Cannula Seal Segmentation for Tether Gas Tightness
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Solution Overview
Problem
Current cannula designs for endoscopic surgery allow gas leaks due to the presence of tethers for magnetic camera systems, which prevents the seal from closing, leading to escape of insufflation gases.
Innovation Solution
A cannula assembly with a housing and compliant membranes that include apertures to accommodate the tether and other endoscopic devices, providing a seal that inhibits gas escape by using a stack of membranes with non-overlapping apertures and a rotating mechanism to position the seal effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional seal is used in the cannula to prevent gas escape, then gas tightness is improved, but the tether cannot pass through the seal
Solution Approach 1:
The seal is divided into multiple segments or lobes that can independently move. When the tether passes through, the segments separate to accommodate it, then return to their closed position to maintain the gas seal. This segmentation allows the seal to dynamically adapt to the presence of the tether while maintaining gas tightness.
Solution Approach 2:
The seal transitions from a static structure to a dynamic one that can change its configuration. The seal elements are designed to be flexible and movable, allowing them to open when a tether passes through and close afterward to prevent gas leakage. This dynamic behavior resolves the contradiction between maintaining a seal and allowing tether passage.
2Reliability
If the seal is made tight to prevent gas leaks, then insufflation pressure is maintained, but the tether prevents the seal from closing
Solution Approach 1:
The seal system is designed to automatically return to its closed, gas-tight configuration after the tether passes through. The elastic or spring-loaded segments self-reposition to close the opening created by the tether, maintaining the gas seal without requiring external intervention. This self-service mechanism ensures both tether passage and pressure maintenance.
Solution Approach 2:
The seal's physical parameters (shape, volume, position) are allowed to change temporarily during tether passage, then return to their original state. The seal elements deform to accommodate the tether and then rebound to their closed configuration, dynamically adjusting their parameters to satisfy both requirements of tether accommodation and gas tightness.
3Reliability
If a duck bill seal is used to prevent gas escape, then gas tightness is improved, but the tether creates a leak path
Solution Approach 1:
The duck bill seal is segmented into multiple flexible lobes that can move independently. When the tether passes through, the segments part to allow passage and then close around the tether to prevent gas leakage. This segmentation enables the seal to maintain gas tightness even in the presence of the tether by dynamically adjusting its configuration.
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 prevents gas leaks during endoscopic procedures by ensuring a tight seal around the tether and other instruments, maintaining insufflation pressure and allowing for easy insertion and removal of devices without compromising the seal.
Implementation Method 1
A plurality of compliant membranes may be arranged as a stack anywhere in the passage or in the proximal or distal openings. The compliant membranes may be made of any compliant material, such as, for example, silicone, latex, or rubber.
Implementation Method 2
MAGS include an internal device attached in some manner to a surgical instrument, laparoscope or other camera or viewing device, and an external hand held device or external control unit ('ECU') for controlling the movement of the internal device. Each of the external and internal devices has magnets which are magnetically coupled to each other across, for example, a patient's abdominal wall.
Data Source
AI summary
A cannula sleeve for a surgical trocar assembly. The cannula sleeve includes a hollow shaft, at least a portion of which is made of a rigid material, and a seal at the distal end of the hollow shaft, the seal being movable between a first open position and a second closed position. The shaft defines a proximal end, a distal end, a periphery, and a longitudinal axis. The shaft further includes a channel at the periphery substantially parallel to the longitudinal axis, the channel being in communication with the hollow shaft.