1. Left to Right: Joseph Teblum, Steven Hellmann, Charles Merritt,
Megan Pence, Christian Rodriguez, Brendan Jones, Billy Hughes
Summary
Project Xavier’s mission is to provide a cost effective
alternative solution to wheelchair mobility for
people who have a disability and cannot use a
joystick. The team’s solution to solve this problem
uses a system of 3 Electromyography (EMG) sensors
which when activated by muscle voltages, trigger a
mechanism to control and direct the power chair.
Acknowledgements
Thanks to Boeing, EZ Lite, Quest Mobility, and Paralyzed
Veterans of America for your support and generous
donations. Special thanks to Limbitless Solutions for
inspiration, guidance, and resources
Design Analysis
To achieve directional control of the power chair's
joystick, two servos were implemented to move in a
combination of forward/backward and left/right
motions. The servos are connected to arm like
devices called Joystick Manipulators (JSMs) that
surround the joystick and move according to muscle
contractions. When a user flexes a muscle, a voltage
difference occurs across the muscle. The EMG sensor
is able to detect the voltage difference. A
programmed Adafruit Trinket® reads in the voltage
and directs power from the battery to the servos
based on the respective muscle signal. A user can
expect a continual operation of up to 8 hours of use.
Our Team
Joseph Teblum, Steven Hellmann, Billy Hughes,
Brendan Jones, Megan Pence, Christian Rodriguez,
John Sparkman, and Albert Manero
EMG Sensors + Cables, $96.00
Electronics,
$51.50
Power
Supply,
$22.00
JSM + B.O.X., $145.50
BUDGET
Electrical Components
Terms Explained
JSM : (Joystick Manipulator) Arm to move the joystick
B.O.X. : (Box) The container in which all electrical
components are held
EMG : (Electromyography) Translation of electrical
signals from muscles into numerical values
Trinket : (“Brains”) Small computer chip that uses
voltage from muscle to control servos
Servo : Motor to control the JSM
Perf Board : Prototyping board to connect electronics
Servo
HiTec® HS-82 Metal
Geared Servos are
used to move the
JSMs for accurate
control of the joystick
Battery
An Anker® 10400 mAh battery provides power to the
servos, EMG sensors, and the Pro Trinket®, and is
expected to last 8+ hours
EMG Cable
& Sensor
Cable attached to muscle
to detect the voltage,
and transfers the signal
to the Sensor to be
processed by the
Trinket®
Pro Trinket®
The “brains” were programmed to be easily calibrated for each
individual, and set thresholds to determine the minimum voltage
required to control the servos
Perfboard + Voltage Inverter
The Prototyping board was used as an electrical
base for the 3 EMGs, Trinket®, Inverter and Servo
to be interconnected through.
The Inverter converted a positive voltage from the
battery to negative to supply to the Pro Trinket
EMG Controlled Wheelchair
Total: $315