Intravascular Blood Pump Sleeve Casting for Compact Motor Cooling
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Solution Overview
Problem
Existing intravascular blood pumps face challenges in reducing size and length while maintaining efficient electric motors, and their manufacturing methods are costly and time-consuming, with thick plastic housings increasing diameter and requiring extensive mold use.
Innovation Solution
A method of manufacturing intravascular blood pumps where the outer sleeve forms the housing, with stator components fixed inside by a casting compound, eliminating the need for expensive molds and allowing for smaller dimensions and improved heat dissipation, using a biocompatible magnetically conductive material for the sleeve.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the stator parts are encapsulated in a thick plastic housing using injection molding, then corrosion protection is provided, but the diameter of the pumping device increases and heat dissipation is reduced
Solution Approach 1:
The patent removes the thick plastic housing from the motor assembly, extracting the corrosion protection function to a separate thin coating applied only where needed. This eliminates the diameter increase caused by encapsulation while maintaining corrosion protection through targeted surface treatment of metal components.
Solution Approach 2:
Instead of uniform thick plastic encapsulation, the patent applies thin protective coatings locally to specific metal surfaces that require corrosion protection. This localized approach maintains the metallic structure's heat dissipation properties while providing necessary corrosion resistance at critical interfaces.
2Reliability
If the stator parts are encapsulated in a thick plastic housing, then corrosion protection is provided, but heat dissipation is reduced leading to undesired heating
Solution Approach 1:
The patent extracts the heat dissipation function from the housing design by eliminating the thick plastic encapsulation that acted as thermal insulation. The metallic motor structure is exposed to facilitate direct heat transfer to the surrounding blood, preventing motor overheating while corrosion protection is provided through thin surface coatings.
Solution Approach 2:
The patent uses composite construction with metallic components providing structural integrity and heat dissipation, combined with thin protective coatings for corrosion resistance. This composite approach combines the thermal conductivity of metal with the corrosion protection of coated surfaces, avoiding the thermal insulation problem of solid plastic encapsulation.
3Stability of the object's composition
If the pumping device is made rigid to facilitate motor operation, then motor stability is improved, but navigation through curved blood vessels becomes difficult
Solution Approach 1:
The patent divides the device into rigid and flexible segments: the motor housing and pump chamber are rigid to maintain motor stability, while the catheter and flow cannula are flexible to navigate curved vessels. The rigid pumping device is mounted on a flexible support structure that absorbs bending stresses, allowing navigation through anatomical curves while maintaining motor operational stability.
4Length of moving object
If the pumping device length is reduced to facilitate insertion, then insertion ease is improved, but the motor efficiency and pump rate are reduced
Solution Approach 1:
The patent employs nested configuration where the rotor is positioned concentrically within the stator, and the impeller is nested within the pump chamber. This nested arrangement maximizes the utilization of the limited axial space, allowing sufficient motor length for efficient operation while minimizing the overall device length for easy insertion. The components are arranged along the longitudinal axis in a compact nested sequence.
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 method enables smaller pumps with efficient electric motors, reducing production costs and time, and enhances heat transfer and structural stability, achieving a pump rate of up to 5.5 liters per minute with reduced risk of breakage.
Implementation Method 1
A casting compound, such as a polymer material, in particular a resin like epoxy, is then injected into said interspace via the molding base to fix the stator components inside
Implementation Method 2
using a biocompatible magnetically conductive material for the sleeve
Data Source
AI summary
An intravascular blood pump comprises a pumping device including an impeller and an electric motor for driving the impeller. A rotor of the electric motor is rotatable about an axis of rotation and coupled to the impeller so as to be able to cause rotation of the impeller. An outer sleeve forms a casing of the pumping device, wherein stator components are fixed inside the outer sleeve by means of a casting compound. In a method of manufacturing the blood pump the stator components are placed on a molding base, including the outer sleeve to thereby form an interspace between the molding base and the outer sleeve in which the stator components are disposed. The casting compound is then injected into the interspace via the molding base to fix the stator components inside the outer sleeve. The outer sleeve preferably comprises a magnetically conductive material to form a yoke of the electric motor.