Endoscope Propulsion Wire Breakage Detection via Motor Speed Monitoring
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing endoscope propulsion systems face issues with reliable detection of wire device breakage, leading to poor operability and failure in removing the propulsion assembly from the gastrointestinal tract due to resonance vibrations and metal fatigue.
Innovation Solution
A propulsion apparatus with first and second wire devices, each connected to motors, includes a monitoring unit that detects speed differences and elapsed time to accurately identify wire breakage, with a controller stopping the motors and potentially reversing the tip device to exit the body cavity upon detection, ensuring reliable breakage detection and maintaining operability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If wire devices are used to drive the propulsion assembly, then the endless track device can be moved effectively, but the wire devices are likely to break with time due to metal fatigue
Solution Approach 1:
The system performs preliminary detection of wire device status by continuously monitoring motor rotational speeds. Before complete breakage occurs, the monitoring unit detects speed differences that indicate wire degradation or impending failure, allowing preventive action to be taken.
Solution Approach 2:
The system implements a feedback mechanism where the monitoring unit continuously measures the rotational speeds of multiple motors and compares them. When a speed difference exceeds a predetermined threshold, the system receives feedback about wire device status and adjusts motor operation accordingly to prevent failure.
2Measurement precision
If speed difference detection is used to identify wire breakage, then breakage can be detected, but resonance vibration of the motors may cause false detection and poor operability
Solution Approach 1:
The system dynamically adjusts the detection threshold based on operating conditions. The predetermined threshold is not fixed but can be modified according to motor load, speed, and vibration characteristics, allowing the system to distinguish between normal resonance vibrations and actual wire breakage.
Solution Approach 2:
The system changes the parameter used for detection from simple speed difference to a more sophisticated metric that accounts for resonance characteristics. By analyzing the temporal pattern and magnitude of speed differences relative to known resonance frequencies, the system can differentiate between vibration-induced speed variations and true breakage conditions.
3Reliability
If the endless track device is stopped upon detecting wire breakage, then safety is improved, but operability for propulsion is lost
Solution Approach 1:
The control system is segmented into multiple response levels. Upon detecting wire breakage, the system does not immediately stop all motors but instead isolates the affected motor while allowing other motors to continue operation. This segmentation maintains partial propulsion capability while ensuring safety.
Solution Approach 2:
The system dynamically adjusts motor operation based on the specific breakage condition. Rather than a static stop-all-response, the controller modifies the operational state of individual motors based on which wire device failed, maintaining propulsion operability through remaining functional components while preventing further damage.
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 system effectively detects wire breakage and maintains propulsion operability by using a monitoring unit and controller to manage motor activity, preventing unnecessary removal attempts and ensuring safe extraction of the endoscope.
Implementation Method 1
first and second motors connected with proximal ends of respectively the first and second wire devices for generating torque for actuating the propulsion assembly
Implementation Method 2
resonance vibration of the motors in rotation may occur due to a moment of inertia of the motors and torsional rigidity of the wire devices according to a change in the speed with the flexure of the wire devices
Data Source
AI summary
A propulsion apparatus for an endoscope includes a propulsion assembly for mounting on a tip device of the endoscope, for propulsion in a body cavity. First and second wire devices are disposed to extend from the tip device in a proximal direction, having a coil winding, for rotating to drive the propulsion assembly. First and second motors are connected with proximal ends of respectively the first and second wire devices, for rotating the first and second wire devices. A timer is actuated if a speed difference between rotational speeds of the first and second motors becomes equal to or more than a reference speed value, for measuring an elapsed time. A break detector detects breakage of the first wire device if the elapsed time becomes equal to or longer than a predetermined time. A controller controls the first and second motors in response to an output of the break detector.