MR RF Coil Non-Conductive Waveguides for EMI Reduction

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Solution Overview

Problem

Current digital MRI RF coils face issues with electromagnetic interference (EMI) from electrical data transmission lines, leading to image artifacts, and high costs and power consumption with fiber optic lines, which compromise operator usability and safety.

Innovation Solution

The use of non-conductive millimeter wave waveguides, specifically standard CMOS devices and plastic waveguides like PTFE, to transfer digital data between ADCs and channel aggregators, eliminating EMI and reducing costs and power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If electrical transmission lines are used to transfer digital data, then data transfer is achieved, but electromagnetic interference causes image artifacts

Engineering Contradiction:

Improveimage qualityVSAvoidelectromagnetic interference

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces electrical transmission lines with optical fiber transmission lines to transfer digital data between ADCs and channel aggregators. This substitution eliminates electromagnetic interference entirely, as optical fibers transmit data as light signals rather than electrical signals, thereby preventing image artifacts while maintaining reliable data transfer.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces optical fiber as an intermediary medium between the ADCs and channel aggregators. This intermediary transfers digital data without conducting electromagnetic signals, acting as a barrier that prevents EMI from affecting the MRI imaging process while still enabling efficient data communication.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If fiber optic transmission lines are used to transfer digital data, then electromagnetic interference is eliminated, but cost and power consumption increase

Engineering Contradiction:

Improveelectromagnetic interferenceVSAvoidcost

Core Design Contradiction:

Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The patent specifies the use of standard CMOS devices for the ADCs and channel aggregators, which are cost-effective compared to specialized high-speed ADCs. While optical fibers themselves have moderate cost, the overall system cost is reduced by using standard CMOS technology and eliminating the need for expensive EMI shielding, filtering components, and cable traps that would be required with electrical transmission lines.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Length of stationary object

If ADCs are placed close to channel aggregator, then data transfer distance is reduced, but electromagnetic interference increases

Engineering Contradiction:

Improvedata transfer distanceVSAvoidelectromagnetic interference

Core Design Contradiction:

Length of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The patent replaces electrical data transmission with optical fiber transmission, enabling ADCs to be placed in close proximity to channel aggregators without increasing EMI. The optical fiber acts as an EMI-free transmission medium, allowing short connection lengths that simplify system architecture while maintaining electromagnetic compatibility.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

4Reliability

If cable traps and shielding are used to suppress EMI, then image artifacts are reduced, but weight and thickness increase

Engineering Contradiction:

Improveimage qualityVSAvoidcoil weight

Core Design Contradiction:

ReliabilityVSWeight of moving object

Solution Approach 1:

The patent substitutes optical fiber transmission for electrical cable transmission, completely eliminating the need for cable traps, shielding, and filtering components. This substitution dramatically reduces the weight and thickness of the coil assembly, improving operator usability and patient comfort while maintaining image quality through EMI-free data transmission.

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

This solution allows ADCs to be placed closer to analog frontends without EMI issues, reduces cable weight and thickness, and lowers costs by eliminating the need for extensive shielding and high-power fiber optic connectors, enhancing usability and efficiency.

Implementation Method 1

non-conductive (e.g., PTFE) waveguides are used to transfer data between the mmWave transmitters and receivers

Methodology Applied

Scientific EffectElectromagnetic wave propagation: Electromagnetic Induction

Data Source

PatentUS11255934B2MR RF coil with non-conductive waveguides

Publication Date: 2022.02.22 CANON MEDICAL SYST CORP

AI summary

A magnetic resonance RF receive coil with non-conductive waveguides for data transfer between the RF coil antennas and the channel aggregator is described. The non-conductive waveguide for each channel includes a plastic waveguide transferring data between a millimeter wave transmitter and a millimeter wave receiver.