Dual Operation Grasping Forceps Snare Mechanism
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Solution Overview
Problem
Current endoscopic grasping forceps face challenges in securely retrieving foreign objects due to thin wire diameter, resulting in low grasping force and difficulty in maintaining the object within the grasping section, leading to increased procedure time and patient discomfort.
Innovation Solution
A dual operation grasping forceps design featuring an elongated tube with a control mechanism, independently connected resilient grasping members, and a cord through loops to form a snare, allowing for independent movement and secure object retention without lateral movement of the grasping members.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the wire diameter of grasping members is made thin to reduce tissue damage, then tissue damage is reduced, but grasping force decreases and ability to secure foreign objects deteriorates
Solution Approach 1:
The invention divides the grasping function into two independent systems: resilient grasping members for gentle tissue interaction and a separate snare cord system for secure foreign object capture. The snare cord passes through loops on the grasping members, creating an independent tightening mechanism that does not rely on the thin grasping member wires for force transmission.
Solution Approach 2:
The snare cord acts as an intermediary element that transfers the closing force independently of the grasping member wires. When the snare is tightened, the cord passes through the loops and pulls the loops together, securing the foreign object without requiring the thin grasping member wires to bear the full closing force.
2Object-affected harmful factors
If grasping members are made with rounded surfaces to prevent tissue damage, then tissue damage is prevented, but ability to grip smooth foreign objects deteriorates
Solution Approach 1:
The invention separates the tissue-contact function (rounded grasping members) from the foreign object securing function (snare cord with loops). The snare cord system provides the secure grip on foreign objects through friction and mechanical interlocking, while the rounded grasping members maintain tissue safety.
Solution Approach 2:
The snare system changes the gripping mechanism from direct surface contact (which requires sharp edges for secure grip) to a loop-and-cord system that secures objects through circumferential encirclement and friction, allowing rounded safe distal ends to effectively capture both smooth and irregular foreign objects.
3Device complexity
If a single operating wire controls grasping member closure, then device complexity is reduced, but ability to maintain object position deteriorates due to simultaneous wire pull
Solution Approach 1:
The control system is segmented into two independent operating wires: one controlling the resilient grasping members and another controlling the snare cord tightening. This allows independent operation of the grasping and securing functions, enabling the operator to maintain object position while closing the snare without the conflicting forces present in single-wire designs.
Solution Approach 2:
The dual-wire system provides dynamic control where the operator can independently adjust the grasping member position and the snare tightening force. This dynamic independence allows for precise control during the closing process, maintaining object stability throughout the procedure.
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 the ability to securely grasp and remove foreign objects with reduced operator effort, minimizing patient discomfort and procedure time by providing greater control and traction.
Implementation Method 1
the resilient grasping section 2 is pushed away from the leading edge of the insertion tube 5 (arrow A′), and the grasping section 2 spreads outward from the center axis of the tube owing to the elastic restoring forces of the respective grasping members 3
Implementation Method 2
the majority of the grasping force applied from the grasping members to the foreign object come from the tensile strength of the tube 5 itself, as the grasping members are retracted within the tube
Data Source
AI summary
A dual operation grasping forceps for use with an endoscope includes an elongated tube having a control mechanism along a first end, and a grasping section along a second end. The grasping section includes a plurality of resilient wire members each having a loop along a distal end. A cable is positioned through the loops to form a circular or triangular shape snare. The grasping members are independently connected to the control mechanism by a first operating wire, and the cable is independently connected to the control mechanism by a second operating wire. The control mechanism selectively moves the grasping section between a retracted position, an extended position and a closed position.