Signal evaluation of capacitive EMG for upper limb prostheses control using an ultra-low-power microcontroller

Upper limb myoelectric prostheses drives are controlled by muscle signal, generated by electrochemical effects in the tissue. State of the art electrodes use the conductive measurement principle for acquiring the signal to control these active prostheses. Some problems, resulting from the necessary conductive skin contact, are associated with the state of the art electrodes. For this reason, a capacitive electromyography (EMG) prototype, consisting of a flexible sensor and measurement electronics, was developed. The electronic circuit, used for signal amplification and filtering, is described. An ultra-low-power microcontroller was used for the implementation of algorithms for EMG signal processing. DSP algorithms are optimized for real time processing and minimal computing power. Muscle signals, measured with this prototype, are presented. The developed capacitive EMG system shall enable a better quality of life and give more independence to amputees.