Magnetic Biopsy Marker Geometry for Uniform Localization Response
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Solution Overview
Problem
Current magnetic biopsy markers face challenges such as limited magnetic response due to size constraints, non-uniform magnetic response due to aspect ratio, and difficulty in being clearly visible under X-ray and ultrasound imaging.
Innovation Solution
The development of magnetic markers with a non-spherical configuration and specific material compositions that provide a more uniform magnetic response, including shapes that change configuration upon deployment and materials with high magnetic mass susceptibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the marker size is increased to maximize magnetic response volume, then the magnetic response strength is improved, but the needle diameter constraint is violated and delivery difficulty increases
Solution Approach 1:
The marker is designed with a nested structure where an inner core is surrounded by an outer layer. This allows maximizing the use of space within the needle constraint, fitting more magnetic material into a compact overall dimension while maintaining deliverability through narrow gauge needles
Solution Approach 2:
The invention transitions from traditional linear/rod-shaped markers to three-dimensional spherical or near-spherical markers. This dimensional change allows achieving maximum volume within the needle diameter constraint, as a sphere provides the largest volume for a given surface area, thereby maximizing magnetic response while maintaining compact size for delivery
2Quantity of substance
If the marker has a high aspect ratio (length significantly greater than diameter) to maximize volume, then the magnetic response strength is improved, but the magnetic response uniformity deteriorates
Solution Approach 1:
The marker is designed with a spherical or near-spherical geometry rather than a high aspect ratio cylindrical shape. This spheroidal form ensures uniform magnetic response from all directions, eliminating the directional dependence inherent in elongated shapes while still achieving maximum volume within the needle delivery constraint
Solution Approach 2:
The marker employs a layered structure with different materials in the inner core and outer layer, each optimized for specific functions. This local differentiation allows the inner core to provide concentrated magnetic response while the outer layer contributes to overall uniformity and imaging visibility, achieving both strong and uniform magnetic signal
3Ease of operation
If the needle diameter is kept narrow to minimize patient discomfort, then patient comfort is improved, but the marker cross section is constrained and magnetic response is reduced
Solution Approach 1:
The nested core-layer structure allows maximizing material utilization within the narrow needle bore. By concentrically arranging magnetic material in multiple layers around a central core, the design achieves maximum volume packing efficiency, thereby maximizing magnetic response despite the constraint of narrow needle diameter for patient comfort
Solution Approach 2:
The marker uses composite construction with an inner core material and an outer layer material, each selected for optimal magnetic properties. This composite approach allows achieving superior magnetic response from a smaller overall volume, enabling effective magnetic signaling through narrow needles while maintaining patient comfort
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
These markers achieve a more uniform magnetic response from any direction, improving localization accuracy and visibility under various imaging modalities while maintaining a compact size for easy delivery.
Implementation Method 1
magnetic markers are also used... they overcome the inconvenience and logistical challenges that arise by using a radioactive material as a marker
Data Source
AI summary
A magnetic marker for marking a site in tissue in the body. In one embodiment, the marker comprises a magnetic metallic glass. In another embodiment, the marker is in a non-spherical configuration having an anisotropy ratio less than 9. In yet another embodiment, the marker is in a non-spherical configuration having an anisotropy ratio less than 6. In yet another embodiment, the marker is in a non-spherical configuration having an anisotropy ratio less than 3.