Circular Stapler Independent Actuation Segmentation
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Solution Overview
Problem
Existing circular stapling instruments require simultaneous actuation for staple formation and tissue cutting, limiting staple formation height to the knife travel distance and necessitating sufficient force for both functions, which can be inefficient and restrictive.
Innovation Solution
A circular stapler with a cartridge assembly that allows independent actuation of staple formation and tissue cutting, where the staple forming mechanism and knife assembly can be advanced separately, enabling independent strokes for forming staples and cutting tissue.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If simultaneous actuation of staple forming mechanism and knife advancement is used, then both functions are performed in one stroke, but the force required is excessive and staple formation height is limited to knife travel distance
Solution Approach 1:
The patent divides the simultaneous actuation into two separate, independently controllable strokes: a first stroke for staple formation and a second stroke for tissue cutting. This segmentation allows each function to be optimized independently, enabling greater staple formation height in the first stroke without being constrained by the knife travel distance required in the second stroke, and reduces the peak force requirement by performing functions sequentially rather than simultaneously.
2Ease of operation
If simultaneous actuation of staple forming mechanism and knife advancement is used, then one stroke performs both functions, but the actuation assembly must provide sufficient force for both functions simultaneously
Solution Approach 1:
The actuation is segmented into two independent strokes controlled by the same actuation assembly. The first stroke advances the staple forming mechanism while the knife remains stationary, requiring force only for staple formation. The second stroke advances the knife while the staple forming mechanism is held stationary, requiring force only for cutting. This temporal segmentation of forces makes the operation easier and more controllable.
Solution Approach 2:
The patent employs a dynamic system where the staple forming mechanism and knife can be independently advanced or held stationary during different phases of actuation. This dynamic control allows the actuation assembly to optimize force application for each specific task at each moment, rather than maintaining constant high force for both simultaneous operations.
3Length of moving object
If staple forming mechanism and knife travel the same distance, then simultaneous actuation is possible, but staple formation height is limited to knife travel distance
Solution Approach 1:
The patent segments the movement of the staple forming mechanism and knife into independent strokes. During the first stroke, only the staple forming mechanism travels the full distance required for optimal staple formation height, while the knife remains stationary. During the second stroke, only the knife travels through the tissue for cutting, while the staple forming mechanism is held in place. This segmented approach allows each component to travel the full distance needed for its function without being constrained by the other component's travel requirements.
Solution Approach 2:
The anvil assembly serves as an intermediary structure that enables independent movement of the staple forming mechanism and knife. The anvil provides a stationary reference point and support surface that allows the staple forming mechanism to be advanced independently for staple formation, and later allows the knife to be advanced independently for cutting, thereby decoupling the travel distances of the two moving components.
Data Source
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AI summary
A circular stapling instrument (10) including a stapling forming assembly that is actuated independently from actuation of the cutting assembly is provided. The instrument includes a handle assembly (20), an elongate body (30) extending from the handle assembly, a cartridge assembly (190) mounted on a distal end of the elongate body. The cartridge assembly (110) includes a pusher (130) and a knife assembly (150). The knife assembly is selectively fixed relative to the pusher.