Two-Part Expandable Ventricular Assist Pumps for Radial Access
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current percutaneous ventricular assist devices (pVADs) require large access sites, such as the femoral or axillary arteries, which increase bleeding complications and are not suitable for radial access, and are too large for many patients, including children and those with smaller body structures.
Innovation Solution
Development of expandable percutaneous ventricular assist devices with a two-part design, featuring a pump impeller that can be inflated or self-expandable, allowing deployment through a radial artery access site and transitioning from a low-profile delivery configuration to a radially expanded configuration for operation, with a flexible drive shaft and motor external to the patient for blood pumping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If current pVADs are used, then hemodynamic support is provided, but large access sites are required which increase bleeding complications
Solution Approach 1:
The pVAD is divided into two separate components: a pump housing delivered through a large-bore sheath and a collapsible impeller delivered through a separate catheter. This segmentation allows the impeller to be delivered through a small radial access site while the pump housing can be delivered through a larger femoral access site, thereby reducing bleeding complications at the impeller access site while still providing hemodynamic support.
Solution Approach 2:
The collapsible impeller is nested within the pump housing during delivery. The impeller is delivered through a catheter that is advanced through the pump housing, allowing both components to be delivered through the same access site. The impeller is then expanded within the pump housing to form the functional pump assembly, reducing the number of access sites required.
2Reliability
If current pVADs are used, then hemodynamic support is provided, but the devices are too large for radial access site
Solution Approach 1:
The impeller is designed with collapsible ribs that allow it to dynamically change its diameter. During delivery, the impeller is collapsed to a small diameter to fit through a radial access site and catheter. Once positioned within the pump housing, the impeller is expanded to its full operational diameter to provide effective hemodynamic support, thus resolving the contradiction between small delivery profile and large operational size.
Solution Approach 2:
The physical parameters of the impeller (specifically its diameter and cross-sectional area) are changed between delivery and operational states. The impeller transitions from a compressed, low-profile configuration during delivery to an expanded, high-volume configuration during operation, allowing it to pass through small access sites while maintaining large operational dimensions for effective pumping.
3Reliability
If current pVADs are used, then hemodynamic support is provided, but large access sites require closure devices or surgical intervention
Solution Approach 1:
The delivery system is segmented into a large-bore sheath for the pump housing and a separate catheter for the impeller. This allows the impeller to be delivered through a small radial access site that can be managed with simple pressure closure, while the pump housing is delivered through a larger femoral access site that may require closure devices. The segmentation thus minimizes the complexity of access site management by allowing different closure strategies for different components.
4Reliability
If current pVADs are used, then hemodynamic support is provided, but the devices are too large for children and patients with smaller body structures
Solution Approach 1:
The collapsible impeller design allows the device to be delivered in a compact form factor suitable for small patients and children, then expanded to the appropriate size for hemodynamic support. The impeller's volume can be adjusted by controlling the expansion of its collapsible ribs, allowing customization for patients of different sizes while maintaining the same delivery system.
Solution Approach 2:
The physical parameters of the pVAD (diameter, volume, cross-sectional area) are made variable through the collapsible impeller design. The impeller can be expanded to different degrees to match the body size of the patient, allowing the same device to be used in children and adults by adjusting the expansion parameter rather than requiring different sized devices.
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 deployment through smaller access sites like the radial artery, reducing complications and making the devices suitable for a wider range of patients, while providing effective hemodynamic support without mechanical bearings, allowing for self-centering and hydrodynamic bearing during operation.
Implementation Method 1
The pump impeller is expandable in response to receiving an inflation fluid supplied to the impeller via the lumen of the drive shaft
Implementation Method 2
providing effective hemodynamic support without mechanical bearings, allowing for self-centering and hydrodynamic bearing during operation
Data Source
AI summary
Some embodiments of percutaneous ventricular assist devices have a two-part design that includes a housing component and a separately deployable rotatable inner catheter component. The housing component can include an expandable pump housing. The inner catheter can include an expandable pump impeller and an associated flexible drive shaft. The drive shaft can be coupled to a motor located external to the patient. The motor can rotate the drive shaft to spin the pump impeller inside of the pump housing, causing blood to be pumped within the patient. In some embodiments, the pump impeller is inflatable or self-expandable. The two-part percutaneous ventricular assist devices with inflatable or self-expandable pump impellers are designed to have very small delivery profiles. Accordingly, various deployment modalities, including radial artery deployment, are practicable using the two-part percutaneous ventricular assist devices described herein.