| 摘要 |
A medical monitor for monitoring a cyclically varying parameter, such as the pressure in an airway of a ventilator used to assist patient breathing, comprises a transducer (1) for measuring the pressure as an electronic signal, means (18) for timing the electronic signal at two defined points in the cycle, storage means (22) for storing electronic set-up information relating to the time taken for the value of the electronic signal to depart from one of the points and arrive at the other point, means (24) for comparing current information relating to this time with the stored, set-up information, and means (28) for generating an alarm signal when the current information varies from the stored information by more than a predetermined amount. A base level of Bt and a peak level of Pt are stored as well as a standard pressure rise time of RTsu. If the rise time for the value to rise from Bt to Pt exceeds RTsu by a predetermined amount, such as the rise time RThc, this indicates a high compliance condition which causes the alarm signal to be generated. In a similar way, if the rise time is much shorter, such as RTob, this indicates an obstructed condition which likewise causes generation of the alarm signal. |
