Performance testing of pulse oximeters. The protocol involves brief stable arterial oxygen desaturation in healthy volunteers and sampling arterial blood when a stable level of hypoxia has been attained. The blood sample is analyzed for oxygen saturation with a gold standard bench CO-oximeter. This protocol is aligned with the latest ISO and FDA guidance documents for pulse oximeter testing.

Inclusion Criteria:

• 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 has both wrist circumferences between 14 and 22cm.
• The subject has provided informed consent and is willing to comply with the study procedures.

Exclusion Criteria:

• The subject is obese (BMI>30).
• 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.
• The subject has any other serious systemic illness.
• The subject is a current smoker.
• The subject has piercings that may cause air leaks during the test
• The subject has 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 a resting heartrate over 120, Systolic BP is over 150, diastolic BP is over 90 or room air SpO2 is less than 94%.
• The subject has carboxyhemoglobin over 3% as measured by Lab blood gas analysis.
• The subject has any other condition, which in the opinion of the investigators' would make them unsuitable to participate.

On the day of the visit