A heart pump and method for the operation of a heart pump are provided. A volume flow and an oxygen saturation may be determined by a sensor device. The sensor device including an oximeter configured to determine the oxygen saturation from blood. The oximeter may be fastened on the pump and include a ring on which a radiation source and a radiation sensor are fastened. Oxygen flow through the pump may be determined from the volume flow and the oxygen saturation. The heart pump may be controlled based on the oxygen saturation and/or the oxygen flow through the pump.