Dynamic Ripple Filter Unit for Radiotherapy Dose Uniformity
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Solution Overview
Problem
Current radiotherapy treatments face challenges in minimizing delivery time while maintaining plan quality, primarily due to the need for multiple energy layers and the time-consuming process of changing ripple filters between layers.
Innovation Solution
A dynamic ripple filter unit comprising two movable ripple filters arranged in series, allowing for adjustable filter characteristics to broaden Bragg peaks optimally for each energy layer without the need for manual filter changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the number of energy layers is increased to maintain dose uniformity, then the dose distribution quality is improved, but the treatment delivery time increases
Solution Approach 1:
The patent applies the dynamics principle by making the ripple filter adjustable and reconfigurable during treatment delivery. The filter can dynamically change its ripple characteristics to broaden Bragg peaks for lower energy layers while maintaining sharp peaks for higher energy layers, eliminating the need to increase the number of energy layers and thus reducing treatment time while maintaining dose uniformity
Solution Approach 2:
The patent applies parameter changes by modifying the energy distribution parameters of the particle beam through adjustable ripple filters. The filter characteristics (ripple amplitude, spacing, and pattern) are changed to control Bragg peak broadening, allowing optimization of dose uniformity without increasing the number of energy layers
2Manufacturing precision
If manual ripple filter changes are performed between energy layers to optimize Bragg peak broadening, then the dose distribution quality is improved, but the treatment delivery time increases
Solution Approach 1:
The patent replaces static manual filter changes with a dynamic programmable ripple filter system that can automatically adjust its characteristics between and during energy layers. This eliminates manual intervention and reduces the time penalty associated with filter changes while maintaining optimized dose distribution
Solution Approach 2:
The programmable ripple filter system is self-controlled through computer automation, eliminating the need for manual operator intervention. The system automatically selects and configures appropriate filter settings based on the treatment plan and current energy layer, reducing treatment delivery time
3Productivity
If fewer energy layers are used to reduce treatment time, then the treatment delivery time is reduced, but the dose uniformity deteriorates
Solution Approach 1:
The patent uses dynamic ripple filter adjustment to compensate for the reduced number of energy layers. By broadening Bragg peaks selectively for lower energy layers through adjustable filter settings, the system maintains sufficient overlap and dose uniformity even with fewer energy layers, thus improving treatment delivery speed without sacrificing dose quality
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 dynamic ripple filter unit reduces the number of energy layers required, thereby shortening treatment delivery time without compromising dose uniformity across the treated volume.
Implementation Method 1
Each particle will deposit most of its energy towards the end of its path, in what is known as the Bragg peak
Implementation Method 2
The particles' energy will be reduced by different amounts, depending on where they hit the ripple filter unit
Data Source
AI summary
A ripple filter unit comprises a first and a second ripple filter, substantially identical, are arranged so that they overlap each other in a beam, with substantially the same orientation and movable relative to each other in such a way as to vary the filter characteristics dynamically. In this way, the modulation characteristics of the ripple filter unit can be varied.