Methods are presented for realizing zero-dispersion segmented flow for transfer of small microfluidic samples onto or within microfluidic analysis or processing devices. Furthermore the invention provides a method of preventing, treating or alleviating the symptoms of acute and chronic inflammatory disorders of the airways of mammals\u2014including asthma and asthma-related pathologies. The source region is connected to a corresponding terminal. The control unit modifies the operation of the ventilator to compensate for the external gas flow rate such that the flow of gas reaching the patient is maintained at a desired level.