MRI Receiver Clock Generation for Distributed RF Coil Digitization

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Solution Overview

Problem

Current MRI systems face challenges with complex and costly analogue designs, electromagnetic interference, and inefficient workflow due to the need for extensive galvanic connections between MR receive chains and analogue to digital converters, which affects image quality and patient throughput.

Innovation Solution

A nuclear magnetic resonance imaging radio frequency receiver with an analogue to digital converter integrated within the coil unit, utilizing a digital interface and clock generators to produce high-quality sampling and system clocks from a digital timing reference, allowing for resampling and demodulation, and enabling daisy chaining of receivers to reduce wiring and enhance signal quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If analogue to digital converters are placed close to RF coils with extensive galvanic connections, then signal conversion quality is improved, but device complexity and electromagnetic interference increase

Engineering Contradiction:
Improvesignal conversion qualityVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system is divided into multiple independent receiver units, each with its own ADC and clock generator. This segmentation allows each unit to operate independently with minimal interconnections, reducing overall system complexity while maintaining high conversion quality at each node.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A digital timing reference signal acts as an intermediary to synchronize clock generators across distributed receiver units. This mediator enables coordinated operation without requiring extensive galvanic connections, resolving the contradiction between conversion quality and system complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If extensive galvanic connections are used between receive chains and ADCs, then signal transmission is achieved, but electromagnetic interference and image quality degradation occur

Engineering Contradiction:
Improvesignal transmissionVSAvoidelectromagnetic interference
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces extensive galvanic (mechanical/electrical) connections with wireless or minimal digital connections. By substituting the physical connection mechanism with digital signal transmission synchronized by timing references, it maintains signal transmission reliability while eliminating electromagnetic interference from cables.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The ADC and clock generation functionality are extracted and placed within each receiver unit near the coil elements. This extraction eliminates the need for long galvanic connections between central ADCs and distributed coils, removing the source of electromagnetic interference while preserving signal integrity.

Inventive Principle:
Principle #2Taking out (Extraction)

3Adaptability or versatility

If multiple individual coils are combined using state of the art wire technology, then coil element integration is achieved, but device complexity and cable clutter increase

Engineering Contradiction:
Improvecoil element integrationVSAvoidcable clutter
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

Each coil element is paired with its own ADC and clock generator in separate receiver units. This segmentation allows multiple coils to operate independently with minimal wiring, achieving high adaptability while reducing cable clutter compared to centralized combining approaches.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The receiver units are designed with universal interfaces that can handle multiple coil elements. Each unit can process signals from different coil configurations, providing adaptability without requiring complex dedicated wiring for each coil combination scenario.

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

4Productivity

If receiver units are distributed in examination room with digital interface, then patient comfort and workflow efficiency are improved, but clock synchronization becomes more challenging

Engineering Contradiction:
Improveworkflow efficiencyVSAvoidclock synchronization
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

A digital timing reference signal serves as an intermediary to synchronize clock generators across distributed receiver units. This mediator enables precise clock synchronization even when units are physically distributed throughout the examination room, supporting improved workflow efficiency without sacrificing synchronization accuracy.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP2223136B1Improved clock generation in MRI receivers
Publication Date: 2011.05.04 KONINKLIJKE PHILIPS NV
  • EP2223136B1 patent drawingFigure 1
  • EP2223136B1 patent drawingFigure 2
  • EP2223136B1 patent drawingFigure 3

AI summary

The invention relates to a nuclear magnetic resonance imaging radio frequency receiver, the receiver being adapted to receive analogue signals from at least one radio frequency receiver coil unit (122; 204; 306), the radio frequency receiver comprising an analogue-digital converter (408) to convert the analogue magnetic resonance signal into a first digital signal, a resampling and demodulation unit (414) to convert the first digital signal into a second digital signal, a communication interface (400: 600; 602) adapted for transmitting the second digital signal via a communication link (202), and a first clock generator (406) for generating a sampling clock, the sampling clock being the direct clock source for the analogue-digital converter (408), the first clock generator (406) being adapted to generate the sampling clock using a digital timing reference, the digital timing reference being received digitally via the communication link (202) by the communication interface (400: 600; 602), wherein the receiver further comprises a second clock generator (410) for generating a system clock, the system clock being the direct clock source for the resampling and demodulation unit (414), the second clock generator (410) being adapted to generate the system clock using the sampling clock.