Virtual reality is finding a surprising application in rehab, as a team of engineers at Arizona State University will soon be using an Oculus Rift headset to help tune prosthetic arms. The problem the investigators are addressing is training the brain to consider a virtual arm, used to develop actual prosthetic interfaces, as part of the body. There’s a neural feedback loop that links feelings, decisions, and actions taken, and seeing a virtual arm react as though a real one does can go a long way to making programming easier.
The high definition of control of a virtual arm is possible in the first place thanks to Arizona State’s recently developed array of 96 microelectrodes that are implanted at the median and ulnar nerves, and can, if programmed accurately, provide a very high degree of resolution when controlling an upper arm prosthetic.
Some details from FULLCIRCLE, ASU’s engineering publication:
“We’re now at the stage in this process where we ask patients to mirror movements between hands,” explains [associate professor of biomedical engineering Bradley] Greger. “We can’t record what the amputated hand is doing, but we can record what a healthy hand is doing.” So, for instance, asking the patient to wave both hands simultaneously, or to point at an object with both hands, will be integral to the latest tech employed in the feedback loop: an Oculus Rift virtual reality headset.
The advantage of the virtual reality headset is that the patient is able to interact directly with his or her virtual limb rather than by watching it on a screen.
“At first, when patients are learning to manipulate their virtual hands, they will be asked to strictly mirror movements of a healthy hand,” explained [postdoc Kevin] O’Neill. “Once we have learned what information the signals contain, we can build a neural decoding system and have patients drive the virtual representation of a missing limb independently of a healthy hand.”
Here you can see a virtual arm being controlled via electrodes implanted in an amputee:
Study in Journal of Neural Engineering: Restoring motor control and sensory feedback in people with upper extremity amputations using arrays of 96 microelectrodes implanted in the median and ulnar nerves…