As a final project in Introduction to Engineering Design, we were asked to design a device to assist stroke patients who had developed balance problems. Our group chose to design a system to address trunk balance problems by using gyroscope controlled Functional Electrical Stimulation (FES) of the trunk muscles.
I built a prototype of the sensor harness system that such a device would use to determine where to apply stimulation to the patient’s muscles. The prototype uses a 6-degree-of-freedom IMU sensor (shown below) and an Arduino to determine the orientation of the users trunk and send electrical pulses to LEDs mounted on the harness representing the different groups of muscles needed to be stimulated to bring the user back into balance. The pulses increase in frequency as the user becomes more unbalanced to indicate the magnitude of stimulation needed to recover.
The IMU board I used was a SparkFun 6 Degrees of Freedom IMU Digital Combo Board. Only 6 degrees of measurement were needed for this project as the device only needed measure orientation of users trunk relative to their body, independent of the users orientation in the environment. To write the software I used the FreeIMU Arduino library.
Building the prototype involved both the assembly of the physical harness and programming the Arduino to process the sensor data into the output electrical pulses.