RESUMO
Lung function monitoring is a critical technique for clinical medicine. Currently, the lung function testing devices used in our domestic hospitals are both expensive and bulky. A portable and accurate lung function parameters testing system is highly desired and is proposed in this paper. The hardware of the system is based on DSP technology. The breathing passage is designed with an aim suitable for the breathe and signal detection. We use the direct detection method to detect the gas flow, the breathing passage pressure and the breathing time. Thanks to the powerful data processing ability and the high operation speed of the DSP, breathing signals can be easily analyzed. Thus, several lung function parameters of clinical significance can be obtained. Experiments show that the accuracy of the system is better than 3%, and could meet the demand of the lung function testing.