Development of a sweat reducing silicone liner for prosthetic sockets
Care Process & Redesign
Technology
National University Health System Quality Improvement
National University Health System
31 December 2024
The objective of this invention is to reduce moisture build up in a prosthetic liner which will result in adverse effects on. The microchannels when added to a prosthetic liner achieved the desired capillary effect ensuring the residuum of the user was drier.
Year Submitted: 2024
Published Date: 31 December 2024
Tags: Quality Improvement, Design Thinking, Care Process ＆ Redesign, Care Continuum, Preventive Care, Patient Education
About this Content
Aims
The objective of this invention is to reduce moisture build up in a prosthetic liner which will result in adverse effects on an amputee’s skin condition. Adopting the principle of capillary reaction, the liner transports secreted sweat upward and out the top of the liner where natural evaporation can occur, maintaining hygiene levels of the enclosed skin.
Background
Prosthetic liners are worn over the amputated limb to provide impact protection and suspension. Existing liners are constructed with an exterior fabric covering that is affixed to the underlying polymeric material. While polymeric materials are able to provide amputees with cushioning and comfort, the liner also behaves like an insulator due to its non-permeable nature. This results in substantial collection of perspiration between the residuum and liner. Moisture inside the liner is uncomfortable, unhealthy for the skin, and invites the growth of bacteria and fungus. These problems reduce the use of the prosthesis and by effect, the eventual mobility levels. Existing sweat removal techniques have not significantly worked or improved mobility levels and standard of living for users in a tropical climate. Hence, there is a need to develop a localized solution for our prosthesis users.
Methods
To develop the correct microchannel diameter for the liner, we first evaluated the theory of capillary action. The calculation for the height of capillary rise was calculated against the safety factor to determine the suitable radius. We then determined the shape of the capillary to achieve the optimal contact angles and simulated these results.
Following on from the simulation an in-situ test of the capillary effect was conducted. We then 3D printed a full-scale mold with the specified diameter for the channels to inject silicone to form the liner. Patient trials were conducted with a unilateral lower limb amputee following a strict protocol that compared their current silicone liner to the test liner.
Results
Temperature recordings between the control and test liners were similar, however the patient observed a preference for the test liner describing his sensations when wearing the test liner with his stump felt cooler and drier and he could walk longer distances. Evidence for the benefits of the microchannels was observed.
Prosthesis users have real pain points with thermal regulation and sweat accumulation. They are ready to try new solutions. The use of microchannels inside a prosthetic liner address both the physiological and physical comfort factors with a prosthesis.
Conclusion
The microchannels when added to a prosthetic liner achieved the desired capillary effect ensuring the residuum of the user was drier and more comfortable.
Lessons Learnt
The biggest lesson learnt was that new inventions and innovation takes time. To develop something impactful for a patient group requires the PI to understand all the stakeholders involved, including the users, clinician, department, and the hospital. In understanding everyone’s needs you can better position your invention to achieve its intended purpose.
Additional Information
PCT Application No.: PCT/SG2022/050070
Claiming priority to Singapore Patent Application No. 10202101506T filed on 15 February 2021
Title of Invention: PROSTHETIC LIMBS, PROSTHETIC LINERS, AND METHODS FOR MANAGING, CONFIGURING, AND USING PROSTHETIC LIMBS AND PROSTHETIC LINERS
Keywords
Prototyping, Prosthetics, Liner, Microchannel
Innovators' Details
Innovators' Details
Healthcare Cluster(s) | National University Health System |
Organization(s) Involved | Tan Tock Seng Hospital, Singapore University of Technology and Design, National Skin Centre |
Platform(s) | National University Health System Quality Improvement |
Healthcare Professional Group(s) | Medical |
Applicable Specialty or Discipline | Rehabilitation Therapy, Prosthesis ＆ Orthotics |
Project Lead(s) | Trevor Binedell |
Project Member(s) | Teo Jia Yee |
Connect with this contributor!
Dr Trevor Binedell - trevor_binedell@ttsh.com.sg