Surgical Instrument Articulation Joint Cover and Locking Mechanism
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Solution Overview
Problem
Existing surgical staplers face difficulties in preventing the end effector from being articulated relative to the shaft assembly after the jaw members are closed, which can apply shear forces to soft tissue, and require significant force to extend the cutting member, leading to premature return and multiple trigger strokes.
Innovation Solution
A surgical instrument with a locking mechanism that engages the shaft assembly and end effector to fix their relative relationship, a closure system that prevents unlocking, and a firing drive with a flexible band and brake to control the movement of the cutting member, ensuring stable tissue handling and efficient operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the end effector is articulated relative to the shaft assembly after the jaw members are closed, then the surgeon can reposition the end effector, but shear force is applied to the soft tissue captured between the jaw members
Solution Approach 1:
The locking mechanism is engaged during the closing operation to prevent articulation of the end effector relative to the shaft assembly. This preliminary constraint prevents the harmful shear force from being applied to the captured tissue, while still allowing the surgeon to reposition the end effector after the closing operation is complete by disengaging the locking mechanism.
2Ease of operation
If a return spring is used to retract the cutting member, then the cutting member can be retracted to its starting position, but significant force is required to extend the spring and the spring may prematurely return the cutting member
Solution Approach 1:
The traditional return spring mechanism is replaced with a flexible band system that works in conjunction with a brake mechanism. The flexible band stores energy during the advancing motion and the brake controls the retraction speed and force, eliminating the need to overcome significant spring force and preventing premature return of the cutting member.
3Reliability
If the brake is engaged with the flexible band, then the cutting member movement is controlled, but the brake must be reliably disengaged to allow retraction
Solution Approach 1:
The brake mechanism is designed with automatic feedback control where the actuator position directly controls brake engagement and disengagement. When the actuator advances, the brake automatically engages to control the movement; when the actuator retracts, the brake automatically disengages to allow smooth retraction. This feedback mechanism ensures reliable movement control while maintaining ease of operation without requiring manual brake adjustment.
Data Source
AI summary
A surgical instrument including a shaft, an end effector, and a joint, wherein the end effector can be moved relative to the shaft about the joint. In various embodiments, the joint can include a cover configured to be positioned intermediate the end effector and the shaft. In at least one embodiment, the cover can be connected to at least one of the end effector and the shaft and can be configured to at least partially surround the joint in order to prevent soft tissue positioned adjacent to the joint from being pulled into and/or pinched by the joint.