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

This is a prospective, single-arm, non-randomized, non-controlled single-center study for the evaluation of the Zynex CM-1600 in 20 healthy adults undergoing a manual blood loss of up to 500mL followed by an infusion of 1 liter of normal saline.


Eligibility Criteria:
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