Dialysis Ultrafilter Filtration With Membrane Integrity Testing
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Solution Overview
Problem
Existing peritoneal dialysis systems face challenges in effectively filtering out bacterial contaminants and endotoxins from dialysis fluid, and there is a need for improved methods to test the integrity of filtration membranes and efficiently remove contaminants using limited fluid volumes.
Innovation Solution
The system incorporates an ultrafilter and a disposable filter set with sterilizing grade membranes to filter out bacteria and endotoxins, and employs a five-phased method to test membrane integrity, as well as a recirculation process to enhance contaminant removal using a fixed volume of fluid, and a user-friendly ultrafilter box for replacement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a peritoneal dialysis system uses conventional filtration methods, then the system structure remains simple, but the filtration effectiveness against bacterial contaminants and endotoxins is insufficient
Solution Approach 1:
The filtration system is divided into multiple stages: a disposable filter set with sterilizing grade membranes for initial filtration, and a reusable ultrafilter with dense filtration layers for advanced filtration. This segmentation allows each filter to specialize in specific contaminant removal, achieving high filtration effectiveness while keeping individual components relatively simple.
Solution Approach 2:
The ultrafilter employs a composite structure with multiple filtration layers having different pore sizes and material properties. The dense filtration layer uses specialized materials with controlled porosity to selectively remove bacteria and endotoxins while maintaining fluid flow, achieving superior filtration performance.
2Measurement precision
If a five-phased method is used to test membrane integrity, then the measurement precision of filter performance is improved, but the testing time and procedure complexity increase
Solution Approach 1:
The five-phased integrity test is performed before the filter is deployed in clinical practice. This preliminary testing ensures that the filter membrane is free of defects and meets performance requirements, allowing for rapid deployment without time-consuming testing during actual use.
Solution Approach 2:
The integrity test is designed as a continuous five-phase process that efficiently sequences through different testing stages without unnecessary interruptions. Each phase builds upon the previous one, maintaining continuous measurement and evaluation to determine filter performance with minimal total testing time.
3Reliability
If a recirculation process is used to remove contaminants, then the logarithmic reduction value increases with minimal fluid usage, but the device complexity and operation complexity increase
Solution Approach 1:
The recirculation system automatically circulates dialysis fluid through the ultrafilter multiple times without requiring manual intervention. The pump and control system autonomously manage the recirculation process, achieving high contaminant removal efficiency while maintaining ease of operation through automation.
Solution Approach 2:
The recirculation process continuously pumps fluid through the ultrafilter in a loop, maintaining constant filtration action. This continuous circulation maximizes contaminant removal efficiency by repeatedly exposing the fluid to the filtration membrane, achieving high logarithmic reduction values with minimal additional fluid consumption.
4Ease of manufacture
If an ultrafilter box is used for filter replacement, then the ease of manufacture and user-friendliness are improved, but the device complexity increases
Solution Approach 1:
The ultrafilter is integrated into a separate, removable ultrafilter box that can be independently replaced without disassembling the main dialysis system. This segmentation simplifies the replacement process for users while containing the necessary filtration components in a dedicated module.
Solution Approach 2:
The ultrafilter box serves as an intermediary component between the dialysis pump and the filtration system. It provides a user-friendly interface for filter replacement while managing the complexity of the filtration mechanism internally, allowing users to simply exchange the entire box rather than dealing with individual filter components.
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
The system effectively filters out contaminants, ensures membrane integrity, and achieves high logarithmic reduction values with minimal fluid usage, providing a user-friendly setup and maintenance process.
Implementation Method 1
The system incorporates an ultrafilter and a disposable filter set with sterilizing grade membranes to filter out bacteria and endotoxins
Implementation Method 2
a recirculation process to enhance contaminant removal using a fixed volume of fluid
Data Source
AI summary
A peritoneal dialysis (“PD”) system having an ultrafilter is disclosed herein. In one example, the PD system includes a housing and a PD fluid pump. The PD system also includes a filter comprising an outer chamber, a central portion, a membrane, an inlet connected to the outer chamber, an outlet, a first venting port connected to the outer chamber, and a second venting port connected to the central portion. The first venting port has a valve preventing air flow into the filter via the first venting port. The PD system further includes a pressure sensor and a control unit configured to control the PD fluid pump. The control unit is further configured to determine a pressure inside the filter based on an output from the pressure sensor and determine an integrity status of the membrane based on the pressure inside the filter.