Design and implementation of FPGA-based muscle conduction velocity tracker in dynamic contractions during the gait

The purpose of this paper is to prove the accuracy and reliability of a novel FPGA-based tracker of the muscle conduction velocity in ordinary dynamic contractions, such as during the gait. In this work, we present the digital signal-processing unit. The system performs the acquisition of the needed bio-signal, from 4 wireless surface EMG electrodes. The acquired data undergo to a dynamic bit-stream description of the signals. The latter ones are analyzed by a fast and accurate algorithm performing the comparison of signals derived by two EMG electrodes suitably positioned on the same muscle. The entire computation system fully operates in real-time on the Altera Cyclone V FPGA. The myoelectric signals have been recorded by 2 left and 2 right electrodes placed on the Left and Right Gastrocnemius of a subject involved in 1250 dynamic contractions. The in vivo measurements show that under the same experimental conditions, in 5 days, the system reveals a MCV mean value of 7.62±0.35 m/s demonstrating a good repeatability (reliability) of the measurements in long-time estimation application. In a real-time application, one step - one MCV, the tool typically shows the 98% (Best: 100%, Worst: 88%) of probability to provide the right MCV values, comparing it with the clinical literature.