Electrosurgical Instrument with Feedback-Controlled Cutting Element
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Solution Overview
Problem
Existing electrosurgical instruments face challenges in creating strong, immediate tissue welds, particularly for large diameter blood vessels, as they often require high strength and precision to seal thick fibrous tissues and maintain the weld's integrity during the healing process.
Innovation Solution
The development of an electrosurgical instrument with a handle, elongate shaft, and end effector featuring movable jaw members and a tissue-cutting element, where a spring and trigger mechanism control the translation of an axially movable member to open and close the jaws, and a tissue-cutting element is positioned at the distal end, allowing for controlled energy delivery and precise tissue transection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If RF energy is applied to seal tissue, then tissue welding strength is improved, but the procedure time increases due to the need for controlled energy delivery and monitoring
Solution Approach 1:
The RF energy delivery system maintains continuous contact between the electrode and tissue throughout the sealing process, ensuring uninterrupted energy application. The jaw closure mechanism ensures continuous pressure contact, allowing the system to deliver energy without interruption until the weld is complete, thereby reducing the time required compared to intermittent application methods
Solution Approach 2:
The system incorporates monitoring capabilities that detect tissue temperature and energy delivery parameters in real-time. This feedback allows the system to automatically adjust energy delivery to maintain optimal sealing conditions, preventing both under-sealing and overheating, thus reducing the time needed to achieve adequate weld strength
2Strength
If high current is used to create strong welds, then tissue sealing strength is improved, but the risk of thermal damage to surrounding tissue increases
Solution Approach 1:
The electrode design concentrates RF energy delivery at a specific contact point with the tissue, creating a localized heating zone. This focused approach ensures that high current density is applied only where needed for welding, while surrounding tissues remain at lower temperatures, preventing thermal damage to adjacent structures
Solution Approach 2:
The system employs intermittent or pulsed RF energy delivery rather than continuous high current application. This periodic action allows heat to dissipate between pulses, building up sufficient temperature for strong welding while preventing excessive thermal accumulation that would cause tissue damage
3Device complexity
If the cutting element is positioned close to the electrode, then device compactness is improved, but the precision of tissue transection after sealing is reduced
Solution Approach 1:
The device is divided into functionally independent segments: the electrode assembly for energy delivery and the cutting element for transection. This segmentation allows each component to be optimized for its specific function while maintaining overall device compactness through efficient spatial arrangement of the separated modules
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 design enables the creation of strong tissue welds with controlled energy application, ensuring effective sealing and transection of tissues, including large diameter blood vessels, by regulating the movement of the cutting element and energy delivery, thereby enhancing surgical precision and tissue integrity.
Implementation Method 1
a spring operably coupled to the trigger, the spring to release energy and distally translate the axially movable member
Implementation Method 2
electrical current can flow from one electrode, through the tissue, and to the other electrode. The surgical instrument can comprise an electrical input, a supply conductor electrically coupled with the electrodes, and/or a return conductor which can be configured to allow current to flow from the electrical input, through the supply conductor, through the electrodes and the tissue
Implementation Method 3
RF energy is a form of electrical energy that may be in the frequency range of 300 kilohertz (kHz) to 1 megahertz (MHz). In application, RF surgical instruments transmit low frequency radio waves through electrodes, which cause ionic agitation, or friction, increasing the temperature of the tissue
Data Source
AI summary
A surgical instrument for supplying energy to tissue can comprise a jaw member comprising an electrode, wherein the electrode is configured to supply energy from a power source to captured tissue. The surgical instrument comprises a tissue-cutting element to transect the captured tissue. The surgical instrument may have a indicator to provide feedback signals during the operational stroke. The feedback signals assist in regulating the rate of distal translation of the tissue-cutting element.