Synchronized Plunger Pumps for Pulsation-Free Dialysate Flow
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Solution Overview
Problem
Existing blood purification devices require additional pumps for water removal and backfiltration, increasing costs, and previous plunger pumps do not simultaneously supply fresh and used dialysate without pulsation.
Innovation Solution
A blood purification device with synchronized plunger pumps in both the fresh dialysate supply and used dialysate discharge lines, allowing for simultaneous operation and adjustable strokes to perform water removal and backfiltration without the need for valves, ensuring a pulsation-free dialysate supply.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If reciprocating pumps are used to supply fresh dialysate and discharge used dialysate, then the supply and discharge functions are integrated, but additional pumps are required for water removal and backfiltration, increasing device complexity and cost
Solution Approach 1:
The plunger pump is designed to perform multiple functions: supplying fresh dialysate, discharging used dialysate, water removal, and backfiltration. By making the plunger pump variable-stroke, a single pump can adapt to different operational modes, eliminating the need for separate dedicated pumps for each function.
Solution Approach 2:
The invention employs a variable-stroke plunger pump where the stroke length can be dynamically adjusted during operation. This dynamic adjustment capability allows the pump to transition between different functions (supply, discharge, water removal, backfiltration) without requiring additional fixed-function pumps, thereby reducing device complexity while maintaining high productivity.
2Device complexity
If plunger pumps are used for dialysate supply, then pump structure is simplified, but pulsation occurs in the dialysate flow
Solution Approach 1:
The invention uses two plunger pumps operating in alternating periodic cycles. While one pump is in the delivery phase, the other is in the suction phase, and vice versa. This periodic alternation ensures continuous dialysate flow without pulsation, while maintaining the simple plunger pump structure.
Solution Approach 2:
The invention combines two plunger pumps into a coordinated system where they work together in parallel. By merging their operations with proper phase synchronization, the system achieves pulsation-free flow output while retaining the structural simplicity of individual plunger pumps.
3Device complexity
If single plunger pump is used, then device structure is simple, but simultaneous supply and discharge of dialysate cannot be achieved
Solution Approach 1:
The invention merges two plunger pumps into a single integrated system with synchronized operation. One pump is dedicated to fresh dialysate supply while the other handles used dialysate discharge, allowing simultaneous operation. The synchronization mechanism coordinates their cycles to maintain balanced flow rates, achieving high productivity without excessive complexity.
Solution Approach 2:
The dialysate management function is segmented into two separate pump systems: one for supply and one for discharge. This segmentation allows each pump to specialize in its specific function, enabling simultaneous operation while maintaining overall system simplicity through modular design.
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 efficient simultaneous supply and discharge of dialysate, reducing costs by eliminating the need for additional pumps and providing a pulsation-free dialysate to the blood purifier, facilitating effective water removal and backfiltration.
Implementation Method 1
plunger pumps individually provided in the fresh dialysate supply line and the used dialysate discharge line so as to form one pair
Data Source
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AI summary
In a blood purification device containing a blood purifier (1), a blood circuit (2), a blood pump (3), and a dialysate line (4) having a fresh dialysate supply line (41) and a used dialysate discharge line (42), a pair of plunger pumps (51, 52) are disposed in the dialysate line (4). The pair of plunger pumps (51, 52) are synchronized so that delivery of a fresh dialysate from one plunger pump (51) and suction of a used dialysate into the other plunger pump (52) simultaneously occur and the stroke of at least one of the pair of plunger pumps (51, 52) is made variable.