Flex Guess

Introduction: Flex Guess

Hey everyone,

Zion Maynard and I designed and developed Flex Guess, which is an interactive hand rehabilitation device. Flex Guess can potentially be used by occupational therapists treating recovering stroke patients or patients with motor complications. This device generates random gestures that light up and only turn off upon performing that particular gesture. The EMG signals received from the arm are used to determine if the correct gesture is performed. The Myo Armband was used to measure muscle activation.

Supervised by Dr. Scott Brandon, PhD.

Acknowledging Satish Pallath and Catherine Louis for their helpful contributions.

Step 1: Components Required


  1. Myo Gesture Control Armband
  2. Arduino Uno
  3. USB-Arduino Cable
  4. ABS box
  5. Mini breadboards
  6. Acrylic Sheet
  7. Four 5-40 screws for the Arduino
  8. Custom made standoffs for 5-40 screws
  9. Four 35Ω resisters (if powering the device using 5V)
  10. Wires
  11. Epoxy Glue
  12. Four different coloured LEDs


  1. Arduino IDE
  2. Myoduino
  3. Myo Connect

Step 2: Circuit Diagram

Step 3: Building the Box

An ABS box (without the lid) and an acrylic sheet were used to create the case that held all the electronic components for the device. The acrylic sheet was cut down to create a base for the electrical components and placed in the ABS box, as displayed in the image in step 1 labelled “ABS Box". Dividers, with 3mm holes for the electrical wires, were then cut from the acrylic sheet, and the custom-made standoffs were fixed in the ABS box with epoxy glue (image labelled “Dividers & Standoffs Placed”). With the remaining acrylic sheet, a cover matching the size and design of the ABS box was created and the four gestures drawn on SolidWorks were laser cut onto the acrylic sheet lid. Below, you can find the four DXF files for the four gestures created on SolidWorks. Lastly, the breadboards were fixed on the base, and the wiring was complete, as seen in the image above labelled “Electrical Setup".

Step 4: Arduino IDE

The Arduino IDE was used to program the Arduino Uno so that it can communicate with the Myo Gesture Control Armband and turn the assigned LED off when the assigned gesture is performed. The Arduino Uno is programmed to generate random gestures that can only be turned off when the gesture is performed and the muscle activity for the particular gesture is recognized by the Myo Gesture Control Armband. Below, you’ll find an attached copy of the Arduino code.

Step 5: Myo Connect & Myoduino

In order to run the program and receive accurate muscle activation signals from the Myo Gesture Control Armband, the user must first calibrate the Myo Armband using the Myo Connect software. The Myoduino software is used to display the gestures being performed simultaneously while the rehabilitation device is being used.

Step 6: Demo

Below is a video of a demo and setup of our interactive hand rehabilitation device. Here, the device is powered by a laptop however, it can be powered by a battery as well.

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    2 years ago

    Cool idea.