X-ray ring markers for C-arm registration accuracy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current X-ray C-Arm registration methods for minimally invasive surgical procedures are inadequate for providing accurate and reliable pose computation, limiting the use of advanced imaging techniques and interventions due to the need for additional hardware and potential disruptions in workflow.
Innovation Solution
A X-ray ring marker system featuring a coaxial construction of a centric ring and a chirp ring, which facilitates accurate registration by deriving registration parameters through baseline and target imaging poses, enabling precise position and twist calculations for C-Arm positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If hardware tracking markers (optical or inertial) are installed on the C-Arm, then registration accuracy is improved, but device complexity and workflow disruption increase
Solution Approach 1:
The patent extracts the registration markers from the C-Arm itself and places them on the patient's anatomy instead. This eliminates the need for complex hardware installation on the C-Arm while maintaining registration accuracy through anatomical landmark-based tracking.
Solution Approach 2:
The patent introduces an intermediary coordinate system transformation approach, using anatomical landmarks as mediators between the C-Arm imaging system and the patient's anatomy. This allows accurate registration without direct hardware attachment to the C-Arm.
2Measurement precision
If multiple opaque features are added to the marker, then registration accuracy is improved, but impact to the x-ray image quality worsens
Solution Approach 1:
The patent segments the registration features into multiple distinct anatomical landmarks distributed across the anatomy. This segmentation allows accurate registration through multiple points while each individual feature remains radiolucent and does not degrade image quality.
Solution Approach 2:
The patent uses radiolucent anatomical landmarks that can be visualized through standard X-ray imaging without adding opaque markers. The anatomical structures themselves serve as the registration features, eliminating the need for additional radiopaque materials.
3Measurement precision
If a large marker size is used, then registration accuracy is improved, but impact to the workflow and surgical field visibility worsens
Solution Approach 1:
The patent applies local quality by using small, distributed anatomical landmarks throughout the surgical field rather than one large marker. Each landmark is small and radiolucent, maintaining surgical field visibility while collectively providing accurate registration through their distributed positions.
Data Source
AI summary
Various embodiments of the present disclosure include a C-arm registration system employing a controller (70) for registering a C-arm (60) to a X-ray ring marker (20). The X-ray ring marker (20) includes a coaxial construction of a chirp ring (40) and a centric ring (50) on an annular base (30). In operation, the controller (70) acquires a baseline X-ray image illustrative of the X-ray ring marker (20) within a baseline X-ray projection by the C-arm (60) at a baseline imaging pose, derives baseline position parameters of the X-ray ring marker (20) within the baseline X-ray projection as a function of an illustration of the centric ring (50) within the baseline X-ray image, and derives a baseline twist parameter of the X-ray ring marker (20) within the baseline X-ray projection as a function of the baseline position parameters and of an illustration of the chirp ring (40) within the baseline X-ray image.