Catheter Pump Stent Structure for Stress Fatigue Resistance
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Solution Overview
Problem
Conventional catheter pumps experience structural instability and reduced service life due to stress fatigue at the ends of the stent bars, leading to potential breakage and disconnection of components during multiple collapses and expansions.
Innovation Solution
The catheter pump incorporates a stent design with edge struts having a greater circumferential width at both ends than at the middle portion, ensuring uniform rigidity and stress distribution by directing stress to the middle region, thereby preventing breakage and enhancing structural stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If bars with uniform width are used in the pump portion, then manufacturing is simplified, but stress fatigue at the ends leads to decreased rigidity and structural instability
Solution Approach 1:
The patent applies local quality by varying the width of edge struts along their length. Specifically, the edge struts have greater width at their ends and smaller width at their middle portions, creating non-uniform local properties. This design compensates for stress fatigue at the ends by providing extra material where needed, while maintaining overall structural integrity. The local quality change directly addresses the contradiction by enhancing reliability at critical stress points without requiring complete redesign of all components.
2Quantity of substance
If bars with uniform width are used, then material usage is consistent, but stress concentration at ends causes breakage and shortens service life
Solution Approach 1:
The patent implements parameter changes by modifying the width parameter of edge struts along their length. The width varies from greater at the ends to smaller at the middle portions, creating a gradient structure. This parameter variation optimizes material distribution to match stress patterns, providing enhanced material presence at high-stress end regions while reducing material in lower-stress middle regions. The result is extended service life through improved stress management without excessive material consumption.
3Strength
If edge struts have greater width at ends, then rigidity at ends is compensated for stress fatigue, but manufacturing complexity increases
Solution Approach 1:
The patent applies local quality by varying the width of edge struts along their length. Specifically, the edge struts have greater width at their ends and smaller width at their middle portions, creating non-uniform local properties. This design compensates for stress fatigue at the ends by providing extra material where needed, while maintaining overall structural integrity. The local quality change directly addresses the contradiction by enhancing reliability at critical stress points without requiring complete redesign of all components.
Data Source
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AI summary
A catheter pump, comprising: a catheter, and a pump head that can be delivered to a desired position of the heart by means of the catheter so as to pump blood. The pump head comprises a pump housing having a blood inlet and a blood outlet and an impeller housed in the pump housing. The impeller is driven to rotate so as to suck blood via the blood inlet into the pump housing and then pump out the blood via the blood outlet. The pump housing comprises a stent, the stent being operably switched between a radially retracted state and a radially deployed state. In the radially deployed state, the stent comprises a substantially cylindrical body portion, an inlet portion located at the distal end in the axial direction of the body portion, and an outlet portion located at the proximal end in the axial direction of the body portion, the inlet portion and the outlet portion being connected and supporting the body portion. The body portion is provided with a plurality of meshes, each mesh being defined by at least two pairs of oppositely-arranged side edges. All the side edges have the same radial thickness, and the circumferential width of the two ends in the axial direction of each side edge is larger than the circumferential width of the middle of same.