Low-force peristaltic pumping segment with interior notches
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing infusion pumps require significant force to completely close off the pumping segment due to the need for overcompression, which causes stress on the tube walls and is inefficient, especially since materials like silicone are expensive and have high gas permeability.
Innovation Solution
A peristaltic pumping mechanism with a tube having sharp notches on its interior surface, dividing it into upper and lower portions with constant wall thicknesses, allowing for reduced shut-off force by ensuring continuous contact at the notch tips, thereby sealing the tube without the need for excessive compression.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a typical round tube is used in a peristaltic pump, then the tube can be compressed to close off flow, but significant force is required and the tube walls experience additional stress due to overcompression
Solution Approach 1:
The tube is segmented into multiple sections with varying wall thicknesses. The pumping segment has a first wall thickness while the non-pumping segments have a second, greater wall thickness. This segmentation allows the pumping segment to be easily compressed for flow closure while the thicker non-pumping segments provide structural support and reduce overall stress on the tube during compression cycles.
Solution Approach 2:
Different portions of the tube are given different wall thicknesses tailored to their specific functional requirements. The pumping segment has thinner walls optimized for compression and flow closure, while the non-pumping segments have thicker walls for durability and stress distribution. This local differentiation of material properties resolves the contradiction between easy closure and reduced stress.
2Reliability
If silicone material is used for the tube, then the tube has sufficient flexibility and resilience, but the material is expensive and has relatively high gas permeability
Solution Approach 1:
The patent changes the material parameter from silicone to a different elastomeric material that has lower gas permeability while maintaining the necessary flexibility and resilience for peristaltic pumping. This parameter change in material composition allows the tube to achieve the same functional performance with reduced gas permeability and potentially lower cost.
3Reliability
If the tube is compressed beyond the point where interior wall touches to completely close off flow, then flow is fully stopped, but this overcompression requires significant force and creates stress in the tube walls
Solution Approach 1:
The tube is divided into pumping and non-pumping segments with different wall thicknesses. The thinner pumping segment allows for complete flow closure with reduced compression force, while the thicker non-pumping segments prevent excessive stress accumulation during the compression cycle, enabling reliable flow closure without overcompression.
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 reduces the force required to shut off the flow in infusion pumps, decreases stress on the tube, and offers a cost-effective alternative to silicone by using materials like thermoplastic elastomers, while maintaining resilience and low gas permeability.
Implementation Method 1
Many infusion pumps operate using a peristaltic mechanism having a series of compressor blocks, or fingers, that sequentially compress and release segments of a flexible tube
Implementation Method 2
This type of mechanism relies on the resilience of the tube to expand the tube when the compressive force is removed, thereby increasing the cross-sectional area of the tube under that finger
Data Source
AI summary
A pumping segment having a low shut-off force is disclosed. The pumping segment includes a tube having an interior surface with at least two notches on opposite sides of the interior surface.