Decoupling Electrosurgical Cutting Member Trigger
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Solution Overview
Problem
Existing electrosurgical instruments with knife lockout features can cause the knife to experience a hard release when jaws reach the correct position, leading to loss of control over the cutting member's speed, potentially resulting in accidental cutting.
Innovation Solution
An electrosurgical instrument with a coupling system that mechanically couples and decouples the cutting member from the cutting member trigger, allowing controlled distal and proximal movement of the cutting member, preventing accidental cutting by ensuring the cutting member is only activated when the jaws are in the correct position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a knife lockout feature is implemented to prevent accidental cutting, then safety is improved, but the cutting member can experience a hard release when jaws reach the correct position, leading to loss of control over cutting speed
Solution Approach 1:
The system dynamically transitions between locked and unlocked states based on jaw position. The lockout feature is not static but changes its state according to the operational phase: locked during positioning to prevent accidental cutting, and unlocked during the cutting stroke to allow controlled motion. This dynamic behavior resolves the contradiction by adapting the safety mechanism to the specific operational requirements at each moment.
Solution Approach 2:
The coupling member is positioned and engaged in advance before the cutting action occurs. The lockout mechanism is activated during the jaw closure phase to prepare for the upcoming cutting stroke, ensuring safety is established before the critical cutting moment. This preliminary action allows the system to be ready for controlled cutting while maintaining safety during the approach phase.
2Ease of operation
If the cutting member is mechanically coupled to the trigger for controlled movement, then ease of operation is improved, but accidental cutting can occur if the trigger is pulled before jaws are in the correct position
Solution Approach 1:
The coupling member acts as an intermediary between the trigger and the cutting member. It receives the operator's input from the trigger and conditionally transmits it to the cutting member based on jaw position. This intermediary component provides a buffer that allows controlled operation while filtering out inappropriate activation attempts, thus enabling ease of operation without sacrificing safety.
Solution Approach 2:
The system incorporates feedback from the jaw position sensing mechanism to the coupling member. The coupling member's state (locked or unlocked) is determined by real-time feedback about whether the jaws are in the correct position. This feedback loop ensures that the cutting member can only be activated when appropriate, maintaining reliability while preserving ease of operation through intuitive trigger control.
3Ease of operation
If the coupling member remains engaged to allow continuous control, then ease of operation is improved, but the cutting member may move too quickly when released from lockout
Solution Approach 1:
The coupling member's engagement level is dynamically adjusted based on operational phase. During the lockout phase, it maintains full engagement for continuous control. When the cutting stroke begins, it transitions to a controlled release that regulates the speed of the cutting member. This dynamic adjustment allows continuous control during positioning while preventing excessive speed during cutting.
Solution Approach 2:
The coupling member is designed to provide a cushioned transition during the unlock phase. Rather than an abrupt release that would cause the cutting member to shoot forward, the coupling mechanism incorporates a controlled disengagement that gradually transfers motion from the trigger to the cutting member. This beforehand cushioning ensures smooth speed control while maintaining continuous operational control.
Data Source
AI summary
An electrosurgical instrument. The electrosurgical instrument includes a first arm, a second arm and a coupling system. The first arm includes a first jaw. The second arm is pivotably connected to the first arm and includes a second jaw, a cutting member movable within the first and second jaws, and a cutting member trigger. The coupling system includes a coupling member mechanically coupled to the cutting member trigger. The coupling member is movable between a first position and a second position. In the first position of the coupling member, the cutting member is mechanically uncoupled from the cutting member trigger. In the second position of the coupling member, the cutting member is mechanically coupled to the cutting member trigger.