Clinical Evaluation of the Zynex Monitoring System, Model CM-1600

Inclusion Criteria: * Participant must have the ability to understand the parameters of participation and provide written informed consent * Male or female of any race * Participant is adult 18 or older * Participant must be willing and able to comply with study procedures and duration * In the Principal Investigator's medical judgment, the participant is suitable for a blood draw of up to 500mL * Participant must weigh at least 110 pounds Exclusion Criteria: * Any upper extremity amputation * Females who are pregnant, who are trying to get pregnant, or have a urine test positive for pregnancy on the day of the study * Participant has a heart condition that may interfere with the Zynex CM-1600 (e.g., pacemakers, defibrillator, irregular heartbeat, dextrocardia, etc.) * Participant has been diagnosed with chronic fatigue syndrome (also known as chronic fatigue, immune dysfunction syndrome, or myalgic encephalomyelitis) * Participant requires equipment and/or devices that may interfere with the Zynex CM-1600 (e.g., life-sustaining equipment, other monitoring devices, insulin pumps, or other implanted devices) * Participant is taking coumadin (warfarin), heparin, or other prescription blood thinners for 7 or more days prior to blood draw * Participant donated blood within 8 weeks prior to the study blood draw * Participant has high or low blood pressure on the day of blood draw (high blood pressure is defined as systolic \> 180 mmHg or diastolic \> 100 mmHg; low blood pressure is defined as systolic \< 100 mmHg or diastolic \< 60 mmHg) * Participant has symptoms of an active infection or a temperature ≥ 100 °F * Female with hemoglobin levels of less than 12.1g/dL or male with hemoglobin levels of less than 13.8g/dL * Participants with self-reported heart or cardiovascular conditions such as: * History of cardiovascular surgery * History of chest pain (angina) * Heart rhythms other than a normal sinus rhythm or respiratory sinus arrhythmia * History heart attack/myocardial infarction * Peripheral arterial disease * Carotid artery disease * Unexplained shortness of breath * Congestive heart failure (CHF) * History of stroke/transient ischemic attack * Myocardial ischemia * Cardiomyopathy * Dextrocardia * Participants with clotting disorders such as: * Hemophilia * History of blood clots * History of bleeding problems * Bruises easily * Self-reported health conditions as identified in the Health Assessment Form including: * 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 headache within the last 2 months * Recent head injury within the last 2 months * History of cancer, with or without chemotherapy within the last 2 months * Other known health conditions deemed unsuitable for participation by the PI when considered upon disclosure on health assessment form