A Spirometer-like System, Providing Indication About Lung Health, Using Air flow Sensor, FPGAs and VHDL

Abstract: A spirometer-like system, based on MD0550 air flow sensor, FPGAs and VHDL, is presented here. The sys- tem is capable of acting as an indicator for lung health by measuring forced expiratory air flow of a human, versus time and subsequently calculate and display both air flow values and the ratio FEV1/FVC of Forced Expiratory Volume in first second (FEV1) to Forced Vital Capacity (FVC). The above ratio is critical for providing useful indication about human lung health and its values must be equal or higher to 0.7 for a healthy person. Our system except from display- ing air flow and ratio values, also uses a LED system for providing information about low, medium or high air flow values, with limits set by user, thus lighting on blue, green or red external LEDs, respectively. Half left or right of board LEDs also light up for low or high air flow values, respectively. In case that FEV1/FVC ratio values are below 0.7 then buzzer sounds and white external LED is ON, while yellow LED lights up in case that FEV1/FVC ratio values are equal or higher than the critical value of 0.7. The system uses DE10-Lite FPGA board, is cheap to manufacture, easy to use and can be also combined with IoT systems, allowing it to share valuable health information of a human, with its doctor.

Keywords: MD0550 air flow sensor, air flow monitoring, lung health, FEV1/FVC ratio, FPGA, VHDL, Buzzer, LEDs.