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CompletedNCT04771663FinSpO2Updated Mar 11, 2026

Variability of SpO2 Measurements Depending on the Choice of Finger for Sensor Placement

An interventional study of Breathing a mixture of O2, N2 and CO2 and monitoring SpO2 on each finger in Hypoxia and Hypercapnia, sponsored by Czech Technical University in Prague. Completed at 1 site in Czechia. Open to participants aged 18 Years to 60 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-03-11.

Sponsored by Czech Technical University in Prague · Not applicable, Interventional, and Basic science

Phase
Not applicable
Study type
Interventional
Enrollment
24
Allocation
Randomized
Ages
18 Years to 60 Years
Sex
All
01

Study 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 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.

02

Conditions studied

  • Hypoxia
  • Hypercapnia
03

Who can participate

Ages eligible
18 Years to 60 Years
Sexes eligible
All
Accepts healthy volunteers
Yes

Inclusion criteria

  • Passing the initial examination, which will determine the following data: finger circumference, heart rate, blood pressure and blood oxygen saturation

Exclusion criteria

Exclusion Criteria:

  • 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.
04

Study design

Phase
Not applicable
Primary purpose
Basic science
Allocation
Randomized
Intervention model
Crossover assignment
Masking
Single (Participant)
Enrollment
24 participants (actual)

Study arms

  • Experimental
    Hypoxic

    In this phase, participants inhale the hypoxic mixture for five minutes.

    Other: Breathing a mixture of O2, N2 and CO2 and monitoring SpO2 on each finger

  • Experimental
    Hypoxic and Hypercapnic

    In this phase, participants inhale the hypoxic and hypercapnic mixture for five minutes.

    Other: Breathing a mixture of O2, N2 and CO2 and monitoring SpO2 on each finger

Interventions

  • OtherBreathing a mixture of O2, N2 and CO2 and monitoring SpO2 on each finger

    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.

05

What researchers measure

Primary outcomes

  1. 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.

    Time frame: Up to 12 weeks

06

Study locations

1 site
  • Czech Technical University in Prague
    Kladno, 27201, Czechia
07

References and documents

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 ↗

Individual participant data

Plan to share: No

08

Registry details

Key details

Study ID
NCT04771663
Lead sponsor
Czech Technical University in Prague
Responsible party
Sponsor
First posted
Feb 25, 2021
Start date
Nov 5, 2020
Primary completion
Feb 15, 2021
Completion
Oct 15, 2025
Last update
Mar 11, 2026

Study contacts

Karel Roubík
study director · Czech Technical University in Prague, FBMI

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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This study is completed, as verified in Mar 2026. You cannot join it, but the record below documents what was studied.

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