Surgical Stapling Instrument Lockout and Firing Member Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Surgical stapling instruments often fire prematurely due to improper installation of staple cartridges, and existing mechanisms may lack sufficient compressive strength to deliver multiple rows of staples without deformation.
Innovation Solution
A lockout member with a lockout shelf and firing member featuring a reduced profile and structural enhancements, such as a lower arcuate segment, which ensures proper cartridge installation before firing and increases compressive strength to deliver multiple rows of staples without deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a lockout mechanism is added to prevent premature firing, then reliability is improved, but device complexity increases
Solution Approach 1:
The lockout member is positioned to engage the firing member before the stapling operation can commence. The lockout shelf physically blocks the firing member's movement path in advance, preventing premature firing until the cartridge is properly installed and the lockout member is released by the cartridge's release legs.
2Device complexity
If the firing member profile is reduced to accommodate additional components, then device complexity is improved, but strength decreases
Solution Approach 1:
The firing member features an arcuate segment with varying thickness distribution - thicker in regions requiring higher compressive strength to deliver multiple rows of staples, and thinner in regions where space is needed for other components. This localized variation in cross-sectional properties optimizes both strength and space utilization.
3Reliability
If the firing member is made stronger to deliver multiple rows of staples, then reliability is improved, but the profile increases
Solution Approach 1:
Rather than uniformly increasing the firing member's profile, the design implements localized thickness variations through the arcuate segment. Critical load-bearing regions have increased thickness for strength, while non-critical regions maintain reduced thickness to minimize overall profile and accommodate other components within the stapling instrument.
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
Prevents improper firing by ensuring proper cartridge installation and enhances the stapling instrument's ability to deliver multiple rows of staples with increased compressive strength and reduced profile, allowing additional space for other components.
Implementation Method 1
a spring, e.g., a torsion spring, is coupled to the lockout member and is operatively engageable with the cartridge body. The spring is configured to normally bias the lockout member toward the locked position.
Data Source
Figure 1
Figure 2
Figure 3~5
AI summary
A surgical stapling instrument (10) includes an anvil body (12) defining a longitudinal axis, a cartridge body (14) coupled to the anvil body (12), a staple cartridge (18) releasably mounted relative to the cartridge body (14), a firing member (34) mounted to the cartridge body (14) and configured for longitudinal movement through the staple cartridge (18), and a lockout member (36) supported by the cartridge body (14). The lockout member (36) defines a single longitudinal slot (40) for at least partial reception of the firing member (34). The lockout member (36) is configured for movement from a locked position preventing longitudinal movement of the firing member (34) to a release position permitting longitudinal movement of the firing member (34) upon mounting of the staple cartridge (18) to the cartridge body (14).