MRI Surface Electric Field Communication for Stable RF Coil Timing

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Solution Overview

Problem

Conventional MRI systems face challenges in stably transmitting a system clock from the main body to a wireless RF coil due to fading, and there is a need to acquire biological information like heartbeat and respiration without imposing a burden on the subject.

Innovation Solution

The MRI apparatus employs surface electric field communication using first and second communication circuitries with electrodes disposed near the object to transmit the system clock and biological information, incorporating phase fluctuation detection and correction, and biological monitoring to synchronize clocks and detect vital signs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If wireless RF coil is used to eliminate wires and improve ease of operation, then stable transmission of system clock becomes difficult due to fading effects

Engineering Contradiction:
Improvewireless operationVSAvoidsystem clock transmission stability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent introduces an electromagnetic coupling mechanism as an intermediary between the main body and RF coil. The main body generates an electromagnetic field that couples with the RF coil through this field intermediary, enabling wireless power and signal transmission without direct wire connection, thus achieving ease of operation while maintaining transmission stability through controlled field coupling.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent employs variable impedance matching and adjustable coupling parameters to optimize the electromagnetic coupling between the main body and RF coil. By dynamically adjusting electrical parameters such as impedance and coupling strength, the system maintains stable system clock transmission despite the wireless interface, resolving the reliability issue while preserving wireless operation benefits.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If surface electric field communication is used to transmit system clock wirelessly, then fading effects are eliminated and stable transmission is achieved, but device complexity increases due to additional communication circuitry

Engineering Contradiction:
Improvesystem clock transmission stabilityVSAvoidcommunication circuitry
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent designs the electromagnetic coupling system to serve multiple functions simultaneously: it transmits both power and system clock signals, and enables both communication and synchronization. By making the communication circuitry multi-functional, the patent reduces the need for separate dedicated components, thereby limiting the increase in device complexity while achieving stable wireless transmission.

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

Solution Approach 2:

The patent combines the system clock transmission function with the existing electromagnetic coupling infrastructure. Instead of adding completely separate communication hardware, the system merges clock signal transmission with the power and data communication channels, reducing overall device complexity while ensuring reliable clock synchronization.

Inventive Principle:
Principle #5Merging (Combining)

3Loss of information

If biological information monitoring is added to acquire heartbeat and respiration data, then valuable physiological information is obtained, but the object is burdened with additional sensors and processing

Engineering Contradiction:
Improvebiological information acquisitionVSAvoidburden on object
Core Design Contradiction:
Loss of informationVSObject-affected harmful factors

Solution Approach 1:

The patent implements self-service monitoring where the RF coil system automatically detects and processes biological information without requiring separate sensors on the object. The electromagnetic field interactions during normal MRI operation naturally provide physiological data, and the system autonomously extracts heartbeat and respiration information from these field variations, eliminating the need for additional burdening components on the subject.

Inventive Principle:
Principle #25Self-service

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

Stable wireless transmission of the system clock is achieved, and biological information is acquired without burdening the subject, enabling synchronized processing and motion correction in MR image reconstruction.

Implementation Method 1

a first communication circuitry configured to transmit a system clock to a second communication circuitry through surface electric field communication

Methodology Applied
Scientific EffectSurface electric field communication: Electric Field

Implementation Method 2

the second communication circuitry is configured to detect a phase fluctuation of the received system clock

Methodology Applied
Scientific EffectPhase fluctuation detection:

Implementation Method 3

magnetic resonance imaging (MRI) apparatus... magnetically excites nuclear spin of an object placed in a static magnetic field by applying a radio frequency (RF) pulse having the Larmor frequency and reconstructs an image on the basis of magnetic resonance (MR) signals

Methodology Applied
Scientific EffectMagnetic resonance: Resonance

Data Source

PatentEP3709041B1Magnetic resonance imaging apparatus with surface electric field communication
Publication Date: 2025.08.27 CANON MEDICAL SYST CORP
  • EP3709041B1 patent drawingFigure 1
  • EP3709041B1 patent drawingFigure 2A~2B
  • EP3709041B1 patent drawingFigure 3

AI summary

A Magnetic Resonance Imaging, MRI, apparatus (1) includes: an RF coil (20) configured to perform A/D conversion on a magnetic resonance, MR, signal received from an object and wirelessly transmit the MR signal; a main body (600) configured to wirelessly receive the MR signal and generate a system clock; first communication circuitry (100) configured to transmit the system clock by surface electric field communication using electric field propagation along a body surface of the object; and second communication circuitry (200) provided in the RF coil (20) and configured to receive the system clock transmitted by the surface electric field communication, wherein the RF coil (20) is configured to operate based on the received system clock.