Tracking Device Accuracy Correction via Calibration Mapping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Tracking devices used in image-guided surgery face accuracy issues due to interactions with metal and conductive materials, stray fields, and environmental factors, leading to distortions and reduced precision in position and orientation measurements.
Innovation Solution
A system and method utilizing a rigid object with embedded position indicating elements, such as magnetic sensor coils, to establish baseline data, which is used to calibrate and correct tracking devices for distortions in various environments, ensuring accurate position and orientation information through comparison and application of correction maps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If tracking devices are used in environments with metal objects and conductors, then position and orientation information can be obtained, but measurement accuracy deteriorates due to field distortions
Solution Approach 1:
The system performs preliminary mapping of the measurement volume by moving the tracking device to multiple known positions and orientations, and storing the relationship between tracker readings and actual positions. This pre-established mapping data is then used to correct measurements taken in the presence of conductors and metal objects, compensating for field distortions without requiring real-time recalibration.
Solution Approach 2:
The system continuously compares tracker readings against the pre-established mapping data and applies corrections based on the detected deviations. The correction algorithm uses feedback from the mapping information to adjust position and orientation measurements in real-time, compensating for distortions caused by conductors and metal objects in the measurement volume.
2Reliability
If conventional accuracy verification methods are used, then some accuracy issues can be detected, but the methods are complicated, time-consuming, and require specialized equipment
Solution Approach 1:
The system performs self-verification by using the tracking device itself to map the measurement volume and verify its own accuracy. The tracker moves to predetermined positions and orientations, compares its readings against the stored mapping data, and automatically generates accuracy reports. This eliminates the need for external specialized verification equipment and reduces both complexity and time requirements.
Solution Approach 2:
The mapping and verification system serves multiple functions: it establishes the measurement volume characteristics, verifies tracking device accuracy, characterizes field distortions, and provides correction data for ongoing measurements. This multi-functional approach replaces multiple separate verification procedures with a single integrated system, reducing complexity and time requirements.
3Reliability
If conventional accuracy verification methods are used, then some accuracy issues can be detected, but they may not be appropriate for the particular operating environment
Solution Approach 1:
The system creates location-specific mapping data by recording the tracking device readings at multiple positions and orientations within the actual operating environment. This local mapping captures the specific field characteristics and distortion patterns of that particular environment, allowing for accurate verification and correction tailored to the local conditions rather than using generic verification methods.
Solution Approach 2:
The system adapts to different operating environments by changing the mapping parameters such as the number of measurement positions, orientations, and the spatial distribution of mapping points. The mapping process can be configured to match the specific requirements and characteristics of different surgical or investigative environments, providing environment-specific accuracy verification.
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 system effectively detects and corrects distortions, enhancing the accuracy of tracking devices in both undistorted and experimental volumes, allowing for precise tracking and registration in surgical and investigative environments.
Implementation Method 1
a magnetic field generator, and a plurality of position indicating elements distributed throughout the volume
Implementation Method 2
the fields set up by these tracking devices may be affected through the interaction of metal and other conductors with position sensors (hereinafter 'position indicating elements') associated with the tracking devices
Data Source
AI summary
The invention provides a system and method for testing and correcting the accuracy of a tracking device in a volume using an accuracy device. The invention may include placing a rigid object into an experimental volume and sampling position and orientation information regarding one or more position indicating elements at known positions relative to a frame of reference of the tracking device. The position and orientation information may then be compared to known baseline position and orientation information. If a difference between the experimental position and orientation information and the baseline position and orientation information exceeds a predetermined threshold, a correction map enabling adjustment of the tracking device to correct for the distortion in the experimental volume may be generated, and the tracking device may be adjusted accordingly.