Electroactive Polymer Prosthetic Liner for Dynamic Fit
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Solution Overview
Problem
Current prosthetic liners and sockets are static, failing to adapt to the dynamic changes in residual limbs throughout the day, leading to discomfort and potential tissue damage due to inadequate fit, as they rely on static molding and suction or vacuum systems that can be restrictive and uncomfortable.
Innovation Solution
The integration of electroactive polymers (EAPs) that contract and expand to maintain a comfortable fit, providing a shape-morphing system that can be used in prosthetic liners and sockets to adapt to changes in limb size and shape, offering a more secure and comfortable fit through strategic expansion and contraction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If static prosthetic liners and sockets are used, then manufacturing simplicity is maintained, but adaptability to dynamic limb changes deteriorates
Solution Approach 1:
The prosthetic liner incorporates electroactive polymer actuators that dynamically change the liner's shape and volume in response to electrical signals, enabling real-time adaptation to limb size changes throughout the day. This transforms the static liner into a dynamic system that can expand or contract as needed.
Solution Approach 2:
The system uses feedback from pressure sensors and limb circumference measurements to automatically adjust the liner fit without requiring patient intervention. The control system autonomously determines when and how to activate the electroactive polymer actuators to maintain optimal fit.
2Force
If suction or vacuum systems are used to improve fit, then holding force increases, but patient comfort deteriorates
Solution Approach 1:
The invention replaces the mechanical suction/vacuum system with electroactive polymer actuators that provide fit adjustment through controlled expansion and contraction. This substitution eliminates the need for vacuum pumps and complex sealing mechanisms, providing a more comfortable and less restrictive experience for the patient.
Solution Approach 2:
The electroactive polymer actuators change their physical state (expanding or contracting) in response to electrical signals, allowing the liner to dynamically adjust its volume and shape. This provides continuous fit adjustment capability without the binary on/off nature of vacuum systems.
3Adaptability or versatility
If manual adjustment of prosthetic socks is required, then adaptability to volume changes is improved, but ease of operation deteriorates
Solution Approach 1:
The system automatically monitors limb circumference and pressure sensor data to detect when fit adjustment is needed, then autonomously activates the appropriate electroactive polymer actuators to restore optimal fit. This eliminates the need for the patient to manually add or remove sock layers.
Solution Approach 2:
Pressure sensors and limb circumference measurements provide continuous feedback to the control system, which uses this information to determine when and how to adjust the liner fit. This closed-loop control ensures the system responds appropriately to actual fit conditions.
4Adaptability or versatility
If static molding is used for prosthetic design, then manufacturing precision is maintained, but adaptability to dynamic changes deteriorates
Solution Approach 1:
The prosthetic liner incorporates electroactive polymer actuators that dynamically change the liner's shape and volume in response to electrical signals, enabling real-time adaptation to limb size changes throughout the day. This transforms the static liner into a dynamic system that can expand or contract as needed.
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 EAP-based system allows for a dynamic and adaptive fit, reducing the need for frequent adjustments and minimizing the risk of tissue damage by automatically adjusting to maintain a snug and comfortable fit, enhancing the usability and comfort of prosthetic devices for amputees and individuals with limb differences.
Implementation Method 1
a first actuator electrically connected to the first electrode and comprising a first electroactive ionic polymer, said electroactive polymer selected to expand or contract on application of an electrical potential
Implementation Method 2
an ionically conductive fluid
Data Source
AI summary
In one aspect, novel robust electroactive polymers (EAPs) is described, which contract and expand at low voltages to provide for a shape-morphing system, e.g., a prosthetic liner, and potentially entire prosthetic socket, to contract and expand in strategic areas as needed to maintain a comfortable and good fit throughout the day. In some embodiments, as the residual limb changes, these novel robust EAPs can change dynamically as needed to maintain a comfortable, snug fit of the prosthetic liner or socket with the hard shell of the prosthetic socket device. In some embodiments, the EAPs used in prosthetic liners or sockets can also be used to detect pressure as the device is being used, and automatically adjust to maintain fit through a control unit, so that the patient does not even have to stop and adjust his or her device as he or she goes about an active day.