MR Local Coil Position Tracking Using Acceleration Sensors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for determining the position and orientation of MR local coil units in magnetic resonance tomography systems, especially in MR-PET imaging, are complex and costly, particularly when the coil units are flexibly arranged, as they require multiple sensors and can interfere with image quality and attenuation correction.
Innovation Solution
A method using a reference sensor system and an acceleration sensor spaced apart in a fixed relative position, calculating the position and orientation of the MR local coil unit by providing a first 3D relative position, retrieving an acceleration vector, and compensating for curvature using a correction value generated by an artificial system, thereby reducing the need for additional complex sensors and improving accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If markers are installed in the MR local coil unit to detect position, then the position can be determined, but the markers can interfere with image quality and require additional complex sensor systems
Solution Approach 1:
The patent extracts the position determination function from complex external marker systems and integrates it into the MR local coil unit itself using simple acceleration sensors. The acceleration sensors are embedded directly in the coil unit to detect gravitational acceleration, eliminating the need for separate marker detection systems while maintaining position measurement capability.
Solution Approach 2:
The patent replaces complex mechanical/optical marker systems with acceleration-based sensing. Instead of using visible or infrared markers that require camera systems, the invention uses acceleration sensors to detect gravitational field changes, substituting a simple mechanical sensing approach for complex optical-mechanical systems.
2Measurement precision
If multiple sensors are provided in the MR local coil unit to ascertain position, then position determination is possible, but the technical complexity and costs increase
Solution Approach 1:
The acceleration sensor serves multiple functions: it determines both the position and orientation of the MR local coil unit by detecting gravitational acceleration components. A single sensor type performs what would traditionally require multiple different sensor systems, achieving multi-functionality with a single component.
Solution Approach 2:
The patent changes the measurement parameter from optical/marker-based detection to acceleration-based detection. By measuring gravitational acceleration components along different axes, the system derives position and orientation information through parameter transformation, reducing the number of physical sensors needed.
3Adaptability or versatility
If the MR local coil unit is flexibly arranged on the examination object, then adaptability is improved, but the position determination becomes more challenging
Solution Approach 1:
The MR local coil unit determines its own position and orientation autonomously using integrated acceleration sensors. The sensors continuously monitor gravitational acceleration, and the control unit calculates position and orientation changes based on these measurements, enabling the flexible unit to self-correct and track its position without external intervention.
Solution Approach 2:
The system implements continuous feedback by constantly monitoring acceleration sensor readings and comparing them against reference values. The control unit processes these feedback signals to determine current position and orientation, enabling real-time adjustment and maintaining accurate position awareness despite flexible movement.
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 approach simplifies the determination of the MR local coil unit's position and orientation, reduces technical complexity and costs, and enhances image quality by eliminating the need for potentially damaging markers and improving the accuracy of attenuation maps.
Implementation Method 1
receiving an acceleration vector from the at least one acceleration sensor
Data Source
AI summary
A method for ascertaining at least one of a position or an orientation of an MR local coil unit for arrangement inside a main magnetic field includes providing a first 3D relative position of a reference sensor system in relation to the main magnetic field; receiving an acceleration vector from at least one acceleration sensor; retrieving a distance vector describing a fixed relative position as a function of the received acceleration vector; calculating a second 3D relative position of the at least one acceleration sensor in relation to the main magnetic field based on the first 3D relative position and the retrieved distance vector; and ascertaining the at least one of the position or the orientation of the MR local coil unit using the first 3D relative position and the second 3D relative position.