Ultrasound Transducer Design for Continuous Fetal Heartbeat Monitoring

Abstract

Stillbirth prevention requires high quality healthcare and early detection. Continuous monitoring of fetal heartbeat can be one of the ways to reduce pregnancy complications and even stillbirths. A Doppler ultrasound transducer is found to be one of the possible devices that can be adopted for home long-term monitoring of the fetal heartbeat. The velocity of the heart phantom was obtained from the time shifts between the consecutive received signals. It was possible to measure the heart velocity if the heart position is changed from the central lobe of the transducer beam in x -direction. However, the measurements are not accurate if the radius of the transducer aperture is decreased to 2 mm. The measured velocity of the heart phantom is in a good agreement with the actual velocity if heart is moved in z -direction. However, the received RF signals from the back heart wall are much weaker as compared to the received signals for the front heart wall. The proposed idea to have a continuous fetal heartbeat monitoring is found to be one of the solutions to reduce number of stillbirths. Doppler transducer shows improved robustness with decreased size of the aperture which lead to a wider beam profile and better detectability of the heart movements.