnea
- What is being tested?
- Voluntary Apnea
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 100 participants
- Where
- 1 siteBelgium
- Study dates
- 3 Aug 2026to 1 Feb 2027
- Phase
- Interventional
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 60 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Healthy adult volunteers aged 18 to 60 years
- Able to perform voluntary apnea for at least 30 seconds
- Written informed consent, read and signed by the participant
Who cannot join
- History of chronic respiratory, cardiac, or hematological disease
- Recent respiratory infection (< 2 weeks)
- Use of vasoactive medications (e.g., beta-blockers, vasodilators)
- Known or suspected pregnancy
- Inability to understand the study information or follow the study instructions
- Refusal to participate or withdrawal of consent
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Belgium1 site, 1 recruiting
- Recruiting
Cliniques Universitaires Saint-Luc
Brussels, 1200
Alexandre Niset, MD, 027641638 ext. +32, alexandre.niset@saintluc.uclouvain.be
Lara Absil, PhD, 027648645 ext. +32, lara.absil@saintluc.uclouvain.be
About this study
Pulse oximeters estimate arterial oxyhaemoglobin saturation (SaO₂) from photoplethysmographic signals recorded at peripheral sites (usually the fingertip), thus measuring the peripheral oxygen saturation (SpO₂). They are ubiquitous in emergency medicine because they offer a non-invasive, continuous measure of oxygenation and can alert clinicians to impending hypoxaemia, both during procedures such as rapid sequence intubation or sedation, or for continuous monitoring of patients. However, the accuracy of SpO₂ is often assumed to be instantaneous. This assumption is particularly hazardous during critical events involving rapid desaturation and resaturation. In such situations clinicians use SpO₂ readings to decide when to stop an apnea period during laryngoscopy and commence reoxygenation. If there is a delay between actual arterial desaturation and the displayed SpO₂, the clinician may not recognise hypoxaemia in time or may resume ventilation too late.
- Conditions
- Healthy Vollunteer, Apnea
- Being tested
- Voluntary Apnea
- Keywords
- healthy vollunteer, pulse oximetry, rapid desaturation, resaturation, apnea, ear sensors, finger probes
- Medical subject headings
- Apnea
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Voluntary ApneaDiagnostic test
Two pulse oximetry sensors (finger and earlobe) will be simultaneously applied, and baseline oxygen saturation (SpO₂), heart rate, and perfusion index will be recorded. The participant will then perform two voluntary apnea tests, during which these parameters will be continuously monitored to assess the timing of apnea, desaturation, nadir, and resaturation.
| Study group | Role | What they receive |
|---|---|---|
| Comparison of Finger and Ear Pulse Oximetry During Voluntary Apnea | Other | After a 5-minute resting period, two pulse oximetry sensors will be placed simultaneously: a finger sensor and an ear sensor (earlobe). Baseline parameters will be recorded.
The apnea protocol will consist of a maximal inspiration followed by voluntary breath-holding. Throughout the procedure, oxygen saturation (SpO₂), heart rate, and perfusion index will be continuously recorded until the values return to baseline.
The monitor screens will be video-recorded to allow precise temporal analysis of events (onset of apnea, resumption of breathing, desaturation, nadir, and resaturation).
After a further 5-minute resting period, the procedure will be repeated a second time. Receives: Diagnostic Test: Voluntary Apnea |
What is being measured
The primary outcome is the main question the study is designed to answer.
Evaluation of SpO₂ Resaturation Following Voluntary Apnea
To characterize the temporal behavior of a modern finger pulse oximeter during voluntary apnea in healthy volunteers, with a particular focus on the delay (in seconds) between physiological reoxygenation and displayed SpO₂ (Time interval in seconds between the first breath following apnea and the first increase in SpO2.)
Measured: From enrollment to the end of the inclusion, estimated at approximately 10 months from the start of enrollment
Secondary outcomes (5)
Comparison of SpO₂ Temporal Parameters Between Finger and Ear Sensors
Saturation sensors will be placed on the ears and fingers of healthy volunteers.
Saturation parameters will be recorded from both sensors and compared with the SpO2 saturation level (baseline SpO2):
- Time (in seconds) between the onset of apnea and a decrease of ≥ 2% from baseline SpO2
- Time (in seconds) between the onset of apnea and the lowest SpO2 observed before the start of resaturation
- Variable describing whether the SpO2 nadir (the lowest value) occurs before or after the resumption of ventilation
Measured: From enrollment to the end of the inclusion, estimated at approximately 10 months from the start of enrollment
Quantification of SpO₂ Measurement Delay Between Measurement Sites
To quantify the magnitude of the SpO₂ measurement delay (in seconds) between the two measurement sites during the reoxygenation phase.
Measured: From enrollment to the end of the inclusion, estimated at approximately 10 months from the start of enrollment
Assessment of Intra-Individual Measurement Variability
To assess intra-individual variability in key measurements (focus on the delay in seconds between physiological reoxygenation and displayed SpO2) across repeated apnea tests (2 different apnea)
Measured: From enrollment to the end of the inclusion, estimated at approximately 10 months from the start of enrollment
Evolution of the Perfusion Index (PI) during Apnea and Reoxygenation by finger/auricular pulse oximeter
To describe changes in the perfusion index (PI in %) during apnea and reoxygenation. Baseline PI (%) will be recorded at finger and auricular sites in healthy volunteers over time in seconds. Minimum PI during apnea, magnitude of PI change during apnea, PI recovery time (in seconds) after rebreathing.
Measured: From enrollment to the end of the inclusion, estimated at approximately 10 months from the start of enrollment
Physiological Factors Associated with SpO₂ Response Delay
To explore physiological factors associated with delayed SpO₂ response (in seconds), including individual characteristics and baseline hemodynamic parameters (BMI in kg/m^2, medical history, chronic treatments).
Measured: From enrollment to the end of the inclusion, estimated at approximately 10 months from the start of enrollment
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 Oct 2026
- Study start3 Aug 2026
- Primary completion1 Feb 2027 (estimated)
- Study completion1 Feb 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Healthy VollunteerStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 100 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Cliniques universitaires Saint-Luc- Université Catholique de Louvain
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07884500
- Sponsor's protocol ID
- 2026/23JUI/280
- Acronym
- PulseOx
- Status last verified
- Oct 2026
- First submitted
- 14 Sep 2026
- Last updated
- 20 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No