Vacuum Pump System for Prosthetic Limb Suspension
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Solution Overview
Problem
Conventional prosthetic pump systems face limitations in versatility, aesthetic appeal, mass, noise levels, and inadequate replication of natural human locomotion dynamics, with existing control systems failing to respond effectively to dynamic loading and volumetric changes in the residual limb.
Innovation Solution
A prosthetic pump system incorporating a vacuum chamber, sensors, electronics, and embedded software that senses pressure and non-pressure parameters, determines activity patterns, and adjusts pressure limits to maintain a secure fit, using a pylon and adaptor for fluid communication and structural support, while minimizing noise and size through acoustic and vibration dampening.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a vacuum pump system is used to improve fit and circulation, then the prosthesis provides better suspension and limb health, but the system increases mass and noise levels
Solution Approach 1:
The pump system is nested within the pylon structure of the prosthesis, utilizing the existing spatial framework to house the vacuum pump and associated components. This integration minimizes additional mass while maintaining the vacuum function, as the pump occupies space that would otherwise be structural or cosmetic.
Solution Approach 2:
The pump system is extracted from the socket structure and relocated to the pylon, separating the vacuum generation function from the fit interface. This extraction allows the socket to be lighter and simpler while the pump handles the vacuum function in a dedicated compartment, reducing overall mass.
2Reliability
If a vacuum pump system is used to maintain fit, then circulation and limb health improve, but audible and inaudible noise levels increase
Solution Approach 1:
The pump system operates in a vacuum environment within the pylon, where the vacuum pressure itself acts as a damping medium to reduce noise propagation. The vacuum condition suppresses acoustic vibrations and airborne sound, converting the vacuum function into a noise-reduction mechanism.
Solution Approach 2:
The pump and its noise-generating components are nested within the pylon's internal cavity, isolated from the external environment by the pylon structure and vacuum seal. This nesting creates an acoustic barrier that contains noise within the pylon while allowing the circulation benefits to reach the residual limb.
3Device complexity
If conventional control systems are used, then the prosthesis structure is simple, but the system fails to respond adequately to dynamic loading and impact
Solution Approach 1:
Pressure sensors are integrated into the socket to continuously monitor vacuum pressure levels, providing feedback to the control system. This feedback loop enables the control system to dynamically adjust pump operation in response to loading conditions, impact, or changes in residual limb contact, improving reliability without requiring complex mechanical structures.
Solution Approach 2:
The control system automatically adjusts vacuum pressure based on sensor feedback and pre-programmed algorithms, eliminating the need for manual intervention. The system self-regulates to maintain optimal fit and circulation under varying conditions, reducing structural complexity while enhancing responsive control.
4Weight of moving object
If the pump system is made smaller to reduce mass, then aesthetic appearance improves, but the pump capacity and effectiveness decrease
Solution Approach 1:
The system uses a vacuum pump that operates within a vacuum environment, leveraging pneumatic principles to generate and maintain negative pressure. The vacuum condition enhances pump efficiency by reducing backpressure and improving the seal effectiveness, allowing a smaller pump to deliver adequate capacity for maintaining prosthesis fit and circulation.
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 system provides a comfortable, secure fit, improved proprioceptive control, and reduced noise, with data recording and analysis capabilities to optimize fit and usability, enhancing the prosthetic experience for amputees by actively managing vacuum pressure and responding to environmental changes.
Implementation Method 1
a pump system that evacuates air from spaces, gaps or other interstices present between the residual limb and the prosthesis
Implementation Method 2
generates a vacuum pressure of up to about fifteen inches of Mercury (50,795 Pascal) on the residual limb
Data Source
AI summary
A vacuum pump system for a prosthesis device includes an enhanced suspension mechanism and cooperates with a pressure source, an adaptor assembly, circuitry, and a power source. A virtually air-tight seal between a residual limb and a socket of the prosthesis allows a vacuum fit to be generated by the pump system. The pump system may be controlled with various circuits and processors receiving instructions from a software program. The pump system may be located within a pylon, but yet remain vibrationally and acoustically de-coupled from the pylon.