Couch Positioning Line for Radiation Isocenter Alignment

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Solution Overview

Problem

In non-in-situ image-guided radiation therapy (IGRT) systems, conventional methods for treatment positioning are inaccurate due to mechanical errors in couch trajectories and require time-consuming calibration, which complicates aligning the treatment isocenter with the radiation isocenter.

Innovation Solution

A system that includes a treatment component with a radiation source, an imaging component, and a movable couch with a positioning line, where images are acquired using both components to determine the treatment isocenter and position the subject such that the radiation isocenter aligns with the treatment isocenter without the need for calibration, utilizing the positioning line's unique cross-sectional features.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If conventional couch encoder positions are used to measure couch travel distance, then the positioning method is simple, but the measurement precision deteriorates due to mechanical errors in couch trajectory

Engineering Contradiction:

Improvepositioning method simplicityVSAvoidcouch position measurement accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The patent introduces a positioning line with positioning features as an intermediary reference object on the couch. Instead of directly measuring couch position using encoder positions (which suffer from mechanical errors), the system images the positioning features and uses them as a mediator to determine couch position and treatment isocenter alignment, thereby eliminating the impact of mechanical trajectory errors

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the mechanical measurement system (couch encoders) with an imaging-based measurement system. By using imaging components to capture images of the positioning line and analyzing the positions of positioning features in the images, the system substitutes mechanical position sensing with optical/image-based position determination, achieving higher precision independent of mechanical errors

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If calibration is performed to facilitate position adjustment, then the treatment positioning accuracy is improved, but the time consumption and operator effort increase

Engineering Contradiction:

Improvetreatment positioning accuracyVSAvoidcalibration time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent enables the system to automatically determine the treatment isocenter and couch position relationships through imaging the positioning features without requiring manual calibration. The system self-calibrates by analyzing the geometric relationships between positioning features in multiple images, eliminating the need for operator-performed calibration procedures and reducing both time and effort

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The positioning line with positioning features is pre-installed on the couch before treatment sessions. This preliminary setup creates a permanent reference system that eliminates the need for repeated calibration operations during each treatment session, as the reference framework is already in place and can be directly used for position determination

Inventive Principle:

Principle #10Preliminary action

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 improves the accuracy and efficiency of treatment positioning by eliminating the need for calibration and reducing operator effort, ensuring precise alignment of the radiation isocenter with the treatment isocenter.

Implementation Method 1

acquire at least one first image relating to the subject and the positioning line using the radiation source of the treatment component

Methodology Applied

Scientific EffectX-Ray: X-Ray

Implementation Method 2

acquire at least one second image relating to the subject and the positioning line using the imaging component

Methodology Applied

Scientific EffectX-Ray: X-Ray

Data Source

PatentUS11534627B2Systems and methods for treatment positioning

Publication Date: 2022.12.27 SHANGHAI UNITED IMAGING HEALTHCARE

AI summary

System for treatment positioning is provided. The system may include a treatment component, an imaging component, and a couch. The treatment component may include a radiation source that has a radiation isocenter. The couch may be movable between the treatment component and the imaging component, and include a positioning line that has a positioning feature. The system may acquire at least one first image relating to a subject and the positioning line using the radiation source at a set-up position. The system may also acquire at least one second image relating to the subject and the positioning line using the imaging component at an imaging position. The system may further determine a treatment isocenter of a target of the subject based on the at least one second image, and determine a treatment position of the subject based on the first image(s), the second image(s), and the positioning line.