Vessel Sealer Blade Cam Assembly for Stable Tissue Transection
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Solution Overview
Problem
Existing electrosurgical instruments struggle to consistently and effectively seal and transect vessels and tissue while minimizing movement of the cutting element and end effector assembly, leading to inconsistent seals and potential thermal spread to adjacent tissue.
Innovation Solution
A blade assembly with a cutting mechanism featuring camming slots and blade springs, actuated by an actuation rod, that allows for precise and controlled tissue transection within a predetermined path, minimizing movement and thermal spread.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a blade assembly is actuated to cut tissue, then tissue transection is achieved, but movement of the cutting element and end effector assembly occurs leading to inconsistent seals and potential thermal spread
Solution Approach 1:
The blade assembly is segmented into a cutting blade and a separate actuation mechanism. The blade is mounted on a pivot pin allowing it to rotate independently within the jaw, while the actuation rod and cam mechanism provide controlled movement. This segmentation allows the cutting function to be separated from the sealing function, enabling precise tissue transection without compromising seal consistency.
Solution Approach 2:
The blade is pre-positioned within the jaw assembly in a retracted state before actuation. The actuation rod and cam mechanism are designed to initiate blade movement only when needed for cutting, while maintaining the blade in a predetermined position during sealing operations. This preliminary positioning ensures that the blade does not interfere with the sealing surfaces during the sealing process.
2Reliability
If clamping pressure is increased to improve seal thickness control, then seal reliability improves, but the poles may touch preventing energy transfer resulting in ineffective seal
Solution Approach 1:
The blade assembly incorporates a dynamic positioning system with a pivot pin and actuation rod that allows the blade to move between retracted and extended positions. During sealing, the blade remains retracted to maintain proper spacing between poles. When cutting is required, the actuation rod extends the blade through the tissue while the jaw remains clamped, providing controlled tissue transection without pole contact.
3Ease of operation
If the blade is designed to move freely to cut tissue, then cutting effectiveness improves, but movement of the cutting element increases causing inaccurate seal and division
Solution Approach 1:
The actuation rod serves as an intermediary mechanism between the user's actuation force and the blade. The rod transmits controlled movement to the blade through a cam mechanism, allowing the blade to move precisely along a predetermined path during cutting while remaining stationary during sealing. This intermediary mechanism provides controlled freedom of movement only when needed for cutting.
Solution Approach 2:
The blade assembly changes its positional parameter from a fixed retracted position during sealing to an extended cutting position during tissue transection. The actuation rod and cam mechanism control this parameter change, allowing the blade to move from a retracted state (where it does not interfere with sealing) to an extended state (where it effectively cuts tissue) and back again.
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
The blade assembly enables consistent, high-quality tissue transection with reduced movement, ensuring accurate sealing and minimizing collateral thermal damage to adjacent tissue.
Implementation Method 1
the blade including one or more blade springs operably associated therewith configured to bias the blade within the blade channel
Data Source
AI summary
A forceps includes a pair of jaw members movable relative to one another, one of the jaw members defining a blade channel therein configured to house a cutting mechanism. The cutting mechanism includes: a blade having camming slots defined along a length thereof and one or more blade springs operably associated therewith configured to bias the blade within the blade channel; and a blade cam including camming surfaces configured to operably engage the corresponding camming slots of the blade. The blade cam includes a proximal end operably coupled to an actuation rod configured to move the blade cam upon movement thereof. The actuation rod, upon movement thereof, moves the camming surfaces of the blade cam into engagement against the camming slots forcing the blade into the blade channel against the bias of the biasing spring to cut tissue therebetween.