University of Pittsburgh researchers have developed a novel therapy for phantom limb pain. Using vibrational motors that can easily be incorporated into a silicone liner for use with a prosthetic, this therapeutic strategy could improve the lives of people with amputations.

Description

Phantom limb pain (PLP) is a common challenge, believed to impact around 70% of persons with amputations. In PLP, pain is perceived as coming from a limb that has been amputated. While the underlying pathophysiology is not well-understood, it is believed to result from disrupted neural signals. PLP could also be linked to neuroma formation at the site of the amputation. PLP can cause extreme discomfort, which can impact mental health and reduce compliance with prosthetic use, contributing to sedentary lifestyle-associated health issues such as obesity, cardiovascular disease and depression. With millions of people living with amputations, there is a great clinical need to develop effective and practical treatment approaches for PLP.

Applications

- Phantom limb pain
- Veteran health

Advantages

Currently, there is no effective treatment for PLP. Vibration therapy (VT) is used to treat acute pain in other areas of medical care and is known to improve vascularity and influence muscle activity. There is potential then, for VT to offer much-needed relief for PLP.

This novel approach goes beyond current VT interventions by directly targeting acute and chronic PLP. Unlike existing approaches, vibration motors are securely embedded into the prosthetic liner between the skin and the prosthesis, offering a non-invasive, non-narcotic intervention that can be applied by the person with PLP in any setting. These vibrating motors have been designed to have a low profile, allowing for an intimate fit to the socket. Use of prosthetic liners is a common practice, making this approach accessible to individuals experiencing PLP. Vibration can be controlled using Bluetooth or other wireless communication, ensuring the use of VT to alleviate PLP without the need to remove the prosthetic. Newly developed algorithms will be used to control the frequency and duration of vibrations to prevent overuse and fatigue.

Invention Readiness

A prototype device has been developed. A small feasibility study was carried out involving two patients with transfemoral amputations and over ten years of prosthetic use experience. Over a period of four weeks, they used the vibration liner at home and rated their experience. Both reported ease of use, comfort and reduction in the intensity of PLP. Of note, one participant reported improvements in non-painful phantom limb sensations. Both participants suggested improvements in design including increasing the vibration strength and potential for improved comfort. Work is now required to develop robust vibration liners and longer-lasting at-home trials.

IP Status

https://patents.google.com/patent/US11577045B2

Related Publications

Roehrich, K., Goldberg, M., & Fiedler, G. (2024). Robotic-Enhanced Prosthetic Liners for Vibration Therapy: Reducing Phantom Limb Pain in Transfemoral Amputees. Sensors, 24(15), 5026. https://doi.org/10.3390/s24155026

Novel Treatment for Phantom Limb Pain