Brachytherapy Catheter Positioning via Fiber Bragg Grating Temperature Sensing

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Solution Overview

Problem

In HDR brachytherapy, it is challenging to ensure that the radioactive radiation source is positioned within the patient's body, as it can be difficult to determine whether the dwell position is inside or outside the body, potentially exposing the patient's skin and medical personnel to radiation.

Innovation Solution

A system that includes an elongate introduction element, such as a catheter, with a temperature determination unit and an inner part determination unit using optical fibers with fiber Bragg gratings to accurately determine the temperature and segmentation of the catheter, ensuring the radiation source is only moved to dwell positions within the body, controlled by a brachytherapy control unit to prevent exposure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the radiation source is moved to dwell positions along the catheter, then the therapeutic effect is improved, but the risk of radiation exposure to skin and personnel increases if dwell positions are outside the body

Engineering Contradiction:
Improvetherapeutic effectVSAvoidradiation exposure
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The system continuously monitors temperature along the catheter and uses this feedback to determine which segments are inside the body. The brachytherapy control unit receives real-time position information and adjusts the radiation delivery accordingly, only allowing dwell positions within the body to be activated. This closed-loop feedback system ensures therapeutic effectiveness while preventing harmful radiation exposure to external areas.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces mechanical position detection methods with optical sensing using fiber Bragg gratings embedded in the catheter. These optical sensors detect temperature-induced strain and provide precise position information without mechanical contact or complex mechanical structures, enabling more accurate and reliable determination of intra-corporal segments.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If temperature-based segmentation is used to determine intra-corporal catheter segments, then the accuracy of position determination is improved, but the device complexity increases

Engineering Contradiction:
Improveposition determination accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The fiber optic cable serves multiple functions: it delivers radiation, provides structural support, and contains embedded temperature sensors for position determination. The fiber Bragg gratings are integrated into the existing catheter structure, allowing a single component to perform multiple functions rather than adding separate sensing elements, thereby reducing overall system complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system utilizes temperature as a parameter change to indicate position. By monitoring temperature variations along the catheter length and detecting temperature-induced strain through fiber Bragg gratings, the system converts thermal parameters into positional information, providing accurate position determination through a relatively simple sensing mechanism.

Inventive Principle:
Principle #35Parameter changes

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 ensures that the therapeutic procedure is performed only within the body, reducing the risk of radiation exposure to the patient's outer skin and medical personnel by accurately determining the catheter's position using temperature-based segmentation and real-time monitoring.

Implementation Method 1

optical fibers with fiber Bragg gratings to accurately determine the temperature

Methodology Applied
Scientific EffectFiber Bragg grating:

Implementation Method 2

an optical fiber configured to perform distributed sensing of temperature-induced strain

Methodology Applied
Scientific EffectTemperature-induced strain:

Data Source

PatentEP3110360B1System for performing a therapeutic procedure
Publication Date: 2019.04.10 KONINKLIJKE PHILIPS NV
  • EP3110360B1 patent drawingFigure 1
  • EP3110360B1 patent drawingFigure 2
  • EP3110360B1 patent drawingFigure 3

AI summary

The invention relates to a system for performing a therapeutic procedure like a HDR brachytherapy. An elongate introduction element is introduced into a body (2), a temperature is determined along the introduction element, and it is determined which part of the introduction element is within the body based on the determined temperature. A therapeutic procedure is performed by using the introduction element depending on the determination which part of the introduction element is within the body (2). This can ensure that the therapeutic procedure is only performed within the body, thereby reducing the likelihood of involuntary affecting, for instance, a patient's outer skin, especially by ionizing radiation which may be used during a HDR brachytherapy.