Abstract: A device is provided for controlling the nitric oxide levels within the lungs of a subject. The device comprises a detector for detecting the respiration cycle of the subject and a stimulator for applying an acoustic or vibratory stimulus to the subject. The stimulator is controlled in dependence on the detected respiration cycle. In particular, acoustic stimulation may be provided at the onset of inspiration. In this way, the nitric oxide flow can be controlled in a way to ensure that the paranasal nitric oxide is nearly fully inspired. This provides a higher nitric oxide concentration in the lung/alveoli.