Portable respiration monitoring system (PRMS) / Abdul Rachit Hushaip Mohd Ismail

Portable respiration monitoring system (PRMS) is a biomedical instrument which is used to sense the respiration rate of on infant or sickly adult. PRMS are designed to sense breathing and to trigger visual and sound alarms when certain length of time elapses without the detection of a breath. In this project the respiration rate is detected using a thermistor placed in front of nostril. As the patiënt breathes, cool air enters the lungs, is warmed by the body, and is expelled. When air passes over the thermistor, changes in temperature affect its electrïcal resistance and register as breaths. This signal is amplified for the first stage by using a preamplifier and the unwanted signal is then filtered. The clean signal is amplified again. The amplified signal is compared to a certain reference voltage at the input of a comparator. The output of this comparator is now inpulseform which isfedto the counter and alarm circuit. The main advantage of using this method is that, there is no motion artifacts. In this design PRMS also provides a digital display for the respiration rate