Monitoring Twin Fhrs; Monitoring Twins Externally; Monitoring Internally; Signals Overlap Verification (Sov) - EDAN F9 User Manual

F9, F9 Express Fetal & Maternal Monitor User Manual Fetal Monitoring

7.4 Monitoring Twin FHRs

7.4.1 Monitoring Twins Externally

To monitor twin FHRs externally, you need to connect a US transducer to US1 socket and the
second US transducer to US2 socket of the monitor. Follow the instructions described in Section
7.2 Monitoring FHR with Ultrasound to acquire FHR signals for both channels. Press
CHANNEL key to switch the FH sound from one channel to the other.
When the two US transducers are fixed, make sure FH sounds from both channels are clear, two
FHR traces and two FHR numerics are displayed on the screen.
NOTE:
To ensure that both transducers stay at the optimum location, each transducer should be
fixed with a separate belt.

7.4.2 Monitoring Internally

Alternatively, you can monitor a FH using ultrasound externally, and monitor the second FH
using DECG internally.
Connect the US transducer to US2 socket; connect DECG cable to DECG socket.
Monitor one twin with a US transducer using the procedures described in Section 7.2 Monitoring
FHR with Ultrasound.
Monitor the other twin with a DECG cable using the procedures described in Section 7.3
Monitoring FHR with DECG.
CAUTION
The US transducer must be connected to US2 socket. If the US transducer connects to
US1 socket while DECG cable is connected to DECG socket, the FHR trace and
numeric from US1 will not be displayed.

7.4.3 Signals Overlap Verification (SOV)

When monitoring twins, there are possibilities that one twin‟s FHR signal is mistaken for the
other one‟s signal. The monitor provides signals overlap verification (SOV) function to reduce
these possibilities.
In the process of monitoring, if the SOV detects signals overlapping, an alarm message "Signals
Overlap (FHR1/DFHR, FHR2)" will appear on the screen to warn you. Checking the patient and
reposition of transducers might be needed.

7.4.4 Changing FHR2 Offset

In order to distinguish FHR1 trace from FHR2 trace, FHR2 offset is provided to help you
separate the two traces by an offset of -20 bpm or +20 bpm.
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