Inclusion Criteria:  Subject must have the ability to understand and provide written informed consent Adult subjects 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. Cleared same day Health Assessment form and health screening. Cleared physical exam by a licensed physician, physician assistant, or advanced practice nurse (medical exam includes 12-lead ECG, medical history and blood test to show no sickle cell disease present) Successful Perfusion Index Ulnar/Ulnar+Radial Ratio test showing adequate collateral blood flow.  Exclusion Criteria  Subject is considered as being morbidly obese (defined as BMI >39.5) Compromised circulation, injury, or physical malformation of fingers, hands, ears or forehead/skull or other sensor sites 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 sites utilized.) Females of childbearing potential, who are pregnant, who are trying to get pregnant or who have a urine test positive for pregnancy on the day of the study Subjects with COHb levels >3% as assessed by CO-Oximetry during the procedure tHb < 10 g/dl as assessed by CO-Oximetry during the procedure MetHb ≥ 2% as assessed by CO-Oximetry during the procedure  Subjects with known respiratory conditions such as:  uncontrolled / severe asthma, flu or influenza type infection pneumonia / bronchitis, shortness of breath / respiratory distress, unresolved respiratory or lung surgery, emphysema, COPD, lung disease  Subjects with known heart or cardiovascular conditions such as:  Hypertension: systolic >140mmHg, or Diastolic >90mmHg on 3 consecutive readings. have had cardiovascular surgery Chest pain (angina) heart rhythms other than a normal sinus rhythm or with respiratory sinus arrhythmia previous heart attack blocked artery unexplained shortness of breath congestive heart failure (CHF) history of stroke transient ischemic attack carotid artery disease myocardial ischemia myocardial infarction cardiomyopathy  Self-reported health conditions as identified in the Health Assessment Form  diabetes, uncontrolled thyroid disease, kidney disease / chronic renal impairment, history of seizures (except childhood febrile seizures), epilepsy, history of unexplained syncope, recent history of frequent migraine headaches, recent symptomatic head injury, within the last 2 months Subjects with known clotting disorders history of bleeding disorders or personal history of prolonged bleeding from injury history of blood clots hemophilia current use of blood thinner: prescription or daily use of aspirin 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 Subjects with prior or known severe allergies to lidocaine (or similar pharmacological agents, e.g. Novocain) or heparin Arterial cannulation within the last 30 days prior to study date, (this may exclude only one radial artery site. Left or right) History of clinically significant complications from previous arterial cannulation. A radial artery with ten or more arterial cannulations right or left, excludes that site. Unwillingness or inability to remove colored nail polish or colored artificial nails other than clear from test digits. Other known health condition, should be considered upon disclosure in Health Assessment form