Intravascular Ventricular Assist Device With Balloon Occluder
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Solution Overview
Problem
Current ventricular assist devices face challenges in durability, complexity, and susceptibility to failure due to the need for compact designs that maintain blood flow and prevent hemolysis and thrombosis, while also requiring invasive surgical procedures.
Innovation Solution
An implantable blood pump with a housing and rotors suspended by magnetic and hydrodynamic forces, featuring a compact design with a diameter of up to 20 mm, capable of pumping 1-3 liters per minute at pressures of 70-120 mm Hg, and equipped with a gripper to engage artery walls, using a seal-less mechanism to prevent wear and thrombosis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a compact pump design with diameter up to 20 mm is used, then the device can be implanted minimally invasively, but the pumping capacity and blood flow delivery are limited
Solution Approach 1:
The patent employs a balloon occluder that is inflated with fluid (hydraulic principle) to occlude the aorta and redirect blood flow through the pump. This allows the compact pump to achieve sufficient blood flow delivery by utilizing the patient's own cardiac output redirected through the device, rather than requiring the pump to generate all flow independently.
Solution Approach 2:
The balloon occluder acts as an intermediary element that modifies blood flow distribution. By inflating the balloon to occlude the aorta, it forces blood to flow through the pump's internal channels, enabling the small pump to deliver adequate blood flow without requiring high pumping capacity from the pump itself.
2Reliability
If the rotor is suspended by magnetic and hydrodynamic forces without contact, then wear and thrombosis are reduced, but the device complexity increases
Solution Approach 1:
The patent replaces traditional mechanical bearing systems with a magnetic field-based suspension system. The rotor is levitated using magnetic forces generated by magnets in the rotor and stator, eliminating mechanical contact between moving parts. This substitution reduces wear and thrombosis risk while the integrated magnetic circuit minimizes the added complexity.
Solution Approach 2:
The magnetic field serves multiple functions: it suspends the rotor without contact, provides the driving force for rotation, and creates the magnetic circuit necessary for pump operation. This multi-functionality reduces the need for separate suspension mechanisms, thereby limiting the increase in device complexity.
3Productivity
If the pump operates at high speed to deliver required blood flow, then productivity increases, but hemolysis and mechanical failure risk increase
Solution Approach 1:
The patent uses a balloon occluder inflated with fluid to create a controlled flow path. By occluding the aorta and redirecting blood flow through the pump's internal channels, the system achieves required blood flow delivery at lower rotor speeds, reducing shear stress and hemolysis risk while maintaining productivity.
Solution Approach 2:
The balloon occluder serves as an intermediary that modifies the flow dynamics. By forcing blood through specific pathways and reducing turbulence, it enables adequate blood flow delivery without requiring excessively high rotor speeds, thereby reducing hemolysis.
4Reliability
If a seal-less mechanism is used to prevent wear and thrombosis, then reliability improves, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent replaces mechanical sealing systems with a magnetic field-based seal-less design. The rotor is suspended and driven by magnetic forces without physical contact or seals, eliminating wear and thrombosis risks associated with traditional seals. The integrated magnetic circuit and simple rotor-stator configuration minimize manufacturing complexity despite the advanced mechanism.
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 pump provides reliable, long-term cardiac assistance with reduced risk of hemolysis and thrombosis, enabling minimally invasive implantation and extended operation without mechanical failure, while maintaining physiological blood flow and pressure.
Implementation Method 1
one or more stators surrounding the bore for providing a rotating magnetic field within the bore to induce rotation of each of the one or more rotors
Implementation Method 2
during operation of the pump the one or more rotors are suspended within the bore of the housing and out of contact with the housing solely by forces selected from the group consisting of magnetic and hydrodynamic forces
Implementation Method 3
during operation of the pump the one or more rotors are suspended within the bore of the housing and out of contact with the housing solely by forces selected from the group consisting of magnetic and hydrodynamic forces
Data Source
AI summary
One aspect of an intravascular ventricular assist device is an implantable blood pump where the pump includes a housing defining a bore having an axis, one or more rotors disposed within the bore, each rotor including a plurality of magnetic poles, and one or more stators surrounding the bore for providing a magnetic field within the bore to induce rotation of each of the one or more rotors. Another aspect of the invention includes methods of providing cardiac assistance to a mammalian subject as, for example, a human. Further aspects of the invention include rotor bodies having helical channels formed longitudinally along the length of the body of the rotor where each helical channel is formed between peripheral support surface areas facing radially outwardly and extending generally in circumferential directions around the rotational axis of the rotor.