A muscle fatigue monitoring system includes an sEMG amplifier module configured to receive sEMG signals and amplify said signals a filter module connected with the sEMG amplifier module a bit-stream converter connected with the filter module to digitize the sEMG signals and convert the sEMG signals to a discrete signal based on a single threshold without digitizing the complete sEMG signals. A bit-stream cross correlator is connected with the bit-stream converter, the bit-stream cross correlator including a plurality of correlation stages connected in series, a plurality of counters connected with the correlation stages respectively, and a maximum value selector connected to the counters, and configured to continuously correlate the sEMG signals in a given time window, count all time instances where the sEMG signals are the same, compares all the counters in cycles, and find distance between specific reference points on the sEMG signals through the counter with a maximum value. The sEMG amplifier module comprises plural dual channel instrumentation amplifiers and an external floating high-pass filter. The filter module comprises two low-pass filters. The bit-stream converter comprises two analogue comparators.
