Meta has developed a prototype wristband that uses electromyography to detect electrical signals from forearm muscles, enabling touch-free control of digital devices. These signals, generated by alpha motor neurons before physical movement occurs, allow the device to interpret user intent.
In particular, the device operates using surface electromyography, a non-invasive way to track the electrical activity of muscles. The wristband captures the signals externally and can move cursors, open apps, or even transcribe air-written text in real time.
More information:
https://mashable.com/article/meta-research-device-wrist-control