Trocar Seal Bending Portion Inversion Prevents Leakage
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Solution Overview
Problem
Existing trocar seals fail to maintain pneumoperitoneum effectively when endoscopic instruments are not inserted, leading to insufflation fluid leakage, and can cause instrument binding during extraction due to inadequate sealing mechanisms.
Innovation Solution
A trocar design featuring a closure valve and instrument seal with a bending portion that inverts to prevent fluid leakage and binding, utilizing a nested arrangement of components with a hinge mechanism to ensure proper alignment and sealing, made from flexible materials like rubber or silicone.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional trocar seal is used, then the structure is simple, but insufflation fluid leaks when instruments are not inserted
Solution Approach 1:
The seal assembly incorporates a movable closure valve that dynamically adjusts its position based on instrument presence. When no instrument is inserted, the closure valve moves to the closed position to seal the cannula opening and prevent insufflation fluid leakage. When an instrument is inserted, the closure valve moves to the open position to allow instrument passage while maintaining seal around the instrument shaft.
Solution Approach 2:
The seal assembly is divided into distinct functional segments: a stationary seal member that provides the primary sealing surface, and a movable closure valve that acts as a secondary sealing element. This segmentation allows each component to perform its specific function independently, with the closure valve handling the dynamic sealing when no instrument is present, while the stationary seal member handles sealing around inserted instruments.
2Reliability
If a tight seal is used to prevent fluid leakage, then sealing effectiveness improves, but instrument extraction becomes difficult due to binding
Solution Approach 1:
The closure valve is designed to be movable rather than fixed, allowing it to dynamically adjust during instrument extraction. As the instrument is pulled through, the closure valve can move along the instrument shaft, maintaining sealing contact without creating excessive friction that would cause binding. This dynamic adjustment prevents the seal from becoming too tight during the extraction process.
Solution Approach 2:
The closure valve acts as an intermediary sealing element between the insufflation fluid and the external environment when no instrument is present. During instrument insertion and extraction, the closure valve moves to accommodate the instrument while the stationary seal member provides the primary sealing interface, distributing the sealing function to reduce binding forces.
3Adaptability or versatility
If the seal remains stationary, then the structure is simple, but it cannot adapt to instrument insertion and extraction
Solution Approach 1:
The closure valve is designed as a movable component that responds to instrument presence through mechanical interaction. When an instrument is inserted, it pushes the closure valve open; when removed, a spring or elastic element returns the closure valve to the closed position. This dynamic behavior provides adaptability without requiring complex electronic controls or actuators.
Solution Approach 2:
The closure valve serves multiple functions: it seals the cannula opening when no instrument is present, it moves to accommodate instrument insertion, and it maintains sealing contact during instrument extraction. This multi-functionality provides adaptability to different operational states while keeping the overall structure relatively simple by using a single movable component for all adaptive responses.
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 design effectively maintains pneumoperitoneum by preventing insufflation fluid leakage when instruments are not inserted and reduces the force required for instrument extraction by preventing binding, enhancing the efficiency and safety of endoscopic procedures.
Implementation Method 1
made from flexible materials like rubber or silicone
Implementation Method 2
utilizing a nested arrangement of components with a hinge mechanism to ensure proper alignment and sealing
Data Source
AI summary
A trocar comprising an alignment channel and an instrument seal comprising a bending portion and a base portion. The bending and base portions of the instrument seal are spaced relative the alignment channel such that when a surgical instrument is retracted the bending portion inverts and the lip does not enter the alignment channel.