Multimodal Marker for MRI-Optical Tracking Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for automatic alignment of MR image planes with moving instruments in MRI-guided procedures are either limited by slow tracking speeds, reliance on manual initiation, or require additional costly hardware, and face challenges with line-of-sight issues and registration complexities in optical tracking systems.
Innovation Solution
A hybrid tracking system combining passive MRI-based and active optical sensor modalities using a multimodal marker with both MR and visual features, processed in real-time by a computer to fuse sensor data and predict image plane alignment, enabling automatic alignment of image planes with respect to a moving marker or instrument.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If manual alignment of image planes is performed by technologist, then alignment accuracy depends on operator experience, but alignment speed is slow and productivity is reduced
Solution Approach 1:
The system performs automatic alignment of image planes using the marker detected in the medical image, eliminating the need for manual intervention by the technologist. The computer automatically calculates and adjusts image plane parameters based on marker position and orientation, making the system self-sufficient and removing dependency on operator skill while maintaining high alignment accuracy
Solution Approach 2:
The manual mechanical alignment process performed by the technologist is replaced by an automated computer-based system that uses image processing and coordinate transformation algorithms. The system substitutes human操作 with automated computational methods, significantly improving both alignment speed and consistency
2Speed
If optical tracking system is used for real-time marker tracking, then tracking speed is high, but line-of-sight issues and registration complexities arise
Solution Approach 1:
The marker serves as an intermediary object that bridges MRI and optical tracking modalities. It contains both MR-visible features and optical features, allowing the system to detect the same physical object through both imaging modalities and establish coordinate transformations without complex registration procedures
Solution Approach 2:
The marker is designed with multi-functionality, containing both MR-visible features (for MRI detection) and optical features (for optical tracking). This universal design allows a single object to serve dual purposes in both imaging modalities, eliminating the need for separate tracking systems and simplifying the overall system architecture
3Reliability
If additional hardware is added for active optical tracking, then tracking capability is improved, but system cost and complexity increase
Solution Approach 1:
The system merges passive MRI-based tracking with active optical tracking into a unified hybrid system. By combining the strengths of both modalities, the system achieves reliable real-time tracking without requiring completely separate hardware systems, optimizing resource utilization and reducing overall system complexity
Solution Approach 2:
The marker functions as a composite structure containing both MR-visible material (for MRI detection) and optical features (for optical tracking). This composite design allows the marker to interact with both imaging modalities simultaneously, enabling the hybrid tracking system to function with integrated rather than separate hardware components
4Measurement precision
If prior registration is performed between optical sensor and MRI scanner, then tracking accuracy is improved, but additional time and complexity are required before procedure
Solution Approach 1:
The marker is pre-configured with both MR-visible and optical features during manufacturing, preparing it in advance for dual-modality detection. This preliminary preparation eliminates the need for time-consuming registration procedures during the actual medical procedure, as the marker is already ready to be detected by both systems simultaneously
Solution Approach 2:
The system performs online registration during the medical procedure rather than requiring offline registration beforehand. The computer automatically calculates coordinate transformations in real-time by detecting the marker in both MRI and optical images, eliminating pre-procedure registration time while maintaining tracking accuracy
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 enhances tracking speed and accuracy, eliminates the need for prior registration, and ensures continuous alignment even with changes in sensor position, providing a robust and efficient method for MRI-guided interventions by integrating the strengths of both MRI and optical tracking.
Implementation Method 1
an MRI scanner (2), the marker being detectable with both the MRI scanner (2) and the at least one external optical sensor (3)
Implementation Method 2
one or several external optical sensors (3) with high frame rate
Data Source
AI summary
A system for an automatic multimodal real-time tracking of moving instruments for image plane alignment inside an MRI scanner includes:an MRI scanner,an MRI multi-plane pulse sequence generating unit allowing to interactively modify the position and orientation of one or several image planes in real-time,one or several external optical sensors with high frame rate, preferably a RGB-D sensor or other similar camera system like a stereovision systems,a multimodal marker including at least one MR visible feature and one visual feature able to be tracked by both the MRI scanner and the at least one external optical sensor,a computer for processing in real-time images from both MRI and optical sensor to fuse the detected marker position and orientation or pose from both modalities, and predict the next image plane position and orientation based on the estimated motion of the moving marker.