Surgical Tool Pivot Assembly Reduces Actuation Force
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Surgical tools often require significant force to actuate grasping instruments, leading to user fatigue and inefficiency, particularly due to bulky mechanisms that occupy substantial space within the tool's housing.
Innovation Solution
A surgical tool design featuring a pivot assembly with a curved slot and tapered pivot pin, which reduces the required actuation force by altering the pivot point's location and incorporating a low-friction coating, allowing for efficient translation of handle movement into yoke movement within a compact housing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If traditional mechanisms are used to transmit force from handle to grasper, then the grasper can be actuated, but the mechanism becomes bulky and requires significant space within the housing
Solution Approach 1:
The mechanism is divided into multiple rigid links connected by pivot joints, creating a segmented kinematic chain that transmits force efficiently. The first link connects the handle to the housing, the second link connects the first link to the yoke, and the third link connects the second link to the grasper assembly, allowing force transmission through a compact series of articulated segments
Solution Approach 2:
The mechanism utilizes rotational motion at pivot joints to transform the linear squeezing motion of the handle into the linear displacement of the yoke. By operating in multiple dimensions through rotational degrees of freedom at each pivot point, the system achieves efficient force transmission in a compact volume
2Ease of operation
If traditional force transmission mechanisms are used, then the grasper can be actuated, but significant force is required on the handle leading to user fatigue
Solution Approach 1:
The pivot assembly acts as an intermediary mechanism between the handle and the grasper assembly. The series of rigid links and pivot joints transforms the user's input force into efficient mechanical motion, reducing the actuation force required while maintaining effective grasper operation
Solution Approach 2:
The mechanism changes the mechanical parameters of force transmission through its kinematic configuration. By utilizing rotational pivot joints and a specific arrangement of links, the system optimizes force transmission efficiency, reducing the input force required at the handle while maintaining adequate output force at the grasper
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 design significantly reduces the actuation force needed to operate the tool, minimizing user fatigue and allowing for more precise control, while maintaining a compact form factor suitable for minimally invasive surgeries.
Implementation Method 1
The slot may include a low-friction coating formed on a region of the slot where the pivot pin contacts the slot
Implementation Method 2
The pivot pin includes a first end and a second end, each of the first end and the second end being tapered
Data Source
AI summary
A surgical tool including a housing having a proximal end and a distal end, a yoke disposed within the housing between the proximal end and the distal end, a handle pivotally coupled to the housing, and a pivot assembly coupling the yoke to the housing. The pivot assembly includes a first link having a first end and a second end. The first end of the first link is rotatably coupled to the housing and the second end of the first link rotatably coupled to a second link at a first end of the second link. The second link has a second end rotatably coupled to the yoke. The handle is coupled to the pivot assembly such that movement of the handle causes movement of the yoke.