Micro Doppler G-51 Handy & small size Convenient for visiting consultants Built in speaker Housed in moulded ABS cabinet Mains & battery operated Ultrasound frequency 2MHZ.   Principle of Operation :   Microdoppler works on the principle of Doppler-effect. Very low intensity ultrasound at frequency 2 MHZ is beamed in to body from a very small transducer which is reflected back from organs & blood particles. Reflected signal is changed slightly in frequency due to movement of foetal heart, blood particles & other moving organs. Reflected signal is received by Micro Doppler, amplilfied & processed electronically to get audible signal through built in speaker or external earphone.   Specifications : Operating Ultrasonic Frequency-2MHZ. Operates on 5-AA size cell or mains supply with mains adapter. Width:   90 mm Height:   50 mm Depth:   160 mm Weight:   500 gms Obstetrical Applications Detect Pregnancy. Monitor fetal well being. Reassure Expectant mother. Determine Missed abortion. Locate placenta. Evaluate Pregnancy Vs.abdominal masses. Determine multiple pregnancies.