Nested Trigger Assembly for Surgical Instrument RF Control
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Solution Overview
Problem
Current surgical instruments using bi-polar radiofrequency energy struggle to achieve high-strength tissue welds, particularly in thick or irregular tissues like large diameter blood vessels, as they often require precise control over energy delivery and tissue compression to ensure immediate post-treatment strength and durability.
Innovation Solution
A surgical instrument with a nested trigger assembly that allows for two-stage operation, where the first stage closes the jaws and the second stage advances a cutting member and applies energy, utilizing positive temperature coefficient bodies in the jaws to modulate RF energy delivery and ensure effective tissue welding and transection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If bi-polar radiofrequency energy is applied to thick or irregular tissues, then tissue welding capability is improved, but control over energy delivery and tissue compression becomes more difficult
Solution Approach 1:
The trigger assembly is divided into two separate triggers: a first trigger that controls jaw closure and a second trigger that controls RF energy delivery and cutting. This segmentation allows independent control of mechanical compression and energy application, enabling precise control over the welding process even in thick or irregular tissues.
Solution Approach 2:
The system allows dynamic adjustment of energy delivery parameters through the two-stage trigger mechanism. The operator can first close the jaws to establish mechanical compression, then independently control the RF energy delivery, enabling real-time adaptation to varying tissue characteristics and thickness.
2Strength
If bi-polar radiofrequency energy is applied to thick or irregular tissues, then tissue welding capability is improved, but precise control over tissue compression becomes more difficult
Solution Approach 1:
The trigger assembly is divided into two separate triggers: a first trigger that controls jaw closure and a second trigger that controls RF energy delivery and cutting. This segmentation allows independent control of mechanical compression and energy application, enabling precise control over the welding process even in thick or irregular tissues.
3Device complexity
If a single trigger controls both jaw closure and energy delivery, then device complexity is reduced, but the ability to achieve high-strength welds in thick tissues is compromised
Solution Approach 1:
The trigger assembly is divided into two separate triggers: a first trigger that controls jaw closure and a second trigger that controls RF energy delivery and cutting. This segmentation allows independent control of mechanical compression and energy application, enabling precise control over the welding process even in thick or irregular tissues.
Solution Approach 2:
The first trigger performs the preliminary action of closing the jaws and establishing mechanical compression on the tissue before the second trigger is activated to deliver RF energy. This sequence ensures that the tissue is properly positioned and compressed before energy application, which is critical for achieving high-strength welds in thick tissues.
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 instrument achieves strong, immediate tissue welds with controlled energy application and mechanical compression, suitable for sealing and welding various tissues, including large diameter blood vessels, by allowing precise control over the cutting and welding functions.
Implementation Method 1
utilizing positive temperature coefficient bodies in the jaws to modulate RF energy delivery
Implementation Method 2
the delivery of Rf energy to the captured tissue elevates the temperature of the tissue
Implementation Method 3
the energy can at least partially denature proteins within the tissue
Data Source
AI summary
A surgical instrument is disclosed. The surgical instrument can include an end effector, a shaft, and a handle. The handle can include a trigger assembly. The trigger assembly can include a first trigger and a second trigger, which are movable as a nested unit during a first actuation of the trigger assembly to affect a first surgical function. The second trigger can be movable away from the first trigger after the first actuation of the trigger assembly and can be movable toward the first trigger during a second actuation of the trigger assembly to affect a second surgical function.