A machine that uses ultrasound technology to detect the heart beats of the fetuses inside the mother’s womb is called a fetal Doppler or just a Doppler. The technology involved with this machine was discovered in the 1950s; Ultrasound waves are bounced off the growing fetus and the returning waves are analyzed to produce the result as sound. The fetal Dopplers are easy to use and an expert practitioner can detect sounds of the baby’s heart beat as early as 5 to 6 weeks. However, inexperienced people find it difficult to detect heartbeats. This happens due to the movement of the fetus inside the womb and not due to the inefficiency of the equipment.

A fetal Doppler consists of a body unit and a probe that is attached to the body via a flexible cord. When switched on, the probe is equipped to beam out ultrasonic waves into the womb of the mother. These waves bounce off the different body parts and reach back to the probe. The reflected or bounced waves are gathered by the probe end of the machine and sent for processing. The machine then analyzed the returned waves, maps the gaps and simulates the sounds with the help of this analysis. Since the fetal heart beat is the only regular sound inside a mother’s womb, it is easy to follow the sound and predict the number of beats per minute.

Fetal Doppler units that have display screens attached can also automatically detect heartbeats, count them and display the beats per minute on the screens. Present day Dopplers are powerful enough to detect heart beats in fetuses as early as the sixth week. There are different manufacturers who produce different types of Dopplers with varying capacities. The most common probe capacities are 2 MHz and 3 MHz. Some machines have a very powerful 5 MHz probe that is very effective on obese women.

Originally intended for medical practitioners’ use, the fetal Doppler has become very common with people who have started using them in their homes. It does take some time to get used to the technique of positioning the probe and covering the entire abdomen area with it. But, once people get the hang of it, it is easy to detect the heart beat of the fetus. Technological advancement and its availability to the masses have enabled people to experience the joy of listening to their baby’s heart beat from the comfort f their homes.