Prosthetic Socket Heat Pipe Cooling via Phase Change
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current prosthetic devices suffer from limited heat transfer due to poor thermal conductivity of liner and socket materials, leading to discomfort and skin irritation from heat and perspiration, with existing cooling systems being either inefficient or bulky and power-intensive.
Innovation Solution
The use of heat pipes with a working fluid and wicking structure to concentrate heat flux into a compact heat sink, where heat is removed by a fan or air duct, and a control system to regulate temperature through a heat sensor and regulator.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If liquid cooling systems are used to improve heat transfer efficiency, then cooling capacity is improved, but device complexity and power consumption increase
Solution Approach 1:
The patent replaces complex liquid cooling systems with mechanical pumps and tubing with a passive heat pipe system that uses phase change (evaporation and condensation) of working fluid to transfer heat. The heat pipe utilizes capillary action and pressure differential from phase change to circulate coolant without mechanical pumps, thereby reducing device complexity while maintaining effective cooling capacity
Solution Approach 2:
The invention employs phase transitions of the working fluid within the heat pipe - the fluid evaporates at the hot end (socket) absorbing heat, and condenses at the cold end (heat sink) releasing heat. This phase change mechanism provides high heat transfer efficiency without requiring complex liquid cooling infrastructure, resolving the contradiction between cooling effectiveness and system complexity
2Temperature
If liquid cooling systems are used to improve heat transfer efficiency, then cooling capacity is improved, but weight and portability worsen
Solution Approach 1:
By replacing heavy mechanical pumps, reservoirs, and complex tubing systems with a passive heat pipe that uses phase change and capillary action, the overall system weight is significantly reduced. The heat pipe structure is inherently lighter than liquid cooling systems with mechanical components, improving portability while maintaining cooling effectiveness
Solution Approach 2:
The phase change mechanism enables high heat transfer capacity in a compact, lightweight form factor. The working fluid's latent heat of vaporization provides efficient heat absorption without requiring large volumes of coolant or heavy cooling infrastructure, achieving effective temperature control with minimal weight
3Device complexity
If conventional cooling materials are used, then simplicity is maintained, but heat transfer efficiency deteriorates
Solution Approach 1:
The patent incorporates phase change materials (PCM) that undergo solid-liquid phase transitions at specific temperatures to absorb and store metabolic heat. This phase change process provides high heat transfer efficiency and thermal regulation capability while maintaining relative system simplicity, as the PCM can be integrated directly into the socket structure without complex mechanical components
Solution Approach 2:
The invention uses composite materials combining PCM with appropriate encapsulation materials and thermal conductors to create an integrated cooling structure. This composite approach enhances heat transfer efficiency by leveraging the high latent heat capacity of PCM while maintaining structural integrity and thermal pathways, achieving effective cooling without complex multi-component systems
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 provides efficient and portable temperature regulation for the residual limb-prosthesis, maintaining a comfortable skin temperature across various activities and environments with adjustable thermal resistance and reduced power consumption.
Implementation Method 1
The working fluid has a boiling point of from 0° C. or more to 90° C. or less such that the working fluid is adapted to evaporate to form vapor under the influence of the heat of the residual limb in the socket, thus drawing heat from and cooling the residual limb
Implementation Method 2
The heat sink section of a heat pipe passes through the heat sink, which reduces the temperature of the working fluid so as to condense vapor within the heat pipe back to working fluid
Implementation Method 3
The wicking structure collects the working fluid and draws it back to the socket section
Implementation Method 4
heat pipes are used to concentrate heat flux from the residual limb into a compact heat sink
Data Source
AI summary
A prosthesis includes a socket for receiving a residual limb, the socket having a socket wall defining a limb-receiving surface; a heat pipe including a working fluid and a wicking structure, the heat pipe having a socket section and a heat sink section, the heat pipe extending along its length through the socket wall proximate to or exposed at the limb-receiving surface, wherein the working fluid has a boiling point of from about 0° C. to 90° C. such that the working fluid is adapted to evaporate to form vapor under the influence of the heat of a residual limb in the socket thus drawing heat from and cooling the residual limb. A heat sink section of the heat pipe passes through the heat sink, the heat sink reducing the temperature of the working fluid.