By Cameron Coward / Huckster.io
Have you ever played one of those games in an arcade where a ring of lights illuminates in sequence, and you have to press the button at the exact moment the target light brightens? Like all arcade games, those cheat a little. But even without the cheat, the task is difficult because it takes a fraction of a second for you to twitch your finger. Developed by researchers at the University of Chicago's Human Computer Integration Lab, led by Associate Professor Pedro Lopes, Myo Action is augmentation technology that reduces that time between thinking and moving.
There is nothing controversial or mysterious about the delay between intention and physical muscle movement. That is a very well-understood symptom of physiology — your brain has to tell your muscle to move, and that takes time.
There also isn’t anything controversial or mysterious about EMS (electrical muscle stimulation), in which an electric current passes through a muscle to force contraction. It is a simple matter to cause involuntary movement with EMS.
That naturally leads to a question: can you use EMS to decrease the time between the decision to move and the movement?
As Myo Action’s creators at the University of Chicago note, there have been attempts to achieve that. Some focus on reading brain activity, detecting intention, and then contracting the muscle with EMS. The idea is that an electronic intermediary can act faster than a human’s own biology. And that is somewhat true, but only by about eight milliseconds. Even then, the activating thought may not quite be the same as a true movement thought, so users feel like they don’t have complete agency.
Myo Action works a little differently — and much better. Instead of reading the brain, it reads electrical activity at the nerves preceding the muscle with EMG (electromyography). The hardware to do that is built around a Seeed Studio XIAO SAM D21, and all of the processing happens on the lightweight wearable device. It then uses standard EMS to contract the muscle.