"It has small vibration motors that send signals to distract Lawton’s brain from trying to create the tremors."https://venturebeat.com/2017/05/10/watch-microsoft-demo-emma-watch-a-wearable-that-counters-parkinsons-tremors/
"The vibration pattern that works depends on the person, so the wearable is connected to a Windows 10 tablet with an app for controlling vibration speed. For Lawton, a rhythmic vibration is effective. Zhang notes that a more random rhythm may work better for other people."