Articulating Prosthetic Digit With Single-Actuator Grasping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing prosthetic digits do not sufficiently mimic natural fingers, leading to inadequate functionality and dexterity for amputees.
Innovation Solution
Prosthetic digits with three articulating segments, including a proximal, middle, and distal segment, articulated by an actuator and mechanical links, allowing for rotation and multiple degrees of freedom, and utilizing a single actuator for enhanced gripping capabilities, with features like a spring-biased worm wheel transmission for manual rotation control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If existing prosthetic digit designs are used, then the structure is simpler, but the functionality and dexterity are insufficient to mimic natural fingers
Solution Approach 1:
The prosthetic digit is divided into three articulating segments (proximal, middle, and distal segments) that can rotate independently relative to each other. This segmentation allows the prosthetic digit to mimic the natural bending and articulation of human fingers, providing enhanced gripping functionality while maintaining a manageable structural complexity through modular design.
2Ease of operation
If multiple actuators are used for each digit segment, then the articulation precision is improved, but the device complexity and power requirements increase
Solution Approach 1:
A single actuator is used to control the articulation of all three digit segments through a system of mechanical links. The actuator connects to the proximal segment, and through the coordinated rotation of mechanical links, it simultaneously controls the relative rotation between proximal-middle and middle-distal segments. This merging approach reduces the number of actuators while maintaining articulation control through mechanical coupling.
Solution Approach 2:
Mechanical links serve as intermediaries between the single actuator and the multiple digit segments. These links transmit and transform the actuator's rotational output into coordinated rotation of the proximal, middle, and distal segments. The mechanical links mediate the control signal distribution, allowing one actuator to effectively control multiple segments with different articulation requirements.
3Power
If a single actuator is used for the digit, then the power consumption and device complexity are reduced, but the control precision for multiple segments may be compromised
Solution Approach 1:
The mechanical link system merges the control function for multiple segments into a single actuator output. By carefully designing the link geometry and pivot points, the system ensures that rotation of the proximal segment through the mechanical links produces coordinated rotation of the middle and distal segments, maintaining articulation precision while using only one actuator.
4Weight of moving object
If the prosthetic digit is made lighter, then the power consumption is reduced, but the strength and durability may be compromised
Solution Approach 1:
The prosthetic digit utilizes composite material construction to achieve an optimal balance between weight and strength. By combining materials with different properties, the design reduces the overall weight of the moving components while maintaining the structural strength necessary to withstand gripping forces and external loads during operation.
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 prosthetic digits provide enhanced gripping functionality, mimicking natural finger movements, offering space, weight, and power savings, and preventing damage from external forces.
Implementation Method 1
A spring-biased worm wheel transmission provides a manual mode for rotation of the digit
Implementation Method 2
A spring-biased worm wheel transmission provides a manual mode for rotation of the digit
Implementation Method 3
The actuator is configured to cause the proximal segment to rotate about the first pivot
Implementation Method 4
The first joint is located offset from the first pivot, such that linear actuation output by the actuator imposes a force at the first joint to cause the proximal segment to rotate about the first pivot
Data Source
AI summary
Features for prosthetic digits are described. The digits mimic natural fingers by having multiple articulating segments, for example three, that can rotate varying amounts. Rotatable and/or linearly expandable mechanical links are configured to provide the digit segments with multiple degrees of rotational freedom. The digit may have an actuator that outputs linear actuation to cause rotation of the digit segments. The digit may have an expandable proximal link to allow for variable relative rotational positions of the segments. Middle and/or distal digit segments may fully rotate independent of rotation of a proximal digit segment. The rotated digit may thus fully surround and grasp small or large objects, objects with irregular outer contours, etc.