Dialyzer Sealing Structure Without Adhesives or Dead Volume
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Solution Overview
Problem
Existing filter devices for hemodialysis suffer from dead volumes due to the use of elastomeric components, leading to platelet coagulation and inefficiencies, and require complex adhesive processes that can contaminate the filtrate or blood.
Innovation Solution
A filter device with a tubular housing and end cap that form sealing surfaces through molecular entanglement, eliminating the need for elastomeric components and adhesives, using materials like polypropylene or polypropylene copolymers, and employing methods like hot-surface welding to create secure, low-dead-volume connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If elastomeric components are used for sealing between flow chambers, then sealing reliability is improved, but dead volumes are formed causing platelet coagulation and blockage
Solution Approach 1:
The invention extracts and eliminates the elastomeric sealing components from the system. Instead of using separate elastomeric seals between flow chambers, the patent integrates the sealing function directly into the housing structure through molded-in seals, removing the source of dead volumes that cause platelet coagulation.
Solution Approach 2:
The sealing function is merged with the housing structure itself. The elastomeric sealing elements are molded directly into the housing as integral parts rather than being separate components, eliminating dead volumes while maintaining sealing reliability between blood and dialysate chambers.
2Reliability
If adhesives are used for sealing, then sealing capability is achieved, but manufacturing complexity increases and adhesive components may contaminate filtrate
Solution Approach 1:
The invention replaces chemical adhesive bonding with mechanical/molded sealing structures. The elastomeric seals are molded directly into the housing during manufacturing, eliminating the need for separate adhesive application processes and reducing manufacturing complexity while avoiding adhesive contamination.
Solution Approach 2:
The sealing elements are designed as integrated molded features rather than separate reusable components requiring adhesive bonding. This approach simplifies manufacturing by incorporating seals directly into the housing structure during molding, eliminating complex multi-step assembly processes.
3Reliability
If elastomeric components are used for sealing, then sealing between flow chambers is achieved, but additional components are required increasing device complexity
Solution Approach 1:
The sealing function is merged with the housing structure. Elastomeric sealing elements are molded directly into the housing as integral features, combining the housing and sealing components into a single integrated structure, thereby reducing the total number of separate components.
Solution Approach 2:
The housing structure serves multiple functions simultaneously: it provides structural support, defines flow chambers, and incorporates sealing elements. The elastomeric seals molded into the housing perform both sealing and structural functions, reducing the need for separate dedicated sealing 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 solution minimizes dead volumes, reduces adverse effects on blood, and ensures a stable, efficient connection without contaminating the filtrate or blood, enhancing separation efficiency and reducing the risk of clogging.
Implementation Method 1
the housing and the at least one end cap have a first sealing surface, the housing and the end cap form a sealing connection, wherein the first sealing surface is located further from the center of gravity of the housing than the at least one opening
Implementation Method 2
employing methods like hot-surface welding to create secure, low-dead-volume connections
Data Source
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AI summary
The invention relates to a filter device for the exchange of substances, comprising a pipe section-shaped housing with a center of gravity and with two housing ends, in which housing a hollow fiber bundle consisting of semi-permeable membranes is arranged, comprising, furthermore, an end cap having a first and second opening, wherein the housing and the end cap configure a first sealing surface which connects the housing and the end cap sealingly, and wherein the first sealing surface is spaced apart further from the center of gravity of the housing than the aperture, and wherein a first fluid chamber is formed between the first sealing surface and the first opening of the end cap, via which first fluid chamber the first opening is connected to the first flow chamber, wherein the housing and the one end cap configure a second sealing surface, wherein the first and second sealing surface are not configured by way of a sealant.