Digital Pulmonary Function Test – Spirometry

ABSTRACT:-

                                

                Pulmonary function test is helpful in diagnosis lung diseases. It helps the doctor to detect the range of respiratory diseases. This test can be helpful to cure respiratory diseases if detected early. The simplest test is spirometry, which measures how fast the lungs can breath in and out, and also the volume of air lung can exhaled in the first and second of test. A peak flow meter can determine how much a patient’s airways have narrowed.

Our aim is to make a microcontroller based spirometer which displays the output in form of signals.

Spirometry (meaning the measuring of breath) is the most common of the Pulmonary Function Tests (PFTs), measuring lung function, specifically the measurement of the amount (volume) and/or speed (flow) of air that can be inhaled and exhaled. Spirometry is an important tool used for generating pneumotachograph to assessing conditions such as asthma, pulmonary fibrosis, and COPD.

The basic FVC test varies slightly depending on the equipment used.

Generally, the patient is asked to take the deepest breath they can, and then exhale into the sensor as hard as possible, for as long as possible. It is sometimes directly followed by a rapid inhalation (inspiration), in particular when assessing possible upper airway obstruction. Sometimes, the test will be preceded by a period of quiet breathing in and out from the sensor (tidal volume), or the rapid breath in (forced inspiratory part) will come before the forced exhalation.

During the test, soft nose clips may be used to prevent air escaping through the nose. Filter mouthpieces may be used to prevent the spread of microorganisms, particularly for inspiratory maneuvers.

SENSOR:

     We have used a Turbine Flow sensor to measure the Tidal Volume. If air is blown into the sensor, the fan inside the sensor rotates and a proximity sensor kept nearby will generate an series of pulse signals, which is then amplified and given as a pulse input to the PIC Microcontroller for Display.

For Eg: if the 7ml of gas goes to the rotor and rotor will give 1 pulse.so we have taken 1pulse=7ml.and as per the count we make program for microcontroller to count pulses.