10
Oper
ation
3.2 Obstetric
Mode
Fetal Dopplex II (FD2)
Obstetric mode is automatically selected when an obstetric probe (OP2HS/
OP3HS) is connected. Fetal Heart Rate (FHR) is displayed with 3 operating
modes, and an RS232 interface provides for FHR printing when connected to
the Dopplex Printa Package.
Obstetric Probes
Two probes are available for obstetric examinations:
OP2HS
2MHz ±1%
OP3HS
3MHz ±1%
Fetal Dopplex (FD1/FD3)
Operates in standard mode to provide FHR display. The probe/cable are
waterproof and can be fully immersed for use in waterbirths.
The FD1/FD3 main unit is not waterproof and must not be
immersed.
Clinical Use
Apply a liberal amount of gel to the abdomen*. Place the faceplate of the probe
fl
at against the abdomen above the symphysis pubis. Adjust the probe to obtain
an optimum audio signal ideally by angling the probe around. Avoid sliding it
over the skin.
In early pregnancy a full bladder may improve sound detection. In later
pregnancy the best signals are generally located higher on the abdomen. The
fetal heart sounds like a galloping horse at approximately twice the maternal
rate. A wind-like sound is heard from the placenta.
*Note: For FD1/FD3 : Gel is not required when probe is used underwater.
Standard Mode - FD1/FD2/FD3
In this mode the FHR, averaged over 4-heart beats, is displayed on the 3-digit
readout. The LCD displays an outline heart symbol.
