Magnetic Coil Valve Adjustment for MRI-Resistant Rotor Control
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Solution Overview
Problem
Current adjustable shunt valves for managing cerebrospinal fluid in patients, such as those used in hydrocephalus treatment, are prone to unintentional setting changes due to external magnetic fields and lack accuracy in setting detection and adjustment, especially under strong MRI fields.
Innovation Solution
A tool with circumferentially distributed magnetic coils that can move along the circumference to attract or repel rotor magnets, allowing for precise adjustment of valve settings without altering existing settings, even under strong magnetic fields, by inducing a rotating moment in the rotor and utilizing a plurality of magnetic coil pairs to radially attract or repulse the rotor within a predetermined angle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a magnetic sensor is used to detect rotor position for valve setting detection, then non-invasive detection is enabled, but strong magnetic fields from MRI machines can interfere with the magnetic sensor and cause unintentional setting changes
Solution Approach 1:
The patent replaces the magnetic sensor-based detection system with an impedance-based electrical measurement system. The rotor includes electrical contacts that connect to different traces on a circuit board depending on rotor position, and the setting detection device measures impedance changes across these traces to determine valve setting. This electrical measurement approach is immune to MRI magnetic field interference while maintaining non-invasive detection capability.
Solution Approach 2:
The patent introduces an intermediary mechanism where the rotor position is indirectly detected through impedance measurements rather than directly through magnetic fields. The circuit board traces and electrical contacts serve as intermediaries that translate mechanical rotor position into electrical impedance variations, which can then be measured without being affected by external magnetic fields.
2Device complexity
If a single magnetic coil is used for rotor adjustment, then device simplicity is maintained, but precise control and accurate setting adjustment are compromised
Solution Approach 1:
The patent divides the single magnetic coil into multiple discrete magnetic coils (first magnetic coil and second magnetic coil) positioned at different angular locations around the rotor. Each coil independently influences the rotor at different positions, enabling precise control of rotor orientation and accurate setting adjustment through coordinated activation of multiple coils rather than a single 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
The solution effectively resists unintentional setting changes and provides accurate, non-invasive adjustment of valve settings, ensuring reliable operation even under strong magnetic fields, such as those from modern MRI machines, while minimizing the need for precise alignment and user expertise.
Implementation Method 1
A plurality of magnetic coils are circumferentially distributed on the circumference of the tool. Each magnetic coil is operable to activate and attract or repulse the at least one rotor magnet
Implementation Method 2
Each magnetic coil is operable to activate and attract or repulse the at least one rotor magnet
Implementation Method 3
by inducing a rotating moment in the rotor and utilizing a plurality of magnetic coil pairs to radially attract or repulse the rotor within a predetermined angle
Data Source
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AI summary
A setting adjustment tool 700 for a magnetically adjustable device implanted in a patient includes a circumference. A plurality of magnetic coils 770, 772, 774, 776 can be circumferentially distributed on a circumference of the tool. One of the magnetic coils can be movable along the circumference between a plurality of predetermined positions associated with the selectable performance settings. The magnetic coils may also be capable of attracting or repulsing the at least one magnet 123b, 125b of the rotor of the implanted device in a radial direction by at least a predetermined angle within a plane of rotation of an at least one magnet of the rotor thereby inducing a rotating moment into the rotor.