Spring-Loaded Bell-Crank Locking Mechanism for Detector Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Integrating cone-beam CT and SPECT systems with X-ray gantries poses challenges due to axial displacement and temporal offset between data acquisitions, leading to subject motion and alignment issues, particularly with asymmetric detector configurations.
Innovation Solution
An articulating arm locking assembly with a bell-crank mechanism and positive spring-force locking mechanism is introduced, allowing for independent multi-directional forces, automated locking, and reduced backlash, fatigue, and misalignment, enabling precise positioning and stability of the flat panel X-ray detector.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If CT and NM detectors are axially displaced to combine modalities, then imaging capability is improved, but subject motion and alignment issues worsen
Solution Approach 1:
An articulating arm with automated locking mechanism serves as an intermediary component to precisely position and stabilize the flat panel detector relative to the SPECT gantry. The locking mechanism with locking pins and bell-crank levers acts as a mediator to eliminate positional drift and ensure accurate alignment between CT and NM detectors, thereby resolving the alignment precision issues while maintaining the benefits of combined modality imaging.
2Manufacturing precision
If flat panel detector is deployed to reduce artifacts, then image quality is improved, but positioning stability requirements worsen
Solution Approach 1:
The automated locking mechanism performs preliminary action by pre-positioning and securing the flat panel detector at the exact required location before imaging begins. The locking pins engage with positioning features and the bell-crank levers lock the articulating arm in place, ensuring the detector remains stably positioned throughout the imaging procedure, thus maintaining both image quality and positioning stability.
3Device complexity
If manual positioning is used for articulating arm, then device complexity is reduced, but positioning precision and repeatability worsen
Solution Approach 1:
The locking mechanism is designed to be self-actuating through a cam-activated system. When the operator rotates the cam, it automatically triggers the locking pins to extend and engage, and the bell-crank levers to lock the articulating arm in position. This self-service mechanism eliminates the need for complex manual adjustment systems while achieving high positioning precision and repeatability, as the locking action occurs automatically at the precise moment of cam rotation.
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 solution ensures accurate and repeatable positioning of the flat panel detector, reducing artifacts and improving image registration between nuclear and CT modalities, enhancing clinical confidence and image quality by minimizing patient movement and scanner complexity.
Implementation Method 1
a first actuator coupled to a first flange via a first spring mechanism, and to a second flange by a first pivot pin
Data Source
AI summary
When locking a medical imaging device detector in position to generate a medical image, an articulating arm includes top and bottom portions, coupled to a gantry and to a distal portion that is coupled to a detector. The top and bottom portions each include an over-the-center bell crank locking mechanism with a shank couple to a central handle. Each shank includes a pair of flanges that are coupled to a pair of actuators by both a pivot pin and a spring mechanism. Each actuator is coupled to a crank. When the handle is rotated to a locked position, a sliding lock extends to lock the articulating arm in position relative to the gantry, and a lever arm is extended to cause a shaft to rotate. Rotation of the shaft actuates a sliding pin linkage, which urges a pair of pins outward to lock the articulating arm in position relative to the detector.