Patent ID: 6726647
Filing Date: 2004-04-27
Classification: A61M,G01F

Abstract:
A method of estimating fluid flow rate (Qa) in a fluid flow access, comprising:removing a first fluid flow from said access at a removal position to an external flow circuit comprising a dialyzer having a semipermeable membrane, said first fluid flow passing along said membrane at one side thereof and a dialysis fluid being emitted from the other side thereof, and returning said first fluid flow from said external flow circuit to said access at a return position downstream of said removal position; measuring a first variable which is essentially proportional to a concentration (Cd norm) of a substance in said dialysis fluid emitted from the dialyzer; reversing the removal position with the return position and measuring a second variable which is essentially proportional to the concentration (Cd rev) of said substance in said dialysis fluid in the reversed position; and calculating the fluid flow rate (Qa) in said flow access from said measured concentrations.