It is impossible, nowadays, to imagine modern medical diagnostic without devices that work on the basis of "Dopplers Effect". Within medicine (in medical diagnostic as well as in medical therapy" "Dopplers Effect" is mainly used indirectly, in other words, using the devices based on "Dopplers Effect", due the the gathering of some useful results, but their physics background or direct usage and understanding of this scientific theory are usually left outside. The physical nature of "Dopplers Effect", biographical facts on J.C. Doppler and main ways of "Dopplers Effect" usage are mentioned in the following thesis.