Which device is used to detect reflected sound from heart motion?

The Doppler device is utilized to detect reflected sound waves produced by the movement of the fetal heart. It operates based on the Doppler effect, which measures changes in frequency or wavelength of sound waves in relation to the motion of the source or observer. When placed on the abdomen of a pregnant person, the Doppler transducer emits sound waves that bounce back from the moving heart, allowing healthcare providers to listen to the fetal heartbeat and assess heart rate patterns.

This method is widely used in prenatal care as it provides critical information about the fetus's health without any invasive procedures, making it safe and non-invasive. The Doppler device is particularly useful in monitoring fetal heart rates in various settings, from routine check-ups to more complicated cases where continuous monitoring is needed. In contrast, other devices mentioned, such as a fetoscope or telemetry monitors, serve different functions and do not operate specifically by detecting the reflected sound from heart motion in the same manner as the Doppler.