RF Antenna Element with Optical Detuning for MRI Noise Reduction

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Magnetic resonance imaging (MRI) RF antenna elements face challenges in noise characteristics, particularly during the transmission of strong RF excitation fields, which can damage sensitive electronics and affect signal-to-noise ratios.

Innovation Solution

A radio frequency (RF) antenna element with an optically detuning system using a photosensitive switching element, coupled with an injection optical source, allows the antenna to switch between resonant and non-resonant states, protecting electronics during strong RF field applications and enhancing signal reception by reducing thermal noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the RF antenna element remains resonant during RF excitation transmission, then signal reception sensitivity is improved, but thermal noise increases and electronics are damaged

Engineering Contradiction:

Improvesignal-to-noise ratioVSAvoidthermal noise and RF field damage

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent implements dynamic switching between resonant and non-resonant states using a photosensitive switching element that responds to optical signals. During RF excitation transmission, the antenna is dynamically switched to non-resonant state to reduce thermal noise and protect electronics. During signal reception, it is switched back to resonant state to maximize sensitivity, thus resolving the contradiction between signal reception quality and noise reduction.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent introduces an optical intermediary (injection optical source and photosensitive switching element) to control the electrical state of the antenna. This optical mediator enables rapid, contactless switching between resonant and non-resonant states, allowing the system to avoid direct electrical contact during high-power RF transmission while maintaining precise control over antenna impedance, thereby protecting electronics and reducing noise.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If the RF antenna element is detuned during RF excitation transmission, then electronics are protected from damage, but signal reception sensitivity decreases

Engineering Contradiction:

Improveelectronics protectionVSAvoidsignal reception sensitivity

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The patent employs periodic switching between resonant and non-resonant states synchronized with the MRI pulse sequence timing. During RF excitation transmission phases, the antenna is periodically switched to non-resonant state for protection. During signal acquisition phases, it is periodically switched to resonant state for optimal sensitivity. This time-dependent periodic action resolves the contradiction by applying the appropriate state at the appropriate time.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The dynamic control of antenna impedance through optical switching enables the system to adapt its resonant properties in real-time according to the operational phase. The photosensitive switching element provides rapid transition between states, ensuring electronics are protected during high-power transmission while maintaining maximum signal reception sensitivity during acquisition phases.

Inventive Principle:

Principle #15Dynamics

3Speed

If a photosensitive switching element is used for detuning, then switching speed is improved, but device complexity increases

Engineering Contradiction:

Improveswitching speedVSAvoidoptical coupling system

Core Design Contradiction:

SpeedVSDevice complexity

Solution Approach 1:

The patent replaces traditional mechanical or electrical switching mechanisms with an optical switching system. The injection optical source and photosensitive switching element provide contactless, high-speed switching without mechanical wear or electrical arc damage. This substitution achieves rapid switching speeds while the optical coupling infrastructure, though added, eliminates the need for complex high-power electrical switches and their associated cooling and protection systems.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 improves noise characteristics and increases signal-to-noise ratios by dynamically detuning the RF antenna element during strong RF field applications, while ensuring sensitivity during weak signal reception, thus enhancing the quality of magnetic resonance signals.

Implementation Method 1

a (de)tuning system including a photosensitive switching element to (de)tune the resonant electrically conductive loop and the (de)tuning system comprises an injection optical source optically coupled to the photosensitive switching element

Methodology Applied

Scientific EffectPhotoelectric Effect: Photoelectric Effect

Data Source

PatentUS11243279B2Radio frequency (RF) antenna element with a (de) tuning system

Publication Date: 2022.02.08 KONINKLIJKE PHILIPS NV

AI summary

A radio frequency (RF) antenna element with a (de)tuning system, with the RF antenna element having a resonant electrically conductive loop and a (de)tuning system including a photosensitive switching element to (de)tune the resonant electrically conductive loop. The (de)tuning system comprises an injection optical source optically coupled to the photosensitive switching element.