HypoxiaFinSpO2NCT04771663
Variability of SpO2 Measurements Depending on the Choice of Finger for Sensor Placement
A study testing Breathing a mixture of O2, N2 and CO2 and monitoring SpO2 on each finger in people with Hypoxia and Hypercapnia, run by Czech Technical University in Prague at 1 site in Czechia.
Trial summary
The aim of the project is to experimentally determine the effect of the choice of finger for the placement of a pulse oximeter sensor on the results of measuring peripheral blood oxygen saturation (SpO2) in a healthy person with short-term hypoxia and hypercapnia. Read more about this study
- Who is it for?
- Ages 18 to 60 yearsHealthy volunteers can take part
- Conditions the study is for
- Hypoxia, Hypercapnia
- What is being tested?
- Breathing a mixture of O2, N2 and CO2 and monitoring SpO2 on each finger
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 24 participants
- Where
- 1 siteCzechia
- Study dates
- 5 Nov 2020to 15 Oct 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
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
- Passing the initial examination, which will determine the following data: finger circumference, heart rate, blood pressure and blood oxygen saturation
Who cannot join
- post-traumatic conditions of the upper limbs affecting the perfusion of the fingers or injuries or skin diseases on the fingers.
- pneumothorax or a condition after cardiovascular surgery.
- anemia, bradycardia, hemoglobinopathy or other diseases of the cardiovascular system, pregnancy, diabetes, hypotension or hypertension.
Trial locations and contacts
1 site in 1 country.
About this study
The aim of the project is to experimentally determine the effect of the choice of finger for the placement of a pulse oximeter sensor on the results of measuring peripheral blood oxygen saturation (SpO2) in a healthy person with short-term hypoxia and hypercapnia.
Read the detailed description
The aim of the project is to experimentally determine the effect of the choice of finger for the placement of a pulse oximeter sensor on the results of measuring peripheral blood oxygen saturation (SpO2) in a healthy person with short-term hypoxia and hypercapnia. This is an intervention prospective study that will take place at the Faculty of Biomedical Engineering, especially on FBMI students. The experiment consists of two phases, in which in the first phase, the volunteers will inhale the hypoxic mixture for five minutes after the stabilization phase. In the second phase, volunteers inhale a hypoxic and hypercapnic mixture. During the experiment, non-invasive SpO2 measurements will be performed continuously on individual fingers of both volunteer hands.
- Conditions
- Hypoxia, Hypercapnia
- Being tested
- Breathing a mixture of O2, N2 and CO2 and monitoring SpO2 on each finger
- Medical subject headings
- Hypoxia, Hypercapnia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Breathing a mixture of O2, N2 and CO2 and monitoring SpO2 on each fingerOther
The experiment consists of two separate phases. In one phase, the volunteers inhale one of the mixtures for five minutes. After enough time of recovery, the volunteers undergo the other phase in which they inhale the other mixture of gases. Both phases of the measurement will begin with a two-minute stabilization phase, during which the physiological values of the volunteer will be checked. During the experiment, non-invasive SpO2 measurements will be performed continuously on the individual fingers of both volunteer hands throughout the experiment.
| Study group | Role | What they receive |
|---|---|---|
| Hypoxic | Experimental | In this phase, participants inhale the hypoxic mixture for five minutes. Receives: Other: Breathing a mixture of O2, N2 and CO2 and monitoring SpO2 on each finger |
| Hypoxic and Hypercapnic | Experimental | In this phase, participants inhale the hypoxic and hypercapnic mixture for five minutes. Receives: Other: Breathing a mixture of O2, N2 and CO2 and monitoring SpO2 on each finger |
What is being measured
The primary outcome is the main question the study is designed to answer.
Does it depend on which finger is the sensor placed for SpO2 values?
The experiment can help determine if it depends on which finger the finger sensor will be placed to measure SpO2. Appropriate finger selection for SpO2 measurements could help to better interpret the measured values and possibly increase the success in diagnosing health events.
Measured: Up to 12 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Feb 2021
- Study start5 Nov 2020
- Primary completion15 Feb 2021
- Study completion15 Oct 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for HypoxiaStudies 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
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- Interventional single blinded randomized crossover prospective study
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 24 participants (actual)
Sponsor and investigators
- Lead sponsor
- Czech Technical University in Prague
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Karel Roubík, Study director, Czech Technical University in Prague, FBMI
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04771663
- Sponsor's protocol ID
- CzechTU
- Acronym
- FinSpO2
- Status last verified
- Mar 2026
- First submitted
- 22 Feb 2021
- Last updated
- 11 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Rafl J, Kulhanek F, Kudrna P, Ort V, Roubik K. Response time of indirectly accessed gas exchange depends on measurement method. Biomed Tech (Berl). 2018 Nov 27;63(6):647-655. doi: 10.1515/bmt-2017-0070.
