Parallel Plate Waveguide EPRI System for Uniform RF Field Generation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electron paramagnetic resonance imaging (EPRI) is limited to small-animal imaging due to short signal lifetimes and challenges in creating uniform magnetic fields at higher frequencies necessary for clinical applications, which affects sensitivity and tissue penetration.
Innovation Solution
The use of antennas and magnetic field generators operating in a traveling wave regime to improve RF penetration uniformity, allowing for higher frequency operation without the limitations of traditional systems, including the implementation of a parallel plate waveguide to generate a uniform RF magnetic field over a volume of interest.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If higher RF/microwave frequencies are used to achieve desired sensitivity, then sensitivity is improved, but uniform magnetic field creation and tissue penetration become challenging
Solution Approach 1:
The patent changes the operating regime from traditional resonant systems to traveling wave systems, fundamentally altering how RF fields are generated. This parameter change enables higher frequencies to be used while maintaining uniform magnetic field distribution across the imaging volume, thus improving sensitivity without sacrificing field uniformity
Solution Approach 2:
The patent replaces traditional resonant cavity systems with transmission line-based traveling wave systems. This substitution eliminates the resonant frequency constraints and standing wave patterns that cause non-uniform fields, allowing higher frequencies to be used for improved sensitivity while maintaining field uniformity through the traveling wave mechanism
2Measurement precision
If higher RF/microwave frequencies are used to achieve desired sensitivity, then sensitivity is improved, but tissue penetration is reduced
Solution Approach 1:
By changing from resonant to traveling wave operation, the system can penetrate deeper into tissue at higher frequencies. The traveling wave regime distributes energy more uniformly through the tissue volume without the skin effect and standing wave patterns that limit penetration in traditional systems, thus improving both sensitivity and penetration simultaneously
3Measurement precision
If higher magnetic field strengths are used to improve sensitivity, then sensitivity is improved, but tissue heating increases
Solution Approach 1:
The patent replaces resonant cavity heating with traveling wave energy distribution. The traveling wave system delivers RF energy more efficiently and uniformly through the tissue, reducing localized heating while maintaining the high magnetic field strengths needed for sensitivity. This substitution allows higher fields to be used without proportionally increasing tissue heating
4Device complexity
If traditional magnetic field generation systems are used, then system simplicity is maintained, but RF penetration uniformity is poor
Solution Approach 1:
The patent substitutes traditional resonant magnetic field generation with transmission line-based traveling wave generation. This substitution creates uniform RF penetration through the tissue volume by eliminating standing wave patterns and resonant hot spots, achieving reliable uniform penetration while using relatively simple transmission line structures
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
This approach enables uniform magnetic field distribution over larger volumes, increasing sensitivity and allowing for higher magnetic field strengths, making EPRI suitable for human and veterinary imaging applications while reducing tissue heating and improving image acquisition times.
Implementation Method 1
a transmission line configured to use a traveling wave to generate a radio frequency (RF) magnetic field
Implementation Method 2
generate a radio frequency (RF) magnetic field
Implementation Method 3
a magnet configured to apply a static magnetic field to a subject to be imaged
Implementation Method 4
a gradient coil configured to apply a magnetic field gradient to the static magnetic field
Implementation Method 5
to elicit electron paramagnetic resonance (EPRI) data from the VOI
Data Source
AI summary
A system and method for an electron paramagnetic resonance imaging (EPRI) system includes a magnet configured to apply a static magnetic field to a subject to be imaged and a gradient coil configured to apply a magnetic field gradient to the static magnetic field. The system also includes a parallel plate waveguide (PPWG) configured to use a traveling wave to generate a radio frequency (RF) magnetic field over a volume of interest (VOI) in the subject to elicit EPRI data from the VOI and a processor configured to reconstruct the EPRI data into an image of the VOI.