MRI Gradient Coil Vacuum Chamber Noise Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional magnetic resonance imaging (MRI) systems face challenges in reducing noise propagation to patients due to sound generated by gradient coils, which is not effectively mitigated by existing vacuum sealing techniques that require complex configurations and hermetic sealing of all spaces.
Innovation Solution
The MRI apparatus configures a vacuum state only in the space between the gradient coil and the bore tube, using annular-shaped vacuum sealing members and a vacuum pump to isolate and evacuate this area, while maintaining air in the space between the gradient coil and the magnetostatic field magnet, thereby reducing noise propagation without the need for hermetic sealing of the latter space.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the gradient coil is arranged in a hermetically-sealed container to bring the space into a vacuum state, then noise propagation to the patient is reduced, but the device complexity and manufacturing cost increase
Solution Approach 1:
The patent divides the internal space into two separate vacuum chambers: a first vacuum chamber between the gradient coil and bore tube, and a second vacuum chamber between the gradient coil and magnetostatic field magnet. This segmentation allows selective vacuum application to only the noise-critical first chamber, reducing the complexity of hermetic sealing while maintaining noise reduction effectiveness.
Solution Approach 2:
The patent applies vacuum conditions locally only in the first space between the gradient coil and bore tube where noise propagation occurs, rather than creating a vacuum throughout the entire gradient coil assembly. This localized approach reduces the extent of hermetic sealing required while achieving the noise reduction goal.
2Object-affected harmful factors
If the entire space around the gradient coil is evacuated, then noise reduction is achieved, but the vacuum pump load and maintenance requirements increase
Solution Approach 1:
The patent segments the vacuum environment into two separate chambers with different vacuum levels. The first chamber (between gradient coil and bore tube) maintains a vacuum to block noise, while the second chamber (between gradient coil and magnet) remains at atmospheric pressure. This reduces the overall volume requiring vacuum maintenance, decreasing pump load and maintenance requirements.
Solution Approach 2:
The patent applies vacuum conditions only in the specific local region where noise propagation occurs (first space), rather than evacuating the entire gradient coil surroundings. This localized vacuum application minimizes the quantity of air to be removed and maintained, reducing vacuum pump load.
3Object-affected harmful factors
If hermetic sealing is applied to all spaces, then complete noise isolation is achieved, but the ease of manufacture and assembly deteriorates
Solution Approach 1:
The patent divides the sealing requirements into two separate sealing interfaces: one for the first vacuum chamber and another for the second chamber. This segmentation simplifies manufacturing by allowing each sealing interface to be designed and assembled independently, reducing overall assembly complexity compared to a single hermetic seal around the entire gradient coil.
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 efficiently blocks air-propagated noise from the gradient coil to the patient, reduces the complexity and cost of the system, and simplifies maintenance by minimizing the load on the vacuum pump, while maintaining effective noise reduction with fewer components.
Implementation Method 1
A first space between the gradient coil and the bore tube is configured to be kept in a vacuum state
Data Source
AI summary
A magnetic resonance imaging apparatus according to an embodiment includes a magnetostatic field magnet, a gradient coil, and a bore tube. The magnetostatic field magnet is formed to have a cylindrical shape. The gradient coil is formed to have a cylindrical shape, on the inside of the magnetostatic field magnet. The bore tube is formed to have a cylindrical shape, on the inside of the gradient coil. A first space between the gradient coil and the bore tube is configured to be kept in a vacuum state while a second space between the gradient coil and the magnetostatic field magnet is configured to be kept in a state not being a vacuum.