Sensitivity analysis of silicon MEMS Thermal Flow Sensor for spirometer application

This paper presents the results of FEM (Finite Element Modeling) analysis of Integrated Thermal Flow Sensor intended to be used in a Spirometer to measure air flow generated by human´s respiratory. Using calculated air flow, the sensor output is used to predict the air flow pattern characterized by two physical parameters, known as FVC and FEV. It is shown that different geometrical design, namely the distance between the heater and the temperature detector has important effects on the sensor sensitivity, and hence its capability for identifying the respiratory health condition of the patient, whether it is normal, resistive or obstructive.