Surgical Forceps Dynamic Mechanical Advantage Trigger
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current surgical forceps designs fail to simultaneously provide fine dissection capability and high mechanical advantage during tissue manipulation, leading to surgeon fatigue and limited control options.
Innovation Solution
A surgical instrument featuring a housing, elongated shaft, end effector assembly with movable jaw members, and a trigger assembly that includes a gear system, spool, and flexible drive member, allowing for adjustable mechanical advantage and precise control through longitudinal and rotational movements of the drive bar and trigger.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a simple pivoted handle is used to provide fine dissection capability, then handle travel for jaw member movement is improved, but mechanical advantage during compression is insufficient
Solution Approach 1:
The trigger assembly incorporates a dynamic mechanical advantage system where the relationship between trigger movement and jaw member movement changes throughout the stroke. The linkage geometry is designed so that mechanical advantage increases as the jaw members close, providing high force during compression while maintaining control during initial positioning
Solution Approach 2:
The system changes the mechanical parameter of mechanical advantage dynamically during operation. The linkage design causes the ratio of trigger travel to jaw member movement to vary continuously, providing fine control at the beginning of the stroke and high mechanical advantage at the end of the stroke when compression is needed
2Force
If a handle with geometrically increasing mechanical advantage is used, then compression force is improved, but fine dissection capability is lost
Solution Approach 1:
The trigger assembly uses a dynamic linkage system where the mechanical advantage is not fixed but changes throughout the stroke. This allows the system to provide both fine control capability and high compression force by optimizing the mechanical advantage at different points in the triggering motion
3Device complexity
If the mechanical advantage is fixed in the drive system, then system simplicity is improved, but operational versatility is reduced
Solution Approach 1:
Rather than using a complex adjustable mechanism, the patent employs a dynamically optimized fixed linkage geometry that provides varying mechanical advantage throughout the stroke. This achieves operational versatility through the natural geometry of the linkage rather than through active adjustment mechanisms
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
Enables both fine control and high mechanical advantage during tissue manipulation, reducing surgeon fatigue and enhancing precision and efficiency in surgical procedures.
Implementation Method 1
The gear assembly includes a first gear and a second gear. The first gear is configured to engage the trigger, and the second gear is configured to engage the spool.
Implementation Method 2
The flexible drive member is configured to engage the gear assembly, the spool, and the slider.
Data Source
AI summary
A surgical instrument includes a housing, an elongated shaft extending distally from the housing, an end effector assembly, and a trigger assembly. The trigger assembly is disposed in mechanical cooperation with the housing and is configured to longitudinally translate a drive member. The trigger assembly includes a trigger, a gear assembly, a spool, a slider, and a flexible drive member. The trigger is disposed in mechanical cooperation with the gear assembly. The flexible drive member is configured to engage the gear assembly, the spool, and the slider. Movement of the trigger with respect to the housing results in movement of the flexible drive member with respect to the housing and longitudinal movement of the slider with respect to the housing.