Switchable Bipolar End-Effector Assembly for Low-Leakage Sealing
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Solution Overview
Problem
There is a need for electrosurgical instruments that combine vessel sealing with bipolar spot heating, minimize the length of conductors to avoid parasitic capacitance and leakage current, and allow for smaller diameter electrical conductors to facilitate smaller incisions, enhanced maneuverability, and increased visibility.
Innovation Solution
The electrosurgical instrument features an end-effector assembly with electrically-conductive tissue-engaging surfaces and switchable bipolar electrodes, utilizing semiconductor switches to enable user selection between energizing these surfaces or electrodes, and includes a configuration that minimizes the need for additional electrical conductors, allowing for smaller shaft diameters and improved surgical capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional monopolar electrosurgery with long conductors is used, then energy delivery is achieved, but parasitic capacitance and leakage current increase
Solution Approach 1:
The patent extracts the return electrode function from the external patient return electrode and relocates it to the distal end of the instrument shaft, creating a bipolar configuration. This removes the long conductor loop that causes parasitic capacitance and leakage current, while maintaining effective energy delivery for tissue sealing and cutting.
Solution Approach 2:
The patent transitions from a monopolar configuration (single active electrode with external return) to a bipolar configuration (two electrodes at the distal end). This dimensional change in electrical circuit topology eliminates the need for long conductors and external return paths, thereby reducing parasitic effects while maintaining therapeutic effectiveness.
2Power
If larger diameter electrical conductors are used, then energy transmission capability is improved, but instrument shaft diameter increases
Solution Approach 1:
The patent removes the need for large-diameter conductors by reconfiguring the electrical circuit to bipolar mode with both electrodes at the distal end. This eliminates the long conductor loop required in monopolar systems, allowing use of smaller conductors that enable thinner instrument shafts while maintaining adequate power delivery for surgical functions.
3Adaptability or versatility
If bipolar electrodes are added to the end-effector assembly, then vessel sealing capability is improved, but device complexity increases
Solution Approach 1:
The patent merges the vessel sealing function and cutting function into a single bipolar end-effector assembly. By placing both active and return electrodes at the distal end and using the same jaw structure for both functions, the design achieves versatility without proportionally increasing complexity. The semiconductor switch enables selective activation of different electrode pairs for different surgical tasks.
Solution Approach 2:
The bipolar end-effector assembly is designed to perform multiple functions including vessel sealing, tissue cutting, and coagulation. The same physical structure with switchable electrode configurations provides adaptability for different surgical needs, reducing the need for multiple specialized instruments while managing complexity through integrated design.
4Ease of operation
If semiconductor switches are implemented for electrode selection, then operational flexibility is improved, but manufacturing complexity increases
Solution Approach 1:
The patent replaces complex mechanical switching mechanisms with semiconductor switches for electrode selection. This electronic switching approach provides operational flexibility and reliability while reducing mechanical complexity and improving manufacturability compared to traditional mechanical contact systems. The semiconductor switches can be integrated into the existing circuit board infrastructure.
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 configuration enhances surgical precision and visibility by reducing thermal spread and collateral damage, enabling smaller incisions and improved maneuverability while maintaining effective tissue sealing and cutting capabilities.
Implementation Method 1
The basic purpose of both monopolar and bipolar electrosurgery is to produce heat to achieve the desired tissue/clinical effect. Bipolar electrosurgical current travels from one electrode, through the intervening tissue to the other electrode to complete the electrical circuit.
Implementation Method 2
Each of the first and second jaw members includes an electrically-conductive, tissue-engaging surface... energizing the at least one electrically-conductive, tissue-engaging surface
Data Source
AI summary
An electrosurgical instrument includes a housing, an elongated shaft, and an end-effector assembly. The proximal end of the shaft is operably associated with the housing. The end-effector assembly is operably coupled to the distal end of the shaft and includes first and second jaw members. Each of the first and second jaw members includes a sealing plate and a bipolar electrode. Either one or both of the first and second jaw members is movable from a position in spaced relation relative to the other jaw member to at least one subsequent position wherein the sealing plates cooperate to grasp tissue therebetween. The electrosurgical instrument includes a semiconductor switch operably coupled to at least one of the sealing plates and at least one of the bipolar electrodes. The semiconductor switch is configured to enable user selection between energizing the at least one sealing plate or the at least one bipolar electrode.