Testing

In order to validate our purpose of targeting the five upper extremity muscle groups, biceps, deltoids, triceps, trapezius and pectoralis we conducted a test using a bicycle. We kept the chain, pedals and the back wheel of the bicycle to complete our test. We forward pedaled in the vertical direction while wearing DELSYS Trigno Wireless EMG System sensors and Vicon Nexus 3D Motion Capture System sensors.

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Vicon Motion Capture System and DELSYS EMG Sensor System

The Trigno Wireless EMG System is a high-performing device unparalleled in its sophistication, its reliability and its ease-of-use. Each EMG sensor has a built-in triaxial accelerometer, a guaranteed transmission range of 40 m and a rechargeable battery lasting a minimum of 7 hours. The system is capable of streaming data to EMGworks Acquisition and Analysis software, and of generating 16 EMG and 48 accelerometer analog channels for integration with motion capture and other 3rd party data acquisition systems. The EMG sensors were attached to each major muscle group – electrode-to-skin using an adhesive. Along with the placement of the the EMG sensors we incorporated the use of the Vicon Motion Capture System sensors which allowed us to track the kinematic data while pedaling.

With each sensor on  we obtained kinematic data and EMG data that we further analyzed to get useful data. The motion sensor placed on the subject were used to make a simulated upper limb model. We obtained a lot of EMG data which make sense, since we are looking at muscle activity. To obtain useful data we had to go through a series of three steps. First, we had to gather the raw data from the EMG sensor and applied a DC offset to each signal to make sure that they have a mean of 0 V in amplitude. Secondly, we rectified the EMG signal. Here only the positive amplitude values are analyzed and this is essential for obtaining the envelope of the EMG signal. Lastly, we processed the linear envelope. We constructed a 5th order low pass filter with cutoff frequency of 10 Hz and a sampling frequency of 2000 Hz. With all this data processing we obtain the graphs shown below.

Kinematic Data          Left/Right Shoulder           Left/Right Elbow

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EMG Signal   Rectified EMG   Low-Pass Filter

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