PubMed 28802098
Study at a glance
From the registry record, last updated by the sponsor on 11 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Variability of SpO2 Measurements Depending on the Choice of Finger for Sensor Placement
- ClinicalTrials.gov ID
- NCT04771663
- Acronym / sponsor ID
- FinSpO2 / CzechTU
- Conditions
- Hypoxia, Hypercapnia
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 24 participants (actual)
- Lead sponsor
- Czech Technical University in PragueUniversity, hospital or other
- Study start
- 5 Nov 2020 (actual)
- Primary completion
- 15 Feb 2021 (actual)
- Study completion
- 15 Oct 2025 (actual)
- First posted
- 25 Feb 2021 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The aim of the project is to experimentally determine the effect of the choice of finger for the placement of a pulse oximeter sensor on the results of measuring peripheral blood oxygen saturation (SpO2) in a healthy person with short-term hypoxia and hypercapnia.
Detailed description
The aim of the project is to experimentally determine the effect of the choice of finger for the placement of a pulse oximeter sensor on the results of measuring peripheral blood oxygen saturation (SpO2) in a healthy person with short-term hypoxia and hypercapnia. This is an intervention prospective study that will take place at the Faculty of Biomedical Engineering, especially on FBMI students. The experiment consists of two phases, in which in the first phase, the volunteers will inhale the hypoxic mixture for five minutes after the stabilization phase. In the second phase, volunteers inhale a hypoxic and hypercapnic mixture. During the experiment, non-invasive SpO2 measurements will be performed continuously on individual fingers of both volunteer hands.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind (participant)
- Number of arms
- 2
- Model description
- Interventional single blinded randomized crossover prospective study
| Arm | Type | Receives |
|---|---|---|
| Hypoxic | Experimental | Other: Breathing a mixture of O2, N2 and CO2 and monitoring SpO2 on each fingerIn this phase, participants inhale the hypoxic mixture for five minutes. |
| Hypoxic and Hypercapnic | Experimental | Other: Breathing a mixture of O2, N2 and CO2 and monitoring SpO2 on each fingerIn this phase, participants inhale the hypoxic and hypercapnic mixture for five minutes. |
Who may qualify
- Ages
- 18 to 60 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (1 listed)
- Passing the initial examination, which will determine the following data: finger circumference, heart rate, blood pressure and blood oxygen saturation
Key exclusion criteria (3 listed)
- post-traumatic conditions of the upper limbs affecting the perfusion of the fingers or injuries or skin diseases on the fingers.
- pneumothorax or a condition after cardiovascular surgery.
- anemia, bradycardia, hemoglobinopathy or other diseases of the cardiovascular system, pregnancy, diabetes, hypotension or hypertension.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Breathing a mixture of O2, N2 and CO2 and monitoring SpO2 on each fingerThe experiment consists of two separate phases. In one phase, the volunteers inhale one of the mixtures for five minutes. After enough time of recovery, the volunteers undergo the other phase in which they inhale the other mixture of gases. Both phases of the measurement will begin with a two-minute stabilization phase, during which the physiological values of the volunteer will be checked. During the experiment, non-invasive SpO2 measurements will be performed continuously on the individual fingers of both volunteer hands throughout the experiment. | Other | Hypoxic, Hypoxic and Hypercapnic |
Primary outcome
Does it depend on which finger is the sensor placed for SpO2 values?
Time frame: Up to 12 weeks
The experiment can help determine if it depends on which finger the finger sensor will be placed to measure SpO2. Appropriate finger selection for SpO2 measurements could help to better interpret the measured values and possibly increase the success in diagnosing health events.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 Mar 2026.
- Background: PubMed 28802098Rafl J, Kulhanek F, Kudrna P, Ort V, Roubik K. Response time of indirectly accessed gas exchange depends on measurement method. Biomed Tech (Berl). 2018 Nov 27;63(6):647-655. doi: 10.1515/bmt-2017-0070.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Karel Roubík study director
Czech Technical University in Prague, FBMI
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Breathing a mixture of O2, N2 and CO2 and monitoring SpO2 on each finger in people with Hypoxia and Hypercapnia, run by Czech Technical University in Prague at 1 site in Czechia.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 11 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Czechia. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Does it depend on which finger is the sensor placed for SpO2 values? (time frame: Up to 12 weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04771663, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 11 Mar 2026.