The present invention relates to a system comprising a mixing device for mixing the content of a bioreactor. The system is comprising at least one movement device for initiating a mixing movement in the bioreactor or in a holder for receiving a bioreactor and at least one sensor that can be arranged in or on the bioreactor for receiving at least one physiological or physical measurement variable. The mixing device or the bioreactor further comprises a sensor or transmitter for generating a synchronization measurement variable.