Capsule Endoscope Position Detection via Subregion Distance Sum

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Solution Overview

Problem

Existing position detection systems for capsule endoscopes face challenges in accelerating the position estimating process due to high calculation amounts and may suffer from reduced accuracy, especially when only detecting the intersection of regions without estimating the orientation of the capsule endoscope.

Innovation Solution

A position detection apparatus that divides the region where the capsule endoscope possibly exists into subregions, calculates the total sum of distances between the center point of the subregion and the spherical surfaces, and detects the center point with the minimum total sum as the capsule endoscope's position, reducing calculation complexity and ensuring constant accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the Gauss-Newton method is used to estimate position and orientation of the capsule endoscope, then measurement precision is improved, but productivity deteriorates due to large calculation amount

Engineering Contradiction:
Improveposition and orientation estimation accuracyVSAvoidposition estimating process speed
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The invention extracts only the position estimation function from the full position and orientation estimation process. By removing the orientation estimation component, the calculation amount is significantly reduced while position detection accuracy is maintained through the use of multiple receiving antennas and signal strength analysis.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The estimation process is segmented into position-only estimation rather than joint position-orientation estimation. This segmentation simplifies the mathematical model from requiring full six-degree-of-freedom estimation to only three-degree-of-freedom position estimation, thereby reducing computational complexity and processing time.

Inventive Principle:
Principle #1Segmentation

2Productivity

If only the intersection of regions is detected as the position of the capsule endoscope, then productivity is improved by simplifying the calculation, but measurement precision deteriorates

Engineering Contradiction:
Improvecalculation simplicityVSAvoidposition detection accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The invention introduces signal strength measurements from multiple receiving antennas as an intermediary parameter to determine capsule position. Instead of simply finding region intersections, the system uses signal strength-weighted positioning that provides more accurate location data while maintaining computational efficiency through a simplified estimation model.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 simplifies the arithmetic process, reduces calculation amounts, and secures constant position detection accuracy by detecting the position where the total sum of distances from spherical surfaces is minimum, while avoiding the need to estimate orientation, thus accelerating the position estimating process.

Implementation Method 1

electromagnetic wave transmitted from the capsule endoscope is received by a plurality of receiving antennas outside the body cavity

Methodology Applied
Scientific EffectElectromagnetic wave reception: Electromagnetic Induction

Data Source

PatentEP2737842B1Position detection apparatus, capsule endoscope system, and position detecting program for capsule endoscope
Publication Date: 2017.02.01 OLYMPUS CORPORATION(JP)
  • EP2737842B1 patent drawingFigure 1
  • EP2737842B1 patent drawingFigure 2~3
  • EP2737842B1 patent drawingFigure 4~5

AI summary

Provided are a position detection apparatus for a capsule endoscope, having a constant accuracy while reducing a calculation amount, a capsule endoscope system including the position detection apparatus, and a position detecting program for the capsule endoscope. An information processor 6 includes a position information estimating unit 62 configured to calculate a first distance rn between each of a plurality of receiving antennas and the capsule endoscope based on each reception strength of a signal received by the plurality of receiving antennas, and configured to estimate, as a position of the capsule endoscope, a position where a total sum of distances from spherical surfaces is minimum inside a region where a plurality of spheres are overlapped. Each of the plurality of spheres has a center at each of the receiving antennas and has a radius of the distance rn for each of the receiving antennas.