MRI Local Coil Frequency Mixing for Flexible IF Selection
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Solution Overview
Problem
Magnetic resonance tomographs face challenges in flexible frequency selection, especially in systems with lower magnetic fields where traditional frequency schemes are not applicable, leading to interference issues with intermediate frequencies.
Innovation Solution
A local coil device that generates first and second mixed-frequency signals using first and second auxiliary frequency signals with different frequencies, allowing for flexible frequency selection through mixing processes, such as intermodulation products generated by non-linear elements or digital signal processing, and utilizing a local oscillator to provide these signals for conversion to intermediate frequencies for transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional frequency schemes from high-field systems are applied to lower field systems, then the system can operate with established frequency plans, but interference occurs from intermediate frequencies that are no longer applicable
Solution Approach 1:
The patent changes the frequency parameters by generating mixed-frequency signals through mixing auxiliary frequency signals with received signals. This creates new frequency components that are specifically suited for lower field systems, avoiding the interference problems of traditional high-field frequency schemes while maintaining reliable system operation.
2Device complexity
If auxiliary frequency signals are used for frequency division multiplexing, then the number of cable connections is reduced, but flexible frequency selection becomes difficult
Solution Approach 1:
The patent introduces dynamic frequency selection through the mixing process. The mixed-frequency signals can be flexibly adjusted by changing the auxiliary frequency signals or the mixing parameters, allowing the system to adapt to different frequency requirements while maintaining the simplified cable structure of frequency division multiplexing.
3Adaptability or versatility
If mixed-frequency signals are generated through mixing, then flexible frequency selection is achieved, but additional signal processing components are required
Solution Approach 1:
The patent segments the frequency processing function into separate mixing stages. Each antenna channel can have its own mixing operation with auxiliary frequency signals, allowing independent frequency selection for each channel while using standardized mixing components. This modular approach manages complexity through functional segmentation.
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
Enables more flexible frequency selection and decouples the selection of auxiliary frequency signals from mixed frequency signals, reducing interference and improving signal transmission in magnetic resonance tomographs, particularly in lower field systems.
Implementation Method 1
Mixing is understood to mean signal processing that generates intermodulation products of the first and/or second auxiliary frequency signal. This can be achieved analogously by non-linear characteristic curves, for example of diodes or amplifier elements.
Data Source
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AI summary
The invention relates to a local coil with a device for providing a first mixed-frequency signal and a second mixed-frequency signal by means of a first auxiliary frequency signal and a second auxiliary frequency signal. The device has an auxiliary mixer which is designed to generate the second mixed frequency signal from the first auxiliary frequency signal and the second auxiliary frequency signal. The local coil has a signal input which is in a first signal connection with the device. The local coil is designed to receive the first auxiliary frequency signal and the second auxiliary frequency signal together via the signal input and to feed them to the device via the first signal connection.