Variable Dialysate Flow Rate Control in Portable Hemodialysis
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Solution Overview
Problem
Current hemodialysis systems are cumbersome, expensive, and difficult to use, limiting their portability and accessibility for home use, and they often rely on sorbent filters that are costly and inefficient, with a risk of single-point failures in pumps, motors, or electronics posing safety hazards.
Innovation Solution
A portable, user-friendly hemodialysis system with a reusable dialysis machine and disposable dialyzer, featuring dual dialysate reservoirs for continuous treatment, sorbent filters for toxin removal, and advanced sensors and control systems to monitor and adjust dialysate flow rates for enhanced efficiency and safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If sorbent filters are used for toxin removal, then dialysis effectiveness is improved, but cost increases and risk of filter exhaustion occurs
Solution Approach 1:
The patent changes the operating parameters of the sorbent filter by varying dialysate flow rate throughout treatment. Flow rate is higher during early treatment when urea concentration is high, and reduced later when sorbent capacity is depleted and urea concentration is lower. This dynamic parameter adjustment optimizes toxin removal efficiency while extending filter life.
2Productivity
If dialysate flow rate is increased, then toxin removal efficiency is improved, but sorbent filter exhaustion risk increases
Solution Approach 1:
The patent implements periodic variation in dialysate flow rate during the dialysis treatment. The flow rate is adjusted in different phases: higher initially for rapid toxin removal, then reduced as treatment progresses to preserve sorbent filter capacity. This periodic action pattern optimizes both productivity and reliability.
3Ease of operation
If home hemodialysis systems are made portable, then accessibility is improved, but device complexity increases
Solution Approach 1:
The patent combines multiple functions into integrated components. The sorbent filter is integrated directly into the dialysate reservoir, eliminating separate filter housings and connections. The system merges pump, reservoir, and filter functions into a compact unified design that reduces overall system complexity while maintaining portability.
Solution Approach 2:
The patent employs a nested structure where the sorbent filter cartridge is placed inside the dialysate reservoir. This nesting arrangement allows the filter to be housed within the existing reservoir volume, reducing overall system size and simplifying the mechanical structure while maintaining both portability and functionality.
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 provides a safe, efficient, and cost-effective means of hemodialysis, maximizing urea removal and reducing the risk of sorbent filter exhaustion, while ensuring patient safety through multiple fail-safes and flexible treatment options, including the ability to operate with or without a sorbent filter.
Implementation Method 1
The diffusion entails the migration of molecules by random motion from regions of high concentration to regions of low concentration
Implementation Method 2
The fibers forming the semipermeable membrane separate the blood plasma from the dialysate and provide a large surface area for diffusion to take place
Implementation Method 3
convection entails the movement of solute typically in response to a difference in hydrostatic pressure
Implementation Method 4
Ultrafiltration is commonly accomplished by lowering the hydrostatic pressure of the dialysate compartment of a dialyzer, thus allowing water containing dissolved solutes, including electrolytes and other permeable substances, to move across the membrane from the blood plasma to the dialysate
Data Source
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AI summary
A portable hemodialysis system is provided including a dialyzer, a closed loop blood flow path which transports blood from a patient through the dialyzer and back to the patient, and a closed loop dialysate flow path which transports dialysate through the dialyzer. Preferably, the hemodialysis system includes a sorbent filter in the dialysate flow path. Furthermore, the hemodialysis machine includes a blood pump, and a pair of dialysate pumps. A processor controls the flow of blood through the blood flow path, and the processor controls the flow of dialysate through the dialysate flow path. In addition, the processor stores a patient treatment plan wherein the flow rate of the dialysate through the dialysate flow path reduces throughout the patient's treatment to maximize the amount of urea removed by the sorbent filter.