Ferromagnetic Incident Detection and Logging for MRI Safety
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Solution Overview
Problem
Current ferromagnetic object detection systems, such as ferromagnetic metal detectors, are insufficient in reducing the occurrence of projectile incidents in MRI rooms, as they lack the capability for independent documentation of incidents, which is essential for corrective actions and root cause analysis, especially when there are no impartial witnesses.
Innovation Solution
An arrangement comprising a ferromagnetic detector with an array of magnetic field sensors and a processor that corrects signals for far-field magnetic disturbances, coupled with an optical image processor and storage system to record incidents, including images and audio, to automatically document and analyze ferromagnetic object presence and movement near the MRI room access opening.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If ferromagnetic metal detectors are used to detect ferromagnetic objects, then detection capability is improved, but the system lacks independent documentation capability for incident analysis
Solution Approach 1:
The patent combines a ferromagnetic metal detector with an optical recording system (camera and audio recorder) to create an integrated safety system. The detector monitors for ferromagnetic objects while the optical system independently documents incidents, merging detection and documentation functions into a unified apparatus that eliminates information loss.
Solution Approach 2:
The optical recording system acts as an intermediary that captures and preserves incident information independently. When the detector identifies a ferromagnetic object, the recording system automatically documents the event, serving as a mediator that ensures incident data is preserved for later analysis without relying on human witnesses.
2Reliability
If access to the MRI magnet room is restricted to reduce projectile risk, then safety is improved, but the ability to perform root cause analysis is worsened due to lack of witnesses
Solution Approach 1:
The system enables self-documentation of incidents through automatic optical and audio recording triggered by the ferromagnetic detector. The safety system serves itself by capturing incident data without requiring human witnesses, allowing root cause analysis to be performed even when the room is restricted and no personnel are present to observe or report events.
3Measurement precision
If an array of magnetic field sensors is used to detect ferrous material, then detection accuracy is improved, but the system responds to far field magnetic disturbances causing false alarms
Solution Approach 1:
The patent employs an array of magnetic field sensors positioned at specific locations around the MRI room entrance. Each sensor monitors its local magnetic field environment, and the system analyzes spatial patterns of magnetic disturbances to distinguish between local ferromagnetic objects (true threats) and far field disturbances (false alarm sources), applying local quality analysis to improve detection accuracy.
Solution Approach 2:
The detection system is segmented into multiple independent magnetic field sensors arranged in an array, each monitoring a specific portion of the access opening. This segmentation allows the system to analyze the spatial distribution of magnetic field changes and differentiate between localized ferromagnetic objects near the entrance and distant magnetic disturbances, reducing false alarms.
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 provides independent documentation of incidents, enabling effective corrective actions and root cause analysis by accurately distinguishing between ferromagnetic objects entering or leaving the MRI room, reducing the risk of projectile incidents and improving safety responses.
Implementation Method 1
a detector to be configured to passively monitor the residual magnetic field at the location of the opening... an array of magnetic field sensors... The magnetic field changes in response to a presence of ferrous material
Implementation Method 2
an operable MRI apparatus located within a room that has an access opening and with the MRI apparatus providing a residual magnetic field that extends to a location of the access opening
Data Source
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AI summary
An arrangement for association with an MRI and detecting presence of ferrous material and discriminating out far field magnetic disturbance. The arrangement includes a detector configured to monitor the magnetic field and includes an array of sensors (52) arranged about the periphery of an opening (24) in a spaced arrangement such that each sensor is associated with a different portion of the opening. Each of the sensors is configured to output a signal having a value indicative of the sensed magnetic field at the associated portion of the opening. The arrangement includes a corrector (80) configured to correct each signal value from the change in response to the far field magnetic disturbance and to provide respective corrected signal values. The arrangement includes a processor (72) configured to use the corrected signal values to determine a ferrous-indicating limit is exceeded and to provide a safety response that addresses the ferrous-indicating limit exceed condition.