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HypoxiaNCT06142019

Pulse Oximeter Accuracy in Healthy Humans During Hypoxia

An observational study of Hypoxia and Skin Pigmentation, run by University of California, San Francisco at 1 site in United States.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial summary

The aim of this project is to test the accuracy of pulse oximeters during mild, moderate and severe hypoxia. This is done by comparing the reading of the pulse oximeter during brief, steady state hypoxia with a gold-standard measurement of blood oxygen. Read more about this study

Who is it for?
Ages 18 to 50 yearsHealthy volunteers can take part
Conditions the study is for
Hypoxia, Skin Pigmentation
Type of treatment
Medical device
How many people
10,000 participants
Where
1 siteUnited States
Study dates
29 Nov 2021to 1 Sep 2028
Phase
Observational
Are there results?
Not yet: the study is under way

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 50 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Study population: Study population consists of healthy volunteers between 18-50 years of age across all ethnic and racial backgrounds.

Who may be able to join

  • The subject is male or female, aged ≥18 and <50.
  • The subject is in good general health with no evidence of any medical problems.
  • The subject is fluent in both written and spoken English.
  • The subject has provided informed consent and is willing to comply with the study procedures.

Who cannot join

  • The subject is obese (BMI>35).
  • The subject has a known history of heart disease, lung disease, kidney or liver disease.
  • Diagnosis of asthma, sleep apnea, or use of CPAP.
  • Subject has diabetes.
  • Subject has a clotting disorder.
  • The subject a hemoglobinopathy or history of anemia, per subject report or the first blood sample, that in the opinion of the investigator, would make them unsuitable for study participation.
Show all 16Show fewer
  • The subject has any other serious systemic illness.
  • The subject is a current smoker.
  • Any injury, deformity, or abnormality at the sensor sites that in the opinion of the investigators' would interfere with the sensors working correctly.
  • The subject has a history of fainting or vasovagal response.
  • The subject has a history of sensitivity to local anesthesia.
  • The subject has a diagnosis of Raynaud's disease.
  • The subject has unacceptable collateral circulation based on exam by the investigator (Allen's test).
  • The subject is pregnant, lactating or trying to get pregnant.
  • The subject is unable or unwilling to provide informed consent, or is unable or unwilling to comply with study procedures.
  • The subject has any other condition, which in the opinion of the investigators' would make them unsuitable for the study.

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

Ella Behnke contact

971-295-4285

ella.behnke@ucsf.edu

Michael Lipnick, MD contact

628-206-7736

Michael.lipnick@ucsf.edu

United States1 site, 1 recruiting

  • Hypoxia Lab, UCSF Department of Anesthesia and Perioperative Care

    San Francisco, California, 94143

    Phil Bickler, MD, PhD, 415-476-1411, Philip.bickler@ucsf.edu

    Recruiting

Other trials in United States

About this study

The aim of this project is to test the accuracy of pulse oximeters during mild, moderate and severe hypoxia. This is done by comparing the reading of the pulse oximeter during brief, steady state hypoxia with a gold-standard measurement of blood oxygen. This study will be done on healthy male or females between the age group of 18-50.

Read the detailed description

This study is to determine the accuracy of pulse oximeters, which measure blood oxygen by shining light through fingers, ears or other parts of the body, without requiring blood sampling.

The aim of this project is to test the accuracy of pulse oximeters during mild, moderate and severe hypoxia. This is done by comparing the reading of the pulse oximeter during brief, steady state hypoxia with a gold-standard measurement of blood oxyhemoglobin saturation (arterial blood sample processed in a laboratory hemoximeter).The data obtained is submitted by pulse oximeter manufacturers to the FDA for device approval.

Studies normally involve 10-14 normal adult volunteer paid subjects, with 20-25 1-2 ml arterial blood samples from each subject obtained at different steady-state levels of hypoxia from 70-100%. Blood samples obtained from an arterial line are measured in a hemoximeter to determine true saturation value. Some sponsors may not require any blood sampling. Some sponsors may require additional blood samples, up to 35 samples may be drawn. Readings from the test pulse oximeters are recorded and compared to these "gold-standard" blood values. The pulse oximeter probes may be located at a variety of sites on the subjects, including fingers, toes, ears, forehead, scalp and bridge of the nose. These detector-probes are all non-invasive.

