Retractable Cutting Blade for Endoscopic Cannula
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing endoscopic surgical instruments for procedures like carpal tunnel release have a cutting blade that always protrudes, leading to unintended tissue cutting during cannula insertion and limited control over cutting actions, which can cause unnecessary damage and complicate surgical precision.
Innovation Solution
A retractable cutting blade mechanism integrated into an endoscopic surgical instrument, where the blade is spring-biased to be retracted within a tube and can be selectively projected through a cannula slot, with a locking mechanism to prevent accidental deployment when using an endoscope, allowing for both viewing and cutting capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the cutting blade always protrudes during cannula insertion, then the blade is ready for immediate use, but unintended tissue cutting occurs and surgical precision is reduced
Solution Approach 1:
The cutting blade is designed to be dynamically positionable between a retracted state (during cannula insertion) and a protruding state (during cutting). The revolver assembly allows the blade to be rotated into alignment with the cannula slot only when needed, transforming the static blade configuration into a dynamic one that adapts to different surgical phases.
Solution Approach 2:
The surgical instrument is segmented into distinct functional components: the cannula, the revolver assembly containing the blade, and the guidance tube. This segmentation allows independent control of each component, enabling the blade to be separated from the cannula path during insertion and only brought into alignment when cutting is required.
2Productivity
If the cutting blade is always protruding, then cutting action is immediate, but control over cutting position and timing is limited
Solution Approach 1:
The revolver assembly provides dynamic control over blade positioning through rotation. The blade can be selectively oriented to protrude through the cannula slot at specific positions along the cannula length, allowing precise control of cutting location while maintaining immediate cutting capability when needed.
3Object-affected harmful factors
If the blade is retracted during cannula insertion, then tissue damage is reduced, but the blade must be deployed which adds complexity
Solution Approach 1:
The cutting blade and revolver assembly are integrated into a single unified structure. The blade is mounted on the revolver assembly, which rotates to bring the blade into alignment with the cannula slot. This merging eliminates the need for separate blade deployment mechanisms while providing controlled blade exposure.
4Ease of operation
If the endoscope is removed to insert the cutting blade, then the blade can be positioned, but the surgical workflow is interrupted and time is lost
Solution Approach 1:
The endoscope and cutting blade functions are merged into a single integrated instrument. The endoscope passes through the cannula, and the cutting blade on the revolver assembly can be deployed without removing the endoscope, allowing continuous visualization and uninterrupted surgical workflow.
Solution Approach 2:
The revolver assembly allows dynamic positioning of the cutting blade while the endoscope remains in place. The blade can be rotated into alignment with the cannula slot at any time during the procedure, providing flexible blade deployment without workflow interruption.
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
Enhances surgical precision by allowing controlled tissue cutting and reduces unnecessary damage by enabling the blade to be retracted during cannula insertion and deployment, improving the surgeon's ability to perform precise procedures like carpal tunnel releases.
Implementation Method 1
A retractable cutting blade assembly is mounted in the distal end of the tube. The blade assembly is spring-biased to be in a retracted state within the tube
Data Source
AI summary
An endoscopic surgical instrument includes a main body assembly, and a cannula having a lumen and formed with a slot. An inner tube, which houses a spring-biased retractable cutting blade assembly having a cutting blade, is mounted on one end of the main body assembly and extends axially therefrom. The tube is receivable within the lumen of the cannula, and may be particularly oriented within the cannula lumen such that the cutting blade may be caused to project from both the tube and the cannula slot. The inner tube has a bore in which the distal end of an endoscope may be received. The instrument may be locked in one position to allow the endoscope to engage the blade assembly and cause the cutting blade to project from the cannula slot during a tissue cutting procedure, or may be locked in another position wherein the cutting blade remains retracted.