Dielectric Mirror Optical Pathway for MRI Monitoring
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Solution Overview
Problem
Magnetic resonance examination systems face challenges in effectively monitoring the examination zone due to obstacles within the camera's direct line of sight, such as auxiliary equipment and patient body parts, which obstruct the view and require complex and costly solutions to maintain clear imaging.
Innovation Solution
The implementation of non-metallic, dielectric mirrors positioned within the examination zone or on auxiliary equipment to create optical pathways that circumvent obstacles, allowing for unobstructed imaging and illumination, using a camera and optionally an infrared light source, without interfering with the magnetic resonance system's operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a camera is mounted outside the MRI device's bore to monitor the examination zone, then the camera avoids electromagnetic interference with the MRI system, but the camera's direct line of sight is obstructed by auxiliary equipment and patient body parts
Solution Approach 1:
The patent introduces a third dimension by mounting mirrors on the inner wall of the examination zone to create indirect optical paths. Instead of relying on direct line-of-sight imaging, the system uses reflected light paths that wrap around obstacles, enabling the camera to capture images of obstructed regions by utilizing the vertical and radial dimensions of the cylindrical bore space.
Solution Approach 2:
The patent employs mirrors as intermediary elements to transfer light from obstructed regions to the camera. These mirrors act as mediators that redirect optical paths around obstacles such as RF coils and patient body parts, allowing the camera to indirectly observe regions that would otherwise be hidden from direct view.
2Area of stationary object
If multiple cameras are used to cover different portions of the examination zone, then complete monitoring coverage is achieved, but system cost and complexity increase
Solution Approach 1:
The patent makes a single camera multi-functional by using multiple mirrors to direct light from different regions of the examination zone to the same camera sensor. This allows one camera to perform the function of multiple cameras would otherwise be needed, reducing system complexity while maintaining comprehensive monitoring coverage of the entire examination zone.
Solution Approach 2:
The patent creates multiple virtual camera viewpoints through mirror reflections. Each mirror produces a reflected image that appears to come from a different spatial position, effectively copying the camera's observational capability to multiple locations without physically placing multiple cameras in the examination zone.
3Ease of operation
If metallic mirrors are used in the examination zone, then optical pathways are created, but electromagnetic interference with the MRI system occurs
Solution Approach 1:
The patent changes the material parameter of the mirror from metallic to non-metallic (dielectric). This material substitution fundamentally alters the electromagnetic properties of the mirror, making it transparent or non-interfering with the MRI's radiofrequency fields while still maintaining its optical reflective function for creating the desired light paths.
Solution Approach 2:
The patent uses dielectric materials with specific optical properties to create mirrors that combine reflective functionality with electromagnetic transparency. These non-metallic mirror materials provide the necessary optical reflection for image capture while being electromagnetically compatible with the MRI system's operating frequencies.
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 comprehensive and unobstructed monitoring of the examination zone, reducing claustrophobia for patients and maintaining the integrity of the MRI system's operations by providing clear views and vital sign monitoring without adding significant cost or complexity.
Implementation Method 1
The non-metallic mirror reflects an image output from an image output device
Implementation Method 2
A dichroic mirror is used in an optical path incident on the eyeball of an examinee from substantially a front direction to present a visual stimulus from a projector and a screen. The eyeball is illuminated by an infrared lamp and movement of the eyeball is monitored by an infrared camera through the dichroic mirror, i.e. using a configuration in which the visual stimulus in the optical wavelength spectrum is reflected by the dichroic mirror while infrared light to illuminate and monitor the eye passes through.
Data Source
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AI summary
A magnetic resonance examination system with an examination zone (11) and comprising a camera (21) and non-metallic mirror (22), in particular within the examination zone (11), arranging an optical pathway (23) between a portion of the examination zone (11), via the non-metallic mirror (22), and the camera (21). The camera can obtain image information from that portion even if the direct line of sight (28) is blocked. The non-metallic mirror is a dielectric mirror having a macroscopically grated base.