Detection of both heartbeat and respiration signals from airflow at mouth by using single catheter flow sensor

We detect both heartbeat and respiration signals from the airflow at the mouth by using a single catheter flow sensor. To the best of our knowledge, this is the first time this was achieved. We developed an endotracheal intubation tube with a flow sensor, and applied it to a rat´s airway. We first measured the airflow rate mostly dominated by respiration signals. We then successfully extracted both heartbeat and respiration signals from the airflow waveform by using filters. The extracted heartbeat signal was compared to an electrocardiogram graph measured directly from the rat, and the periodic peaks in both were confirmed to be almost coincident.