Magnetic Handle Assembly for Prosthesis Delivery
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Solution Overview
Problem
Current delivery devices for prostheses, such as stents and stent grafts, lack a mechanism for controlled and sequential deployment, which can lead to improper or premature release of the prosthesis during medical procedures.
Innovation Solution
A handle assembly with a rotatable inner cannula and magnetic components that translate torque from a physician-actuated handle to rotate the cannula, allowing for sequential release of the prosthesis, ensuring that each deployment step is completed before proceeding to the next, using a magnetic dipole-dipole interaction for precise control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a delivery device uses a simple release mechanism, then the device complexity is reduced, but the control precision and reliability of sequential deployment deteriorates
Solution Approach 1:
The patent replaces traditional mechanical coupling mechanisms with a magnetic coupling system. Magnets are embedded in the rotary collar and inner cannula to create a magnetic field that transmits rotational force without direct mechanical contact. This substitution maintains precise control over the inner cannula's rotation while simplifying the overall mechanical structure, as the magnetic field inherently provides both coupling and controlled slippage characteristics.
Solution Approach 2:
The magnetic field acts as an intermediary between the rotary collar and the inner cannula. Instead of direct mechanical contact, the magnetic field transmits torque from the rotary collar to rotate the inner cannula for prosthesis release. This intermediary approach allows for controlled force transmission while maintaining the ability to prevent unintended rotation, thereby ensuring sequential deployment control without complex mechanical linkages.
2Power
If magnets are placed in close proximity for strong magnetic attraction, then the torque transmission efficiency is improved, but the risk of unintended rotation or premature release increases
Solution Approach 1:
The magnetic coupling system employs localized magnet placement with specific polarity arrangements. Magnets are positioned at discrete locations on the rotary collar and inner cannula with alternating polarities to create controlled attraction zones. This local quality approach ensures strong torque transmission at specific angular positions while maintaining gaps and non-magnetic zones that prevent continuous or unintended rotation, thereby balancing power transmission with release accuracy.
Solution Approach 2:
The magnetic coupling exhibits dynamic characteristics where the magnetic attraction strength varies with the relative angular position of the rotary collar and inner cannula. The system is designed so that magnetic attraction provides sufficient torque for intentional rotation during controlled release, while friction and magnetic detent effects prevent rotation under lower torque conditions. This dynamic behavior allows the system to adapt between strong coupling during deployment and controlled slippage during positioning.
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 controlled and sequential deployment of prostheses, preventing premature release and ensuring all steps are completed in the correct order, enhancing the precision and safety of prosthesis delivery in vascular procedures.
Implementation Method 1
The at least one magnet disposed on the rotatable inner cannula and the at least one magnet disposed on the inner surface of the rotary collar comprise a magnetic attraction, wherein the attraction translates torque from the rotation of the rotary collar to rotate the inner cannula
Data Source
AI summary
A prosthesis delivery comprising a rotatable inner cannula and a prosthesis releasably coupled to a proximal end of the inner cannula is disclosed. The inner cannula has a first position in which the prosthesis is retained on the cannula and a second position in which the prosthesis is released. At least one magnet is disposed on the inner cannula. A handle assembly is disposed about a distal portion of the inner cannula, the handle assembly comprising a rotary collar having at least one magnet disposed on the inner surface thereof, wherein the at least one magnet disposed on the rotatable inner cannula and the at least one magnet disposed on the inner surface of the rotary collar comprise a magnetic attraction. The magnetic attraction translates torque from rotation of the rotary collar to rotate the inner cannula from the first position to the second position to thereby release the prosthesis.