Wearable Device Enables Touch-Free Control

The Myo armband. (Image courtesy of Myo.)

Touch-Free Technology

The Myo armband is a wearable device that enables the user to have touch-free control over technology.

The Myo Market is essentially an App Store that features applications and products that can be controlled with the armband. There are currently over 100 applications and connections available for the armband, with more added weekly. The armband can connect to any device with a Bluetooth function, so long as there is an app available.

Some of the more popular uses for the armband include flipping through a PowerPoint presentation, controlling music, commanding drones and playing video/computer games.

The armband uses proprietary sensors to read the electrical activity of the user’s muscles. Using muscle sensors instead of a motion-sensing camera (like Microsoft Kinect or Leap Motion) allows the user to operate the device just about anywhere, instead of just where the camera is.

Check out the video below.

Innovative Muscle Sensors

The sensors read the electrical pulses in the user’s muscles when they make specific hand gestures or movements, letting the device know what their hands and fingers are commanding it to do. Using a Bluetooth Low Energy connection, the armband then sends the command to the device it is currently connected to.

Two kinds of sensors in the armband track movements and gestures: eight medical-grade electromyographic (EMG) sensors and one nine-axis inertial measurement unit (IMU). The IMU consists of a three-axis gyroscope, a three-axis accelerometer and a three-axis magnetometer. In combination, these sensors can register in a near-infinite amount of inputs.

“When we started building the Myo armband, we were using proprietary discrete capacitive EMG sensors built on a printed circuit board (PCB) substrate. Due to the form factor of the Myo armband, we had to build many separate boards instead of one large PCB to maintain separation around the forearm and have it bend appropriately around the arm,” explained Stephen Lake, Thalmic Labs CEO.

The Myo armband is a one-size-fits-all device. (Photo courtesy of Myo.)

In order to function properly the armband must sit snug on the user’s arm, so it was designed to be a one-size-fits-all device. Rubber flex holding the device together runs electronics throughout the armband.

“Creating these EMG sensors for the Myo armband was quite expensive due to the small size of the individual pods and the number of separate boards required to make the device function. We used wire harnesses from board to board to daisy chain the 8 rigid discrete PCBs to the main digital communications PCB.”

Thousands of data samples were collected to enable the device to classify each gesture correctly. The apps are developed both in-house and by third party developers.

Powering the armband is a built-in lithium ion battery that charges via a micro-USB cable. A single charge will power the device for a day. The armband also features dual indicator LED’s, an ARM Cortex M4 Processor and haptic feedback with short, medium and long vibrations. More tech specs can be found on Myo’s website.

Applications

One of the more popular apps that the Myo armband can connect to is Spotify. Making a fist and rotating one’s arm right or left can turn the volume up or down and waving left or right skips to the next or previous track.

For those who are intrigued by the data produced from the eight EMG sensors and the 9-axis IMU, there is an app on the Myo Market called MTO Data Capture. The app provides four CSV files that store all of the data that is streamed by the app, including data from the accelerometer, gyroscope, orientation, orientation in Euler angles (instead of Quaternions) and EMG.

The EMG data is received at 200Hz while the IMU data comes in at 50Hz. To see what their movements and muscles look like, users can visit the Myo Diagnostics Page.

Devices like the Myo armband have the potential to revolutionize how humans interact with machines and other technology. For more information about the Myo armband, visit their website.