Ratcheting Trigger Mechanism for Surgical Stapler Firing Control
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Solution Overview
Problem
Current surgical stapling instruments lack a reliable mechanism to ensure proper alignment and complete firing of staples, leading to incomplete stapling and potential tissue damage during anastomotic procedures.
Innovation Solution
The design incorporates a ratcheting mechanism with a trigger assembly that prevents the trigger from returning to the unfired position until a full firing stroke is completed, along with an indicator system to ensure the anvil gap is within a desired range, and automatic release features to facilitate safe instrument removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a trigger mechanism is used to actuate the stapling instrument, then the instrument can be operated to fire staples, but the trigger may return to the unfired position prematurely causing incomplete stapling
Solution Approach 1:
The ratcheting mechanism is engaged in advance to lock the trigger in the fired position, preventing premature return before stapling is complete. This preliminary locking action ensures that once the trigger is pulled, it remains actuated throughout the entire stapling process.
Solution Approach 2:
The ratcheting mechanism serves as an intermediary between the trigger and the stapling action, mediating the trigger's movement to ensure it remains in the fired position. This intermediate mechanism prevents direct premature return of the trigger while allowing controlled firing.
2Adaptability or versatility
If the trigger can return to the unfired position, then the instrument can be reset for another firing, but incomplete stapling may occur causing tissue damage
Solution Approach 1:
The ratcheting mechanism is engaged in advance to lock the trigger in the fired position, preventing premature return before stapling is complete. This preliminary locking action ensures that once the trigger is pulled, it remains actuated throughout the entire stapling process.
Solution Approach 2:
The ratcheting mechanism serves as an intermediary between the trigger and the stapling action, mediating the trigger's movement to ensure it remains in the fired position. This intermediate mechanism prevents direct premature return of the trigger while allowing controlled firing.
3Reliability
If a ratcheting mechanism is added to prevent premature trigger return, then stapling reliability is improved, but device complexity increases
Solution Approach 1:
The trigger assembly is segmented into distinct functional components: the trigger itself, the ratcheting mechanism with teeth and pawl, and the spring system. This segmentation allows each component to perform its specific function independently while working together to achieve reliable trigger locking.
Solution Approach 2:
The ratcheting mechanism operates through periodic engagement of the pawl with the teeth, creating a series of locked positions. This periodic action allows the trigger to be locked in discrete stages, providing reliable positioning without requiring a completely continuous locking system.
4Reliability
If the trigger is locked in the fired position, then complete stapling is ensured, but automatic release for instrument removal is hindered
Solution Approach 1:
The spring-loaded ratcheting mechanism automatically releases the trigger after firing, allowing the trigger to return to the unfired position without manual intervention. This self-service feature facilitates easy instrument removal while maintaining the locked position during the critical stapling phase.
Solution Approach 2:
The ratcheting mechanism operates through periodic engagement of the pawl with the teeth, creating a series of locked positions. This periodic action allows the trigger to be locked in discrete stages, providing reliable positioning without requiring a completely continuous locking system.
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 ensures complete stapling, prevents tissue damage, and allows for precise control during surgical procedures, enhancing the reliability and safety of anastomotic procedures.
Implementation Method 1
a ratcheting mechanism with a trigger assembly that prevents the trigger from returning to the unfired position until a full firing stroke is completed
Data Source
AI summary
A surgical instrument includes a body, a pivotable trigger, and a ratcheting assembly. The ratcheting assembly may include a rotary ratchet coupled to the trigger and a pawl coupled to the body. The rotary ratchet may further include a ramp that disengages the ratchet from the pawl. A release feature may be included to selectively disengage a second member of the ratcheting assembly from a first member. In some versions, the release feature may include a rotation knob or a slidable handle. In another configuration, the ratcheting assembly may have a first member coupled to an actuator and a second member coupled to the body. The assembly may include a lock member coupled to the body that selectively engages a plurality of teeth disposed on the actuator. Alternatively, the assembly may include a pivotable pawl coupled to the actuator that engages one or more notches formed in the body.