Expanding Cannula with Continuous Membrane for Tissue Retraction
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Solution Overview
Problem
Existing cannula devices for arthroscopic and laparoscopic surgery often require external inflation or deflation and can trap tissue during retraction, leading to inefficiencies and potential complications.
Innovation Solution
A cannula and retractor device with a continuous, expandable membrane that mechanically deploys and relaxes without external inflation or deflation, using a first and second tube configuration with a flexible membrane that forms an annulus for tissue contact and retraction, preventing tissue trapping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If external inflation or deflation mechanisms are used, then the cannula can maintain portal position, but the device complexity increases and reliability decreases due to additional components
Solution Approach 1:
The patent removes the external inflation/deflation mechanisms (balloons, syringes, stop-cocks) from the system entirely. The cannula uses a self-contained mechanical expansion mechanism where the distal portion expands by relative movement of its components rather than by external inflation, thereby eliminating the need for complex external control systems and improving reliability.
Solution Approach 2:
The cannula's distal portion is designed to expand and maintain portal position through its own mechanical structure. The expansion is achieved by relative movement between the outer and inner cannula portions, which activates the expansion mechanism without requiring external intervention. This self-service approach reduces device complexity and eliminates potential failure points associated with external inflation systems.
2Reliability
If discontinuous slat structures are used for expansion, then the cannula can expand to maintain portal, but tissue gets trapped within the openings during retraction
Solution Approach 1:
The patent employs a continuous flexible membrane as the expansion surface instead of discontinuous slats. This continuous membrane expands uniformly and maintains contact with tissue without creating gaps or openings that could trap tissue. The flexible nature of the membrane allows it to conform to tissue surfaces while preventing entrapment, thereby eliminating the harmful effect of tissue trapping during retraction.
3Ease of operation
If separate inflation ports and control mechanisms are added, then the cannula can be inflated and deflated, but the ease of operation decreases and potential for error increases
Solution Approach 1:
The patent eliminates separate inflation ports, syringes, and stop-cocks from the system. The expansion and contraction of the distal portion are achieved through relative movement of the outer and inner cannula portions, which directly actuates the expansion mechanism without requiring separate control systems. This simplifies operation and reduces the potential for user error.
Solution Approach 2:
The patent combines the functions of inflation, deflation, and retraction control into a single mechanical action. The relative movement between the outer and inner cannula portions simultaneously controls the expansion state and the retraction process, eliminating the need for separate control mechanisms and improving ease of operation.
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 device provides reliable deployment and retraction with reduced failure risk, eliminating the need for external inflation or deflation and preventing tissue entrapment, enhancing surgical efficiency and safety.
Implementation Method 1
The membrane expands into an annulus by the relative movement of the second tube with respect to the first tube
Implementation Method 2
The annulus is configured to contact the tissue to maintain the position of the device with respect to the tissue
Data Source
AI summary
Expanding cannula and retractor devices and methods of use are provided. An expanding cannula and retractor device includes a first tube, a second tube positioned within the first tube, and an expandable continuous membrane connecting distal portions of the first and second tubes. The membrane can expand into an annulus based on the movement of the second tube relative to the first tube in order to contact tissue and maintain the position of the device.