Data will be collected with the MultiSense® pulse oximetry system during non-motion conditions over the range of 70-100%. A Clinimark reference system, previously correlated to arterial blood CO-Oximetry will be the basis for comparison. A minimum of fifteen (15) up to fifty (50) healthy adult subjects, ranging in pigmentation from light to dark, with at least six (6) subjects with dark pigmentation (Fitzpatrick 5-6), will be enrolled in the study to meet the study design requirements defined by ISO 80601-2-61 and by the FDA's Guidance for Pulse Oximeters (March 4, 2013). SpO2 data will be evaluated during non-motion conditions. SpO2 data will be evaluated during stable step plateaus of induced hypoxic levels. The investigational device will be placed on the thorax of the subjects (patch on the upper back and external electrode on the right pectoral). Simultaneous data collection will be set up for the reference and the systems under test.

Inclusion Criteria:

• Subject must have the ability to understand and provide written informed consent
• Subject is 18 to 50 years of age
• Subject must be willing and able to comply with study procedures and duration
• Subject is a non-smoker or who has not smoked within 2 days prior to the study.
• Male or female of any race
• Subject demographics include a range of skin pigmentations, including at least 3 darkly pigmented subjects or 15% of the subject pool, whichever is larger.

Exclusion Criteria:

• Subject is considered as being morbidly obese (defined as BMI >39.5)
• Compromised circulation, injury, or physical malformation of fingers, toes, hands, ears or forehead/skull or other sensor sites, tattoo in the optical path which would limit the ability to test sites needed for the study. (Note: Certain malformations may still allow subjects to participate if the condition is noted and would not affect the particular sites utilized.)
• Females who are pregnant, who are trying to get pregnant, (confirmed by positive urine pregnancy test unless the subject is known to be not of child-bearing potential)
• Subjects who have smoked in the last 2 days with COHb levels >3% as assessed with a Masimo Radical 7 (Rainbow)
• Subjects with known respiratory conditions (self-reported)
• Subjects with known heart or cardiovascular conditions (self-reported, except for blood pressure and ECG review) or with an implantable active medical device such as pacemaker or automatic defibrillator
• Self-reported health conditions as identified in the Health Assessment Form (self-reported)
• Subjects with severe contact allergies to standard adhesives, latex or other materials found in pulse oximetry sensors, ECG electrodes, respiration monitor electrodes or other medical sensors (self-reported)
• Unwillingness or inability to remove colored nail polish from test digits.
• Unwillingness to have chest or other test site shaved
• Other known health condition, should be considered upon disclosure in health assessment form