C-arm X-ray Heart Model Generation via EKG Triggering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Generating a solid model of a heart in a specific phase of its periodic pumping movement using C-arm X-ray technology is challenging due to the heart's periodic motion, which requires flexible imaging protocols and results in a high radiation dose for the patient.
Innovation Solution
A method that uses EKG triggering to capture X-ray images during specific phases of the heart's cycle within a single C-arm rotation, combined with heart pacing to ensure consistent and reproducible heart rates, allowing for the generation of a solid model with reduced radiation exposure by selecting and processing images based on heart phase and geometry parameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple X-ray images are captured during C-arm rotation to cover different heart phases, then the radiation dose to the patient increases, but the ability to generate a solid model of the heart in a specific phase is improved
Solution Approach 1:
The system uses periodic EKG triggering to capture X-ray images only at specific phases of the heart cycle (e.g., 70% RR interval). By synchronizing image acquisition with the periodic cardiac rhythm, the system obtains temporally resolved heart phase data while minimizing the number of images captured, thereby reducing radiation exposure compared to continuous or frequent sampling approaches.
2Loss of time
If the C-arm rotates at high speed to complete imaging quickly, then the imaging time is reduced, but the geometric accuracy of the C-arm position degrades due to deformation from centrifugal forces
Solution Approach 1:
The system continuously monitors the actual C-arm geometry during rotation using measurement data from the imaging process. By comparing the measured geometric parameters against the expected positions, the system can detect and correct for deformations caused by centrifugal forces. This feedback mechanism allows the system to maintain geometric accuracy even when rotating at speeds that would otherwise cause significant deformation.
3Manufacturing precision
If calibration is performed frequently to maintain geometric accuracy, then the positioning precision is improved, but the time required for calibration procedures increases
Solution Approach 1:
The system performs calibration automatically as part of the imaging workflow itself, using the imaging data to refine geometric parameters on-the-fly. Rather than requiring separate, time-consuming calibration procedures, the system continuously improves its geometric model using feedback from actual imaging operations, making the calibration process self-sustaining and integrated into routine operations.
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 enables the creation of a solid model with precise temporal resolution and reduced radiation exposure, using fewer X-ray images while maintaining high image quality, by aligning X-ray imaging with the heart's natural and controlled rhythm.
Implementation Method 1
X-ray images which are generated by means of a C-arm X-ray unit
Implementation Method 2
The C-arm is deformed as a result of the net weight of the C-arm and the weight of the X-ray source and of the X-ray detector as well as by centrifugal forces during the C-arm rotation
Data Source
AI summary
A method for generating a solid model of a heart in a predetermined phase of its periodic pumping movement is proposed. During a single C-arm rotation of a C-arm X-ray unit an electrocardiogram signal with consecutive RR intervals is observed by an EKG trigger. In each RR interval a digital X-ray image is generated by EKG triggering of the C-arm X-ray unit as soon as a time difference between the current phase and the predetermined phase is less than a predetermined value. For each of the X-ray images in addition a parameter influencing the geometry of the C-arm X-ray unit is ascertained. The solid model is generated from several of the X-ray images. At least one X-ray image is selected from each RR interval and for each of the selected X-ray images a projection data set for the calculation of the solid model is ascertained by the ascertained parameter.