Impeller Blood Pump Pulsation Synchronization
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Solution Overview
Problem
Existing extracorporeal blood treatment devices, particularly in hemodialysis, face inefficiencies due to pulsating flow patterns caused by peristaltic pumps, which lead to noise interference and inefficient blood circulation, and lack synchronization with patient heartbeats, resulting in undesired fistula recirculation and reduced treatment efficiency.
Innovation Solution
An extracorporeal blood treatment device with an impeller blood pump controlled by a computing unit that adds a pulsating speed component to a constant speed, synchronized with patient pressure pulse waves, allowing for targeted pressure pulsation and minimized fistula recirculation by measuring and filtering pressure amplitude signals to regulate the pump's operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If peristaltic pumps are used to pump blood in extracorporeal circulation, then blood can be pumped through the circuit, but strong pressure pulses and pulsating flow rate are generated that mask other pressure signals as noise
Solution Approach 1:
The patent replaces the peristaltic pump's mechanical occlusion mechanism with a magnetic drive system that rotates an impeller within the blood circuit. The magnetic coupling transfers rotational motion from the drive shaft to the impeller without mechanical contact, eliminating the occlusion-induced pressure pulses while maintaining effective blood circulation.
Solution Approach 2:
The patent introduces a magnetic field as an intermediary between the drive mechanism and the impeller. The magnetic coupling allows power transmission without direct mechanical contact, enabling the impeller to rotate smoothly and generate flow without creating harmful pressure spikes associated with mechanical occlusion.
2Stability of the object's composition
If impeller blood pump operates at constant speed, then stable blood flow is maintained, but fistula recirculation occurs and treatment efficiency is reduced
Solution Approach 1:
The patent implements periodic speed modulation of the impeller pump by superimposing a pulsating speed component on the constant base speed. This periodic variation in pump speed creates corresponding pressure variations that prevent fistula recirculation while maintaining overall flow stability, thereby improving treatment efficiency without sacrificing flow consistency.
Solution Approach 2:
The patent transitions from a static constant-speed operation to a dynamic speed control system. The control unit continuously adjusts the impeller speed based on detected pressure pulse waves, creating a dynamically adapted flow pattern that eliminates recirculation while preserving the stability needed for effective dialysis treatment.
3Productivity
If pump speed is pulsated to create pressure pulsation, then fistula recirculation is minimized, but the average flow rate may deviate from specified flow rate
Solution Approach 1:
The patent employs a feedback control mechanism where pressure pulse waves detected in the blood circuit are used to dynamically adjust the impeller speed. The control unit processes these pressure signals and modulates the pump speed in real-time, ensuring that the pulsations needed to prevent recirculation do not cause significant deviations from the target average flow rate.
Solution Approach 2:
The patent changes the operational parameters of the impeller pump by varying its rotational speed around a constant mean value. By carefully controlling the amplitude and frequency of speed variations, the system achieves pressure pulsations sufficient to prevent fistula recirculation while maintaining the average flow rate within acceptable tolerances of the specified flow rate.
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 approach ensures a pulsatile blood flow synchronized with the patient's heartbeat, maintaining a consistent mean flow rate while reducing fistula recirculation and enhancing treatment efficiency by directly using pressure pulse waves for pump modulation.
Implementation Method 1
the impeller blood pump is operated in a pulsating manner by adding a pulsating rotational speed component to a first constant rotational speed... allowing for targeted pressure pulsation
Implementation Method 2
measuring at least one first course of the pressure amplitude at at least one pressure measuring point of the extracorporeal blood circuit and extracting the course of at least one pressure pulse wave caused by cardiac contraction
Implementation Method 3
the pulsating operation of the impeller blood pump is synchronized with the course of the pressure pulse waves caused by cardiac contraction in the patient's extracorporeal blood circulation
Data Source
Figure 1~2
Figure 3~4
AI summary
The present invention discloses a method for operating an extracorporeal blood treatment device with an extracorporeal blood circuit for hemodialysis and/or hemofiltration and/or hemodiafiltration by controlling an impeller blood pump. It is provided that the impeller blood pump is operated in a pulsating manner by adding a pulsating rotational component to a first constant rotational speed.