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. The subject will then be returned to breathing 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% fraction of carboxyhemoglobin (FCOHb)
• Subject has a physical status of ASA I or II (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) as it applies to the systemic disease portion of the classification.
• Blood pressure: Systolic Blood Pressure ≤ 140 mmHg and ≥ 90 mmHg, Diastolic Blood Pressure ≤ 90 mmHg and ≥ 50 mmHg, and if blood pressure is lower than 100/60 subject passes an orthostatic blood pressure test.
• Subject is able to read and communicate in English and understands the study and risks involved.

Exclusion Criteria (* = per physician discretion)

• Subject is pregnant.
• Subject has a Body Mass Index (BMI) > 35 and has been classified as morbidly obese or at an increased risk for participation by a medical professional.
• Subject has a history of fainting (vasovagal), blacking out or losing consciousness during or after blood draw, or has a fear of blood draws.
• Subject smokes one pack of cigarettes or more in one week, and/or the equivalent of e- cigarette liquid, and smokers are not being recruited as indicated in the Case Study Report Form (CSRF).
• Subject has open wounds, inflamed tattoos or piercings, and/or any visible healing wounds that a medical professional renders them at an increased risk for participation.*
• Subject has known drug or alcohol abuse and/or use of recreational drugs.
• Subject experiences frequent or severe headaches and/or migraine headaches, migraine auras, altitude sickness, and/or headaches accompanied by visual changes or sensitivity to light or sound.
• Subject has experienced a concussion or head injury with loss of consciousness within the last 12 months.
• Subject has any history of a stroke, myocardial infarction, seizures or heart attack.
• Subject has a chronic bleeding disorder (i.e. hemophilia).
• Subject who has taken anticoagulant medication within the last 30 days (excluding nonsteroidal anti-inflammatory drugs (NSAIDS)).
• Subject has donated blood within the past 4 weeks.
• Subject has Wolff-Parkinson-White Syndrome or Stokes-Adams Syndrome.
• Subject has any symptomatic cardiac dysrhythmia (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, Multiple Sclerosis, Huntington's Disease) that interferes with the subject's level of consciousness.
• Subject has taken opioid pain medication 24 hours before the study.
• Subject has any type of infectious disease (i.e. Hepatitis, HIV, Tuberculosis, Flu, Malaria, Measles, etc.).
• Subject is taking medications known to treat any type of infectious disease.*
• Subject has either signs or history of peripheral ischemia or carpal tunnel syndrome.
• Subject has had invasive surgery within the past year- including but not limited to major dental surgery*, appendix*, plastic surgery*.
• Subject has had invasive surgery within the past year- including but not limited to gallbladder, major fracture repairs (involving plates/ screws), jaw surgery, urinary tract surgery, major ears, nose, and throat (ENT) surgery, joint replacement or gynecological surgeries, heart surgery or thoracic surgery.
• Subject has symptoms of congestion, head cold, 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 any cancer or history of cancer (not including skin cancer).*
• Subject has chronic unresolved asthma, lung disease (including chronic obstructive pulmonary disease (COPD)) or respiratory disease.
• Subject is allergic to lidocaine, latex, adhesives, or plastic.
• Subject has heart conditions, insulin-dependent Diabetes or uncontrolled hypertension.
• Subject has delivered vaginally, has had a pregnancy terminated, a miscarriage with hospitalization, or had a C-section within the last 6 months.
• Subject intends on participating in any heavy lifting, repetitive movement of their wrist (including riding a motorcycle, tennis) 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 following a study that involves an arterial line.
• Subject has any medical condition which in the judgment of the investigator and/or medical staff, renders them ineligible for participation in this study or subject is deemed ineligible by the discretion of the investigator/study staff.

1 to 5 hours