Floating Current Trap for MRI Cable Interference
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Solution Overview
Problem
Conventional current traps for MRI systems require complex soldering processes, which can degrade coil-interfacing cables and limit their reconfiguration and positioning flexibility due to the need for precise coupling to the cables.
Innovation Solution
A floating current trap assembly featuring a spiral core made of nonconductive material and a coiled wire with tuning capacitors, allowing mechanical engagement without soldering and enabling reconfiguration along the cables, thereby blocking transmitter-driven currents effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional grounded baluns are coupled to coil-interfacing cables to block induced currents, then common mode impedance is improved, but the soldering process degrades the conductors and reduces flexibility
Solution Approach 1:
The current trap is divided into separate modular components: a coil-interfacing cable portion and a trap portion with spiral core and coiled wire. This segmentation eliminates the need for soldering between the balun and cable, as they can be mechanically coupled or positioned independently along the cable length, resolving the contradiction between maintaining high common mode impedance and avoiding conductor degradation from soldering.
Solution Approach 2:
The floating current trap design allows the trap portion to be positioned at different locations along the cable without fixed attachment points. This dynamic positioning capability provides flexibility in installation and reconfiguration while maintaining electrical performance, eliminating the static, fixed-position requirement of conventional soldered baluns.
2Reliability
If conventional baluns are soldered to coil-interfacing cables, then electrical connection is improved, but cable flexibility and reconfiguration capability are reduced
Solution Approach 1:
By separating the current trap function into a distinct portion that can be independently positioned along the cable, the design maintains electrical connection reliability through the resonance circuitry while enabling flexible reconfiguration. The trap portion can be moved to different locations without requiring resoldering or complex reconnection procedures.
Solution Approach 2:
The floating current trap design serves multiple functions: it provides common mode current blocking, allows flexible positioning, and enables easy reconfiguration. This multi-functionality resolves the contradiction by incorporating adaptability as a core feature rather than a compromise.
3Ease of operation
If floating current trap assembly is used without soldering, then ease of installation and reconfiguration is improved, but coupling to cables must be achieved without traditional electrical connection methods
Solution Approach 1:
The separation into cable portion and trap portion with distinct functions simplifies installation - the trap portion can be mechanically attached or positioned along the cable without requiring electrical connection procedures. This segmentation reduces installation complexity despite the unique coupling approach.
Solution Approach 2:
The spiral core acts as an intermediary structure that provides both mechanical support and magnetic coupling for the coiled wire. This intermediary element enables the floating trap to couple effectively with the cable's electromagnetic field without direct electrical contact or soldering, resolving the contradiction between ease of installation and effective coupling.
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 solution reduces cable degradation, simplifies installation, and enhances flexibility in positioning the current trap along the MRI system's cables, improving image quality by minimizing field distortions and unpredictable heating.
Implementation Method 1
one or more tuning capacitors physically attached to the spiral core and electrically connected to the coiled wire to form a resonance circuitry with the coiled wire
Implementation Method 2
The coil-interfacing cables may be subjected to electro-magnetic fields and as a result, transmitter-driven common mode currents may adversely affect coil tuning
Data Source
AI summary
Various methods and systems are provided for a current trap. In one example, the current trap has a spiral core made of a nonconductive material, a coiled wire having a plurality of turns wound around the spiral core, and one or more tuning capacitors physically attached to the spiral core and electrically connected to the coiled wire to form a resonance circuitry with the coiled wire.