Method and apparatus for measuring the flow differential in a dialysis machine, and method for calibrating the apparatus
AssigneeGambro AB
InventorsSture Hobro, Erik Linderup, Leif Mattisson
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Abstract
Methods for measuring the flow differential through a dialysis machine are disclosed in which the dialysis machine includes a heat exchanger having a primary side and a secondary side for exchanging heat therebetween. The method includes measuring the temperature differences across the primary and secondary sides of the heat exchanger and calculating the flow differential based upon these measured temperature differences. Apparatus for measuring such a flow differential is also disclosed, as are methods for calibrating that apparatus.
Claims12
A method for calibrating apparatus for measuring the flow rate differential through a dialysis machine including ultrafiltration means for effecting ultrafiltration, a heat exchanger including a primary side and a secondary side for exchanging heat between the flow of an inlet fluid having an inlet flow rate through said primary side of said heat exchanger into said dialysis machine and the flow of an outlet fluid having an outlet flow-rate through said secondary side of said heat exchanger from said dialysis machine, and dosage fluid supply means for supplying a dosage fluid to said inlet fluid, said method comprising discontinuing said ultrafiltration by disconnecting said ultrafiltration means from said dialysis machine while continuing to operate said dialysis machine, varying an amount of dosage fluid supplied to said inlet fluid by said dosage fluid supply means, and measuring said flow rate differential based upon said variation of said amount of dosage fluid.
Apparatus for measuring the flow differential through a dialysis machine comprising a flow inlet for a flow of an inlet fluid at an inlet flow rate to said dialysis machine, a flow outlet for a flow of an outlet fluid at an outlet flow rate from said dialysis machine, ultrafiltration means for effecting the flow of an ultrafiltration fluid in said dialysis machine, means for disconnecting said ultrafiltration means from said dialysis machine, a heat exchanger including a primary side and a secondary side for exchanging heat between the flow of said inlet fluid in said flow inlet and the flow of said outlet fluid in said flow outlet, dosage fluid supply means for supplying a dosage fluid to said inlet fluid at a plurality of dosage fluid flow rates, means for measuring said flow differential, and first calculating means for calculating a calibration factor for said measuring means using said dosage fluid flow rates.
Dependencies are inferred from the claim text.