Breathable residual-limb socket system
Inventors
Hansen, Andrew • Koehler-Mcnicholas, Sara • Nickel, Eric • Barrons, Kyle • Starker, Felix • Mion, Spencer • Ferguson, John • FAIRHURST, Stuart • Ramasamy, Ellankavi • Koester, Karl • Schneider, Urs
Assignees
Fraunhofer Gesellschaft zur Foerderung der Angewandten Forschung eV • US Department of Veterans Affairs
Publication Number
US-11938045-B2
Publication Date
2024-03-26
Expiration Date
2038-07-10
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Abstract
Breathable residual-limb system that admits air and allows sweat to evaporate from the surface of the residual limb. In an embodiment, the system comprises a liner sock to be worn on the residual limb, and comprising air-permeable textile forming a substantially cylindrical portion that is closed on a distal end and open on a proximal end and comprising an internal surface and an external surface. The liner sock further comprises a friction-interface material that covers only a portion of the internal surface of the air-permeable textile, such that, when worn on the residual limb, the friction-interface material contacts a surface of the residual limb, and an uncovered portion of the air-permeable textile which the friction-interface material does not cover allows air to pass between an external environment of the liner sock and the surface of the residual limb.
Core Innovation
The invention is a breathable residual-limb socket system that allows air to permeate and sweat to evaporate from the surface of the residual limb. The system includes a liner sock worn on the residual limb comprising an air-permeable textile forming a substantially cylindrical portion with an internal surface and an external surface. A friction-interface material covers only a portion of the internal surface of the air-permeable textile such that it contacts the residual limb's surface, while the uncovered portions allow air to pass between the external environment of the liner sock and the residual limb.
The air-permeable textile may include sections of unidirectional-stretch and bidirectional-stretch textiles connected by seams covered by the friction-interface material. The friction-interface material may be arranged as spaced strips, circumferential strips, dots, or a distal cup, providing necessary friction for suspension and comfort while preserving significant air-permeable areas for evaporative cooling. The liner sock's distal end can also include a distal cap with a threaded hole to receive a screw pin used for prosthetic limb suspension.
The system may further include a socket worn over the liner sock comprising a perforated inner layer with small holes allowing air passage and an outer frame with one or more fenestrations exposing the perforated inner layer to the external environment. This design facilitates airflow between the internal and external environments of the socket, enhancing breathability. The outer frame may be constructed of carbon fiber for durability and weight reduction and may have strategically placed anterior and posterior fenestrations to ventilate regions of the residual limb that heat the most during prosthesis use.
Claims Coverage
The independent claims define two main inventive features of the system: the liner sock's structure and the socket's construction, which together provide breathability and comfort for a residual limb.
Liner sock with air-permeable textile and partial friction-interface material coverage
The liner sock comprises an air-permeable textile forming a cylindrical portion closed distally and open proximally, with internal and external surfaces. A friction-interface material covers only portions of the internal surface, contacting the residual limb where covered, while uncovered textile portions allow air flow. The friction-interface material is arranged as spaced strips, and the air-permeable textile includes a first section of unidirectional-stretch textile and at least one second section of bidirectional-stretch textile joined by seams covered by the friction-interface material.
Socket comprising a perforated inner layer and an outer frame with fenestrations
The socket is designed to be worn over the liner sock and includes a perforated inner layer with small holes (5 mm or less) allowing air passage. An outer frame contains one or more fenestrations through which the perforated inner layer is exposed to the external environment, facilitating airflow. The outer frame may have anterior and posterior fenestrations, and can be made of carbon fiber.
The claims cover a residual limb system featuring a liner sock with selectively covered friction-interface material on an air-permeable textile, and a socket designed with perforations and fenestrations to promote ventilation and evaporative cooling for the residual limb.
Stated Advantages
Improves ventilation and breathability to the user’s residual limb, providing an 'air-conditioned' effect.
Allows evaporative cooling on the surface of the residual limb due to the air-permeable textile and uncovered portions.
Provides comfort and a friction fit to prevent slipperiness without compromising air permeability.
Allows strategic ventilation in areas prone to heating by incorporating fenestrations in the socket.
Enables size customization of the liner sock without losing proximal friction fit, due to the arrangement of circumferential strips.
Documented Applications
Use as a residual-limb socket system for prosthetic limbs to improve comfort and reduce heat and moisture buildup.
Application with prosthetic limb suspension systems, including pin-suspension and others such as sleeve, suction, and elevated vacuum suspension.
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