COSTA, W. E. M.; http://lattes.cnpq.br/0653277765333483; COSTA, Wendell Eduardo Moura.
Resumo:
The objective of the dissertation is the development of a system able to measure the
respiratory flow as well as its direction, using hot-wire sensors. The measure of the flow is
fundamental in the characterization of the respiratory system. With the flow and the
pressure is possible to determinate some characteristics of the respiratory system, which
possibilities to the doctor the most exact diagnosis of some pathologies. For tests and
measurements of the flow was utilized an senodal pressure generator that is used in the
Forced Oscillations Technique (FOT). The system uses a sinusoidal pressure of frequency
and width constants, wich were measured using a pneumotacometer, a platinum sensor, and
a pressure sensor. After several tests it was verified that it is possible to determine the flow
velocity with only a platinum sensor. But with just a sensor it is not possible to determine
the flow direction. For measurement of the flow direction it was used two sensors, tends
between them a heat generator (resistance), with this it was possible to observe the
anemometers out signs differed in a flow semicycle, a platinum sensor received heat in the
flow positive semicycle and the other in the negative semicycle. It was verified that to
receive heat the platinum sensors had its amplitudes varied, and this way it was possible to
determine which the direction of the respiratory flow.