Healthy Volunteer Study to Evaluate the Impact of Various Common Interventions on Venous Pressure Signal Captured by PIVA

Inclusion Criteria: * Has reviewed, understood and signed an informed consent. * Age between 18-55 years. * Body mass index between 18.5-35 kg/m2 with a minimum weight of 45 kg. * Willing and able to comply with study procedures and duration. * Subjects wearing any type of nail polish and/or acrylic nails must be willing to remove them prior to admission. Exclusion Criteria: * Female subjects who are pregnant. * Subjects who are currently participating in, or have within the past 30 days participated in, another interventional clinical study or have used an investigational device or drug within the past 30 days. * Subjects with known respiratory conditions including but not limited to: * uncontrolled / severe asthma * flu / influenza * pneumonia / bronchitis * shortness of breath / respiratory distress * respiratory or lung surgery * emphysema, chronic obstructive pulmonary disease, lung disease * any other health condition that the Principal Investigator thinks can affect respiratory health * Subjects with self-reported heart or cardiovascular conditions including but not limited to: * hypertension * history of 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 * history of stroke * transient ischemic attack * carotid artery disease * myocardial ischemia * myocardial infarction * restrictive or constrictive cardiomyopathy * congenital heart disease other than patent foramen ovale, repaired atrial or ventricular septal defect * any type of cardiac valve disease * history of cardiac arrhythmias * 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 * history of migraine attacks in the last 3 months * head injury within the last 2 months * cancer / chemotherapy * other known health condition should be considered upon disclosure in health assessment form * history of substance abuse or addiction to alcohol and or drugs within the last 12 months * Subjects with self-reported bleeding disorders including but not limited to: * hemophilia * von Willebrand disease * history of blood clots * history of bleeding problems * bruises easily with everyday activities * Subjects taking prescription blood thinners (like aspirin, clopidogrel, dipyridamole, or ticlopidine). * Subjects may be excluded at the discretion of the Investigator.