Double Wall Needle for Sterile Dialysis Bag Filling
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Solution Overview
Problem
Existing apparatuses for filling dialysis solution bags struggle to achieve sterile filling and subsequent sealing in a simple and effective manner, often compromising sterility and potentially damaging the solution with unwanted heat.
Innovation Solution
A double wall needle apparatus with a thermally conductive outer wall and insulated inner wall allows for controlled heating to disinfect and melt the bag material for sealing, while maintaining the solution at a safe temperature, using a heating element and UV light or disinfectant for sterilization, and clamping jaws for sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the needle is heated to disinfect and melt the bag material, then sterile filling and sealing are achieved, but the solution may be damaged by unwanted heat
Solution Approach 1:
The needle is divided into two separate walls: an outer wall that can be heated for disinfection and sealing, and an inner wall that remains thermally insulated to protect the solution. This segmentation allows differential temperature control - the outer wall reaches high temperatures for sterilization while the inner wall maintains lower temperatures compatible with the solution
Solution Approach 2:
Thermal insulation acts as an intermediary layer between the heated outer wall and the solution-containing inner wall. This insulation layer blocks heat transfer, allowing the outer wall to be heated for disinfection without transmitting harmful heat to the solution inside the needle
2Reliability
If the outer wall is heated to melt the bag material for sealing, then effective sealing is achieved, but the heating process becomes more complex
Solution Approach 1:
The heating function is extracted from the entire needle system and applied only to the outer wall. This allows selective heating of just the portion needed for sealing and disinfection, simplifying the overall heating system design compared to heating the entire needle or using multiple heating zones
Solution Approach 2:
The outer wall is given the specific quality of being thermally conductive and heat-resistant, while the inner wall maintains thermal insulation. This local differentiation of thermal properties allows the outer wall to perform sealing functions through controlled heating without affecting the solution temperature
3Temperature
If a double wall needle with thermal insulation is used, then temperature control is improved, but the needle structure becomes more complex
Solution Approach 1:
The inner wall is nested within the outer wall, creating a concentric double-wall structure. The thermal insulation fills the space between these nested walls, providing temperature control through a compact, integrated design rather than requiring separate heating and insulation 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
Enables reliable sterile filling and sealing of dialysis solution bags, ensuring microbial kill and preventing solution damage, with efficient disinfection and sealing processes that maintain sterility and operational efficiency.
Implementation Method 1
the outer wall and the inner wall being thermally insulated from one another so that different temperatures can be reliably realized between the outer wall and the inner wall
Implementation Method 2
The heating element that is directly or indirectly connected to the outer wall is designed such that it can move the temperature of the outer wall, in particular of its outer side, to a value above the temperature of the inner wall
Implementation Method 3
the outer wall and the inner wall being thermally insulated from one another
Implementation Method 4
The apparatus has a UV light source and/or a nozzle for spraying the needle with disinfectant
Implementation Method 5
A temperature is preferably selected during the heating to melt the plastic material of the solution bag at the inner surface of the filling line or filling opening
Data Source
AI summary
The present invention relates to an apparatus and to a method for filling a solution bag for dialysis with a liquid, wherein the apparatus comprises a needle for introduction into a filling line or filling opening of the bag, wherein the needle is a double wall needle having a preferably thermally conductive outer wall and having an inner wall, with a thermal insulation being present between the outer wall and the inner wall; and with a heating element being provided that is configured to heat the outer side of the outer wall to a temperature above the temperature of the inner side of the inner wall.