The invention relates to a suction device for suctioning liquids, comprising a suction element, which is provided with at least one suction opening for receiving the liquid, and a pump which is connected to the suction element and which is equipped to generate a suction vacuum in the suction element, wherein a control device and at least one sensor which is connected to the control device are provided, wherein the control device is equipped to influence the suction power acting at the suction opening dependent on the signals received from the sensor.The object of the invention is to provide a suction device for suctioning liquids, said device working with greater efficiency than known suction devices. Additionally, there is a requirement in the medical field to provide a medical suction device which to the greatest possible extent prevents the damage that occurs to blood components during automatic operation.This object is achieved by the fact that the sensor is designed as an acoustic wave sensor. The acoustic wave sensor is equipped to detect acoustic waves which are generated by the suction element during the operation thereof.
