The patients were required to take morning and evening measurements by breathing into an electronic flow meter. The asthma patient switches the flow meter on, connects a cable from the meter to the xda, and blows three times into the meter. Within a few seconds, the PEF and FEV-1 measurements have automatically been transmitted by the phone
and appear, together with an accurate time stamp, at a remote server.  The flow meter is connected via a serial cable to an O2 xda, installed with e-San software.   The xda transmits the data to the e-San server over GPRS connectivity.  Software on the e-San server tracks the readings, identifies values which may be of concern, and spots developing trends as early as possible.  