Dielectric Elastomeric Actuator for Implantable Cardiac Assist
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current cardiac assist devices, such as intra-aortic balloon pumps and axial flow pumps, face limitations including patient mobility restrictions, risk of infection, device failure, and inefficient blood flow due to their mechanical design and reliance on percutaneous tubing, which restricts their use to short-term hospital-based treatments.
Innovation Solution
A cardiac assist device utilizing a dielectric elastomeric actuator with a tubular structure that contracts radially upon voltage application, providing a fully implantable solution with reduced power consumption and minimal exposed non-biological materials, allowing for bi-directional blood flow and potential integration with the aorta for optimized pumping effect.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If percutaneous tubing is used to connect the pump to the external environment, then the device can be operated and controlled, but the patient is restricted to bed rest and faces infection risks
Solution Approach 1:
The patent removes the percutaneous tubing connection from the system by making the pump fully implantable with wireless power and control. The pump is contained entirely within the body, eliminating the external catheter that caused infection risks and mobility restrictions.
Solution Approach 2:
The patent introduces wireless communication and power transmission as intermediaries between the external controller and the implanted pump. This allows the pump to be controlled and powered without physical connections through the skin, eliminating the infection pathway while maintaining operability.
2Productivity
If a mechanical pump with moving parts is used, then pumping function is achieved, but device failure and thrombolic complications occur
Solution Approach 1:
The patent replaces traditional mechanical pump components (impellers, valves, seals) with a diaphragm-based pumping mechanism actuated by a shape memory alloy. This reduces the number of moving parts and mechanical failure points while maintaining effective blood pumping function.
Solution Approach 2:
The patent uses shape memory alloy that changes its physical state (phase transition) in response to temperature changes. The alloy transitions between martensite and austenite phases to drive the diaphragm, replacing complex mechanical actuation systems with a simpler thermally-driven mechanism.
3Duration of action of moving object
If the pump is designed for long-term implantation, then chronic cardiac support is provided, but arterial wall trauma and sepsis risks increase
Solution Approach 1:
The patent uses a flexible diaphragm made of biocompatible material as the pumping element. This thin film structure conforms to the aortic wall, distributing mechanical stress evenly and minimizing arterial wall trauma while enabling long-term implantation.
Solution Approach 2:
The patent removes the percutaneous catheter connection that caused insertion site infections and sepsis risks. By making the system fully implantable with wireless power transmission, the device can remain in place chronically without the infection pathway provided by external tubing.
4Adaptability or versatility
If thin silicone balloons are used in IABP, then the device is flexible and implantable, but the balloons are prone to rupture
Solution Approach 1:
The patent uses a composite structure combining a flexible diaphragm made of biocompatible polymer material with embedded shape memory alloy actuators. This composite design maintains flexibility for implantation while the shape memory alloy provides structural integrity and eliminates rupture risks associated with thin silicone balloons.
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 device enables prolonged, efficient cardiac assistance with improved patient mobility and reduced hospital stay, minimizing risks of infection and device failure, while achieving effective blood flow and counter-pulsation synchronized with the heartbeat.
Implementation Method 1
comprising a plurality of layers of a dielectric elastomeric material and a tubular elastic support structure, the elastic support structure configured to maintain a pre-stress in the dielectric elastomeric material layers
Data Source
AI summary
The invention relates to actuators based on electroactive polymeric materials for use in pumping fluids or in other applications where a contractile actuation is required, in particular, although not necessarily exclusively, for use in vascular pulsation devices such as a variable aortic tension device. Embodiments disclosed include an actuator comprising: an inner tubular structure; an outer tubular structure surrounding the inner tubular structure and comprising a plurality of layers of a dielectric elastomeric material and a tubular elastic support structure, the elastic support structure configured to maintain a pre-stress in the layers of the dielectric elastomeric material, wherein the outer tubular structure is configured to contract in a radial direction around the inner tubular structure upon application of an actuation voltage signal across the dielectric elastomeric material layers.