User's Manual

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Figure 1 Product structure composition
1.5 Product performance
1.5.1 Measuring the amount of principle introduction
The device uses a flow sensor to measure the gas flow and volume of the patient's exhaled
or inhaled gas. According to the volume-time curve and the flow-volume curve, the
pulmonary ventilation indicators of human respiratory physiology are analyzed, such as
slow vital capacity, maximum minute ventilation and forced vital capacity and other
parameters.
The flow sensor is realized by the pressure difference method, and the flow rate R=ΔP/ΔQ
is determined by the dependence of the pressure P change of the air flow in the flow pipe
with certain resistance and the flow rate. The differential pressure flow sensor consists of
two parts: the flow pressure transducer with known resistance or resistance curve: realizes
a conversion between gas flow and pressure difference. According to the difference of the
gas flow through the transducer, the sensitive parts at both ends of the transducer are
corresponding to the pressure difference, that is, the pressure difference signal changes