Bipolar Forceps Jaw Drive Mechanism for Consistent Tissue Sealing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrosurgical forceps face challenges in consistently applying the required mechanical forces to seal large tissue structures within a specific pressure range, leading to variability in seal quality and reliance on surgeon expertise.
Innovation Solution
The design of a bipolar electrosurgical forceps with a movable handle and drive assembly that provides a mechanical advantage, allowing jaw members to be closed with lesser force while maintaining the necessary closure pressure between 3 kg/cm2 to 16 kg/cm2, and incorporating a knife assembly for tissue cutting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a large closure force is applied between jaw members to seal large vessels, then the sealing effectiveness is improved, but the risk of pin shear failure increases
Solution Approach 1:
The forceps assembly is divided into separate components: insulative pivot pins that provide electrical isolation and structural support, and metal reinforcement elements that provide mechanical strength. This segmentation allows each component to perform its specific function without compromising the other, resolving the contradiction between sealing force requirements and pin failure risk.
Solution Approach 2:
The pivot pin assembly combines insulative material (to prevent electrical conduction and allow independent jaw activation) with metal reinforcement elements (to provide mechanical strength and resist shear forces). This composite construction simultaneously achieves electrical isolation and mechanical robustness, resolving the contradiction between sealing effectiveness and structural integrity.
2Strength
If metal pivot pins are used to provide structural support, then the mechanical strength is improved, but the electrical insulation is compromised
Solution Approach 1:
The pivot pin is segmented into functional portions: an insulative body that provides electrical isolation between jaws, and integrated metal reinforcement elements that provide structural support. This segmentation allows the pivot pin to simultaneously achieve electrical insulation and mechanical strength without requiring separate components that would compromise either function.
Solution Approach 2:
The pivot pin is constructed as a composite structure combining insulative material (to prevent electrical conduction between independently activated jaws) with metal reinforcement (to provide structural strength and resist shear forces). This composite design resolves the contradiction by integrating both electrical isolation and mechanical strength into a single component.
3Device complexity
If the jaw members are positioned close to the pivot with small moment arms, then the device complexity is reduced, but the closure force requirement increases
Solution Approach 1:
The jaws are pre-positioned in a relaxed state with minimal separation, and the spring mechanism is pre-loaded to provide baseline contact pressure. This preliminary configuration reduces the additional force required during activation, resolving the contradiction between simple geometry and force requirements by preparing the system in advance.
Solution Approach 2:
The spring-loaded mechanism automatically maintains appropriate jaw separation and contact pressure without requiring complex active control systems. The mechanical design self-regulates the closure force based on spring characteristics, eliminating the need for complex force modulation mechanisms while maintaining effective sealing pressure.
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 forceps consistently apply the required closure pressure for effective tissue sealing and cutting, reducing the reliance on surgeon skill and enhancing the consistency and quality of tissue seals.
Implementation Method 1
Each of the jaw members is adapted to connect to an electrosurgical energy source, thus enabling the jaw members to conduct energy through tissue held between the jaw members to create a tissue seal
Implementation Method 2
electrosurgical forceps for sealing and/or cutting large tissue structures... by heating the tissue and blood vessels to coagulate, cauterize and/or seal tissue
Implementation Method 3
The drive assembly moves the jaw members relative to one another from a first position wherein the jaw members are disposed in spaced relation relative to one another to a second position wherein the jaw members are closer to one another
Data Source
AI summary
An endoscopic bipolar forceps includes a housing having a shaft affixed thereto the shaft including jaw members at a distal end thereof. The shaft includes a longitudinal axis defined therethrough and the jaw members are adapted to connect to a source of electrosurgical energy such that the jaw members are capable of conducting energy through tissue held therebetween to effect a tissue seal. A movable handle is included that is rotatable about a pivot to force a drive assembly to move the jaw members between the first and second positions. The pivot is located a fixed distance above the longitudinal axis. A cutting assembly is included having at least one blade element disposed within one of the jaw members. The blade element is selectively moveable from a first recessed position within the jaw member to a second extended position for cutting tissue. The cutting assembly also includes a remote actuator which reciprocates a camming element to move the blade element between the first and second positions.