Patent ID: 8523798

Claim:
A method of determining the amount of recirculation in a catheter having a inflow lumen and an outflow lumen, comprising: placing a distal portion of the catheter into an artificial fluid loop, the fluid loop including a blood simulant with a viscosity of about 3.5 cps flowing in a pulsatile manner; directing the blood simulant from the fluid loop to flow through into the catheter through the inflow lumen and out from the catheter through the outflow lumen; measuring the density of blood simulant flowing into the outflow lumen; measuring the density of blood simulant flowing out of the inflow lumen; changing the density of blood simulant being returned through the outflow lumen by delivering a fluid of a higher density into the outflow lumen; determining if there is a density change in blood simulant flowing through the outflow lumen; determining if there is a density change in blood simulant flowing through the inflow lumen; and comparing changes in blood simulant density in the inflow lumen to changes in blood simulant density in the outflow lumen to determine the amount of recirculation in the catheter.