Surgical Navigation Using Dual Reference Markers
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Solution Overview
Problem
Conventional surgical navigation systems using magnetic localizer technology face inaccuracies and complexity, particularly when the distance between the needle tip and the magnetic emitter is significant, leading to measurement errors and user interaction challenges.
Innovation Solution
A method and device that utilize a first and second reference marker to minimize the distance between the magnetic emitter and tracker, enhancing precision by reducing artefact effects from metallic elements, and allowing fully automatic operation without user intervention, using a magnetic tracking system integrated with CT imaging for precise tool navigation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If magnetic localizer technology is used for navigation, then ease of operation is improved, but measurement precision deteriorates when distance between emitter and tracker is large
Solution Approach 1:
The system divides the navigation space into multiple zones by placing multiple emitters at different positions. Each emitter serves a specific region, allowing the tracker to remain close to at least one emitter regardless of tool position. This segmentation resolves the contradiction by maintaining small emitter-tracker distances across the entire surgical field while preserving the ease of magnetic-based operation.
Solution Approach 2:
The system transitions from a single emitter to a three-dimensional array of multiple emitters distributed throughout the surgical space. This spatial distribution across multiple dimensions ensures that whichever region the surgical tool occupies, there is always a nearby emitter providing accurate magnetic field data, thus maintaining measurement precision without compromising operational ease.
2Measurement precision
If distance between needle tip and magnetic emitter is reduced to improve precision, then measurement precision is improved, but device complexity increases
Solution Approach 1:
Each magnetic emitter is designed to perform multiple functions: it generates the magnetic field for tracking, serves as a spatial reference point, and defines a operational zone. This multi-functionality allows the system to achieve high precision through multiple emitters without proportionally increasing complexity, as each component serves several purposes simultaneously.
Solution Approach 2:
The emitters are pre-positioned in the surgical space before the procedure begins, establishing a ready-made three-dimensional coordinate system. This preliminary arrangement eliminates the need for complex real-time calculations or dynamic repositioning during surgery, reducing operational complexity while maintaining precision through predetermined optimal emitter-tracker distances.
3Measurement precision
If multiple reference markers are used to minimize distance between magnetic components, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The system merges the functions of multiple reference markers into a unified multi-emitter framework where each emitter simultaneously serves as a tracking reference and a spatial delimiter. This consolidation approach achieves the precision benefits of multiple markers while reducing overall system complexity through functional integration and standardized emitter designs.
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
The solution provides highly accurate and simplified navigation of surgical tools, reducing measurement errors and user interaction, enabling quicker and more precise interventions by minimizing the distance between the magnetic components and reducing artefact effects from metallic elements.
Implementation Method 1
the localizing system comprises an emitter which emits a magnetic field generated by coils, and a tracker operating as a receiver which measures the magnetic field around itself when positioned in the emitted magnetic field
Implementation Method 2
a tracker operating as a receiver which measures the magnetic field around itself when positioned in the emitted magnetic field. Those measures are sent to a computer system that calculates the position and orientation between the emitter and the trackers
Data Source
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AI summary
The invention relates to a method of navigation of a tool to be used in a surgical operation for treating a target region within the body of a patient, characterised in that it comprises the following steps for preparing the navigation: - Disposing a first reference marker on the body of the patient, Detecting the image position of said first reference marker by an image system, and detecting the spatial position of said first reference marker by a localizing system, Calculating a first transform matrix between the image coordinate system of the imaging system and the spatial coordinate system associated with the first reference marker by using detected image and spatial positions of the first reference, in order to register data of the localizing and imaging systems together, Detecting the spatial position of a pointer by the localizing system, Constructing and displaying a navigation image, wherein a representation of the spatial position of the pointer is displayed on image data from the imaging system using the first transform matrix, Determining an entry point through which the tool should be inserted for reaching the target region by using the representation of the pointer in the navigation image, Disposing a second reference marker under sterile conditions on the body of the patient in the vicinity of the entry point, Detecting the image position and spatial position of said second reference marker, Calculating a second transform matrix between the image coordinate system of the imaging system and the spatial coordinate system associated with the second reference marker by using detected image and spatial positions of the second reference, in order to register data of the localizing and imaging systems together.