Endoscope Pull Wire Electrical Circuit for Tension Detection
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Solution Overview
Problem
Existing steerable elongate medical devices, such as catheters, face challenges in accurately detecting tendon tension and breakage due to noise from sensor size and placement, and the complexity of integrating resistance measuring wires, which increases cost and complexity.
Innovation Solution
The implementation of electrically conductive tendons with a sensing circuitry that measures electrical resistance to detect tension and breakage, allowing for accurate and reliable detection of tendon tension and breakage in steerable elongate medical devices like catheters, using a system with a plurality of electrically conductive tendons and a sensing circuit configured to measure resistance changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional strain gauge sensors are used to measure tendon tension, then tension measurement capability is provided, but sensor size and placement result in noise or inaccurate readings
Solution Approach 1:
The patent replaces traditional mechanical strain gauge sensors with an electrical resistance-based measurement system. The tendon itself becomes the sensing element, where changes in electrical resistance directly correlate with tendon tension and elongation. This substitution eliminates the need for separate mechanical sensors, reducing noise and improving measurement accuracy while simplifying the overall device structure.
Solution Approach 2:
The tendon serves dual functions: it provides mechanical steering capability and simultaneously acts as the sensing element for tension measurement. By making the tendon electrically conductive and measuring its resistance changes, the system uses the tendon's own physical properties for sensing, eliminating the need for external sensors and reducing system complexity.
2Reliability
If external force sensors are used to detect wire breakage, then breakage detection capability is provided, but reliability is reduced and complexity, size, and cost increase
Solution Approach 1:
The patent replaces external mechanical force sensors with an electrical resistance-based detection system. Since the tendon is electrically conductive, a breakage event results in an immediate and detectable change in electrical continuity and resistance. This provides highly reliable breakage detection while eliminating the need for separate force sensors, thereby reducing device complexity, size, and cost.
3Measurement precision
If resistance measuring wires are integrated into steerable guidewire, then tension measurement capability is achieved, but manufacturing complexity and difficulty in delivering power increase
Solution Approach 1:
The patent merges the tendon's mechanical function with its electrical sensing function into a single integrated component. The tendon is constructed with electrically conductive materials that allow it to serve both as the steering mechanism and the tension sensor. This integration simplifies manufacturing by eliminating the need to separately install and connect resistance measuring wires, as the tendon itself provides the sensing capability.
4Reliability
If tendon tension is not accurately detected, then device simplicity is maintained, but slack removal and control reliability are compromised
Solution Approach 1:
The patent replaces complex mechanical tension detection systems with a simple electrical resistance measurement system. The conductive tendon's resistance changes provide direct, real-time feedback on tension levels, enabling accurate slack detection and removal without requiring complex mechanical sensors or algorithms. This approach improves control reliability while maintaining device simplicity.
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 enables easy and accurate detection of tendon tension and breakage, reducing slack and improving the reliability of steerable medical devices, while being cost-effective and minimizing additional complexity, allowing for precise control and feedback in medical procedures.
Implementation Method 1
a sensing circuit configured to measure resistance changes
Data Source
AI summary
An endoscopic system includes an elongate shaft, a pull wire that runs a length of the elongate shaft, a handle coupled to a proximal portion of the elongate shaft, the handle housing a proximal portion of the pull wire, the handle being couplable to a robotic driver configured to tension the pull wire to cause articulation of the elongate shaft, and one or more conductors that run the length of the elongate shaft, the one or more conductors being electrically coupled to the pull wire at a distal portion of the elongate shaft and configured to form part of a closed electrical circuit with the pull wire.