Articulating Grasper End-Effector Cam Mechanism
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Solution Overview
Problem
Existing endoscopic medical instruments with articulating grasper jaws fail to maintain a rigid position during angular movement, leading to tissue abrasion, injury, or ineffective suturing due to lack of stability in their articulation mechanism.
Innovation Solution
A system featuring an elongated shaft with a cam assembly and actuator rods that allow angular displacement of the grasper end-effector relative to the main axis, utilizing a ratchet mechanism to lock the position and provide controlled angular movement within a range of -45 to +45 degrees, ensuring the grasper remains rigid during tissue manipulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a cable or actuator rod system is used for articulation, then the grasper can move angularly, but the distal end cannot be held rigid in position
Solution Approach 1:
A cam mechanism acts as an intermediary between the actuator rod and the grasper jaw articulation. The cam profile translates linear actuator movement into controlled angular jaw movement while maintaining stable positioning at selected angles, resolving the conflict between mobility and rigidity
Solution Approach 2:
The system changes the geometric parameters of the cam profile to control the angular displacement characteristics. By adjusting cam geometry, the system achieves both angular movement capability and stable positioning at specific angles, eliminating the rigidity problem
2Adaptability or versatility
If the grasper articulates during angular movement, then it can grasp tissue at angles, but tissue abrasion and injury occur due to lack of rigidity
Solution Approach 1:
The cam mechanism serves as a mediator that ensures smooth, controlled angular transitions and prevents unintended jaw movement. This controlled articulation eliminates tissue abrasion while preserving the ability to grasp at various angles
Solution Approach 2:
The cam profile is designed to provide controlled deceleration and positioning before the grasper contacts tissue at the desired angle. This pre-positioning control prevents sudden movements that could cause tissue injury
3Adaptability or versatility
If the grasper articulates without rigid positioning, then angular movement is possible, but suturing effectiveness is reduced
Solution Approach 1:
The cam mechanism mediates between the actuator and jaw, providing stable angular positioning that ensures consistent needle capture and suture placement. This reliability is essential for effective suturing while maintaining angular orientation capability
Solution Approach 2:
The invention replaces the traditional cable-pulley mechanical system with a cam-based mechanism that provides both movement and stable positioning. This substitution ensures reliable suturing performance while maintaining angular versatility
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
The solution enables controlled angular movement of grasped organs relative to the main shaft axis while maintaining the grasper in a rigid position, reducing tissue injury and improving the effectiveness of surgical procedures by providing precise and stable articulation.
Implementation Method 1
The cam assembly includes a cam, and the proximal ends of the first and second actuator rods are configured to be slidably attached to first and second locations of the cam, respectively
Implementation Method 2
The cam includes a ratchet on a portion of the cam periphery and a trigger extending radially from the cam periphery and activation of the trigger rotates the cam around an axis perpendicular to the main axis
Implementation Method 3
The elongated shaft assembly includes first and second actuator rods arranged parallel to each other and the first actuator rod is longer than the second actuator rod
Implementation Method 4
The articulating distal end assembly extends along the main axis and is pivotally connected to the distal ends of the first and second actuator rods
Data Source
AI summary
An endoscopic medical device system includes an elongated shaft assembly, a cam assembly and an articulating distal end assembly. The elongated shaft assembly extends along a main axis and includes first and second actuator rods arranged parallel to each other and the first actuator rod is longer than the second actuator rod. The cam assembly includes a cam, and the proximal ends of the first and second actuator rods are configured to be slidably attached to first and second locations of the cam, respectively, and the distal ends of the first and second actuator rods are positioned at the same distance from the cam center. The articulating distal end assembly extends along the main axis and is pivotally connected to the distal ends of the first and second actuator rods. Rotation of the cam around an axis perpendicular to the main axis provides angular displacement of the distal end assembly relative to the main axis.