The purpose of the study is to assess device performance in the presence of carbon monoxide.

Inclusion Criteria:

• The subject is male or female.
• The subject is of any racial or ethnic group.
• The subject is between 18 years and 50 years of age (self-reported).
• The subject does not have significant medical problems (self-reported).
• The subject is willing to provide written informed consent and is willing and able to comply with study procedures.
• Exclusion Criteria:
• Has a BMI greater than 30.0 (calculated from self-reported weight and height).
• Has had any relevant injury at the sensor location site (self-reported).
• Has a deformity or abnormalities that may prevent proper application of the device under test (based on visual inspection).
• Has a known respiratory condition (self-reported).
• Is currently a smoker (self-reported).
• Has a known heart or cardiovascular condition (self-reported).
• Is currently pregnant (positive serum pregnancy test at screening visit or positive urine POC test on day of study).
• Is female and actively trying to get pregnant (self-reported).
• Has a clotting disorder (self-reported).
• Has Raynaud's Disease (self-reported).
• Is known to have anemia (hemoglobin value below lower range of normal for gender)
• Is known to have a hemoglobinopathy such as sickle-cell anemia or thalassemia (abnormal hemoglobin electrophoresis).
• Is known to have a inherited or congenital methemoglobinemia (self-reported).
• Has unacceptable collateral circulation from the ulnar artery (based on exam).
• Is unwilling or unable to provide written informed consent to participate in the study.
• Has another health condition which in the opinion of the principal investigator makes him/her unsuitable for testing.

Healthy male and females.