Repeatability and Reproducibility of Oxygen Reserve Index (ORi)

Inclusion Criteria: * Subject is 18 to 50 years of age. * Subject weighs a minimum of 110 lbs. * Hemoglobin value ≥ 11 g/dL. * Baseline heart rate ≥ 45 bpm and ≤ 85 bpm. * Blood Pressure: Systolic BP ≤ 140 mmHg and ≥ 90 mmHg, Diastolic BP ≤ 90 mmHg and ≥ 50 mmHg, and if systolic BP is lower than 100 mmHg and/or diastolic BP is lower than 60 mmHg, subject passes an orthostatic blood pressure test. * CO value ≤ 3.0% FCOHb. * Subject is able to read and communicate in English and understands the study and the risks involved Exclusion Criteria: * Subject has a positive hCG test. * Subject has a BMI \> 35. * Subject has a history of fainting (vasovagal syncope), blacking out or losing consciousness during or after a blood draw, or has a fear of blood draws. * Subject has open wounds, inflamed tattoos or piercings, and/or has any visible healing wounds that a medical professional determines may place them at an increased risk for participation. \* * Subject has known drug or alcohol abuse. * Subject uses 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 past 12 months. * Subject has any history of a stroke, myocardial infarction (heart attack), and/or seizures. * Subject has any chronic bleeding disorder (e.g., hemophilia). * Subject has taken anticoagulant medication within the past 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 cardiac dysrhythmia (e.g., atrial fibrillation) and has not received clearance from their physician to participate. \* * Subject has a known neurological and/or psychiatric disorder (e.g., 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 active signs and/or symptoms of infectious disease (e.g., 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, appendectomy, plastic surgery, jaw surgery, major ENT surgery, major abdominal and/or pelvic surgery, heart surgery, or thoracic surgery. \* * Subject has symptoms of congestion, head cold, or other illnesses. * Subject has been in a severe car accident(s) or a similar type of accident(s) requiring hospitalization within the past 12 months. * Subject has any cancer or history of cancer (not including skin cancer). \* * Subject has chronic unresolved asthma, lung disease (including COPD) and/or respiratory disease. * Subject is allergic to Lidocaine, chlorhexidine, latex, adhesives, or plastic. * Subject has a heart condition, 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 past 6 months. * Subject intends on participating in any heavy lifting, repetitive movement of their wrist (including riding a motorcycle, tennis), exercise (working out, riding a bike, riding a skateboard, 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 investigator/study staff.