Inertial Measurement Units (IMU)
Our sensors are designed and assembled in house. The wireless IMUs allow for the capturing of movement data through the use of an accelerometer, a gyroscope, and a magnetometer. Using Bluetooth Low Energy, a sensor communicates with an iPad on a set interval, allowing the iOS application to process the incoming samples and provide feedback to the user.
A key factor in how our sensors work is the virtual alignment. Data from an alignment trial is processed using a Gauss Newton minimizer to virtually align the sensors with the knee joint axis. This method is preferable to manual alignment because it standardizes sensor placement across subjects regardless of anatomical differences while allowing sensors to be attached at a location with minimal soft tissue artifact.