A Modified Mask for Continuous Cardiac Monitoring during Positive Airway Pressure Therapy

A Positive Airway Pressure mask was modified to be able to measure the heart rate of the wearer during Positive Airway Pressure (PAP) therapy. The mask was modified by attaching sensors to measure Electrocardiography (ECG) and Photoplethysmography (PPG) signals, from which a heart rate was extracted. The ECG signal was recorded using stainless steel electrodes positioned on the wearer's head and neck. The PPG signal was measured from the wearer's forehead using a reflectance pulse oximeter attached to the mask. The modified device was tested on 19 healthy participants (mean age30.5 ± 9 years) in a simulated sleeping environment. For both the ECG and PPG signals, the device was able to correctly identify more than 95% of heartbeats for the majority of the participants. However, it was found that by combining the ECG and PPG heartbeat data, the percentage of heartbeats that could be detected was increased to 99%. The results showed that it may be possible to use this device to monitor sleep apnoea patients during PAP therapy in their homes.