Unobtrusive Continuous Monitoring of Fetal Cardiac Electrophysiology in the Home Setting

The current home fetal heart rate (fHR) measurement devices and clinical cardiotocography (CTG) use ultrasound Doppler detectors that are highly position and movement dependent making it difficult to capture the fHR, often causing unnecessary alarm and concerns. The U.S. Food and Drug Administration (FDA) has also been concerned about the unknown rate of repeat and prolonged use of ultrasound detectors. Fetal electrocardiogram (fECG) and HR monitoring devices based on bio-potential acquisition have been developed; however, they are bulky and intrusive, thus not widely accepted. Here, we present innovative non-contact electrode ECG sensors on a small unobtrusive patch which could be attached to the abdomen, or inside garment, incorporated with Bluetooth low energy (BLE) wireless communication, to transfer the acquired data to a smartphone. An Android app was developed to extract the mixed maternal/fetal ECG (f/mECG) signals. In this paper, we demonstrate a simple and robust scheme to provide accurate 24/7 monitoring of f/mHR, with the potential to expand to f/mECG monitoring in the home setting.