Design and development of mainstream capnometer

Abstract

This thesis deals with the design and construction of a mainstream capnometer for the continuous measurement of carbon dioxide concentration in the patient´s respiratory circuit during mechanical ventilation, performed by an optical sensor using infrared absorption spectroscopy. The device was designed with technical focus on individual components needed for subsequent implementation as an open system, intended to be used in intubated neonates during high frequency ventilation. The data obtained from the sensor is processed externally using LabVIEW software, displaying the results as capnography curves with real-time changes of CO2 concentration. The main goals were to verify the functionality of the final implemented device to measure changes in CO2 concentration, create the characteristic calibration curve of the device from the results of the measurements and verify if it is usable in high frequency ventilation modes. For these purposes, static and dynamic tests were performed and the results were analysed and compared using a reference capnometer.

This thesis deals with the design and construction of a mainstream capnometer for the continuous measurement of carbon dioxide concentration in the patient´s respiratory circuit during mechanical ventilation, performed by an optical sensor using infrared absorption spectroscopy. The device was designed with technical focus on individual components needed for subsequent implementation as an open system, intended to be used in intubated neonates during high frequency ventilation. The data obtained from the sensor is processed externally using LabVIEW software, displaying the results as capnography curves with real-time changes of CO2 concentration. The main goals were to verify the functionality of the final implemented device to measure changes in CO2 concentration, create the characteristic calibration curve of the device from the results of the measurements and verify if it is usable in high frequency ventilation modes. For these purposes, static and dynamic tests were performed and the results were analysed and compared using a reference capnometer.