When traumatic cervical spinal cord injury (SCI) results in the loss of motor function in both arms and legs, known as quadriplegia, life expectancy shortens. Quality of life is substantially affected through a loss of independence. Quadriplegia is most commonly caused by traffic accidents with people under 30, followed by falls with the elderly. The incidence of quadriplegia varies among countries, but is highest in the U.S. with 906 per million population. Among patients with SCI, the highest priority is regaining hand and arm function.
Scientists at University of Tübingen’s Applied Neurotechnology Lab have developed a robotic hand specifically for people with quadriplegia. The noninvasive, hybrid brain/neural hand exoskeleton (B/NHE) allowed patients to open and close their paralyzed hands. In testing, the scientists showed “full restoration of specific independent daily living activities, such as eating and drinking, in an everyday life scenario across six paraplegic individuals.”
The test subjects controlled the robotic hand by wearing a cap that measured electric brain activity. The cap, which also sensed eye movement, enabled the subjects to send signals to a tablet that in turn controlled the glove-like, articulated device attached to their thumb and forefinger. According to the researchers, the participants were able to use the device within 10 minutes and reported no discomfort in using the robotic hand. Surjo R. Soekadar, the lead author of the study published in Science Robotics, wrote that the test subject could grasp and drink from a bottle, eat with a fork, grasp and hand over a credit card, eat potato chips, and sign their name with a pen.
The results of the Tübingen study give hope to enabling quadriplegics to regain their independence and autonomy in daily life tasks, although the researchers noted that with the current device the participants had to be able to lift their upper arms. The promise of further developments in brain/machine interfaces is appealing. Much work remains before products are available. Another area of study is whether repeated use of BMI exoskeletal devices could facilitate limb control recovery.