The level of hypoxia is measured and controlled by the investigator. A computer program that displays a prediction, breath by breath, the arterial oxygen saturation, (SaO2) of the study subject. SaO2 is computed from end-expired Po2 and Pco2 as determined by mass spectrometer gas analysis. This information permits the inspired gas mixture of air, plus CO2 and nitrogen, to be adjusted by an operator watching the value computed after each expiration on an analog meter. This computer-estimated saturation is adjusted by the operator to one of 6 levels of predicted saturation, and is held stable for about 30 seconds at each level. Two or three "runs" are conducted per subject. Each "run" lasts 10-15 min and 4 to 5 plateaus are tested per run. The manufacturer may choose the target values. Plateaus are typically sought at 96%, 87%, 77%, 92%, 82% and 72%. Other manufacturers have asked for an equal number of data points but with all points between 70% and 100%. Some sponsors may also request additional variables to be measured during testing including high or low CO2, where subjects will be asked to hyperventilate; low perfusion, where subjects will be asked to lay flat, or with their head up or down; testing pulse oximeters during motion, or with the subject's hand fixed to a motion machine. The subject's will be informed by the study staff and in the consent form if any of these additional procedures apply.

Being tested
Controlled desaturation (hypoxemia)
Medical subject headings
Hypoxia, Pigmentation Disorders

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Controlled desaturation (hypoxemia)Device

    Stable hypoxemia is created in healthy subjects by having them breathe hypoxic air mixtures

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. SpO2

    Reading on pulse oximeter device which is an estimate of the patient's blood oxygen level.

    Measured: 08/01/2025

Secondary outcomes (4)

  1. Blood gas SO2

    Arterial blood gas sample results showing exact SpO2 levels. SpO2 ranges from 1% to 100%. Our target SpO2 levels are between 67% and 100%.

    Measured: 08/01/2025

  2. Skin Pigmentation by ITA

    ITA stands for individual typology angle from a spectrophotometer which is an objective measurement of skin pigmentation. The categories for the ITA scale are the following: > 55 Very Light, 41 to 55 Light, 28 to 41 Intermediate, 10 to 28 Tan, -30 to 10 Brown, < -30 Dark.

    Measured: 08/01/2025

  3. Finger Diameter

    Finger diameter is measured to ensure that the pulse oximeters being tested work with a variety of finger sizes. Finger diameter is measured in mm.

    Measured: 08/01/2025

  4. Skin Pigmentation by Monk Scale

    The Monk scale is a subjective categorization of skin pigmentation. The Monk Scale is a 10 shade scale designed to to be easy-to-use for development and evaluation of technology while presenting a more representative range of skin tones than other common qualitative scales. The Monk Scale is from A to J. A being the lightest skin color and J the darkest.

    Measured: 08/01/2025

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted21 Nov 2023
  2. Study start29 Nov 2021
  3. Primary completion1 Sep 2028 (estimated)
  4. Study completion1 Sep 2028 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Observational model
Cohort
Time perspective
Prospective
Enrolment
10,000 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT06142019
Sponsor's protocol ID
21-35637
Status last verified
Oct 2026
First submitted
21 Sep 2023
Last updated
14 Oct 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
Yes
Individual data sharing
No

Publications

  • Feiner JR, Bickler PE, Mannheimer PD. Accuracy of methemoglobin detection by pulse CO-oximetry during hypoxia. Anesth Analg. 2010 Jul;111(1):143-8. doi: 10.1213/ANE.0b013e3181c91bb6. Epub 2009 Dec 10.

    PubMed 20007731

  • Feiner JR, Severinghaus JW, Bickler PE. Dark skin decreases the accuracy of pulse oximeters at low oxygen saturation: the effects of oximeter probe type and gender. Anesth Analg. 2007 Dec;105(6 Suppl):S18-S23. doi: 10.1213/01.ane.0000285988.35174.d9.

    PubMed 18048893

  • Bickler PE, Feiner JR, Severinghaus JW. Effects of skin pigmentation on pulse oximeter accuracy at low saturation. Anesthesiology. 2005 Apr;102(4):715-9. doi: 10.1097/00000542-200504000-00004.

    PubMed 15791098

  • Hughes C, Chen D, Law T, Bickler P, Feiner J, Shmuylovich L, Behnke E, Ortiz L, Leeb G, Zamora RV, Monk E, Lipnick MS; Collaborators. Pulse Oximeter Performance and Skin Pigment: Comparison of 34 Oximeters Using Current and Emerging Regulatory Frameworks. Anesth Analg. 2026 Nov 1;143(5):1137-1147. doi: 10.1213/ANE.0000000000008048. Epub 2026 Apr 15.

    PubMed 42012940

Questions about this trial

What is this clinical trial studying?

An observational study of Hypoxia and Skin Pigmentation, run by University of California, San Francisco at 1 site in United States.

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 4 inclusion and 16 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: looking for participants now, as of the sponsor's last update on 14 Oct 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 United States. 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?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Ella Behnke (971-295-4285, ella.behnke@ucsf.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

SpO2 (time frame: 08/01/2025). 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 NCT06142019, which also lists 4 linked publications.

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 14 Oct 2026.

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