Liver Coil Position Projection Using Optical Body-Surface Estimation
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Solution Overview
Problem
The miniaturization of receive coil units in MRI systems narrows the allowable range for misregistration, making it difficult to accurately attach the coil to the liver, which has a variable position due to individual physique, often requiring radiography for positioning, which is undesirable.
Innovation Solution
A projection control device uses optical imaging and a processor to estimate the liver's position based on optical images, projecting a marker to guide the appropriate attachment of the receive coil unit without radiography, utilizing evaluation values and reference information to determine the liver's location.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the receive coil unit is miniaturized, then the portability and ease of attachment are improved, but the allowable range for misregistration is narrowed, making accurate positioning difficult
Solution Approach 1:
The system performs preliminary action by estimating the liver position and projecting guidance markers onto the subject's body surface before the receive coil unit is attached. This allows the operator to position the coil accurately based on visual guidance, eliminating the need for precise pre-measurement and enabling easy attachment while maintaining positioning accuracy.
Solution Approach 2:
The projection marker serves as an intermediary between the estimated liver position (internal target) and the receive coil unit (external device). By projecting a visual marker onto the body surface, the system creates an intermediate reference that guides the operator to attach the coil at the correct position, resolving the contradiction between easy attachment and precise positioning.
2Volume of moving object
If a small receive coil unit is used, then the portability is improved, but the degree of misregistration allowed is reduced, requiring more precise positioning
Solution Approach 1:
The system performs self-service by automatically estimating the liver position based on optical images of the subject's body and generating guidance markers without requiring external radiography equipment. This self-contained positioning capability enables precise attachment guidance even with miniaturized coils, maintaining positioning precision while benefiting from the small coil size.
3Manufacturing precision
If radiography is performed to determine liver position, then the positioning accuracy is improved, but the subject is exposed to radiation and the apparatus complexity increases
Solution Approach 1:
The system replaces the radiography-based positioning method with an optical imaging-based estimation method. Instead of using ionizing radiation (X-rays) to visualize internal structures, the system uses optical cameras to capture body surface images and estimates the liver position based on body measurements and anatomical relationships. This substitution eliminates radiation exposure while maintaining positioning accuracy through computational estimation and visual guidance.
4Manufacturing precision
If radiography is used to understand liver position, then the positioning accuracy is improved, but the apparatus configuration becomes complicated
Solution Approach 1:
The system achieves universality by using a multi-functional approach: optical cameras capture body surface images, the processor estimates liver position based on these images, and projection apparatus displays guidance markers. This integrated system replaces the need for separate radiography equipment, positioning devices, and multiple imaging systems, simplifying the overall apparatus configuration while maintaining positioning accuracy through the unified optical estimation and guidance workflow.
Data Source
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AI summary
A projection control device includes a processor, in which the processor is configured to acquire an optical image of a subject, estimate a position of a liver of the subject based on the optical image, and control a projection apparatus to project a marker representing the estimated position of the liver onto the subject, as a marker representing a position at which a receive coil unit of a magnetic resonance imaging apparatus is attached.