Design of a pulse-type ultrasonic Doppler fetal heart detection system

This article presents a pulse-type ultrasonic Doppler fetal heart detection system. An ultrasonic probe based on pulse detection technology was designed, including a single piezoelectric ceramic chip transducer and an ultrasonic transmitting and receiving module. A pulse ultrasonic detection signal transformation model was constructed, and a fetal heart detection system was built, which was composed of a main control module, a timing control module, an ultrasonic transmitting module, an echo receiving module, a signal demodulation module, a signal conditioning module, a human-computer interaction module, a Bluetooth communication module, an output processing module, a power management module, and other key circuits such as four-level low-noise amplifier and filter were designed. The designed system was tested according to JJG 893-2007 <i>Ultrasonic Source of Ultrasonic Doppler Foetal Meters</i>, and its indication error and repeatability of fetal heart rate can meet the requirements of JJG 893-2007. Meanwhile the designed system can complete fetal heart detection efficiently and accurately.