Prosthetic Feedback Device Using Air Chamber for Tactile Sensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current prosthetic hands, particularly under-actuated ones, lack the ability to provide feedback to users about the interaction with the external environment, such as the hardness or softness of an object, which is crucial for users who have lost a limb due to acquired causes and still experience latent sensations.
Innovation Solution
A prosthetic feedback device that includes a motor system with an encoder to measure motion output, an air chamber system that provides tactile feedback through inflation based on motor operation parameters, and a control board that adjusts the inflation according to the measured output and residual current, allowing users to perceive the characteristics of objects being gripped.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If prosthetic hands are designed to be under-actuated with fewer actuators, then the device complexity and weight are reduced, but the ability to provide tactile feedback to users is lost
Solution Approach 1:
The patent implements a feedback mechanism where an encoder measures the motor's output motion and a control board processes this information along with residual current data. The system then actuates an air chamber to provide tactile feedback to the user, closing the loop between motor action and user perception. This resolves the contradiction by adding feedback capability without requiring additional actuators for each finger.
Solution Approach 2:
The patent introduces an air chamber as an intermediary element between the motor system and the user's residual limb. The air chamber translates electrical control signals into mechanical expansion that the user can perceive tactilely, serving as a mediator that converts information about motor operation into sensory feedback without requiring direct mechanical coupling between multiple actuators and finger joints.
2Loss of information
If a feedback system is added to provide tactile information, then the user's perception of object characteristics is improved, but the device complexity increases
Solution Approach 1:
The patent makes the existing motor system multi-functional by using it both for driving the prosthetic fingers and for providing tactile feedback through the air chamber. The encoder and control board, while adding components, leverage the motor's existing operational parameters (output motion and residual current) to generate feedback, rather than requiring completely separate sensing and actuation systems.
Solution Approach 2:
The system uses the motor's own operational data (output motion measured by the encoder and residual current from the power supply) to generate the tactile feedback signal. This self-service approach means the feedback system draws information from the motor's inherent operation rather than requiring external sensors to measure interaction forces, reducing the need for additional complex sensing components.
3Reliability
If an air chamber system is integrated into the user attachment body, then the tactile feedback capability is enhanced, but the manufacturing complexity increases
Solution Approach 1:
The patent integrates the air chamber directly into the user attachment body structure, nesting the feedback mechanism within the existing prosthetic housing. This nested integration allows the air chamber to be incorporated as part of the overall assembly rather than as a separate add-on component, simplifying the manufacturing process while maintaining reliable tactile feedback delivery to the user's residual limb.
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
Enables users to regain the sensation of gripping by providing tactile feedback, enhancing the user experience with prosthetic hands, making the device lightweight, easy to use, and compatible with existing prostheses without significant modifications.
Implementation Method 1
the prosthetic feedback device (1) may comprise at least one air chamber (3) integrated into the body (2) and configured to contact the user appropriately at the contact surface
Implementation Method 2
The board (5) may be configured to control the inflation of the at least one chamber (3) according to the output of said motor (12) appropriately measured by the encoder (13)
Data Source
AI summary
A prosthetic feedback device to be associated with a prosthesis equipped with a motor for controlling the same prosthesis is provided The device includes an attachment body configured to be in direct contact with the user; at least one air chamber interposed at least partially between the body and the user; an inflation circuit for inflating the chamber; and a circuit board to control the inflation of the chamber by the motor.