Removable Registration Appendage for Surgical Navigation CT Visibility
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Solution Overview
Problem
In prior surgical navigation systems, markers attached to a patient tracker are often outside the field of view of the CT scanner, making it difficult to achieve repeatable registration of three-dimensional CT images.
Innovation Solution
A registration appendage with radio-opaque markers arranged in a predetermined geometric pattern is attached to the patient tracker in a known position and orientation, ensuring the markers are visible within the CT scanner's field of view, even when the locators are outside the scanner's field, allowing for repeatable registration of CT images.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If markers are attached to the patient tracker on the side away from the patient's body, then the markers are easier to access and attach, but the markers may not be visible in the CT scanner's field of view
Solution Approach 1:
The registration appendage extends the patient tracker in a direction toward the patient's body (opposite from conventional outward extension), creating a new spatial dimension for marker placement that resolves the conflict between accessibility and CT visibility
2Reliability
If the patient tracker is positioned on the forehead with locators outside the CT scanner field of view, then the tracking system can monitor patient movement, but the markers are not visible for image registration
Solution Approach 1:
The system separates the tracking function (locators on patient tracker) from the registration function (markers on registration appendage), allowing each to be optimized for its specific purpose while working together as an integrated system
Solution Approach 2:
The registration appendage acts as an intermediary structure that bridges the gap between the patient tracker and the CT scanner field of view, providing visible markers for registration without interfering with the tracking locators
3Productivity
If the CT scanner uses collimation to scan only the volume of interest, then the scan time and radiation exposure are reduced, but the markers must be precisely positioned within the limited field of view
Solution Approach 1:
The registration appendage is pre-positioned on the patient tracker at a known location and orientation before the CT scan, ensuring markers are within the collimated field of view without requiring precise adjustment during the scan
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 solution enables accurate and repeatable registration of three-dimensional CT images, allowing for precise tracking of patient position and orientation relative to previous images, even during collimated scans, enhancing surgical navigation accuracy.
Implementation Method 1
A registration appendage including radio-opaque markers arranged in a predetermined geometric pattern is attached to the patient tracker
Data Source
AI summary
A surgical navigation system includes a CT scanner that takes a plurality of x-ray images of a patient. A patient tracker including locators is attached to the patient, and a registration appendage is removably secured to the patient tracker in a known position and orientation. The registration appendage includes radio-opaque markers arranged in a predetermined geometric pattern. The registration appendage is viewable in a CT scan in situations where the locators of the patient tracker are outside of a field of view of the CT scanner.