The Bistos BT-200 Vascular Fetal Doppler detects the fetal heart rate quickly from about 10-12 weeks through labor, and is safe and simple to use. This hand-held fetal heart rate monitor is small and lightweight, features an audio speaker as well as a clear LCD display of the fetal heart rate. The BT-200  also features built-in loudspeaker and audio output for earphones with dedicated PC software to manage FHR and heart sound data.