A customized Transonic Flow-QC® ADT1010 Tubing Set is used for measurements of Cardiac Output, and calculation of associated cardiac parameters with the HD03 Hemodialysis Monitor. To perform cardiac output measurements, a Flow-QC® Tubing Set is inserted into the extracorporeal bloodlines of an arteriovenous fistula or graft. Arterial and Venous Sensors are applied to the Flow-QC® tubing, and saline is injected through a port of the tubing to initiate the cardiac output measurement.