MRI Vacuum Chamber Load Assembly for Compact Magnet Ramp-Down

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Solution Overview

Problem

Existing magnetic resonance imaging (MRI) systems with high magnetic field strengths face challenges due to large and heavy aluminum storage units required for energy dissipation during power or cooling failures, which occupy valuable space, cause transport difficulties, and alter dynamic vibration behavior.

Innovation Solution

The magnetic resonance system incorporates a load assembly within an external vacuum chamber, utilizing diodes and resistors to convert current into heat, with a heat storage device and a cooling circuit, allowing for compact design and efficient energy dissipation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If aluminum storage units are used for energy dissipation during ramp-down, then the magnetic field energy can be absorbed, but the storage units become large and heavy, occupying valuable space and causing transport difficulties

Engineering Contradiction:
Improveenergy dissipation capabilityVSAvoidweight of aluminum storage unit
Core Design Contradiction:
ReliabilityVSWeight of stationary object

Solution Approach 1:

The patent changes the temperature parameter by which the heat storage device operates. Instead of using room-temperature aluminum storage units, the invention uses a heat storage device that operates at cryogenic temperatures (4K), utilizing the extremely low temperature environment already present in the vacuum chamber. This parameter change allows for much smaller and lighter storage capacity while maintaining the same energy dissipation capability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent makes the vacuum chamber serve multiple functions: it simultaneously provides vacuum isolation for the superconducting magnet AND houses the heat storage device for energy dissipation. By making the vacuum chamber multi-functional, the invention eliminates the need for separate large aluminum storage units outside the chamber, thereby reducing weight and space requirements.

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

2Reliability

If aluminum storage units are used for energy dissipation, then the magnetic field energy can be absorbed, but the storage units occupy valuable space on the magnet that is needed for electronics

Engineering Contradiction:
Improveenergy dissipation capabilityVSAvoidspace occupied by storage unit
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The patent merges the heat storage device with the vacuum chamber structure. The heat storage device is integrated into the vacuum chamber rather than being a separate external component. This merging allows the same space to serve dual purposes: maintaining vacuum for superconductivity and storing thermal energy, thereby eliminating the need for additional space that would be required for separate aluminum storage units.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

By changing the operating temperature parameter to cryogenic levels, the patent dramatically reduces the volume required for heat storage. The heat capacity of materials at 4K is much lower than at room temperature, allowing the same energy to be stored in a much smaller volume, thus freeing up space for electronic components.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If large aluminum masses are distributed asymmetrically for accessibility, then service technicians can access the components, but the dynamic vibration behavior (floor-born vibrations) is altered

Engineering Contradiction:
Improveaccessibility for maintenanceVSAvoidvibration behavior
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The patent extracts the heat storage function from separate large aluminum masses and integrates it into the vacuum chamber structure itself. By taking out the need for external storage units and incorporating the thermal storage capability into the existing vacuum chamber, the invention eliminates the asymmetric mass distribution problem while maintaining accessibility for maintenance activities.

Inventive Principle:
Principle #2Taking out (Extraction)

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 configuration reduces space requirements, minimizes weight, and enhances transportability while ensuring rapid magnet recovery after power or cooling failures by utilizing the vacuum chamber's space efficiently.

Implementation Method 1

a superconducting magnet coil assembly (3), arranged in a cryoshield (12) within an outer vacuum chamber (11)

Methodology Applied
Scientific EffectSuperconductivity: Superconductivity

Implementation Method 2

The first load unit (17) comprises a first diode arrangement (18) and/or a first resistor arrangement

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 3

a cooling circuit (21) within the outer vacuum chamber (11), to which the first load unit (17) is connected for cooling

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 4

a cryoshield (12) within an outer vacuum chamber (11), wherein a vacuum is provided between the outer vacuum chamber and the cryoshield to largely prevent heat transfer

Methodology Applied
Scientific EffectVacuum insulation: Vacuum

Data Source

PatentEP4386412B1Magnetic resonance system with heat sink in an outer vacuum chamber
Publication Date: 2026.04.08 SIEMENS HEALTHINEERS AG
  • EP4386412B1 patent drawingFigure 1
  • EP4386412B1 patent drawingFigure 2

AI summary

The cooling of a magnetic resonance system (1) is to be implemented in a more cost-effective and space-saving manner. For this purpose, a magnetic resonance system (1) is proposed comprising a superconducting magnet coil assembly (3), an outer vacuum chamber (11) in which the superconducting magnet coil assembly (3) is arranged, and a first load assembly (17) for ramping down the superconducting magnet coil assembly (3) by introducing electric current from the magnet coil assembly (3) into the first load assembly (17). The first load assembly (17) is arranged within the outer vacuum chamber (11).