Spinal Cord Injury Innovations
Last week, six-time Olympic gold medalist Amy Van Dyken-Rouen left the hospital after two months of rehabilitation following a spinal cord injury that left her paralyzed from the waist down. On June 6, she was riding an all-terrain vehicle when she hit a curb and was thrown from the ATV, resulting in the severing of her spine. After several weeks of intensive therapy, Van Dyken-Rouen has learned to accommodate for her injuries and now gets around using a wheelchair.
Innovations in Spinal Cord Treatment
Although Van Dyken-Rouen is optimistic about her future, scientists are a long way from finding a cure. However, recent innovations are inspiring hope in those seeking viable alternatives to restore mobility in patients with paraplegia. A Japanese research group led by scientists at the National Institute for Physiological Sciences (NIPS) published a report in The Journal of Neuroscience detailing their method of bypassing damaged neural pathways to stimulate leg movement. Researchers utilized a computer interface that enabled volitionally-controlled muscle activity. In the experiment, 10 healthy male participants wore a full-body prosthesis and were instructed to relax their legs to allow their movement to be controlled by the device. Electrodes detected activity in shoulder muscles as participants swung their arms. The signals were converted by a computer into stimulations delivered to the spine and a nerve near the ankle. This caused their legs to begin moving in a walking motion, slowing to a stop as participants rested their arms. The device also allowed for speed control, with pace increasing as subjects pumped their arms faster.
This innovation came about thanks to a critical realization: in most cases of spinal cord injury, the loss of a link between the brain and the locomotion center causes problems with walking. However, the neural pathways surrounding the site of injury are usually unaffected. By taking advantage of intact neurological activity along with the strong connection between arm and leg movement, the research team was able to develop a method of mimicking the usual processes involved in generating movement.
“Neural networks in the spinal cord locomotion center are capable of producing rhythmic movements – such as swimming and walking – even when isolated from the brain. The brain controls the spinal locomotion center by sending command to the spinal locomotion center to start, stop and change walking speed. In most cases of spinal cord injury, the loss of this link from the brain to the locomotion center causes problems with walking,” explained lead researcher Shusaku Sasada.
Scientists hope that this method will revolutionize the therapeutic approach taken to treating paralysis and allow for an alternative way of mobility for the millions of sufferers of paralysis, which total more than 1 in 50 people in the United States. Researchers are quick to point out that more work must be done to establish clinical applications of the device. For example, the technology does not help users dodge obstacles nor maintain posture.
The Future of Mobility
Similarly taking advantage of intact neural activity, another Japan-based team is developing the Hybrid Assistive Limb (HAL), a robotic exosuit currently being tested on paralyzed patients at the Center for Neurobiotic Movement Training in Bochum, Germany.
Developed by Dr. Yoshiyuki Sankai, a professor in the Graduate School of Systems and Information Engineering at the University of Tsukuba, HAL picks up on weakened signals through sensors that are attached to a patient’s skin and sets its motors, located in the pelvis and knee areas, in motion. By effectively connecting the robotic suit to the nervous system, the individual is able to regain some mobility. Other versions of exoskeleton suits exist that allow for options such as weight shifting forward to move or activating device controllers, however this method is unique in its ability to allow patients more direct control of their movements through neurological processes similar to that of individuals without mobility disorders. The HAL suit possesses a cybernic control system consisting of both a user-activated “voluntary control system” named Cybernic Voluntary Control (CVC) and a “robotic autonomous control system” named Cybernic Autonomous Control (CAC)” for automatic motion support.
Paraplegia carries an estimated lifetime cost of over $2 million. By developing treatments and preventing new spinal cord injuries, the United States could save as much as $400 billion on associated costs. More importantly, mobility aides would allow sufferers to return to the life they once enjoyed before their devastating injury.
- Swimmer Leaving Hospital After Spinal Cord Injury [2014-08-13; AP / FOX Sports]
- Bypass Commands From the Brain to Legs Through a Computer [2014-08-14; Yukio Nishimura, Neuroscience News]
- Bionic Exoskeleton Could Help Paralyzed Patients Walk [2014-08-14; Agata Blaszczak-Boxe, Live Science]
- Cyberdyne [Robot Suit HAL; Dr. Yoshiyuki Sankai, University of Tsukuba, Japan]