What Does the Ultrasound Transducer Do?

In external fetal monitoring, two transducers work together to provide a complete picture of labor: the toco (tocodynamometer) tracks uterine contractions, and the ultrasound transducer tracks fetal heart rate. The ultrasound transducer is positioned on the maternal abdomen over the fetal heart and uses pulsed Doppler technology to detect the motion of the fetal heart wall, translating that motion into a continuous beat-per-minute reading displayed on the fetal monitor. This real-time fetal heart rate tracing, shown alongside uterine activity data from the toco, forms the electronic fetal monitoring (EFM) strip that clinicians use to assess fetal well-being throughout labor.

9-Crystal Pulsed Doppler Technology

The GE Corometrics Nautilus ultrasound transducer uses a 9-crystal pulsed Doppler array operating at 1.151 MHz with a 2 kHz pulse repetition frequency. The 9-crystal configuration provides a wider focal region than conventional 7-crystal designs, improving signal reliability when the fetal heart shifts position during labor. The autocorrelation processing technique helps the monitor distinguish true fetal heart signals from maternal movement artifacts, supporting more consistent beat-to-beat tracking. The detectable heart rate range spans 50–210 BPM, covering the full range of clinically relevant fetal heart rates.

The Combo Knob & Wings Advantage

The Nautilus ultrasound transducer is available in three belt attachment configurations: wings (loop) only (5700LAX), knob (button) only (5700HAX), and this combo version (2108346-001) that incorporates both attachment styles on a single modified top cover. With the combo unit, staff can use either the button or the loop to secure the transducer to the monitoring belt without needing a different SKU. Departments that currently stock both the 5700LAX and 5700HAX separately can simplify their transducer inventory by standardizing on this single combo configuration. All other clinical and technical specifications are identical across the three variants.

Monitor Compatibility

This compatible ultrasound transducer is designed for use with GE Healthcare Corometrics fetal monitors that accept a round, keyed 12-pin connector. Compatible models include the 116, 118, 120, 128, 129, 130, 145, 150, 151, 155, 170, 171, 172, 173, 174, 250, 250cx, 256cx, 259, 259cx, and 340 series. If you are unsure whether this transducer is compatible with your specific monitor configuration, contact IPR Medical before ordering — our team can confirm compatibility based on your monitor model.

Materials

This transducer is latex-free and DEHP-free, supporting use in facilities with latex-sensitivity protocols. It is non-sterile and is not intended for invasive use. The watertight housing supports in-water monitoring and facilitates thorough surface disinfection between patients

IPR Medical — Your Source for Fetal Monitor Accessories

IPR Medical stocks compatible GE Corometrics ultrasound fetal transducers in all three configurations — wings only (5700LAX), knob only (5700HAX), and this combo knob-and-wings unit (2108346-001) — alongside the matching toco transducer lineup, so your labor and delivery department can source both transducers from a single supplier. Whether you need a single replacement or are stocking multiple units across a busy OB floor, IPR Medical can fulfill your order and answer compatibility questions before you buy.

IPR Medical stocks compatible GE Corometrics combo ultrasound fetal transducers (knob & wings). Contact us at 855-477-8866 or cs@iprmed.com.