Self-adjusting Pneumatically Sealed Trocar with Telescopic Cannula
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Solution Overview
Problem
Laparoscopic surgery trocars lack effective anchoring systems to prevent accidental removal during procedures and fail to maintain insufflation gas within the abdominal cavity without conventional mechanical seals, leading to gas leakage.
Innovation Solution
A self-adjusting pneumatically sealed trocar with a telescopic cannula assembly and an elastomeric sheath that secures to the abdominal wall, featuring a radially enlarged distal anchor portion that reduces in diameter as the cannula extends, combined with an annular nozzle assembly generating a continuous pressure barrier to prevent gas egress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional mechanical seals are used to prevent gas leakage, then gas sealing is improved, but device complexity and tissue trauma increase
Solution Approach 1:
The patent removes conventional mechanical seals from the trocar system and replaces them with a pneumatically controlled sealing mechanism. The sealing function is extracted from mechanical components and achieved through controlled gas pressure differentials created by the nozzle assembly, eliminating complex mechanical moving parts while maintaining reliable gas sealing.
Solution Approach 2:
The patent substitutes mechanical sealing systems with a pneumatic control system. Instead of using mechanical seals that require precise manufacturing and maintenance, the invention uses a nozzle assembly that creates a pressure barrier through controlled gas flow, replacing mechanical sealing with a pneumatic field-based solution.
2Reliability
If anchoring systems are added to prevent accidental removal, then reliability is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent employs a dynamic anchoring mechanism where the distal section of the cannula can be extended or retracted relative to the proximal section. This telescopic design allows the anchor portion to be deployed into the abdominal wall tissue when needed and retracted when not required, providing reliable anchoring without permanent fixation devices.
Solution Approach 2:
The patent implements a nested telescopic structure where the distal section of the cannula is housed within the proximal section. The distal section can be extended outward to engage with tissue for anchoring, then retracted back into the proximal section, creating a compact nested configuration that provides anchoring functionality without adding permanent external components.
3Manufacturing precision
If the cannula is made rigid for stability, then positioning accuracy is improved, but ease of operation and instrument freedom of movement deteriorate
Solution Approach 1:
The patent divides the cannula into multiple functional sections: a proximal section that provides stable positioning, a telescopic distal section that provides flexibility, and an intermediate connection mechanism. This segmentation allows each section to optimize its function - the proximal section maintains positioning accuracy while the distal section accommodates instrument movement freedom.
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 solution effectively secures the trocar to the abdominal wall and maintains pneumoperitoneum by preventing gas leakage, ensuring stable instrument movement and reducing tissue trauma.
Implementation Method 1
The elastomeric sheath is adapted and configured to stretch in elongated manner when the distal section of the telescopic cannula assembly is moved from the retracted position to the extended position, such that an outer diameter of the radially enlarged distal anchor portion of the elastomeric sheath is reduced
Implementation Method 2
the annular nozzle assembly which generates a continuous pressure barrier within a central lumen of the tubular body portion that inhibits egress of insufflation gas from an abdominal cavity of a patient
Data Source
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AI summary
A surgical access device including a housing having a nozzle assembly, a gas supply plenum, a gas return plenum, and a pressure sensing plenum, as well as an elongated tubular body that extends from the housing portion and defines a central lumen communicating with the nozzle assembly and the gas return plenum, a telescopic cannula assembly associated with the tubular body and including a proximal section arranged coaxially within the tubular body and a distal section coaxially supported within the proximal section and mounted for movement relative to the proximal section between retracted and extended positions, and an elastomeric sheath associated with the telescopic cannula assembly and having a distal anchor portion for securing the surgical access device during a laparoscopic surgical procedure.