A first evaluation signal includes a first excitation element adapted to excite pressure fluctuation in liquid contained in the pressure chamber and a first ejection element which follows the excitation element after a first time period to eject a first liquid droplet from the nozzle. This method is particularly useful for the detection of peroxide-based explosives. By selectively heating or cooling a portion of the catheter lying within the blood vessel, heat may be transferred to or from blood flowing within the vessel and the patient’s body temperature may thereby be increased or decreased as desired. A multitude of mapped frames and associated information is maintained. The method includes receiving an event, which should be processed using information managed by a second system providing a second service, from a first system providing a first service; and performing an interface so that the second system performs an operation corresponding to the event by using the information.