MRI ECG Signal Correction for MHD-Related T-Wave Distortion
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Solution Overview
Problem
The magnetohydrodynamic (MHD) effect induced by MRI scanners distorts ECG signals, particularly the T-wave, leading to gating errors in MRI imaging, as the amplified T-wave is confused with the R-wave, necessitating improved systems for accurate ECG-based MRI image collection.
Innovation Solution
A system comprising an MRI scanner, ECG monitor, and an MRI-compatible camera captures patient images and ECG signals, using an image processing unit (IPU) to derive patient information and calculate a T-wave correction factor, which is applied to correct the ECG signal for accurate gated imaging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If MRI gradient fields are used for image generation, then MRI imaging capability is achieved, but ECG signal distortion occurs due to MHD effect
Solution Approach 1:
The patent utilizes the MHD effect itself to generate the correction signal. By measuring the potential difference induced by the gradient fields across the patient's body, the system obtains information about the MHD distortion, which is then used to correct the ECG signal. This converts the harmful MHD effect into a useful correction mechanism.
Solution Approach 2:
The system continuously monitors the ECG signal during MRI scanning, detects T-wave distortions caused by MHD effect, and applies real-time correction based on the measured potential differences. This closed-loop feedback approach maintains accurate ECG gating throughout the MRI procedure.
2Power
If T-wave amplitude is amplified by MHD effect, then signal strength increases, but gating accuracy decreases due to T-wave misidentification as R-wave
Solution Approach 1:
The patent introduces a correction signal as an intermediary element between the distorted ECG signal and the gating decision process. This correction signal, derived from the MHD-induced potential difference, is subtracted from the ECG signal to remove the T-wave amplification artifact, allowing accurate R-wave detection to proceed.
3Device complexity
If conventional ECG gating is used in MRI environment, then gating mechanism is simple, but gating errors increase due to signal distortion
Solution Approach 1:
The patent makes the MRI scanner's potential measurement system serve a dual function: its primary function for image generation and a secondary function for ECG signal correction. By utilizing the existing gradient fields and body potential measurements already present in the MRI system, the correction mechanism adds minimal complexity while significantly improving gating reliability.
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
The corrected ECG signal prevents confusion between T-waves and R-waves, ensuring accurate MRI image gating and reducing errors in MRI image collection.
Implementation Method 1
The MHD effect occurs due to a patient undergoing magnetic resonant imaging (MRI). In an MRI environment, the gradients produced by the MRI scanner can induce a potential on the vascular system of the patient as their blood circulates, known as the magnetohydrodynamic (MHD) effect.
Implementation Method 2
The systems and methods derive patient information (such as heart rate) from images captured by a camera
Data Source
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AI summary
Systems and methods for correcting an electrocardiogram (ECG) impacted by the magnetohydrodynamic (MHD) effect are provided. The systems and methods derive patient information from images captured by a camera, and use this information to calculate a T-wave correction factor used to counteract the amplification of the T-wave due to the MHD effect. While the patient undergoes an MRI scan, an ECG monitor captures an ECG signal for the patient, and the camera captures a series of images of the patient. The series of images are provided to the image processing unit (IPU). The IPU processes the images to derive patient information to calculate the T-wave correction factor. The IPU then attenuates the amplitude of the T-wave of the captured ECG signal to generate a corrected ECG signal. This corrected ECG signal is then used by the MRI scanner for more accurate gated imaging.