The Feeling of Empowerment

Technological advances have undoubtedly transformed how we interact with the world around us in recent years. Portable and wearable electronics, for instance, have unleashed previously unimaginable levels of productivity and connectivity for their users. But looking ahead, the impact of these devices may prove to be nothing in comparison to what can be done for those with physical impairments due to spinal cord injuries or neurological disorders. Work in this area may still be in the early stages, but it is becoming increasingly clear that technology may help these individuals to overcome many of their physical challenges in the future.

In the most severe cases involving total paralysis, implantable brain-computer interfaces (BCIs) have already shown that they can capture and interpret the brain’s normal motor signals. While injuries or illness may prevent these instructions from being carried out normally, they can be leveraged to control prosthetic devices in similar ways to carry out the same basic functions. While this alone is quite impressive, it does miss a crucial part of the equation — sensory feedback.

Without actually experiencing the sense of touch, users of prosthetics are quite limited in their interactions with the world. That may not be a problem in the future, however, thanks to the work of a team at the Cortical Bionics Research Group. They have developed a novel system that restores two-way communication between prosthetic devices and the brain, allowing for both control of the device and the experience of tactile sensations.

The team’s work required years of collaboration with two patients with severe spinal injuries that left them unable to control their limbs. These individuals have implanted BCIs that enabled the researchers to capture and decode the electrical patterns in their brains related to both sensory information processing and hand and arm movement. They then used this information to build a system that can stimulate the brain with signals that mimic natural sensations of touch, in addition to interpreting the individual’s intended limb movements.

By integrating this system with a robotic arm that was outfitted with touch sensors to collect sensory information, it enabled the study participants to not only control the arm, but also distinguish between complex shapes and sensations, such as the feeling of the edge of a table or the motion of an object across its surface. This tactile feedback was achieved by converting sensor measurements into highly precise, encoded signals that were then used to stimulate the brain.

Despite this progress, the technology is still in its early stages. Future advancements, such as prosthetic e-skin capable of collecting and interpreting tactile data in real time, are still needed to fully restore the sense of touch for everyday use. A number of companies are investing heavily in BCIs, bringing additional attention and resources to the field, which may speed this process along.

In any case, this work represents a significant step toward restoring complex tactile sensations to individuals with spinal cord injuries, offering hope for a future where bionic limbs provide a sense of touch that is indistinguishable from that of a natural hand.