A system for detecting the onset of seizures, such as epileptic seizures, comprising - a measuring unit having at least one sensor configured to detect an electromyographic signal generated by a muscle on the body of a user; and - a data processing unit connected to the measuring unit and configured to process and analyse the detected signal, wherein the data processing unit comprises: - a pre-processing module having a high-pass filter configured to filter out signals having a frequency below a predetermined cut-off frequency, - a feature extraction module connected to the pre-processing module, wherein the feature extraction module is configured to apply a number of predetermined time windows to the filtered signal, and - a classification module connected to the feature extraction module and configured to generate an event signal as an output signal, characterised in that - the feature extraction module further comprises a threshold detector with a predetermined hysteresis value, defining a positive and a negative threshold value, and is configured to use the threshold detector to count a number of zero-crossings of the filtered signal within each time window, and - the classification module is configured to compare the count with a first threshold value, to compare the number of time windows which have a count above the first threshold value with a second threshold value, and to generate the event signal if the number of time windows which have a count above the first threshold value is above the second threshold value. - a measuring unit having at least one sensor configured to detect an electromyographic signal generated by a muscle on the body of a user; and - a data processing unit connected to the measuring unit and configured to process and analyse the detected signal, wherein the data processing unit comprises: - a pre-processing module having a high-pass filter configured to filter out signals having a frequency below a predetermined cut-off frequency, - a feature extraction module connected to the pre-processing module, wherein the feature extraction module is configured to apply a number of predetermined time windows to the filtered signal, and - a classification module connected to the feature extraction module and configured to generate an event signal as an output signal, - a pre-processing module having a high-pass filter configured to filter out signals having a frequency below a predetermined cut-off frequency, - a feature extraction module connected to the pre-processing module, wherein the feature extraction module is configured to apply a number of predetermined time windows to the filtered signal, and - a classification module connected to the feature extraction module and configured to generate an event signal as an output signal, - the feature extraction module further comprises a threshold detector with a predetermined hysteresis value, defining a positive and a negative threshold value, and is configured to use the threshold detector to count a number of zero-crossings of the filtered signal within each time window, and - the classification module is configured to compare the count with a first threshold value, to compare the number of time windows which have a count above the first threshold value with a second threshold value, and to generate the event signal if the number of time windows which have a count above the first threshold value is above the second threshold value.