Dialysis Pump Cassette Layout for Automated Sterile Fluid Handling
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Solution Overview
Problem
The complexity and size of past machines and associated disposables for Automated Peritoneal Dialysis (APD) modalities have dampened widespread patient acceptance, necessitating a more user-friendly and efficient solution for peritoneal dialysis systems.
Innovation Solution
A disposable fluid handling cassette with integrated pump chambers, flowpaths, and a flexible membrane for automated peritoneal dialysis systems, featuring spacer elements to prevent membrane deformation and air trapping, and a cap stripper mechanism for automated line connection, minimizing human interaction and potential contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If conventional peritoneal dialysis machines and disposables are used, then automated dialysis function is achieved, but device complexity and size increase
Solution Approach 1:
The system is divided into separate functional modules: a reusable cycler device that provides automated control and a disposable cassette that contains all fluid handling components (reservoirs, pump chambers, flowpaths, membranes). This segmentation allows the complex automated functions to be isolated in the reusable portion while the disposable portion remains relatively simple and can be easily replaced.
Solution Approach 2:
The patent employs a disposable cassette design where all fluid-containing components (dialysate reservoir, waste reservoir, pump chambers, flowpaths) are contained in a single-use disposable unit. This eliminates the need for complex cleaning, sterilization, and maintenance of fluid handling components, reducing overall system complexity while maintaining automated functionality.
2Ease of operation
If manual drain and fill procedures are performed, then patient can perform dialysis, but time consumption increases
Solution Approach 1:
The disposable cassette is designed with integrated pump chambers and flowpaths that automatically perform drain and fill operations without requiring manual manipulation by the patient. The cycler device controls the pump chambers to automatically drain spent dialysate and infuse fresh dialysate, eliminating the time-consuming manual procedures while maintaining patient autonomy.
3Reliability
If automated line connection is implemented, then contamination risk is reduced, but device complexity increases
Solution Approach 1:
The solution line connectors and cassette inlet ports are designed as pre-aligned, self-mating components that automatically connect when the disposable cassette is installed in the cycler. This merging of connection functions into a single integrated action reduces contamination risk by minimizing manual manipulation while avoiding the need for complex automated robotic connection mechanisms.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enhances patient convenience by reducing manual intervention and contamination risks, facilitating efficient and automated peritoneal dialysis processes, thereby increasing patient acceptance of APD modalities.
Implementation Method 1
a pump chamber to move fluid in a useable space... a pump control chamber arranged so that a pressure change in the pump control chamber causes movement of at least a portion of the membrane and thereby movement of fluid in the pump chamber
Implementation Method 2
Diffusion and osmosis exchanges take place between the solution and the bloodstream across the natural body membranes
Implementation Method 3
Diffusion and osmosis exchanges take place between the solution and the bloodstream across the natural body membranes
Implementation Method 4
The diffusion of water across the peritoneal membrane during dialysis is called ultrafiltration
Data Source
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AI summary
A fluid handling cassette for use in a medical infusion system, the fluid handling cassette comprising: a generally planar body having first and second pump chambers each formed as a depression in a first side of the body, each pump chamber having a first port and a second port connecting the respective pump chamber to a second side of the body; a plurality of valve wells on the first side of the body each comprising a valve port and an opening connecting a respective valve well to the second side of the body; a flexible membrane attached to and covering the first side of the body over the first and second pump chambers and the plurality of valve wells, first and second pump chamber portions of the membrane over the first and second pump chambers, respectively; a plurality of cassette ports located on a first end of the body; and a first and second fluid flowpath on the second side of the body, each fluid flowpath connected to the first or second port of a respective pump chamber via at least one of the plurality of valve wells; wherein the first and second fluid flowpaths are each connected to at least one of the plurality of cassette ports via a respective one of the plurality of valve wells.