2
signal. And the Doppler frequency is consistent with the rhythm of the
fetal systole and diastole. Once cardiac valves vibrate and a Doppler
frequency excursion is formed. It is transmitted an output signal of
cardiac valves vibrating, and it is sent to the loudspeaker for getting a
rhythmical sound with the fetal heartbeat. Simultaneously, it is sent to a
counter which calculate periods of heartbeat that is fetal heartbeat rate
(bpm=beat per minute).
SECTION 2: SAFETY GUIDANCE
2.1 INDICATIONS FOR USE
The product is normally applied to fetus above 9~12 weeks growth,
difference in pregnant mater.
Listen to SFH:
The sound of fetal heartbeat can be played through earphone or
speaker.
Record SFH:
When the device is connected to record devices with USB cable,it can
transmit the sound of the fetal heartbeat to record devices,such as
cellphone and computer, and save it into the record devices.
Playback SFH:
Operator can playback the sound of the fetal heartbeat saved in the
record devices which recorded with the device.
Transient FHR:
Automatically the instrument displays the value according to the fetal
heartbeat detected by the probe instantly.
Average FHR:
