Baxter International Inc.
PERITONEAL DIALYSIS SYSTEM USING PRESSURIZED CHAMBER AND PUMPING BLADDER

Abstract:

A peritoneal dialysis system includes a chamber; a hydraulic pump; an inflatable bladder located within the chamber and in hydraulic fluid communication with the hydraulic pump; and a control unit configured to cause known amounts of hydraulic fluid to be metered to and from the inflatable bladder and to determine (i) a first amount of air before a discharge stroke via a first ideal gas law calculation, (ii) a second amount of air after the discharge stroke via a second ideal gas law calculation, and (iii) a discharge volume of fresh or used dialysis fluid for the discharge stroke by subtracting a difference between the first and second amounts of air from a known amount of hydraulic fluid metered to the inflatable bladder for the discharge stroke.