Hemodialysis Substitution Pump Integration
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Solution Overview
Problem
Existing hemodialysis machines have inaccuracies in external peristaltic pumps, leading to complex and costly external fluidic tubing setups, and require complex pump adapters for error-free application.
Innovation Solution
The substituate pump is integrated into the internal fluid system, designed as a non-peristaltic positive displacement pump, such as a ceramic piston pump, allowing for precise volumetric accuracy and simplifying the external fluidic tubing setup by eliminating the need for external pump adapters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of repair
If external peristaltic hose pumps are used in the external fluid system, then the pump mechanism is accessible from outside for simple replacement, but the flow rate accuracy deteriorates to around 10% inaccuracy
Solution Approach 1:
The patent divides the fluid system into internal and external parts. The substitution pump is placed in the internal fluid system where high accuracy is needed, while the external tubing set remains simple and disposable. This segmentation allows the critical pumping function to be isolated in the reusable internal system.
Solution Approach 2:
The substitution pump is extracted from the external fluid system and placed in the internal fluid system. This removes the source of inaccuracy from the external disposable tubing set, allowing the external system to be simpler while maintaining overall system accuracy through the internal pump's precision.
2Ease of operation
If peristaltic hose pumps with replaceable fluid-carrying parts are used, then the tubing set can be replaced easily, but complex pump adapters are required for error-free application
Solution Approach 1:
The substitution pump is extracted from the external fluid system and placed in the internal fluid system. This eliminates the need for complex pump adapters in the external tubing set, as the pumping function is now handled by the internal pump with fixed fluid-carrying parts.
Solution Approach 2:
The external tubing set becomes a simple disposable component without integrated pumping mechanisms. The complex pumping function is handled by the reusable internal substitution pump, allowing the external tubing to be inexpensive and easily replaceable without requiring complex adapters.
3Ease of operation
If the substitution pump is placed in the external fluid system, then the tubing set is disposable and easy to replace, but the pump requires replaceable fluid-carrying parts increasing complexity
Solution Approach 1:
The system is segmented into internal and external fluid systems. The substitution pump with its fixed fluid-carrying parts is placed in the internal reusable system, while the external system uses simple disposable tubing without integrated pumping components. This segmentation resolves the contradiction by assigning the complex pump to the reusable internal system.
4Ease of operation
If external peristaltic pumps are used, then the pump mechanism is accessible from outside, but the application requires sophisticated pump adapters for error-free connection
Solution Approach 1:
The substitution pump is extracted from the external fluid system and placed in the internal fluid system. This eliminates the need for sophisticated pump adapters in the external system, as the pumping function is now handled by the internal pump with straightforward connections.
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
This design enhances handling ease, reduces costs, and ensures long-term accuracy and disinfectability, providing a more reliable and cost-effective hemodialysis process.
Implementation Method 1
The substitute pump is designed as a non-peristaltic positive displacement pump. Preferably, the substitute pump is designed as a ceramic piston pump. A positive displacement pump offers volumetric accuracy in the single-digit percentage range.
Implementation Method 2
The amount of fluid removed from the blood-side lines via the dialyzer membrane of the dialyzer is always exactly the same as the amount of fluid supplied to the respective blood-side line via the substitution line. The amount of fluid supplied to the blood-side lines via the substitution access is ultrafiltered through the dialyzer membrane from the blood chamber to the dialysate chamber.
Data Source
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AI summary
The apparatus (10) has an interchangeable disposable external fluidic (14) comprising blood-side ducts (60, 80) and a dialyzer (50). A permanent and disinfected internal fluidic (12) comprises a balance pump (30) i.e. diaphragm pump, which is formed from a dialyzate pump (32) and a waste pump (34) that is coupled with the dialyzate pump. The dialyzate pump pumps dialyzate from a dialyzate source (20) to a dialyzer. The waste pump pumps the dialyzate from the dialyzer to a target. A separate substitute pump (90) pumps the dialyzate from the dialyzate source to the external fluidic. The substitute pump is designed as a non-peristaltic displacement pump, a piston pump or a ceramic pump.