Adjustable Outflow Heart Pump for Percutaneous Full-Flow Support
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Solution Overview
Problem
Conventional heart pumps with fixed cross-sections are too large for percutaneous insertion and cannot provide full cardiac flow rates, posing a challenge for patients in need of mechanical circulatory support.
Innovation Solution
A heart pump with a cannula and impeller that can adjust its effective area and provide relative motion along a longitudinal axis, allowing percutaneous insertion and full cardiac flow rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a conventional fixed cross-section ventricular assist device is designed to provide near full heart flow rate, then the pumping function is improved, but the device size becomes too large for percutaneous insertion
Solution Approach 1:
The ventricular assist device employs a collapsible cannula that can dynamically change its cross-sectional area. During insertion, the cannula is in a collapsed state to minimize profile size for percutaneous advancement. Upon deployment, the cannula expands to a larger cross-section to accommodate the impeller and provide full cardiac flow rates, thus resolving the contradiction between device size and pumping capacity.
Solution Approach 2:
The impeller is positioned within the collapsible cannula, creating a nested configuration. The impeller can be advanced through the collapsed cannula during insertion, then deployed within the expanded cannula to function. This nesting allows the high-flow pump mechanism to be contained within a small insertion profile.
2Object-affected harmful factors
If a percutaneous insertion approach is used, then surgical stress is reduced, but the device must be small enough to advance through the femoral artery
Solution Approach 1:
The cannula is designed with dynamic collapsibility, transitioning from a small-diameter configuration during percutaneous advancement through the femoral artery to a larger diameter configuration upon deployment in the heart chamber. This dynamic size change enables percutaneous insertion while maintaining adequate flow capacity.
Solution Approach 2:
The cannula is divided into multiple segments or collapsible sections that can be compressed together for insertion and then expanded to their full size for operation. This segmentation allows the device to pass through narrow vascular pathways while providing sufficient cross-sectional area for high-flow pumping when deployed.
3Productivity
If the cannula cross-section is increased to provide full cardiac flow rates, then the pumping capacity is improved, but the device cannot be advanced percutaneously
Solution Approach 1:
The cannula cross-sectional area is made dynamically adjustable through collapse and expansion mechanisms. During the advancement phase, the cannula maintains a small cross-section for ease of percutaneous insertion. After deployment, the cannula expands to a large cross-section to enable full cardiac flow rates, thus resolving the contradiction between ease of insertion and pumping capacity.
Solution Approach 2:
The cannula is pre-collapsed to a small profile before percutaneous advancement to facilitate easy insertion through the femoral artery. After successful insertion and positioning, the cannula is then expanded to its full operational size to provide adequate flow capacity. This preliminary collapse action enables the device to overcome the size limitation during insertion.
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 percutaneous insertion and provides effective mechanical circulatory support for both left and right sides of the heart, reducing surgical stress and improving patient recovery.
Implementation Method 1
an impeller positioned in the cannula and configured to pump blood through the outlets along a longitudinal axis when the impeller is rotated at an operational speed
Implementation Method 2
The heart pump can be configured to adjust an effective area of the outlets while the impeller is rotating
Implementation Method 3
The diffuser can include a flow directing surface. The diffuser is disposed between the distal end of the catheter body and the impeller
Data Source
AI summary
A heart pump includes a cannula having a sidewall defining a longitudinal blood flow passage and a plurality of outlets extending through the sidewall. A rotatable impeller hub includes at least one impeller blade, wherein the at least one impeller blade is shaped to convey blood through the blood flow passage toward the plurality of outlets when the impeller hub is rotated at an operational speed. A diffuser defines an outer, flow directing surface having a geometry that is configured to control at least one property of the conveyed blood prior to flowing through the plurality of outlets.