University of Pittsburgh researchers have developed a novel system to control and power instrumental prosthetic liners. Robotic prosthetic liners (RPLs) can be used to monitor biomechanical and other variables in prosthetic limb users or to deliver novel treatment for phantom limb pain (PLP). Developing a durable method to power and control these liners has been a major hurdle to the widespread use and development of RPLs. This novel system, based on low profile copper tape and embedded motors, could improve the durability of RPLs to increase their use in research and patient care.
A novel prosthetic liner has been developed with integrated conductive hook and loop pads embedded between the silicone and fabric layers of the liner. These pads align with flat copper tape in the socket of the prosthetic limb and can be used to provide power and control to the liner via an external rechargeable battery source.
Description
Millions of Americans live with limb loss, and for many, prosthetic limbs are vital to their quality of life. Traditionally, flexible silicon- or polyurethane-based liners are used to cover the residual limb prior to connection of any prosthetic limb, for limb and skin protection. RPLs are being developed for therapeutic potential including adaptive liners to improve patients’ comfort or to deliver vibrational therapy to ease PLP, a painful condition impacting 60–80% of amputees. To improve the applications of RPLs there is a need to develop a robust product where wires are not damaged by bending or stretching of the liner, and electronics do not interfere with donning and doffing of lines. This novel liner and socket design protects wires and connections from damage using detachable connections between any liner-integrated hardware and a power source. When fully optimized, these liners could expand the use of RPLs, improving the lives of patients with prosthetic limbs.
Applications
• Phantom limb pain treatment
• Biomechanical studies
Advantages
Current designs of RPLs have been limited by damage to ridged wires during donning and doffing of the liner (typically 400 times in the lifetime of the liner). Additionally, the termination of wires at the cut end of the liner interferes with the donning and doffing process.
This novel design overcomes the damaged wire challenge by using conductive hook and loop pads embedded between the silicon and the fabric layer of the RPL, adding negligible thickness to the liner, and not interfering with the donning or doffing process. Power to the RPL is only provided following a connection with a conductive hook and loop in the socket and connected to a power supply. This solution is low profile and designed to withstand repeated bending and stretching of the liner during use. Additionally, the RPL is not affected by moisture or contaminants that may occur during typical use.
Invention Readiness
A prototype system was developed. Two amputees tested the product at home over four weeks and reported these liners were comfortable and no more difficult to don and doff than existing liners. The liners and sockets were unaffected by cleaning. Further design optimization and larger scale testing is now required.
IP Status
https://patents.google.com/patent/US11577045B2
