Figure 5.1 Ultrasound Transducer & TOCO Transducer Positioning
5.1.1 Ultrasound Monitoring of FHR
Ultrasound monitoring can be used for antepartum monitoring; it is a method to obtain FHR
through maternal abdominal wall. Put the FHR transducer on maternal abdomen to transmit lower
energy ultrasound wave to fetal heart, then receive the echo signal from it.
Operation Procedure:
1
Preparing the Monitor
Turn the monitor on and verify that the normal monitoring screen appears on the display.
Check the ultrasound transducer to verify proper attachment to the monitor. For twins monitoring,
make sure the second ultrasound transducer if properly connected.
Set the current heart rate channel to channel US1
,
and adjust FHR1 volume well.
Attach the buckle of the ultrasound transducer to the belt. Apply aquasonic coupling gel to the
face of the transducer.
2
Acquiring the Fetal Heart Signal
Determine the location of the fetal heart using palpation or a fetoscope.
Place the ultrasound transducer on the abdomen over fetal site and move it slowly until the
characteristic hoof-beat sound of the fetal heart is heard. And then fix up the ultrasound transducer.
The elasticity of belt can be adjusted, which make the patient monitored in the comfortable
situation, and the fetal heart rate value will be shown on the screen. At the same time, the
ultrasound wave will be drawn in green color on the screen.
3
Acquiring Twins’ Heart Rates Signal
CMS800G is able to monitoring twins’ heart rates through two ultrasound transducers during the
whole pregnant time.
Follow the step
②
mentioned above to acquire the heart rate for the first fetus.
Set the current heart rate channel to US2, and adjust FHR2 volume well so that the second heart
sounds can be heard
