Medical Retrieval End-Effector Indicia for In Vivo Stone Sizing
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Solution Overview
Problem
Existing medical retrieval devices face inefficiencies in determining the size of large stones within the body, leading to increased procedure time and potential tissue or device damage through trial-and-error methods.
Innovation Solution
A medical device with an end-effector featuring alternating indicia of different colors and friction coefficients on expandable legs, allowing precise in vivo size estimation of stones by alternatingly gripping and sliding on uneven surfaces for optimal capture and removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If trial-and-error method is used to gauge stone size by withdrawing captured stone toward working channel, then stone size can be determined, but procedure time increases and damage to surrounding tissue, end-effector, and insertion device may occur
Solution Approach 1:
The patent applies preliminary action by providing indicia on the end-effector legs before the stone is captured, enabling size estimation to be performed in advance during the capture process rather than after withdrawal. The indicia allow the operator to gauge stone size immediately when the stone is captured in situ, eliminating the need for subsequent trial-and-error withdrawal procedures.
2Measurement precision
If trial-and-error method is used to gauge stone size, then stone size can be determined, but damage to surrounding tissue, end-effector, and insertion device may occur
Solution Approach 1:
The indicia are pre-positioned on the end-effector legs to enable size assessment before any withdrawal or manipulation occurs. This preliminary measurement capability allows the operator to determine stone size in its original position, avoiding the harmful effects of repeated withdrawal attempts and trial-and-error maneuvers that could damage tissue or the device.
3Device complexity
If traditional retrieval device without size indicators is used, then device complexity is reduced, but ability to determine stone size in vivo is lost
Solution Approach 1:
The patent applies segmentation by dividing the end-effector legs into multiple segments with indicia markings. Each leg is segmented with multiple indicia at different positions, creating a scale system that enables size measurement. This segmented approach adds measurement capability without requiring a completely new device architecture.
Solution Approach 2:
The patent utilizes color changes or visual contrasts through differently colored indicia on the end-effector legs. The indicia are configured with contrasting colors or visual characteristics that make them easily distinguishable, enabling clear size measurement. This visual differentiation approach adds measurement functionality while maintaining device simplicity.
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
Enables quick and accurate size determination of stones, reducing the need for trial-and-error and minimizing damage to surrounding tissue or devices by providing a direct measurement of stone dimensions during the procedure.
Implementation Method 1
Each of the first plurality of indicia includes a first coefficient of friction and each of the second plurality of indicia may include a second coefficient of friction greater than the first coefficient of friction. The first and second coefficients of friction are configured to enable the first and second indicia to alternately grip and slide on an uneven surface of a stone
Data Source
Figure 1
Figure 2A~2C
AI summary
A medical device may include a handle assembly having an actuator and a sheath. The sheath may extend between a proximal end and a distal end. The proximal end of the sheath may be coupled with the actuator. The medical device may further include an end-effector moveable relative to the sheath between an extended configuration and a retracted configuration. The end-effector may include a plurality of expandable legs. Each of the plurality of expandable legs may include a plurality of first indicia and a plurality of second indicia. A color of each of the first plurality of indicia may be different than a color of each of the second plurality of indicia.