The signal looks funny and doesn’t look like an airflow thermistor. Why?
The signal from an Airflow Pressure Transducer looks sinusoidal during normal breathing just like an airflow thermistor, but appears differently during sleep-disordered breathing. This is what you want to see if your system is set up properly. Specifically, the shape (or morphology) of the waveform looks differently when there is snoring, UARS, apnea, and hypopnea . When the top of the inspiratory waveform looks flat (i.e., there’s a plateau), this means you are seeing a change from the normal sinusoidal waveform and are now observing flow limitation and UARS. Pressure Transducer technology actually offers you much more diagnostic information than a thermistor because all temperature sensing devices – disposable or reusable – have a low frequency filter built into the product. This means the signal returns to baseline faster and reduces your chances of seeing the clinically important flow limitation. On the one hand, the low frequency filter built into the temperature sensing devices w
