The non-invasive measurement of dysfunctional hemoglobins allows physicians to monitor levels in affected individuals without requiring blood samples or laboratory testing. Nonin Medical Inc, has recently developed a multi-wavelength device that measures carboxyhemoglobin and methemoglobin non-invasively. The primary objective of this study is to validate %MetHb and SpO2 accuracy performance of the study device. Evaluations will be for the range of 0 to 15% MetHb with 95-100% SaO2 as assessed by CO-oximetry, and 0-15% MetHb accuracy under conditions of elevated HHb (SaO2 80-100%) as assessed by CO-oximetry, and SpO2 with 80-100% SaO2 during elevated MetHb as assessed by CO-oximetry.

The goal of this study is to collect data with induced hypoxia, with induced methemoglobinemia, and with induced hypoxia and methemoglobinemia. This will be accomplished in three runs with 24 to 28 plateaus total. The number of plateaus will be dependent on the subject's tolerance of the study procedure. The first run will be strictly induction of hypoxia down to approximately 70% saturation. The second run will be induction of hypoxia down to approximately 80% saturation with mild hypoxia at 7% MetHb. The third run will be induction of hypoxia down to approximately 80% saturation with a target MetHb of 11-15%.

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 31 (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 (self-reported).
• 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 a hemoglobinopathy such as (anemia, bilirubinemia, sickle-cell anemia, inherited or congenital methemoglobinemia) (self-reported).
• The subject has a COHb greater than 3% or MetHb greater than 2% (based on the first blood sample analysis).
• Has taken blood thinners or medication with aspirin within the last 24 hours (self-reported).
• Has unacceptable collateral circulation from the ulnar artery (based on exam).
• Has donated more than 300 mL of blood within one month prior to start of study (self-reported).
• Is unwilling or unable to provide written informed consent to participate in the study.
• Is unwilling or unable to comply with the study procedures for the primary objectives.
• Has another health condition which in the opinion of the principal investigator makes him/her unsuitable for testing.

A minimum of 12 subjects with a minimum of 200 data points for each primary and secondary objective will be enrolled in the study. The subject population will include both male and female subjects and will include a variety of skin tones.