X-Ray Camera Calibration Using Gantry-Mounted Laser Indications
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing medical imaging systems, such as DXA/DEXA, require an additional optical marker for camera calibration, which is undesirable due to the need for an extra component and logistical challenges.
Innovation Solution
A method and system for camera calibration in medical imaging systems that utilizes a gantry-mounted laser to project an indication on the patient table, allowing registration of the camera referential to the system referential without the need for an optical marker, using image processing to determine corresponding positions and calculate a transformation matrix for accurate alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an optical marker is used for camera calibration, then the camera can be calibrated to the system, but an additional component is required which creates logistical challenges
Solution Approach 1:
The patent extracts the calibration function from a separate optical marker component and integrates it into the existing laser indicator already present on the gantry. The laser serves dual purposes: indicating patient positioning and providing calibration features, thereby eliminating the need for an additional optical marker component while maintaining calibration accuracy
Solution Approach 2:
The laser indicator on the gantry is given multiple functions: it serves as both a patient positioning guide and a calibration target for the camera system. By making the laser multi-functional, the patent eliminates the need for separate calibration components, reducing device complexity while preserving measurement precision
2Measurement precision
If a separate optical marker is used for calibration, then camera positioning can be determined, but logistical challenges arise from manufacturing and deployment
Solution Approach 1:
The patent merges the calibration function with the existing laser indicator system on the gantry. The laser's known position and characteristics are used for calibration purposes, combining two functions (positioning indication and calibration reference) into a single integrated system, thereby simplifying manufacturing and deployment logistics
3Measurement precision
If an optical marker is positioned on the table, then calibration can be performed, but the system requires additional components to be manufactured and sent to deployment location
Solution Approach 1:
The gantry-mounted laser serves its own primary function of indicating patient positioning while simultaneously providing calibration reference points for the camera system. The system uses itself (the laser already present) for calibration purposes, eliminating the need for external calibration components and reducing the quantity of parts that need to be manufactured and deployed
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
Enables efficient camera calibration without additional components, improving positioning accuracy and reducing logistical complexities by directly correlating camera and system coordinates for precise patient and imaging setup.
Implementation Method 1
a laser disposed on the gantry adjacent the x-ray detector
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Various methods and systems are provided for calibrating a camera-based feature detection system (81) for an x-ray system (10) having a support surface (20), and a gantry (12) operably connected to the support surface (20) and a light source (85) disposed on the gantry (12), where the gantry (12) defines a system referential (33). The x-ray system (10) includes a camera (80) spaced from the gantry (12) and operably connected to a calibration system (81), the camera (80) defining a camera referential (83) within which the support surface (20) and gantry (12) are positioned. The calibration system (81) registers the camera referential (83) to the system referential (33) by operating the light source (85) to position an indication (90) on the support surface (20) and by obtaining a number of camera images of the indication (90) on the support surface (20) and corresponding indication location in the system referential (33).