Low-Field MRI Gradient Waveform Design for Voltage Overshoot
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional gradient waveforms designed for high-field MRI systems are not suitable for low-field MRI systems due to power and hardware constraints, leading to distortions in the generated gradient magnetic field and reduced MR image quality.
Innovation Solution
The development of trapezoidal gradient waveforms with non-linear ramp-up and ramp-down portions, optimized using the resistance and inductance of the gradient coil, to prevent voltage overshoot and adhere to hardware constraints, ensuring efficient generation of gradient fields within low-field MRI systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional gradient waveforms designed for high-field MRI systems are used in low-field MRI systems, then the gradient magnetic field can be generated, but voltage overshoot occurs and hardware constraints are violated leading to image quality degradation
Solution Approach 1:
The patent modifies the gradient waveform parameters specifically for low-field MRI systems by implementing non-linear ramp-up and ramp-down portions. The waveform design adjusts the time-varying characteristics of the gradient signal to match the hardware constraints of low-field systems, preventing voltage overshoot while maintaining gradient field generation efficiency. This parameter optimization resolves the contradiction between productivity and reliability in low-field MRI applications.
2Reliability
If the gradient waveform is optimized to prevent voltage overshoot and adhere to hardware constraints, then image quality is maintained, but the waveform design becomes more complex
Solution Approach 1:
The patent employs dynamic waveform design where the gradient signal transitions from static linear ramps to dynamic non-linear ramps. The ramp-up and ramp-down portions are designed with time-varying characteristics that adapt to the hardware constraints of low-field MRI systems. This dynamic approach maintains image quality while managing design complexity through systematic optimization rather than arbitrary complexity.
3Reliability
If the gradient waveform uses non-linear ramp-up and ramp-down portions optimized for low-field systems, then voltage overshoot is prevented and hardware constraints are satisfied, but the waveform generation requires more sophisticated control
Solution Approach 1:
The patent implements feedback mechanisms in the gradient waveform generation process for low-field MRI systems. The controller uses feedback to adjust the gradient signal in real-time, ensuring that voltage overshoot is prevented and hardware constraints are satisfied. The non-linear ramp-up and ramp-down portions are controlled through feedback loops that monitor system response and adjust waveform parameters accordingly, resolving the contradiction between reliability and control sophistication.
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 allows for the generation of time-efficient gradient waveforms that maintain image quality by preventing voltage overshoot and adhering to hardware constraints, thereby improving the clinical utility of MR images acquired using low-field MRI systems.
Implementation Method 1
a gradient coil and a gradient power amplifier for driving the gradient coil
Data Source
AI summary
Systems and methods for generating a gradient waveform for use by a low-field MRI system to generate a gradient magnetic field are provided herein. The gradient waveform can be determined using first information indicative of the gradient waveform and second information indicative of hardware constraints of the low-field MRI system including a maximum voltage of the gradient power amplifier, a maximum slew rate of the gradient coil, a resistance of the gradient coil, and an inductance of the gradient coil. In some embodiments, the gradient waveform can be a trapezoidal gradient waveform determined to have a non-linear ramp-up portion and/or a non-linear ramp-down portion.