Embedded Eucapnic Hyperventilation

Student: Izuddin Bin Husen Ashrul

Supervisor: Stephen Wilson

Category: Engineering Thesis Project - Electronics

Asthmatic is chronic inflammatory disorder of the respiratory airways. Asthmatic sometimes may cause life-threatening disorder, but with proper management, it can be controlled. Eucapnia (state in which the arterial CO2 pressure is optimal) and hyperventilation (breathing rates greater than that required to maintain normal CO2 levels) is a possible cause for asthma. The higher the breathing, the lower the CO2 level and this may cause unpleasant effects to the patient.

The aim of this thesis project is to produce an embedded control system that can be use to measure and test lung function in order to determine whether the person should be diagnosed as having an asthma. The device detects the amount of CO2 lost after the patient blow through the filter. Measurement will be displayed on the LCD (liquid crystal display). The unit will detect the amount of CO2 lost and produce a recovery procedures so that the person tested will not be feeling sick due to hypocarbia (low CO2 level). The device uses an Atmel micro controller for its onboard software development.

Fuzzy logic control is used in this device to drive the PWM (pulse width modulator) which control the level of CO2 required to be send to the mixing chamber before pumping back the initial amount of CO2 lost into the person through the subject re-breathing process. The fuzzy logic control uses C language operator for the micro controller programming. The fuzzy logic uses its fuzzy theory to implement the control. This method provides simplicity and flexibility towards the design of the controller. It also provides an accurate representation of the way the device behaves in real world.

Thesis Document (PDF)

Poster Presentation (PDF)