Retrieval Basket Cam Control for Single-Hand Operation
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Solution Overview
Problem
Existing medical devices for removing objects like kidney stones require two hands for operation, leading to inefficiencies and a high risk of losing fragments during the basket closing process due to fixed sheaths.
Innovation Solution
A single-hand operable endoscope medical device featuring a basket device with a longitudinally sliding sheath and a cam-controlled mechanism that allows for independent manipulation of the sheath and basket, enabling the surgeon to close and open the basket section without axial rotation, thus reducing fragment loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a fixed sheath design is used in existing medical devices, then the device structure is simple, but the risk of losing fragments during basket closing is high and two hands are required for operation
Solution Approach 1:
The holder integrates multiple functions: it serves as the connection interface to the endoscope, the mounting structure for the bracket, and the rotational axis for the cam member. By combining these functions into a single component, the design enables single-hand operation without proportionally increasing complexity
Solution Approach 2:
The cam member acts as an intermediary mechanism that translates rotational motion into longitudinal sheath movement. This mechanical intermediary allows indirect control of the sheath position, enabling single-hand operation while maintaining manageable device complexity through well-understood mechanical principles
2Reliability
If the sheath is fixed in position, then the device structure is simpler, but fragment loss risk increases during basket closing
Solution Approach 1:
The sheath transitions from a fixed component to a dynamically controllable one. The cam mechanism enables the sheath to move longitudinally in response to rotational input, allowing the basket to close reliably around fragments while the sheath adjusts its position dynamically during the closing process
Solution Approach 2:
The cam member utilizes a curved cam surface that converts rotational motion into linear longitudinal movement of the sheath. This curved geometry provides smooth, controlled sheath movement throughout the basket closing cycle, ensuring reliable fragment retention without complex control systems
3Ease of operation
If the bracket is limited to linear sliding only, then the control mechanism is simpler, but the sheath cannot be properly positioned for basket closing
Solution Approach 1:
The bracket's movement is segmented into two distinct phases: linear sliding along the holder's longitudinal axis for initial positioning, and rotational movement for final sheath positioning during basket closing. This segmentation allows each movement type to be controlled independently through simple mechanical constraints
Solution Approach 2:
The bracket transitions from one-dimensional linear sliding to two-dimensional movement by adding rotational capability. This additional degree of freedom enables precise sheath positioning for basket closing while maintaining relatively simple mechanical constraints through the holder-bracket-cam geometry
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 the surgeon to perform procedures like lithotripsy and urology surgeries with one hand, reducing the need for additional assistance and minimizing the risk of losing fragments during the basket closing process.
Implementation Method 1
The control may comprise a cam member having a cam surface adapted to cam against a portion of the sheath as the sheath and the cam member are rotated relative to each other
Data Source
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AI summary
An object removal tool including a basket device having a basket section; a sheath on the basket device, where the sheath is adapted to longitudinally slide on the basket device; and a control, comprising a holder and a bracket, connected to the basket device and the sheath. The control is configured to longitudinally move the sheath on the basket device to close the basket section on an object. The bracket is movably connected to the holder and a proximal end of the basket member is fixedly connected to the bracket. The bracket is limited to longitudinally slide along a first length of travel of the bracket on the holder and is rotatable on the holder at an end of the first length of travel. The control comprises a cam member having a cam surface adapted to cam against a portion of the sheath as the sheath and the cam member are rotated relative to each other.