Radiography Arm Friction Control for Stable Manual Positioning

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Solution Overview

Problem

Existing radiography apparatuses face challenges in maintaining stable manual operation forces for arms holding both irradiation and image receiving units, leading to potential inadvertent rotation during surgeries due to varying weights and external contacts.

Innovation Solution

A radiography apparatus with a displacement mechanism and a switchable friction mechanism that adjusts frictional force to manage manual operation loads, incorporating an electromagnetic brake and a rotation mechanism for precise arm positioning, and includes an attachment detection system to enhance stability during image receiving unit detachment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the friction mechanism is set to apply high frictional force to prevent inadvertent rotation, then the arm stability is improved, but the manual operation force required to position the arm increases

Engineering Contradiction:
Improvearm stabilityVSAvoidmanual operation force
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The friction mechanism is designed to be switchable between different frictional force states, allowing the system to dynamically adapt to different operational requirements. The switching mechanism enables transition between a first state with high frictional force for stability during surgery and a second state with reduced frictional force for easier positioning, resolving the contradiction between stability and ease of operation.

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If the friction mechanism is set to apply low frictional force to enable easy positioning, then the ease of operation is improved, but the arm becomes susceptible to inadvertent rotation due to external forces

Engineering Contradiction:
Improvemanual operation forceVSAvoidarm stability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The switchable friction mechanism allows the operator to select between different frictional force levels based on the operational phase. During positioning operations, the second state with lower frictional force enables easy arm movement. During surgery, switching to the first state with higher frictional force prevents inadvertent rotation, thus resolving the contradiction between ease of operation and arm stability.

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If the arm is designed to hold both irradiation unit and image receiving unit, then the functionality is improved, but the arm weight increases leading to greater operation force requirements

Engineering Contradiction:
ImprovefunctionalityVSAvoidoperation force
Core Design Contradiction:
Adaptability or versatilityVSForce

Solution Approach 1:

The switchable friction mechanism compensates for the increased arm weight by providing controllable frictional force. In the second state with reduced frictional force, the arm can be easily repositioned despite its weight. The mechanism effectively manages the operation force requirement while maintaining the enhanced functionality of holding both irradiation and image receiving units.

Inventive Principle:
Principle #15Dynamics

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 apparatus effectively reduces manual operation forces, prevents inadvertent arm rotation, and maintains stable positioning, even with weight imbalances, by dynamically controlling friction and using an electromagnetic brake, thus ensuring precise and secure operation during surgeries.

Implementation Method 1

a friction mechanism that is switchable between a first state in which a frictional force is applied to the arm in a direction opposite to a direction in which the arm is displaced

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

incorporating an electromagnetic brake and a rotation mechanism for precise arm positioning

Methodology Applied
Scientific EffectElectromagnetic force: Electromagnet

Data Source

PatentEP3797701B1Radiography apparatus
Publication Date: 2025.08.20 FUJIFILM CORP
  • EP3797701B1 patent drawingFigure 1
  • EP3797701B1 patent drawingFigure 2A
  • EP3797701B1 patent drawingFigure 2B

AI summary

Provided is a radiography apparatus that can change a load due to a manual operation force of an arm. A radiography apparatus includes: an irradiation unit that emits radiation; an arm that can hold the irradiation unit and an image receiving unit in a facing posture; a first rotation mechanism that rotates the arm; and a friction mechanism that is switchable between a first state in which a frictional force is applied to the arm in a direction opposite to a direction in which the arm is rotated and a second state in which the frictional force applied to the arm is less than that in the first state.