Integrated Balun Shield Capacitor for MRI Signal Feedback Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing balun shield designs in MRI systems face performance degradation due to gaps that allow unwanted signal feedback, leading to instability in components and reduced shielding effectiveness.
Innovation Solution
An integrated parallel plate capacitor is incorporated into the balun shield, eliminating gaps by forming a capacitance with the end cover, which, along with a common-mode inductance, creates a parallel resonant circuit to reduce common-mode currents and enhance shielding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a gap is present in the balun shield to allow connection of the capacitor unit, then the capacitor can be connected to the coil conductor, but the shielding effectiveness is degraded and signal feedback occurs
Solution Approach 1:
The capacitor unit is integrated directly into the end cover of the balun shield, merging the capacitor connection with the shield structure itself. This eliminates the need for separate gaps in the shield while maintaining electrical connection, thus preserving shielding effectiveness while achieving the desired electrical connectivity.
Solution Approach 2:
The end cover serves as an intermediary component that simultaneously provides mechanical support, electrical connection for the capacitor, and continuous shielding. By integrating the capacitor connection through the end cover rather than requiring gaps, the shield maintains its integrity while achieving the necessary electrical connections.
2Ease of manufacture
If a gap is present in the balun shield for capacitor connection, then the capacitor unit can be attached, but component stability is reduced due to unwanted feedback
Solution Approach 1:
The capacitor unit is merged with the end cover structure, creating an integrated assembly that eliminates gaps. This integration ensures that the capacitor remains securely attached while the continuous shield structure prevents unwanted feedback, thereby maintaining component stability and reliability.
3Device complexity
If the balun shield has a gap for capacitor connection, then the capacitor can be connected, but the overall shielding performance is reduced
Solution Approach 1:
The shield and capacitor connection are merged into a single integrated structure through the end cover. This eliminates gaps that would allow common-mode currents to propagate, while still providing the necessary electrical connection for the capacitor unit, thus maintaining shielding performance.
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 integrated capacitor design improves the balun shield's ability to reduce common-mode currents, thereby enhancing the overall performance and stability of the MRI system by minimizing signal feedback and improving signal quality.
Implementation Method 1
The capacitor unit, together with the coil, creates a parallel resonant circuit that can be tuned to the imaging frequency to significantly reduce common mode currents propogating down the co-axial conductor
Implementation Method 2
the balun including a balun shield having a capacitance and a common-mode inductance
Implementation Method 3
a common-mode inductance to create a parallel resonant circuit
Data Source
AI summary
A balun is included in a magnetic resonance imaging system. The balun conditions electromagnetic signals received from at least one RF receiver coil. The balun includes a balun shield having an integrated capacitor therein. The balun blocks unwanted feedback from effecting performance of any components contained within the balun shield.