Flexible MRI Probe with Shape Memory Alloy Tip
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Solution Overview
Problem
Conventional MRI antennas are too large for intravascular procedures, limiting their miniaturization and compatibility with interventional tools, and they often require removal for tool transitions, which complicates diagnostic and therapeutic maneuvers in vascular interventions.
Innovation Solution
A flexible MRI probe with a non-magnetic core, insulator/dielectric layers, and a shielding layer, featuring a whip antenna design that can steer and transmit torque, allowing for multiple tool exchanges without removal, and is compatible with MRI machines for real-time imaging guidance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If conventional MRI antennas are miniaturized for intravascular procedures, then the antenna size is reduced to fit vascular structures, but the mechanical strength and structural stability deteriorate
Solution Approach 1:
The patent employs a flexible tip made of shape memory alloy (Nitinol) that can be transformed between compressed and expanded states. When expanded, the flexible tip provides enhanced mechanical strength and structural stability to support the antenna, while when compressed, it allows the antenna to be miniaturized for intravascular insertion. This flexible shell structure resolves the contradiction between small size and mechanical strength.
Solution Approach 2:
The patent implements a dynamic structure where the flexible tip can change its mechanical properties on demand. The shape memory alloy tip is compressed during insertion to minimize size, then expanded at the target location to provide structural support. This dynamic transformation allows the antenna to adapt between miniaturized and structurally robust states, resolving the size-strength contradiction.
2Measurement precision
If conventional MRI antennas are used for intravascular procedures, then imaging capability is achieved, but compatibility with interventional tools and ability to remain during tool transitions is poor
Solution Approach 1:
The patent creates a universal platform where the guidewire antenna system can accommodate multiple interventional tools through its flexible tip structure. The expandable flexible tip provides a stable base that supports various tools while maintaining MRI imaging capability throughout the procedure. This multi-functional design allows the same antenna system to be used for both imaging and as a platform for diverse interventional maneuvers.
3Strength
If the antenna structure is made rigid for structural stability, then mechanical strength is improved, but flexibility for navigating tortuous vessels deteriorates
Solution Approach 1:
The patent employs a dynamic structure where the flexible tip can change its mechanical properties on demand. The shape memory alloy tip is compressed during insertion to minimize size and maximize flexibility for navigating tortuous vessels, then expanded at the target location to provide structural stability. This dynamic transformation allows the antenna to adapt between flexible and rigid states as needed.
Solution Approach 2:
The flexible tip constructed from shape memory alloy provides a flexible shell structure that can be compressed to navigate tortuous vasculature, then expanded to provide structural stability. The flexible shell maintains the antenna's ability to conform to vessel geometry while providing sufficient mechanical support when expanded.
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 precise, real-time MRI imaging within vascular structures, facilitating advanced diagnostic and therapeutic procedures by providing a guidewire-like functionality that is both mechanically and electrically suitable for navigating tortuous vessels and supporting various interventional tools.
Implementation Method 1
Magnetic resonance imaging (MRI) is a well known, highly useful technique for imaging matter. It has particular use with imaging the human body or other biological tissue
Implementation Method 2
This second field pulls the net magnetism of the atomic nuclei off the axis of the original magnetic field. As the second magnetic field pulses, it pulls the spins off axis. When it is turned off, the spins 'relax' back to their position relative to the initial magnetic field. The rate at which the spins relax is dependent on the molecular level environment. During the relaxation step, the precessing magnetization at the Larmor frequency induces a signal voltage that can be detected by antennas tuned to that frequency.
Implementation Method 3
This static magnetic field tends to cause the vector of the magnetization of the atomic nuclei placed therein to align with the magnetic field.
Implementation Method 4
During the relaxation step, the precessing magnetization at the Larmor frequency induces a signal voltage that can be detected by antennas tuned to that frequency.
Data Source
AI summary
Herein is disclosed a magnetic resonance imaging probe, having a probe shaft including a magnetic resonance antenna, and a spring tip attached to a distal end of the antenna.