This study is designed to compare the accuracy of a noninvasive measurement of oxygen saturation compared to reference values obtained by a laboratory blood gas analyzer. Arterial blood samples will be collected from healthy adult subjects while undergoing a desaturation procedure wherein the concentration of oxygen inhaled is slowly reduced until the subject's arterial oxygen concentration is approximately 70%. The subject will then be returned to inhaling room air.

Inclusion Criteria:

• Subject is 18-50 years of age.
• Subject weighs a minimum of 110 lbs and no more than 250 lbs unless subject is over 6 feet tall.
• Hemoglobin value is greater than or equal to 11 g/dL.
• Baseline heart rate ≥ 45 bpm and ≤ 85 bpm.
• Carbon monoxide (CO) value ≤ 2.0% fractional carboxyhemoglobin (FCOHb)
• Subject has a physical status of American Society of Anesthesiology Class I; Healthy subjects without any systemic disease at all. American Society of Anesthesiology Class II; subjects with mild systemic disease (ASA I or II) as it applies to the systemic disease portion of the classification.
• Systolic Blood Pressure ≤ 140 mmHg and Diastolic Blood Pressure ≤ 90 mmHg.
• Subject is able to read and communicate in English and understands the study and risks involved.

Exclusion Criteria:

• Subject is pregnant.
• Subject smokes (smoking includes e-cigarette use).
• Subject has a BMI > 35 and has been classified as morbidly obese or at an increased risk for participation by a medical professional.
• Subject has open wounds, inflamed tattoos or piercings, visible healing wounds.
• Subject experiences frequent or severe headaches and/or migraine headaches.
• Subject has known drug or alcohol abuse and/or use of recreational drugs.
• Subject has experienced a concussion or head injury with loss of consciousness within the last year.
• Subject has any chronic bleeding disorders (i.e. hemophilia).
• Subject has any history of a stroke, myocardial infarction, seizures or heart attack.
• Subject has any cancer or history of cancer (not including skin cancer).
• Subject has a chronic neurological disease (i.e. multiple sclerosis, Huntington's Disease).
• Subject has any cardiac dysrhythmia(s) (i.e. atrial fibrillation) and has not received clearance by their physician to participate.
• Subject has a known neurological and/or psychiatric disorder (i.e. schizophrenia, bipolar disorder) that interferes with the subject's level of consciousness.
• Subject has any medical condition which in the judgment of the investigator and/or medical staff, renders them ineligible for participation in this study (Discretion of investigator).
• Subject has Wolff-Parkinson-White Syndrome or Stokes-Adams Syndrome.
• Subject who has taken anticoagulant medication within the last 30 days.
• Subject has taken opioid pain medication within 24 hours of start of study.
• Subject has either signs or history of peripheral ischemia.
• Subject has had invasive surgery within the past year- including but not limited to major dental surgery, gallbladder, heart, appendix, major fracture repairs (involving plates/ screws), jaw surgery, urinary tract surgery, plastic surgery, major ears, nose and throat (ENT) surgery, joint replacement or gynecological surgeries, heart surgery or thoracic surgery.
• Subject has donated blood within the past 30 days.
• Subject has symptoms of congestion, head colds, flu or other illnesses.
• Subject experiences claustrophobia or has generalized anxiety disorder.
• Subject has been in severe car accident(s) or a similar type of accident(s) requiring hospitalization within the last 12 months.
• Subject has chronic unresolved asthma, lung disease or respiratory disease.
• Subject is allergic to lidocaine, latex, adhesives, or plastic.
• Subject has heart conditions, insulin-dependent Diabetes or uncontrolled hypertension.
• Subject has given vaginal delivery, had a pregnancy terminated, a miscarriage with hospitalization, or had a C-section within the last 6 months.
• Subject intends to participate in any heavy lifting, repetitive movement of their wrist (including riding a motorcycle) or exercise (working out, riding a bike, riding a skate board etc.), or any activity that will put additional stress on the wrist within 24 hours of the study.
• Discretion of investigator/study staff.

1 to 5 hours