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, viewed alongside uterine activity data from the toco, forms the electronic fetal monitoring (EFM) strip that clinicians use to assess fetal well-being throughout labor.

GE Corometrics 5700HAX — Knob (Button) Style

The 5700HAX is the knob (button) style variant of the GE Corometrics Nautilus ultrasound transducer line. The knob threads into the corresponding receptacle on the monitoring belt, creating a secure, twist-lock attachment that many clinicians prefer for its positive engagement feel and resistance to accidental dislodgement during patient movement. Like all Nautilus ultrasound transducers, it uses a 9-crystal pulsed Doppler array operating at 1.151 MHz with a 2 kHz pulse repetition frequency, providing a wide focal region and reliable fetal heart rate detection across a range of fetal positions. The autocorrelation processing technique helps distinguish true cardiac signals from motion artifacts, supporting consistent beat-to-beat tracking. The detectable heart rate range spans 50–210 BPM.

This compatible replacement transducer performs the same clinical role as the OEM unit at a more accessible price point, allowing facilities to maintain adequate transducer inventory without single-source supply constraints. It ships individually bagged, non-sterile, and ready for immediate clinical use.

Knob vs. Wings — Choosing the Right Style

The GE Corometrics Nautilus ultrasound transducer is available in three attachment configurations that are otherwise electrically and functionally identical. The wings (loop) style — OEM part number 5700LAX — uses a sliding loop that snaps into the belt quickly, which many clinicians prefer for speed during fast-paced admissions. The knob (button) style — OEM part number 5700HAX — uses a threaded knob that provides a firmer, locked feel once attached. The combo knob-and-wings version — OEM part number 2108346-001 — incorporates both attachment options on a single modified top cover, allowing staff to choose whichever method they prefer without stocking two separate SKUs. IPR Medical stocks all three configurations — contact us if you need help deciding which is right for your unit.

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 — knob only (5700HAX), wings only (5700LAX), and the combo knob-and-wings unit (2108346-001) — alongside the full 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 5700HAX ultrasound fetal transducers. Contact us at 855-477-8866 or cs@iprmed.com.