Modular Prosthetic Hand With Crushable Palm And Segmented Digits
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current prosthetic hands, such as the Hosmer Hook and advanced robotic hands, are limited in their ability to grasp irregularly shaped objects, lack dexterity, and are not aesthetically appealing, with most being non-scalable, fragile, and visually intimidating.
Innovation Solution
A mechanical hand design featuring a crushable palm with laterally-only pivoting metacarpal members, scalable finger and thumb assemblies, and a modular structure that mimics the human hand, allowing for customizable and adjustable digit control, and the option to be powered by either body or myoelectric systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If sophisticated robotic hands with five fingers are used, then dexterity and grasping ability are improved, but device complexity, cost, and fragility increase
Solution Approach 1:
The prosthetic hand is divided into modular components including metacarpal members, finger digit assemblies, and phalange digits that can be independently manufactured and assembled. Each finger assembly is a separate module that can be customized and replaced individually, reducing overall system complexity while maintaining dexterity.
Solution Approach 2:
The hand incorporates flexible polymer materials and spring elements that provide dynamic, adaptive grasping capability. The flexible knuckle spacers and spring-loaded mechanisms allow the fingers to naturally conform to objects being grasped, improving dexterity without requiring complex mechanical actuators for each finger.
2Ease of manufacture
If fixed-length rigid pinchers are used, then manufacturing simplicity is maintained, but ability to grasp irregularly shaped or large objects is limited
Solution Approach 1:
The finger assemblies incorporate flexible polymer materials and spring elements that allow the fingers to dynamically adapt their shape and length during grasping operations. The flexible knuckle spacers enable the fingers to bend and conform to irregularly shaped objects, while the spring mechanisms provide adjustable tension for different grasp forces.
Solution Approach 2:
The prosthetic hand allows for parameter adjustments including finger flexion angles, grasp force through spring tension, and finger positioning. These adjustable parameters enable the same basic structure to effectively grasp objects of varying sizes, shapes, and weights without requiring multiple fixed configurations.
3Ease of manufacture
If non-scalability is accepted in prosthetic design, then manufacturing simplicity is maintained, but availability for children or women is limited
Solution Approach 1:
The prosthetic hand is designed as a modular system where each component (metacarpals, finger assemblies, phalanges) can be independently sized and configured. This segmentation allows the same design to be scaled to different sizes for children, adults, and women by simply adjusting the dimensions of individual modules rather than redesigning the entire system.
Solution Approach 2:
The finger assemblies are designed with nested components where smaller phalange segments fit within larger metacarpal structures. This nesting approach allows for compact storage and easy adjustment of finger lengths by adding or removing segments, enabling scalability across different user sizes while maintaining a consistent manufacturing process.
4Strength
If a monolithic palm structure is used, then structural strength is improved, but flexibility and lifelike appearance are reduced
Solution Approach 1:
The palm is divided into separate metacarpal members that are independently mounted to the palmar plate, rather than forming a single rigid monolithic structure. This segmentation allows each metacarpal and attached finger assembly to move and flex independently, providing lifelike motion and adaptability while maintaining overall structural integrity through the rigid palmar plate foundation.
Solution Approach 2:
The prosthetic hand incorporates flexible polymer materials in the finger assemblies and knuckle spacers that allow bending and flexion. These flexible elements are strategically placed to enable natural hand motion and adaptation to objects, while the rigid metacarpal members and palmar plate provide the necessary structural strength and support.
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 mechanical hand provides a robust, flexible, and aesthetically pleasing solution for grasping various objects, offering improved dexterity and scalability while being durable and adaptable to different user needs, with a design that prevents damage from mechanical loads and allows for individual customization.
Implementation Method 1
a torsion spring operably connected to the proximal end of the distal phalange digit
Implementation Method 2
a cable extending through the distal phalange digit, middle phalange digit, and proximal phalange digit and having its distal end affixed to the distal end of the distal phalange digit
Data Source
AI summary
A body-powered articulated prosthetic hand where each of the segments of the digits, the palmer plate, the thumb pivot plate and the wrist are individually sizeable. This allows for both a proportionately scalable hand as well as individual customization of geometric configurations tailored to specific use patterns. The hand is crushable since it has flexible and pivotable connections between digits along the length and width of the hand. It has a hollow member construction that imparts a strong lightweight design. It is modular so individual parts can be replaced for quick repair. From an aesthetics point, it is visually pleasing and can be offered in different colors, and with custom digit sleeves for specific applications. Fingers can be operated individually or in groups via pairs of cables which allow operation in either voluntary open or voluntary closed modes of control. The flexible construction allows gripping of irregularly shaped objects and deforms before failing giving indication of overload prior to failure.