An observational study in Hypoxia and Skin Pigmentation, sponsored by University of California, San Francisco. Recruiting at 1 site in United States. Open to participants aged 18 Years to 50 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-10-14.
Sponsored by University of California, San Francisco · Observational
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.
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.
1,076 studies on the registry are indexed under Hypoxia; 213 are open to participants now.
This study's planned enrollment of 10,000 is above the median of 79 across 277 observational studies indexed under Hypoxia.
Browse Hypoxia studies →University of California, San Francisco is the lead sponsor of 2,169 studies on the registry; 372 are open to participants now.
Of its 267 completed or terminated interventional studies of FDA-regulated products, 202 (76%) have results posted.
Counted across the registry records on this site, refreshed daily.
Study population consists of healthy volunteers between 18-50 years of age across all ethnic and racial backgrounds.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Stable hypoxemia is created in healthy subjects by having them breathe hypoxic air mixtures
SpO2
Reading on pulse oximeter device which is an estimate of the patient's blood oxygen level.
Time frame: 08/01/2025
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%.
Time frame: 08/01/2025
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.
Time frame: 08/01/2025
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.
Time frame: 08/01/2025
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.
Time frame: 08/01/2025
Plan to share: No
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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