Microprocessor-based system for the measurement and analysis of an expiratory flow-volume curve

Analogue recording and plotting on an xy plotter of flow-time signals to produce inaccurate analysis of respiratory data. To improve on the accuracy of the measurement and reduce the time required for such an analysis a microprocessor-based system has been developed. The system is designed to be easily operated and requires minimum time from the user. It give the operator an indication of the drift in the transducer based on calibration at a standard flow rate. The system is interactive with the user via a visual display terminal. It offers the user full freedom in selecting the parameters to be measured. The displayed results are calculated from the measured signal and compared with predicted values. Hard copy of the displayed information can be produced upon user command. The software is flexibly designed to allow for any modification or future expansion.