Virtual Instrumentation Based Monitoring of Respiration Parameters

Abstract

This work proposes a respiration measurement system comprising of differential air pressure sensor and a mouthpiece. Exchange of air in and out of the lungs is a result of pressure difference created between chest cavity and atmosphere. A differential air pressure sensor is employed for measurement of Tidal Volume, Inspiratory Reserve Volume) and Expiratory Reserve Volume). Differential pressure sensor has two ports: positive pressure port (port 1) and vacuum pressure port (port 2). The subject is instructed to exhale in port 1 and port 2 is exposed to atmosphere. The pressure difference between these two ports is obtained as differential voltage in order of millivolts. The same signal is then amplified using precision instrumentation amplifier. The amplified signal is interfaced with the virtual instrumentation.