Chapter 4 Fhr Examining - EDAN SD5 User Manual

SD5/SD6 Ultrasonic TableTop Doppler User Manual

Chapter 4 FHR Examining

1 Always check if the main unit and the probe are in good condition prior to use.
2 To avoid inaccurate diagnosis: (a) relocate the probe for the best FHR signal as the
fetal position changes; (b) when intrauterine fetal death is doubted by using this
examination method, try to verify it with other methods.
Handle the probe with care. Do not drop it on hard surfaces.
The 2 MHz and 3 MHz obstetrical probes are designed for FHR examining. The 2 MHz probe is
optimized for deep penetration and is widely used in the third trimester pregnancy. The 3 MHz
probe is a general purpose probe. It has better resolution and wider detection range than the 2
MHz probe, therefore is optimized for early fetal heart detection.
Follow these procedures to perform FHR examining:
1 Feel the position of the fetus by hand to find the best position to detect the fetal heart.
2 Switch on the Doppler and the probe.
3 Apply a small amount of coupling gel to the acoustic face of probe; place the probe face at the
best position for detecting fetal heart. Angle the probe to obtain an optimum audio signal.
Adjust the volume if required.
When an audible fetal heart signal is detected, a clear fetal heart sound will be heard from the
speakers/earphone, and numeric FHR value will be displayed on the LCD.
NOTE:
1 The best quality records will only be obtained if the probe is placed in the optimum
position.
2 Positions with strong placental sounds or umbilical blood flow sound should be
avoided.
3 If the fetus is in the cephalic position and the mother is supine, the clearest heart
sound will normally be found on the midline below the umbilicus. During examining,
the pregnant woman's prolonged lying in the supine position should be avoided
owing to the possibility of supine hypotension. Sitting up or lateral positions are
preferable and may be more comfortable.
4 It is not possible to obtain accurate FHR unless an audible fetal heart signal is
detected. If the calculated FHR is not in accordance with the beat of the fetal heart
sound, the fetal heart sound auscultation result shall prevail.
WARNING
CAUTION
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FHR Examining