Membrane Pump Drive Piston Dynamics for Blood Damage Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing drive devices for membrane fluid pumps, particularly those used in cardiac support systems, are not suitable for small pumps and often result in inefficient pump performance and a higher risk of blood damage due to non-uniform fluid flow.
Innovation Solution
A drive device with a working piston that operates in three phases: acceleration, constant speed/pressure, and deceleration, controlled by a unit that regulates the movement to achieve high pump performance and reduce the risk of blood damage, using an electric motor and a control unit to manage the piston's movement and equalizing valve for efficient fluid transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If existing drive devices are used for small membrane fluid pumps, then the device structure is simple, but pump performance is inefficient and blood damage risk increases
Solution Approach 1:
The drive device employs dynamic control of the working piston through three distinct movement phases (acceleration, constant speed, deceleration) rather than uniform motion. This dynamic approach optimizes fluid flow characteristics throughout the pumping cycle, improving pump performance while minimizing blood damage by avoiding sudden pressure changes and non-uniform flow patterns.
Solution Approach 2:
The system changes the movement parameters of the working piston over time, transitioning between different speed and acceleration states. By carefully controlling the acceleration phase, constant speed phase, and deceleration phase, the system achieves optimal fluid transfer efficiency while maintaining gentle flow conditions that protect blood cells from damage.
2Productivity
If the working piston moves rapidly to increase pump output, then productivity improves, but fluid flow uniformity decreases and blood damage risk increases
Solution Approach 1:
The working piston executes periodic motion following a predetermined trajectory that repeats each pumping cycle. This periodic action is divided into three phases: acceleration to optimal speed, maintenance of constant speed for efficient fluid transfer, and controlled deceleration. This structured periodic motion ensures both high productivity and uniform fluid flow by preventing abrupt changes in velocity.
3Stress or pressure
If a pneumatic cylinder with equalizing valve is used, then pressure control is improved, but device complexity increases
Solution Approach 1:
The equalizing valve is extracted as a separate, independently controllable component from the main drive mechanism. This allows the control unit to manage the valve separately from the working piston movement, enabling precise pressure control during the three-phase motion without complicating the core pumping mechanism. The valve can be opened or closed at specific moments to equalize pressure differences.
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 solution enables high pump performance and reduces the risk of blood damage by achieving uniform fluid flow and efficient energy transfer, making it suitable for small membrane fluid pumps while maintaining reproducibility and stability.
Implementation Method 1
The movement of the piston causes the volume of a working chamber that is inside the pneumatic cylinder and that connects to the pressure line in a pressure exchange connection to increase and decrease
Implementation Method 2
The working chamber furthermore has an equalizing valve via which the working chamber is connected to the environment for exchanging air
Data Source
AI summary
A drive device is provided comprising a working pump, the working pump connected to a membrane fluid pump, and the working pump having a working piston able to oscillate axially between two reversal points for contracting and expanding a working chamber, and a control unit for controlling a movement of the working piston between the two reversal points. The controlled movement of the working piston comprises three temporally successive phases, in a first phase the working piston is accelerated to a speed that is greater than a speed at the end of the first phase, in a second phase the working piston is moved such that a specified speed of the working piston, a specified relative pressure in the working chamber, or a specified force of the working piston is substantially kept constant, and in a third phase the working piston is moved at a negative acceleration.