Ultrasonic Surgical Instrument Alignment Features
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Solution Overview
Problem
Current ultrasonic surgical instruments lack effective alignment and stiffness adjustment features, which can lead to suboptimal tissue cutting and coagulation due to misalignment of clamp arms with ultrasonic blades and inconsistent clamping forces.
Innovation Solution
The design incorporates various guide features such as curved projections, tapered recesses, and adjustable set screws to ensure proper alignment of clamp arms with ultrasonic blades, along with adjustable stiffness mechanisms like integral stiffening rods and sliding rings to vary clamping force.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If fixed pivot design is used for clamp arm, then device structure is simple, but alignment precision between clamp arm and ultrasonic blade deteriorates
Solution Approach 1:
The patent transforms the fixed pivot design into a dynamic adjustable mechanism. The clamp arm pivot point can be repositioned along the ultrasonic blade using a set screw, allowing the system to adapt its geometry rather than being constrained to a single fixed position. This dynamic adjustment capability resolves the contradiction by enabling precision alignment without requiring complex multi-component mechanisms.
2Device complexity
If fixed stiffness clamp arm is used, then device structure is simple, but adaptability to different tissue types deteriorates
Solution Approach 1:
The clamp arm incorporates an adjustable stiffness mechanism through a set screw that can be positioned at different locations along the ultrasonic blade. By changing the pivot position, the effective stiffness of the clamp arm changes, allowing adaptation to different tissue types and surgical requirements while maintaining a relatively simple monolithic structure.
Solution Approach 2:
The patent enables parameter changes in the clamp arm's mechanical properties by allowing repositioning of the pivot point. This changes the moment arm length and effective stiffness without requiring multiple different clamp arm components, thus achieving adaptability while controlling device complexity.
3Ease of manufacture
If monolithic clamp arm is used, then ease of manufacture is good, but adjustability of clamping force deteriorates
Solution Approach 1:
The monolithic clamp arm is enhanced with a dynamic adjustment feature in the form of a set screw that can be positioned at various locations. This simple additive feature to the monolithic structure provides adjustability of clamping force without requiring complex assembly of multiple components, thus maintaining ease of manufacture while achieving adaptability.
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
This enhances the precision and effectiveness of tissue cutting and coagulation by ensuring accurate alignment and adjustable clamping forces, improving the overall performance of ultrasonic surgical instruments.
Implementation Method 1
one or more piezoelectric elements that convert electrical power into ultrasonic vibrations
Implementation Method 2
a blade element that vibrates at ultrasonic frequencies to cut and/or seal tissue (e.g., by denaturing proteins in tissue cells)
Data Source
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AI summary
An ultrasonic instrument comprises a body, a shaft assembly, an ultrasonic blade, and a pivoting member. The shaft assembly extends distally from the body. The ultrasonic blade is positioned distal to the shaft assembly. The pivoting member is pivotable with respect to the blade from an open position to a closed position to thereby clamp tissue between the pivoting member and the blade. One or both of the shaft assembly or the pivoting member comprise a guide feature. The guide feature is configured to provide lateral alignment of the distal portion of the pivoting member with the blade as the pivoting member is pivoted to the closed position.