MRI Local Coil Using Segmented Coaxial Cable for 3D Molding
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Solution Overview
Problem
Existing local coils for magnetic resonance imaging are limited in flexibility and durability due to the use of flexible substrates and rigid components, which restricts three-dimensional molding and increases the risk of damage during bending, and also generates excessive heat from transmitted power.
Innovation Solution
A local coil design utilizing a coaxial cable with interruptions in the internal and external conductors to form an antenna loop, allowing for flexibility in multiple axes and reduced heat generation through a detuning circuit and adaptation elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a flexible substrate with copper tracks is used for the antenna, then the local coil can be bent uniformly along one axis, but three-dimensional molding to body parts curving along multiple axes is limited and the copper tracks may detach or break
Solution Approach 1:
The antenna is divided into multiple independent coaxial cable segments that can be individually positioned and oriented. Each segment maintains electrical continuity through controlled interruptions and connections, allowing the antenna to conform to complex three-dimensional body surfaces without the risk of track detachment or breakage associated with flexible substrates.
Solution Approach 2:
The patent replaces the flexible substrate with flexible coaxial cables that have inherent flexibility and durability. The coaxial cable structure with its flexible jacket allows bending in multiple directions while protecting the internal conductors, enabling reliable three-dimensional molding to body parts without the limitations of planar flexible substrates.
2Adaptability or versatility
If rigid electronic components such as SMD capacitors are integrated into the local coil, then the resonance of the antenna can be adapted to the imaging frequency, but the flexibility of the substrate is restricted and the components may be damaged during bending
Solution Approach 1:
The patent achieves resonance adaptation by changing the physical parameters of the antenna itself - specifically the length, geometry, and configuration of the coaxial cable segments - rather than relying on rigid SMD capacitors. The resonance frequency is adjusted through the antenna's dimensional parameters and the characteristics of the flexible coaxial cable, maintaining full flexibility.
Solution Approach 2:
The patent extracts the rigid SMD capacitor components from the design and replaces them with flexible coaxial cable structures that provide both the necessary electrical characteristics for resonance adaptation and the mechanical flexibility required for body contouring. This eliminates the conflict between rigid components and flexible substrate.
3Measurement precision
If the local coil is positioned close to the body part for optimum image quality, then signal reception is improved, but the coil generates excessive heat from transmission power radiated by other coils
Solution Approach 1:
The patent incorporates a detuning circuit that can dynamically adjust the antenna's resonance characteristics in real-time. When exposure to transmitted power from other coils is detected or anticipated, the detuning circuit shifts the antenna's resonance frequency away from the transmitted frequency, reducing heat absorption while maintaining the ability to return to optimal reception tuning when needed.
Solution Approach 2:
The detuning circuit is designed to preemptively counteract the harmful thermal effects by shifting the resonance frequency before excessive heat buildup occurs. This preliminary anti-action prevents the harmful resonance condition rather than merely responding to it after the fact, allowing the coil to remain positioned close to the body for optimal signal reception while protecting against overheating.
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 coaxial cable design enables flexible molding to body parts with minimal risk of damage, while the detuning circuit and adaptation elements ensure optimal resonance and reduced heat generation, improving image quality and coil durability.
Implementation Method 1
The antenna of the local coil, which antenna is used to receive the signals during the imaging
Implementation Method 2
the further components are used, e.g., to adapt the resonance of the antenna according to the frequency of the magnetic resonance imaging
Data Source
AI summary
A local coil for magnetic resonance imaging is disclosed herein. The local coil includes an electrical circuit arrangement and a coaxial cable with an internal conductor and an external conductor surrounding the internal conductor. The two ends of the coaxial cable are connected to the electrical circuit arrangement and the internal conductor and the external conductor together form an antenna loop. The internal conductor and/or the external conductor has at least one interruption and the at least one interruption divides the internal conductor and/or the external conductor into at least two separate segments in each case.