NMR Sample Vessel with Susceptibility-Matched Boundaries
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional NMR sample containers cause magnetic field distortions due to their design, leading to reduced measurement quality and inefficient use of sample volume, especially when a small amount of sample is available, as they require a significant portion of the sample to be diluted to fill the container, resulting in a compromised signal-to-noise ratio.
Innovation Solution
The sample container is designed with outer and inner boundary surfaces that minimize magnetic field inhomogeneities by carefully matching their shapes and susceptibility jumps, ensuring that the relative field changes caused by these interfaces cancel each other out, allowing for a more compact construction and improved homogeneity of the magnetic field within the sample volume.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the sample container uses a conventional design with a bowl-shaped end section and uniform wall thickness, then the container structure is simple to manufacture, but strong magnetic field distortions occur in the measurement area
Solution Approach 1:
The patent applies local quality by differentiating the wall thickness of the sample container: the cylindrical section has a first wall thickness while the end section has a second wall thickness that differs from the first. This localized variation in wall thickness compensates for magnetic field distortions in the end section without complicating the overall manufacturing process, thereby maintaining ease of manufacture while improving magnetic field homogeneity in the measurement area.
2Measurement precision
If the lower end of the sample container is positioned far from the measurement area to avoid field distortions, then magnetic field homogeneity is improved, but the available sample volume for measurement is reduced
Solution Approach 1:
The patent changes the geometric parameters of the sample container, specifically the wall thickness distribution and end section shape, to reduce magnetic field distortions. This allows the lower end of the container to be positioned closer to the measurement area without compromising field homogeneity, thereby increasing the usable sample volume while maintaining measurement precision.
3Measurement precision
If the sample container material is selected to match the magnetic susceptibility of the liquid sample, then field distortions are reduced, but material selection becomes difficult and expensive
Solution Approach 1:
The patent applies local quality by varying the wall thickness in the end section rather than changing the material composition throughout. This allows the container to be made from a single material type (maintaining versatility and ease of selection) while achieving reduced field distortions through localized geometric modification, avoiding the need to match material magnetic susceptibility to the sample.
4Measurement precision
If the inner boundary surface is designed with a rotationally ellipsoidal shape to reduce distortions, then magnetic field homogeneity is improved, but the container geometry becomes more complex
Solution Approach 1:
The patent employs spheroidality by designing the end section with a curved, rotationally symmetric shape that approximates an ellipsoid. This curved geometry reduces magnetic field distortions at the container ends while maintaining rotational symmetry, which simplifies manufacturing compared to asymmetric designs and avoids excessive geometric complexity while still improving field homogeneity.
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 design significantly improves NMR measurement quality by allowing a larger portion of the sample volume to be used effectively, reducing the need for sample dilution and enhancing the signal-to-noise ratio, while also enabling a more compact and efficient sample container geometry.
Implementation Method 1
the outer boundary surface, including the shape of the outer end surface, and the inner boundary surface, including the shape of the inner end surface, are designed in such a way that when an outer, homogeneous magnetic field B0 parallel to the z-axis applies: due to the susceptibility jump from χ1 to χ2 in the area of the sample volume, the outer interface causes a field Bz(1)
Data Source
Figure 1
Figure 2a~2c
Figure 3
AI summary
The vessel (80) has an outer interface (82) that limits the vessel with respect to an environment (85) and includes an outer cylindrical surface (81) shaped as cylinder envelope with an axis of symmetry which is aligned parallel to a z-direction. An outer closing surface closes the vessel at a lower end and is contiguous to the outer cylindrical surface. An inner interface (84) limits the vessel with respect to a sample volume, and has an inner cylindrical surface (83) shaped as a cylinder envelope with an axis of symmetry which is aligned parallel to the z-direction. An independent claim is also included for a method for determining a shape of outer and inner interfaces of the sample vessel.