Optical Shape Sensing with Multiple Fibers

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Solution Overview

Problem

Current optical shape sensing technologies are limited to a length of 1.5-2 meters, which is insufficient for certain medical and industrial applications, and extending this length with separate devices compromises accuracy and practicality.

Innovation Solution

Mechanical concatenation of two or more optical shape sensing fibers, where the position data of the second fiber is registered in the coordinate system defined by the first fiber, allowing for high-precision 3D shape sensing over longer distances by overlapping and stitching shape sensing data between fibers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of moving object

If a single optical fiber is used for shape sensing, then measurement precision is maintained, but the sensing length is limited to 1.5-2 meters

Engineering Contradiction:
Improvesensing lengthVSAvoidshape sensing accuracy
Core Design Contradiction:
Length of moving objectVSMeasurement precision

Solution Approach 1:

The patent divides the long optical fiber into multiple segments, each with its own coordinate system. By segmenting the fiber and independently calibrating each segment, the system maintains measurement precision while extending the total sensing length beyond the 1.5-2 meter limitation of single-segment systems.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a hierarchical coordinate system structure where multiple local coordinate systems are transformed into a global coordinate system. This dimensional transformation allows the system to extend sensing length by adding spatial layers (multiple segments) while maintaining precision through coordinate transformations and calibration.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Length of moving object

If two separate optical shape sensing devices are used to extend sensing length, then sensing length is increased, but device complexity and operational difficulty increase

Engineering Contradiction:
Improvesensing lengthVSAvoidsystem complexity
Core Design Contradiction:
Length of moving objectVSDevice complexity

Solution Approach 1:

The patent merges multiple optical fiber segments into a unified shape sensing system by establishing coordinate transformations between them. The processor integrates data from multiple segments and transforms them into a common coordinate system, creating a unified long-range sensing capability while managing complexity through systematic coordinate management.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent creates a universal coordinate transformation framework that can handle any number of fiber segments. The system uses a standardized approach with a global coordinate system and multiple local coordinate systems that can be systematically transformed, making the system scalable and multi-functional for different sensing length requirements.

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

3Length of moving object

If two separate optical shape sensing devices are used to extend sensing length, then sensing length is increased, but measurement precision and reliability decrease

Engineering Contradiction:
Improvesensing lengthVSAvoidaccuracy
Core Design Contradiction:
Length of moving objectVSReliability

Solution Approach 1:

The patent implements a feedback mechanism through calibration procedures where the system determines transformation parameters between coordinate systems by analyzing overlapping sensing regions. The processor uses feedback from the calibration data to optimize coordinate transformations, ensuring high reliability and accuracy when combining multiple fiber segments.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent performs preliminary calibration actions to establish accurate coordinate transformations between segments before actual shape sensing. By pre-determining the transformation parameters through calibration in overlapping regions, the system ensures high reliability and precision is maintained when the segments are combined for long-range sensing.

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

Enables high-precision 3D shape sensing over longer distances without compromising accuracy, allowing for reliable visualization and navigation of elongated medical devices and other objects, even beyond the initial 1.5-2 meter limit, by using a hierarchical data structure for error correction and redundancy.

Implementation Method 1

This is possible by optical interrogating the optical fiber e.g. with optical shape sensing elements by means of Fiber Bragg Gratings or Rayleigh based elements

Methodology Applied
Scientific EffectFiber Bragg Gratings:

Implementation Method 2

This is possible by optical interrogating the optical fiber e.g. with optical shape sensing elements by means of Fiber Bragg Gratings or Rayleigh based elements

Methodology Applied
Scientific EffectRayleigh scattering: Rayleigh Scattering

Data Source

PatentEP3014214B1Optical shape sensing with a plurality of optical fibers
Publication Date: 2021.08.11 KONINKLIJKE PHILIPS NV
  • EP3014214B1 patent drawingFigure 1~2
  • EP3014214B1 patent drawingFigure 3~4
  • EP3014214B1 patent drawingFigure 5

AI summary

An optical shape sensing system and method with at least two optical fibers (OSF1, OSF2) both comprising optical shape sensing elements. A processor (P) is arranged to register a coordinate system indicative of a position of one of the optical fibers (OSF1) in space, and to register a position (R2) of the other optical fiber (OSF2) in relation to this coordinate system. An optical console system (C, C1, C2) serves to interrogate the optical shape sensing elements in both optical fibers (OSF1, OSF2), and to accordingly determine a measure of a three-dimensional shape (I) of both optical fibers (OSF1, OSF2), based on the registered position (R2) of the second optical fiber (OSF2) in relation to the coordinate system. This provide the possibility of providing 3D optical shape sensing of the length of both optical fibers (OSF1, OSF2), thus allowing 3D shape reconstruction of e.g. long medical devices with lengths of several meters. More than two shape sensing optical fibers, e.g. incorporated in separate devices, can be registered in this manner in a hierarchical data structure, thus allowing shape sensing of very long instruments.