A method for dynamic investigation of a subject lung, the method comprising the steps of: (i) imparting an oscillation to the lung at one or more forcing frequencies so as to elicit a lung response, (ii) sensing the response of the lung simultaneously with the imparting of the oscillation to elicit a lung response, (iii) choosing at least one parameter used in the sensing to define the lung motion associated with the lung response, (iv) comparing one of the chosen parameters at each forcing frequency with the response at the forcing frequency in at least one region of the lung, and (v) recording the comparison of step (iv).
