BT-350 indicates FHR as numeral by irradiating ultrasound at the abdomen, abstracting Doppler frequency of heart oeat cycle from the signals reflected from fetal heart, and outputting FHR change as s sound, and analyzing these signals. Bes des, you can measure UC oy using pressure sensor. BT-350 prints FHR, UC, and FM on the thermal paper and displays them on the LCD display. Especially, the doppler probe has 9 crystal sensors for catching FHR effectively, and it is water-proof type. BT-350 has 2 kinds of installation functions such as notebook, and wall mount.