Dosimeter with Magnetic Position Sensor for Radiotherapy

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current radiation dosimetry systems face challenges in accurately measuring radiation doses during medical procedures, particularly in radiation therapy, due to limitations in tracking target volume movement and positioning of radiation detectors, leading to potential exposure of healthy tissues and inaccuracies in dose delivery.

Innovation Solution

A dosimeter system incorporating a radiation detector and a magnetic position sensor, separated by a predetermined distance, generates a magnetic field to track the position of the detector in real-time, allowing for accurate correlation of radiation levels with their measurement locations, even during movement caused by bodily functions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If radiation detectors are positioned in or near the target volume to measure radiation dose, then dose measurement capability is improved, but the ability to track detector position during body movement deteriorates

Engineering Contradiction:

Improveradiation dose measurementVSAvoiddetector position tracking

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent combines a radiation detector and a position sensor (magnetic field sensor) into a single integrated dosimeter unit. This merging ensures that both radiation dose measurement and position tracking are performed by components that move together as a unified system, eliminating the reliability issue of tracking detector position during body movement.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent introduces a magnetic field sensor as an intermediary to track the position of the dosimeter. The magnetic field sensor detects changes in magnetic field strength caused by body movement, providing reliable position information that correlates with the radiation detector's location without requiring direct visual or mechanical tracking methods.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Manufacturing precision

If imaging techniques are used to align target volume with fiducial marks, then initial positioning accuracy is improved, but the ability to monitor movement during therapy deteriorates

Engineering Contradiction:

Improveinitial positioning accuracyVSAvoidmovement monitoring during therapy

Core Design Contradiction:

Manufacturing precisionVSMeasurement precision

Solution Approach 1:

The patent replaces mechanical or visual imaging-based tracking systems with a magnetic field-based sensing system. The magnetic field sensor continuously monitors position changes during therapy without requiring repeated imaging procedures, providing real-time movement data that complements the initial positioning accuracy achieved through imaging techniques.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If the irradiated volume is increased to compensate for target movement, then treatment coverage is improved, but damage to neighbouring healthy tissue worsens

Engineering Contradiction:

Improvetreatment coverageVSAvoiddamage to healthy tissue

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent implements a feedback system where the magnetic field sensor continuously monitors the position of the dosimeter and target volume during therapy. This real-time position information is fed back to the treatment planning system, allowing for dynamic adjustment of the radiation beam to maintain precise targeting without increasing the irradiated volume, thereby protecting healthy tissues from unnecessary exposure.

Inventive Principle:

Principle #23Feedback

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 system enables precise measurement and monitoring of radiation doses and their positions over time, allowing for real-time adjustments to treatment plans and minimizing exposure to healthy tissues, thereby improving the accuracy and safety of radiation therapy.

Implementation Method 1

magnetic field sensor means responsive to movement of the dosimeter relative to the magnetic field to provide a position sensor signal

Methodology Applied

Scientific EffectMagnetic field sensing: Magnetic Field

Data Source

PatentUS7831016B2Radiation dosimetry apparatus and method, and dosimeter for use therein

Publication Date: 2010.11.09 BEST THERATRONICS

AI summary

In order to overcome or at least mitigate difficulties in compensating for movement of the target, for example a tumour during radiotherapy, a dosimetry apparatus and method embodying the present invention employ a dosimeter having at least one radiation detector and at least one magnetic position sensor located a predetermined distance apart. Radiation level readings from the radiation detector and position readings from the position sensor are monitored and correlated, conveniently according to time, to obtain the position of the radiation detector when a particular radiation level was detected.