MRI RF Coil Impedance Matching via Switchable Ports

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Solution Overview

Problem

Magnetic Resonance Imaging (MRI) systems face high costs due to expensive components in the impedance matching network for radio-frequency (RF) coils, which also consume significant power during scans.

Innovation Solution

The system controls the number of RF ports to which RF power is supplied, allowing for dynamic impedance matching without a full impedance matching network, using multiple switchable RF ports to adjust the current-voltage relationship and reduce the need for expensive components like circulators.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a full impedance matching network with expensive components like circulators is used, then reliable impedance matching is achieved, but manufacturing cost increases

Engineering Contradiction:
Improveimpedance matching reliabilityVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent extracts and removes expensive components (circulators and full impedance matching networks) from the MRI system by utilizing the intrinsic multiple RF ports of the coil assembly. The coil assembly's own ports are used to provide impedance matching functionality, eliminating the need for separate expensive matching components while maintaining reliable impedance matching performance.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If a full impedance matching network is used, then proper impedance matching is achieved, but power consumption increases

Engineering Contradiction:
Improveimpedance matching qualityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent eliminates power-hungry impedance matching networks and circulators by using the coil assembly's inherent multiple RF ports. This extraction of the matching function from separate active components to the passive coil structure itself dramatically reduces power consumption while maintaining proper impedance matching quality.

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of manufacture

If multiple RF ports are used to reduce components, then cost and power consumption decrease, but system complexity increases

Engineering Contradiction:
Improvemanufacturing costVSAvoidsystem complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent makes the coil assembly multi-functional by equipping it with multiple RF ports that simultaneously serve both as signal transmission channels and as impedance matching elements. This universality allows the same component (coil assembly) to perform multiple functions, reducing overall system complexity despite the added ports, because no separate matching network is needed.

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Reliability

If expensive components are used in the impedance matching network, then matching performance is improved, but overall system cost increases

Engineering Contradiction:
Improvematching performanceVSAvoidsystem cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces expensive, fragile components like circulators with simpler, more robust alternatives - the inherent RF ports of the coil assembly. These ports provide the same impedance matching function but are cheaper, more durable, and require no additional expensive components, thereby improving matching performance while reducing system cost.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Data Source

PatentEP3523667B1Impedance matching using multiple RF ports
Publication Date: 2022.07.20 KONINKLIJKE PHILIPS NV
  • EP3523667B1 patent drawingFigure 1
  • EP3523667B1 patent drawingFigure 2~3
  • EP3523667B1 patent drawingFigure 4~5

AI summary

The invention provides for a magnetic resonance imaging system (100) comprising a main magnet (104) for generating a main magnetic field within an imaging zone (108). The magnetic resonance imaging system further comprises an RF coil (114) for acquiring magnetic resonance data (164) from the imaging zone, wherein the RF coil comprises multiple RF ports (124, 412, 414, 416, 500, 502, 702, 1004, 1006). The RF coil comprises a switch unit (120) for at least one of the multiple RF ports to individually couple or uncouple the at least one of of the multiple RF ports from the RF coil. The magnetic resonance imaging system further comprises a radio-frequency system (125) for supplying radio-frequency power to each of the multiple RF ports and an RF matching detection system (122) for measuring impedance matching data (166) between the radio-frequency system and the RF coil. Execution of the machine executable instructions causes a processor controlling the magnetic resonance imaging system to measure (200, 300, 302, 304) the impedance matching data using the RF matching detection system; determine (202) switch unit control instructions (168) using the impedance matching data, wherein the switch control instructions contain commands that control the at least one of the multiple RF ports to couple or decouple to impedance match the radio-frequency system to the RF coil; and control (204) the switch unit of the at least one of the multiple RF ports with the switch unit control instructions.