Patient Imaging Table Deflection Compensation for Stable Positioning
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Solution Overview
Problem
In medical imaging systems, patient weight causes the patient table to sag, leading to vertical position shifts within the gantry, which complicates height adjustments, reduces patient comfort, and degrades image quality due to increased stiffness and material thickness, especially in multi-modality imaging.
Innovation Solution
A patient support table system with a table portion that generates feedback on pallet deflection, using springs and sensors to tilt the table and maintain constant altitude and angle, eliminating the need for catchers and allowing thinner pallets with improved image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a catcher mechanism is used to receive the patient pallet, then the vertical positioning stability is improved, but the device complexity and system bulk increase
Solution Approach 1:
The patent removes the catcher mechanism entirely from the system. Instead of adding a catcher to receive the pallet, the invention uses a deflection compensating mechanism integrated into the table portion that actively counteracts pallet sagging through feedback control, thereby eliminating the need for the catcher and reducing system bulk while maintaining positioning stability.
Solution Approach 2:
The patent implements a feedback control system that monitors pallet deflection and adjusts the table portion accordingly. Sensors detect the amount of sagging, and this information is fed back to actuators that modify the table portion's position to compensate for deflection, maintaining stable vertical positioning without requiring a catcher mechanism.
2Strength
If a support rod or beam is added to stiffen the pallet, then the deflection resistance is improved, but the image data interference increases
Solution Approach 1:
The patent introduces the table portion as an intermediary element between the patient pallet and the imaging system. Rather than modifying the pallet itself with support rods, the table portion acts as a mediator that provides deflection compensation through its adjustable position, controlled by feedback from sensors about pallet sagging, thereby avoiding direct interference with image data.
3Strength
If the patient table is made thick and dense to support patient weight, then the deflection resistance is improved, but the image attenuation increases
Solution Approach 1:
The patent removes the need for thick, dense pallet construction by extracting the support function to the table portion. The pallet can remain thin and less attenuating since the table portion, which is not in the imaging path, provides the necessary structural support and active deflection compensation through its feedback-controlled positioning adjustments.
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 maintains patient positioning consistency, reduces image artifacts, and simplifies adjustments, enhancing image quality and reducing system bulk while accommodating varying patient weights without manual adjustments.
Implementation Method 1
a potentiometer that is coupled to the first spring and measures compression thereof
Implementation Method 2
a first spring and a second spring, which couple support arm and support arm, respectively, to the table portion
Implementation Method 3
A sensor that senses deviation in altitude or angle of a patient on the pallet from a desired altitude or angle
Implementation Method 4
A lever pivots on a fulcrum to pull a pair of wires over a pair of pulleys to exert a downward force on a rearward portion of the table portion
Implementation Method 5
A lever pivots on a fulcrum to pull a pair of wires over a pair of pulleys
Data Source
AI summary
When inserting a patient into a bore of a patient imaging device (e.g., CT, SPECT, PET, MRI, fMRI, etc.), a cantilevered pallet supported by an adjustable table deflects under the patient's weight. A pair of springs couples the table to first and second support arms, which are coupled to each other at a pivot point. A lever is coupled to the front end of the table and pivots on a fulcrum. A pair of wires are coupled to a rearward end of the lever and passed over respective pulleys before being coupled to a rearward portion of the table. A component of the patient's weight applied to the front edge of the table causes the lever to pivot on its fulcrum, raising the forward ends of the wires, which pass over the pulleys and pull the rearward end of the table downward to maintain the patient at a desired altitude and/or angle.