Expandable Catheter Heart Pump With Hydrodynamic Bearings
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Solution Overview
Problem
Conventional heart pumps with fixed cross-sections are too large for percutaneous insertion, making it difficult to provide full cardiac flow rates for both left and right sides of the heart, which is necessary for effective mechanical circulatory support in heart failure patients without causing additional stress.
Innovation Solution
A percutaneously applicable heart pump design featuring a catheter assembly with an impeller assembly and hydrodynamic bearings, capable of supporting pressure-velocity ranges of up to 50,000 psi-ft/min, and an expandable housing to facilitate full cardiac flow rates while minimizing biocompatibility issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a fixed cross-section heart pump is surgically inserted into the heart chamber, then full cardiac flow rates can be provided, but the device causes additional serious stresses in heart failure patients and requires invasive surgery
Solution Approach 1:
The heart pump employs a dynamically expandable cross-section design where the catheter can transition from a compressed state for percutaneous insertion to an expanded state for full cardiac flow support. This dynamic adaptation allows the device to minimize invasiveness during insertion while maximizing pumping capacity during operation, thereby reducing stress on the heart muscle compared to traditional fixed large-bore surgical implants.
Solution Approach 2:
The device changes its physical parameters (cross-sectional area, diameter) from a small compressed configuration during insertion to a large expanded configuration during operation. This parameter transformation enables the pump to deliver full cardiac flow rates equivalent to surgical devices while being inserted through a percutaneous route, thus avoiding the trauma and stress associated with open surgery.
2Productivity
If a fixed cross-section heart pump is designed to provide full heart flow rates, then adequate cardiac support is achieved, but the device is too large to be advanced percutaneously
Solution Approach 1:
The catheter incorporates a dynamic structure that allows it to be compressed to a small cross-section for percutaneous advancement through blood vessels, then expanded to a large cross-section once positioned in the heart chamber. This dynamic size adaptation resolves the contradiction by enabling the device to be small during insertion while large during operation, achieving full cardiac flow rates without the size limitations of fixed cross-section designs.
Solution Approach 2:
The expandable catheter design allows the large functional pump structure to be nested within a smaller delivery sheath or compressed configuration during insertion. Once positioned, the catheter expands from its nested state to its full operational size, enabling full cardiac flow support while being advanced through small percutaneous access points.
3Productivity
If surgical insertion is used to insert a heart pump, then full cardiac flow rates can be provided, but additional serious stresses are caused to heart failure patients
Solution Approach 1:
The device uses a dynamic expandable structure that transitions from a compressed insertion configuration to an expanded operational configuration. This allows percutaneous insertion through small vascular access points, avoiding the need for open surgical procedures while maintaining the capability to provide full cardiac flow rates once deployed in the heart chamber.
Solution Approach 2:
The catheter undergoes parameter changes from a small-diameter compressed state during percutaneous insertion to a large-diameter expanded state during operation. This parameter transformation enables minimally invasive insertion while maintaining adequate pumping capacity, thereby improving ease of operation and reducing patient stress compared to traditional surgical insertion methods.
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
Enables minimally invasive insertion and effective support of both left and right heart ventricles with reduced patient stress, providing efficient blood flow and enhanced biocompatibility through the use of hydrodynamic bearings and an expandable impeller design.
Implementation Method 1
One or more bearings supporting the impeller shaft can be a hydrodynamic bearing
Data Source
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AI summary
A heart pump and a catheter assembly therefor are provided that include a flexible catheter body having a proximal end and a distal end, the catheter body having a plurality of lumens therethrough. The catheter body can be sufficiently flexible to extend from a peripheral access to a patient's heart. The catheter assembly can also include an impeller assembly having an impeller and a housing. The impeller assembly can be coupled with the flexible catheter body such that a tensile force applied to opposite ends of the catheter assembly enhances the security of the connection between the catheter body and the impeller assembly.