Peritoneal dialysis system using pressurized chamber and pumping bladder
Inventors
Assignees
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Publication Number
US-12447250-B2
Publication Date
2025-10-21
Expiration Date
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 a known amount of hydraulic fluid to be metered to the inflatable bladder and to determine (i) a first amount of air before a discharge stroke of the hydraulic pump via a first ideal gas law calculation, (ii) a second amount of air after the discharge stroke of the hydraulic pump 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 amount of air and the second amount of air from the known amount of hydraulic fluid metered to the inflatable bladder for the discharge stroke.
Core Innovation
The invention relates to a peritoneal dialysis system that includes a chamber and a hydraulic pump with an inflatable bladder located within the chamber and in hydraulic fluid communication with the hydraulic pump. A pressure sensor is positioned and arranged to sense pneumatic pressure within the chamber, and a flexible container or bag is removably placed inside the chamber to receive fresh or used dialysis fluid. The flexible container or bag is fluidly coupled to at least one fluid line, and at least one valve is fluidly located between the flexible container or bag and the at least one fluid line.
A control unit determines a first amount of air within the flexible container or bag and/or the chamber before a discharge stroke of the hydraulic pump via a first ideal gas law calculation when the at least one valve is closed, based on a first pressure reading, a first measurement amount of hydraulic fluid being metered into the inflatable bladder, and a second pressure reading used with the first ideal gas law calculation. The control unit then determines a second amount of air after the discharge stroke via a second ideal gas law calculation using first and second pressure readings and a second measurement amount of hydraulic fluid metered into the inflatable bladder, with the at least one valve closed.
The control unit determines a discharge volume of the fresh or used dialysis fluid for the discharge stroke by subtracting a difference between the first amount of air and the second amount of air from a known amount of the hydraulic fluid metered to the inflatable bladder for the discharge stroke. In additional aspects, a control unit causes draw and discharge strokes along with first and second air amount determinations based on pressure sensor measurements before and after attempting to compress air, and determines the discharge volume by subtracting a difference between the first and second air amounts from measured hydraulic fluid delivered to the inflatable bladder.
Claims Coverage
The document includes two independent claims (clm-00001 and clm-00020). Both claims share the same core inventive concept: use a pressure sensor sensing pneumatic pressure within a chamber and ideal gas law calculations to determine air amounts before and after draw/discharge, then determine dialysis discharge volume by subtracting an air difference from a known or measured hydraulic fluid amount.
Pressure-sensed chamber pneumatic pressure for air amounts
A pressure sensor positioned and arranged to sense pneumatic pressure within the chamber to provide pressure readings used in determining a first amount of air and a second amount of air within the flexible container or bag and/or the chamber.
Ideal gas law determination of first and second air amounts
A control unit configured to determine a first amount of air before a discharge stroke and a second amount of air after the discharge stroke via first and second ideal gas law calculations, when the at least one valve is closed, and via first and second air amount determinations based on taking pressure measurements before and after attempting to compress air within the chamber.
Discharge volume determination by subtracting air difference from metered hydraulic fluid
Determining a discharge volume of fresh or used dialysis fluid for the discharge stroke by subtracting a difference between the first amount of air and the second amount of air from a known amount of the hydraulic fluid metered to the inflatable bladder for the discharge stroke, or from the measured amount of the hydraulic fluid delivered to the inflatable bladder.
Hydraulic pump with inflatable bladder in hydraulic fluid communication
An inflatable bladder located within the chamber and in hydraulic fluid communication with the hydraulic pump, where hydraulic fluid is metered into and delivered to the inflatable bladder during draw and discharge strokes to draw fresh or used dialysis fluid into the flexible container or bag and discharge fresh or used dialysis fluid from the flexible container or bag.
Removably placed flexible container or bag coupled to fluid lines
A flexible container or bag removably placed inside the chamber, the flexible container or bag fluidly coupled to at least one fluid line and configured to receive fresh or used dialysis fluid, with at least one valve fluidly located between the flexible container or bag and the at least one fluid line.
Across the two independent claims, the system determines air amounts using pressure sensor readings and ideal gas law calculations, then computes a dialysis fluid discharge volume by subtracting the difference between first and second air amounts from a hydraulic fluid amount delivered or metered to the inflatable bladder. The claims additionally define the use of draw and discharge strokes with measured hydraulic fluid movement.
Stated Advantages
Volumetric accuracy for determining discharge volume of fresh or used dialysis fluid by using pressure-based air amount determinations.
Precise pressure control based on a pressure sensor sensing pneumatic pressure within the chamber.
Quiet and safe operation regarding patient air infusion.
Use of the same disposable item for pumping/heating.
Low-cost disposable set.
Portability needs are addressed.
Documented Applications
Automated peritoneal dialysis (APD) cycler operation using a reusable rigid chamber and a disposable set to receive fresh or used dialysis fluid, including fill and drain cycles based on target fill/drain volumes or a drain condition.
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