Rotating Trocar Seal for Off-Axis Instrument Insertion
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Solution Overview
Problem
Minimally invasive surgical procedures face challenges in maintaining sterility and preventing gas and liquid leakage due to non-uniform deformation of seal elements when instruments are delivered off-axis through trocar assemblies.
Innovation Solution
A trocar assembly with a rotatable seal unit, featuring a spherically shaped seal element and dual ring-type seals, allows off-axis insertion without lateral movement, ensuring effective sealing and preventing contamination or gas escape.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a seal element is disposed within the housing to provide a sealed environment, then sterility is maintained and liquid/gas leakage is prevented, but off-axis instrument delivery causes non-uniform deformation of the seal, reducing sealing effectiveness
Solution Approach 1:
The seal unit is configured to be movable relative to the housing, transitioning from a static seal position to a distorted seal position when an instrument is inserted off-axis. This dynamic adjustment allows the seal to maintain contact with the instrument surface regardless of insertion angle, preserving sealing effectiveness while accommodating versatile instrument delivery paths
Solution Approach 2:
The seal element changes its deformation parameters based on instrument insertion conditions. During off-axis delivery, the seal transitions from a uniform deformation state to a non-uniform deformation state that adapts to the instrument's angular position, maintaining sealing contact through parameter adjustment rather than fixed geometric configuration
2Object-affected harmful factors
If the seal unit is fixed in position to maintain sealing, then sterility is preserved, but the seal cannot accommodate off-axis instrument insertion without lateral movement
Solution Approach 1:
The seal unit incorporates controlled mobility that allows it to dynamically respond to instrument insertion forces. When an instrument is inserted off-axis, the seal unit moves laterally within defined constraints to maintain sealing contact, rather than remaining fixed and risking seal failure or instrument damage
3Strength
If a rigid seal structure is used to maintain structural integrity, then sealing force is maintained, but the seal cannot deform uniformly to accommodate off-axis instruments
Solution Approach 1:
The seal unit employs a non-uniform structural design where different regions have varying degrees of rigidity and deformability. This allows localized deformation in specific areas to accommodate off-axis instrument insertion while maintaining overall structural integrity and sealing force through reinforced regions
Data Source
AI summary
Methods and devices for accessing a body cavity are disclosed. In general, a trocar assembly is provided that can include a housing having a cannula that extends therefrom to define a working channel that is sized and configured to receive a surgical instrument. The trocar assembly can also include a seal unit that is disposed in the housing. The seal unit can be generally configured to allow off-axis insertion of an instrument through the working channel without lateral movement of the seal unit. For example, in one exemplary embodiment, the seal unit can be rotatably disposed in the housing and have at least one seal element that is adapted to selectively seal the working channel. The seal unit can also be adapted to rotate about a longitudinal axis of the assembly and an axis perpendicular thereto.