Fetal doppler or fetal heart rate monitor is a handheld device which is used to listen to the baby’s heartbeat inside the womb of the mother. Fetal doppler works on the principle of Doppler effect, discovered in 1842 by a famous Austrian mathematician and physicist Christian Doppler (1803-53). Doppler discovered that when high-frequency sound waves are reflected from a moving object, their frequency change and this can be analysed.
The Federal Drug Administration (FDA) is responsible for the regulation medical devices, such as fetal dopplers and ultrasound imaging devices. Though fetal ultrasound imaging and fetal Dopplers are placed in the same class by the FDA, they are very different from one another.