Surgical Stapling Instrument with Manual Retraction Mechanism
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Solution Overview
Problem
Existing surgical stapling instruments require additional retraction force to overcome spring forces during firing, especially when using articulating end effectors, which can increase the required firing force and lead to binding or malfunction concerns.
Innovation Solution
A surgical instrument with a manually actuatable retraction mechanism that does not employ a retraction spring, utilizing a linked rack and gear system to facilitate multiple-stroke firing without additional retraction forces, allowing for ergonomic and efficient stapling and severing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a retraction spring is used to automatically retract the firing member, then the retraction action is achieved, but additional retraction force must be overcome during firing which increases the required firing force and may cause binding or malfunction
Solution Approach 1:
The patent removes the retraction spring from the system entirely. Instead of using a spring to provide retraction force, the design employs a linked rack mechanism that passively returns the firing member to its starting position through mechanical linkage, eliminating the need to overcome spring force during firing and thus reducing the required firing force and preventing binding.
Solution Approach 2:
The patent replaces the spring-based retraction mechanism with a linked rack and gear system. The linked rack provides the retraction function through mechanical linkage rather than elastic recovery, substituting a different mechanical principle that does not require overcoming spring force during the firing stroke.
2Device complexity
If a spring is used to retract the firing member, then retraction is achieved, but the spring force increases the complexity of the firing mechanism and may lead to ergonomic issues
Solution Approach 1:
The patent extracts and removes the spring component from the firing mechanism, simplifying the overall device complexity. By eliminating the spring and its associated mounting structures, adjustment mechanisms, and interaction points, the design achieves a cleaner, simpler mechanism that is easier to manufacture and operate.
Solution Approach 2:
The patent substitutes the spring-based retraction system with a linked rack mechanism that uses pure mechanical linkage. This replacement eliminates the need for spring force management, reducing mechanical complexity and improving ergonomic handling by removing the need to account for variable spring forces during operation.
Data Source
AI summary
A surgical stapling and severing instrument particularly suited to endoscopic procedures incorporates a handle that produces separate closing and firing motions to actuate an end effector. In particular, the handle produces multiple firing strokes in order to reduce the required amount of force required to fire (i.e., staple and sever) the end effector. A linked transmission reduces the required handle longitudinal length, yet achieves a rigid, strong configuration when straightened for firing. A traction biased firing mechanism avoids binding in driving this straightened linked rack. The instrument further has a manually actuatable retraction system that does not require the use of additional springs or other mechanisms to generate retraction forces which must be overcome when generating the forces necessary to fire the device. In various embodiments, the retraction system provides a visual indication to the surgeon as to how far firing has progressed.