Snare Wire Loop Tilting for Angled Lesion Excision
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Solution Overview
Problem
Existing endoscopic treatment tools face difficulties in placing a loop around a lesioned portion when the longitudinal axis of the sheath is angled near a right angle with respect to the lesioned portion, making it challenging to excise the lesion effectively.
Innovation Solution
The method involves an elongated sheath with a snare wire that can move forward or backward, forming a loop and tilting it transverse to the longitudinal axis, allowing the snare wire to function as a cantilever and be curved, enabling the loop to be placed around the lesioned portion even when the sheath is positioned transversely.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the loop spreads along a plane including the longitudinal axis of the sheath, then the loop formation is simple, but it is difficult to place the loop around the lesioned portion when the sheath is angled near a right angle with respect to the lesioned portion
Solution Approach 1:
The patent applies dimensionality change by transitioning the loop from spreading along the longitudinal axis (one dimension) to spreading in a plane transverse to the longitudinal axis (another dimension). This is achieved by pushing the wire out of the distal end of the sheath while it is in a curved state, causing the loop to form perpendicular to the sheath's longitudinal axis, thereby enabling effective placement around lesions even when the sheath is angled at near right angles.
Solution Approach 2:
The patent employs dynamics by making the sheath flexible and capable of curving rather than maintaining a rigid straight configuration. The sheath can be bent to a curvature radius of 10 mm or less, and the wire is pushed out while the sheath is in this curved state, allowing the loop to dynamically adapt its orientation to match the spatial relationship between the sheath and the lesioned portion.
2Device complexity
If the wire is pushed out straight from the sheath, then the structure is simple, but the loop cannot be tilted transverse to the longitudinal axis
Solution Approach 1:
The patent makes the sheath dynamic by introducing flexibility that allows it to curve rather than remain rigidly straight. The sheath can be bent to a curvature radius of 10 mm or less, and the wire is pushed out while the sheath is in this curved state, allowing the loop to dynamically adapt its orientation to match the spatial relationship between the sheath and the lesioned portion.
Solution Approach 2:
The patent applies preliminary action by pre-curving the sheath before pushing the wire out. The sheath is bent to an appropriate curvature radius (10 mm or less) in advance, and only then is the wire pushed out from the distal end. This preliminary curving action enables the loop to form in the desired transverse orientation without requiring complex mechanisms during the wire advancement itself.
Data Source
AI summary
The disclosed technology is directed to a method of operating a treatment tool for excising a lesioned portion of a body tissue. The method comprises applying a treatment tool to the lesioned portion. The treatment tool includes an elongated sheath having a snare wire disposed therein. The snare wire is configured to be movable forward or backward along a longitudinal direction. Next, forming the snare wire into a loop and tilting the loop in a plane transverse to the longitudinal axis of the elongated sheath with a force tending to push a snare wire portion out of a distal-end opening of the elongated sheath. And finally, placing the loop around the lesioned portion of the body tissue to excise the lesioned portion in a state in which the snare wire positioned transverse to the lesioned portion.