Creating Biomedical Technologies to Improve Health


Science Highlight: April 24, 2014

Implanted, Networked Modules Let Patients Move Paralyzed Muscles

Roughly 6 million people in the United States live with some form of paralysis, most commonly resulting from stroke, spinal cord injury, or multiple sclerosis.1 This paralysis may affect one or both legs, one half of the body, or almost the entire body—both arms, both legs, and the torso. Some people experience temporary paralysis while for others it is permanent. Some also lose feeling in affected limbs.

Since each case of paralysis is slightly different, doctors and patients may have a hard time finding the right therapies. To better serve such varying individual needs, NIBIB-funded researchers led by Hunter Peckham, Ph.D., of Case Western Reserve University, developed a “networked neuroprosthesis system” (NNPS), consisting of multiple, small, implantable modules. Some modules stimulate nerves or paralyzed muscles, some receive and transmit signals from nerves and muscles, and some sense changes in the body’s internal environment. All of the modules are connected by very thin high-speed data cables to each other and to an implantable power source.

photo and illustration of networked neuroprosthetic system

The fully implantable networked neuroprosthetic system (left) consists of small modules that send or receive electrical signals from nerves or paralyzed muscles, with each module linked by a network of thin, high-speed data cables and connected to a rechargeable, centralized power module. The illustration (right) shows an example of an implanted system for upper limb paralysis. Source: Hunter Peckham, Case Western Reserve University

The NNPS mirrors the body’s peripheral nervous system and is able to bridge the gap in internal electrical communication between the brain and muscles that occurs in paralysis. With training, a patient can flex non-paralyzed muscles to send signals through the networked modules, activating paralyzed muscles with very low-powered electric currents. Depending on which muscles are connected, the NNPS can allow patients with paralysis to independently initiate and perform specific tasks such as holding a cup or turning a key. Activating the patient’s own muscles helps preserve muscle tone and mass, which may also help prevent problems with blood circulation and other conditions associated with inactivity.

Unlike some other types of implantable devices for paralysis, the NNPS can be customized to an individual’s needs and even upgraded without needing to remove the implanted modules. The NNPS can also be configured to restore a broad range of functions, including hand grasp, upper limb movement, abdominal control for maintaining posture, and standing balance and stability to enable patients to transfer themselves from a wheelchair to a bed, for example. Regaining a degree of independence following a diagnosis of paralysis can improve a person’s quality of life and help reduce caregiver burden.

1 “One Degree of Separation: Paralysis and Spinal Cord Injury in the United States.” Christopher & Dana Reeve Foundation.

Health Terms: 
Injury - Spinal Cord Injury,