Single-Motor Electromagnetic Actuation for Prosthetic Hand Digit Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current prosthetic hand designs face challenges such as weight, cosmetic appearance, grasping forces and speeds, noise reduction, and increased functionality due to their underactuated and bulky nature, which hinder their ability to mimic the natural human hand's dexterity and efficiency.
Innovation Solution
A cost-efficient electromagnetic driving mechanism for prosthetic hands that uses a single motor to individually control each digit, incorporating a magnetic actuation system, ratchet and pawl mechanism, and spline nut and shaft configuration, allowing for precise control and locking of digits, and optionally featuring an electromagnetic rotary solenoid clutch for enhanced functionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If traditional body-powered or cable transmission mechanisms are used, then the prosthetic hand can be controlled, but the device becomes bulky and heavy
Solution Approach 1:
The patent combines multiple driving functions into a single electromagnetic actuator that can independently control multiple digits through a unified mechanism, eliminating the need for separate motors for each finger and reducing overall device weight while maintaining individual digit control capability
Solution Approach 2:
The electromagnetic actuator serves multiple functions simultaneously - it can drive different digits with different forces and speeds, provide both active grasping and passive support functions, and adapt to various grasp types, replacing what would traditionally require multiple specialized components
2Adaptability or versatility
If multiple motors are used to control each digit individually, then dexterity is improved, but device complexity and weight increase
Solution Approach 1:
Multiple driving functions are merged into a single electromagnetic actuator that uses a unified mechanism with separate drive belts and pulleys for each digit, reducing the number of motors from five (one per digit) to one while maintaining individual digit control through the shared actuator
Solution Approach 2:
The unified electromagnetic actuator is segmented into multiple independent driving systems within it, with separate drive belts, pulleys, and cable routing for each digit, allowing individual control while sharing the common actuator body and control electronics
3Force
If pneumatic or hydraulic systems are used, then grasping force is improved, but noise and complexity increase
Solution Approach 1:
The patent replaces pneumatic or hydraulic mechanical systems with an electromagnetic actuation system that uses electromagnetic fields to generate force, eliminating the noise associated with compressors, valves, and fluid flow while maintaining high grasping force capability through direct electromagnetic conversion
4Device complexity
If underactuated mechanisms are used, then device simplicity is improved, but functionality and dexterity are reduced
Solution Approach 1:
The electromagnetic actuator provides dynamic control capability that allows the system to transition between underactuated and fully-actuated modes, enabling simple grasps when only basic functionality is needed while providing full individual digit control when complex grasping tasks are required, thus adapting to different functional demands
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
This solution reduces the weight and size of the prosthetic hand, minimizes noise, decreases power usage, increases grasping forces and speeds, and provides a more aesthetically appealing design, while enabling greater dexterity and functionality, including the ability to hold heavier objects without damage.
Implementation Method 1
an electromagnetic actuation system. The ratchet gears are on the main shaft as with the spline shaft and spline nut configuration, and the pawls are located on the secondary shaft, parallel to the main shaft, driven by the main drive belt in a directional manner due to the implementation of a one-way bearing on the pawl shaft
Data Source
AI summary
The disclosed invention is an innovative, cost-efficient driving mechanism for the prosthetic hand industry that makes the use of only one motor to individually control each digit on a prosthetic hand separately. The use of the novel electromagnetic actuation system, locking mechanism, and spline nut and shaft configuration coupled with the single motor greatly reduces the weight, size and power usage of the prosthetic, increases functionality, minimizes noise, increases and speeds and forces, and orients the parts of the device in a manner that creates an aesthetically appealing design.