Neural prostheses
Smart underwear to prevent pressure sores is part of a bigger project this team is tackling; namely, the development of neural prostheses—devices that connect with the nervous system and restore functions lost because of nerve damage. One of the most highly regarded neural prostheses available today is the WalkAide, invented by Dr. Richard Stein, a physiologist at the University of Alberta and a principal investigator in the neural prostheses team. The WalkAide stimulates a nerve in the muscle that lifts the foot, helping people who cannot lift their foot properly to walk normally.
Building on the success of the WalkAide and the knowledge gained from the smart underwear, Dr. Stein and Dr. Mushahwar are developing devices that help people with spinal-cord injuries to stand and walk. But whereas the WalkAide stimulates only one nerve, a device to enable standing or walking requires carefully coordinating the stimulation of many nerves all at once.
Such a device will likely use the intraspinal microstimulation (ISMS) technology that Dr. Mushahwar pioneered—which uses hair-like microelectrodes implanted directly into the spinal cord. Moreover, Dr. Stein explains, the ISMS device would also record sensory feedback from the legs and hips to help the patient navigate. "It will allow the device to function in the real world, because when you're walking you need to deal with obstacles in your way."
Using the knowledge gained from ISMS, Calgary neurosurgeon and AHFMR Clinical Investigator Dr. Zelma Kiss leads a project aimed at restoring sensation to the arms and legs of people with spinal-cord injuries or neural diseases. "These patients often lose the ability to sense where their limbs are," she says. "This is incredibly disabling."
Dr. Kiss specializes in deep brain stimulation, a technique which involves surgically implanting an electronic device (similar to a pacemaker) into the patient's brain. Dr. Kiss will apply patterns of electrical stimulation to specific parts of the brain, and test whether the brain can interpret these signals as sensation. "We want to see if we can evoke more natural feelings of sensation. This is incremental work—I hope by the end of five years we'll have proven the principle that we can take a damaged nervous system and reactivate it by stimulating the right places."
"Some of the devices, like the pressure ulcer garment, are closer to commercialization, and others will take longer to develop," Dr. Mushahwar explains. "In the end, we hope to achieve a repertoire of enabling technologies that could be applied to restore various functions and significantly improve quality of life."
Dr. Stein notes that "the time is right to build on the success we've had in Alberta with neural prostheses; not just my research, but other labs in Edmonton and Calgary. What has been science fiction for so long—restoring movement and sensation in people whose nervous systems have been damaged—can now be turned into science fact." Important advances in three key areas have been made over the last decade: Neuroscience has moved ahead—in fact, it has been estimated that 90% of what we know about the brain has been learned in the last 10 years. Microchips are now much smaller and far more powerful. And computing power has increased dramatically.
"We need all these advancements to make smart neural prostheses, and they are coming together now," adds Dr. Stein.