Miniature Transvalvular Ventricular Assist Device
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current mechanical circulatory support devices, such as ventricular assist devices (VADs), face limitations including high incidence of serious adverse events, poor durability, and invasive surgical requirements, which restrict their effectiveness and acceptance for patients with NYHA class III heart failure.
Innovation Solution
A miniature axial flow pump is designed to be implanted within one-third of the aortic or pulmonary valve area, eliminating the need for inflow and outflow cannulae, and integrated with a functional valved outflow channel to minimize regurgitation and resistance, allowing for minimally invasive surgery and safe shutdown.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a pump is placed within the entire valve orifice to eliminate inflow and outflow grafts, then device complexity and surgical invasiveness are reduced, but the natural heart cannot pump effectively if the pump stops and massive aortic regurgitation occurs
Solution Approach 1:
The valve annulus is divided into two functional zones: a first zone occupied by the axial flow pump and a second zone serving as a valved outflow channel. This segmentation allows the pump to occupy only part of the valve area, preserving sufficient space for natural valve function and outflow when the pump is not operating, thereby maintaining reliability while reducing overall device complexity.
2Productivity
If an axial pump with a large cross sectional flow area is used, then flow capacity is improved, but massive aortic regurgitation occurs and the natural heart fails
Solution Approach 1:
Different regions of the valve annulus are assigned different functions with different flow requirements. The first zone (pump area) is optimized for mechanical pumping with specific flow characteristics, while the second zone (valved outflow channel) is optimized for natural valve function with appropriate flow area to prevent regurgitation. This local differentiation allows the pump to have sufficient flow capacity without causing massive aortic regurgitation.
3Object-generated harmful factors
If an axial pump with a small cross sectional flow area is used, then aortic regurgitation is minimized, but high resistance prevents sufficient blood ejection
Solution Approach 1:
The valve annulus is divided into two functional zones: a first zone occupied by the axial flow pump and a second zone serving as a valved outflow channel. This segmentation allows the pump to occupy only part of the valve area, preserving sufficient space for natural valve function and outflow when the pump is not operating, thereby maintaining reliability while reducing overall device complexity.
Solution Approach 2:
The invention merges the artificial pump function with the natural valve outflow function into a single integrated structure. The pump and the valved outflow channel work together as a unified system, combining mechanical pumping capability with natural valve function to achieve both sufficient blood ejection and minimized regurgitation.
4Reliability
If traditional VADs with inflow and outflow conduits are used, then reliable blood flow is achieved, but surgical invasiveness and device complexity increase
Solution Approach 1:
The invention merges the pump body directly with the valve annulus structure, eliminating the need for separate inflow and outflow conduits. The pump is positioned within the valve annulus such that blood flows directly from the ventricle through the pump into the aorta, integrating multiple functions into a single implantable unit and significantly reducing device complexity while maintaining reliable blood flow.
Solution Approach 2:
The invention extracts and eliminates the external inflow and outflow conduits that are characteristic of traditional VADs. By positioning the pump directly within the valve annulus and utilizing the native valve structure for outflow, the design removes unnecessary components that contribute to surgical invasiveness and device complexity while preserving essential blood flow function.
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 provides a highly miniaturized, durable, and safe heart assist device that can be implanted using minimally invasive techniques, reducing adverse events and maintaining natural heart function, with a design that prevents thrombosis and promotes bio-integration.
Implementation Method 1
The pump has an inlet in communication with the ventricular cavity and an outlet in communication with the aorta or pulmonary artery distal to the valve leaflets
Implementation Method 2
the valve leaflets are positioned to open in response to ventricular pressure and close in response to aortic or pulmonary artery pressure
Data Source
AI summary
A tiny electrically powered hydrodynamic blood pump is disclosed which occupies one third of the aortic or pulmonary valve position, and pumps directly from the left ventricle to the aorta or from the right ventricle to the pulmonary artery. The device is configured to exactly match or approximate the space of one leaflet and sinus of valsalva, with part of the device supported in the outflow tract of the ventricular cavity adjacent to the valve. In the configuration used, two leaflets of the natural tri-leaflet valve remain functional and the pump resides where the third leaflet had been. When implanted, the outer surface of the device includes two faces against which the two valve leaflets seal when closed. To obtain the best valve function, the shape of these faces may be custom fabricated to match the individual patient's valve geometry based on high resolution three dimensional CT or MRI images. Another embodiment of the invention discloses a combined two leaflet tissue valve with the miniature blood pump supported in the position usually occupied by the third leaflet. Either stented or un-stented tissue valves may be used. This structure preserves two thirds of the valve annulus area for ejection of blood by the natural ventricle, with excellent washing of the aortic root and interface of the blood pump to the heart. In the aortic position, the blood pump is positioned in the non-coronary cusp. A major advantage of the transvalvular VAD is the elimination of both the inflow and outflow cannulae usually required with heart assist devices.