Endoscope Position Tracking Using Inertial Sensors

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Solution Overview

Problem

Current navigation systems for endoscopes, such as electromagnetic and optical tracking systems, are prone to failures, costly, and hinder surgical efficiency due to limited accuracy and interference from metallic objects or the need for a constant line of sight, while inertial sensors provide limited accuracy in determining spatial position and orientation.

Innovation Solution

A method using acceleration and rotation rate sensors, combined with insertion sensors and image-based motion detection, to determine the position and orientation of the endoscope tip within a cavity, correcting for sensor drift and improving accuracy by incorporating insertion length and rotational movements, and optionally using magnetic field sensors for further precision.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If electromagnetic tracking systems are used to determine position and orientation of the endoscope, then navigation capability is provided, but metallic objects disrupt the magnetic field and cause tracking failure

Engineering Contradiction:

Improvetracking reliabilityVSAvoidmagnetic field disruption by metallic objects

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces electromagnetic tracking systems with inertial sensors (accelerometers and gyroscopes) that measure physical motion and orientation directly, eliminating susceptibility to magnetic field disruption by metallic objects while maintaining navigation capability

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If optical tracking systems are used to determine position of the endoscope, then navigation capability is provided, but a constant line of sight between the endoscope and optical sensor is required

Engineering Contradiction:

Improvetracking reliabilityVSAvoidoperational flexibility

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent replaces optical tracking systems with inertial sensors that autonomously measure position and orientation through acceleration and rotation detection, eliminating the requirement for constant line of sight and external optical sensors while maintaining navigation accuracy

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If optical or electromagnetic navigation systems are used, then position and orientation can be determined, but high costs and space requirements for coils and sensors arise

Engineering Contradiction:

Improveposition and orientation accuracyVSAvoidsystem complexity and space requirements

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent employs inexpensive inertial sensors (accelerometers and gyroscopes) that can be integrated directly into the endoscope, replacing costly optical and electromagnetic navigation systems while maintaining sufficient measurement precision for surgical navigation

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent combines acceleration and rotation rate measurements from inertial sensors to simultaneously determine both position and orientation of the endoscope, eliminating the need for separate tracking systems and reducing overall system complexity

Inventive Principle:

Principle #5Merging (Combining)

4Ease of manufacture

If inertial sensors alone are used to determine position and orientation, then cost is reduced, but accuracy is limited due to sensor drift

Engineering Contradiction:

Improvecost-effectivenessVSAvoidposition and orientation accuracy

Core Design Contradiction:

Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent integrates multiple inertial sensors (accelerometers and gyroscopes) that provide complementary measurement data, using feedback from both sensor types to compensate for individual sensor drift and improve overall measurement accuracy while maintaining cost-effectiveness

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 method enhances the accuracy and cost-effectiveness of determining the endoscope's position and orientation, reducing inaccuracies and enabling more precise navigation during endoscopic procedures by integrating data from various sensors and image-based motion detection.

Implementation Method 1

an acceleration acting on the endoscope, a rotational movement of the endoscope are detected with at least one acceleration sensor, at least one rotation rate sensor assigned to the endoscope

Methodology Applied

Scientific EffectGravitation: Gravitation

Implementation Method 2

an acceleration acting on the endoscope, a rotational movement of the endoscope are detected with at least one acceleration sensor, at least one rotation rate sensor assigned to the endoscope

Methodology Applied

Scientific EffectGyroscope: Gyroscope

Data Source

PatentEP3056145B1Method for determining a position and an orientation of an endoscope within a cavity

Publication Date: 2023.12.06 KARL STORZ SE & CO KG

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AI summary

In a method according to the invention for determining the position and/or orientation of an endoscope (1, 15) in a cavity (4), wherein the endoscope (1, 15) comprises an elongated shaft (2, 17) extending into the cavity (4) through an endoscopic insertion device connected to an access opening (17) of the cavity (4), an acceleration acting on the endoscope (1, 15) is detected by at least one acceleration sensor associated with the endoscope (1, 15), and a rotational movement of the endoscope (1, 15) is detected by at least one rotational rate sensor associated with the endoscope (1, 15). An insertion movement of the shaft (2, 17) relative to the insertion device is detected by at least one insertion sensor associated with the insertion device, and a position and orientation of the endoscope (1, 15) are determined based on the detected acceleration, rotational movement, and insertion movement. The invention also relates to a corresponding endoscope system.