Overview

The Philips Avalon FM50 (M2705A) is the intrapartum model of the Avalon FM40/FM50 fetal/maternal monitor pair, built for labor and delivery rooms, antepartum testing areas, and postpartum recovery in the hospital. It shares every feature of the Avalon FM40 and adds the internal measurements needed during active labor: direct fetal ECG (DECG) from a fetal scalp electrode and intrauterine pressure (IUP) from a catheter, both connected through a Toco+ transducer or an ECG/IUP module. Philips labels the FM50 with the IP (intrapartum) designation for this reason. Externally, the monitor tracks fetal heart rate by ultrasound for singletons and twins as standard, with triplet monitoring available as an option, along with uterine activity by Toco and gross fetal body movements through the Fetal Movement Profile. The Avalon family, which also includes the FM20, FM30, and FM40, shares transducers, accessories, and software, so facilities running mixed Avalon fleets can standardize on one set of transducers, one paper stock, and one software release across bedside and triage locations. Philips states that the FM50 is not intended for intensive care units or operating rooms.

Display and User Interface

The FM50 is operated almost entirely from its 6.5-inch color touchscreen, which shows measurement numerics, maternal and fetal ECG waves, alarm fields, status indicators, and menus. The only hardware control outside the screen is the On/Standby button. Configurable SmartKeys give one-touch access to common tasks such as starting the recorder, entering notes, starting NIBP, calling an ambulating patient wearing cableless transducers, and quick-admitting a patient. Smart transducers are recognized automatically when plugged in, and the monitor rebuilds its screen layout around the active measurements, while a finder LED on each transducer helps staff identify which one is assigned to which channel. A rear VGA output drives an external display approved for medical use at a cable run of up to about 33 feet, and an optional MIB interface supports an external touch display so the monitor can be operated from across the room or a family-facing screen. Optional PS/2 and USB interfaces add a keyboard, mouse, or bar code reader for admission workflows. With IntelliSpace Perinatal revision K or later and the IntelliVue XDS solution, clinicians can also view and operate a LAN-connected FM50 remotely.

Clinical Measurements and Transducer Support

External fetal heart rate is measured by 1 MHz pulsed Doppler ultrasound across 50–240 bpm, with Philips specifying that thermal and mechanical index remain below 1.0. Twin FHR monitoring is standard, and the triplet option adds a third ultrasound channel with configurable trace separation offsets on the recorder so overlapping traces remain readable. Internal fetal heart rate is derived from a single-lead DECG across 30–240 bpm, and the FM50 displays the DECG waveform for signal-quality assessment. Uterine activity is measured externally by a strain-gauge Toco transducer or internally by IUP over a measurement range of -100 to +300 mmHg. On the maternal side, heart rate comes from MECG electrodes, and a Toco MP or Toco+ MP transducer adds Smart Pulse, an optical maternal pulse measurement from 40–240 bpm. The operator manual lists maternal NIBP, SpO₂ (Philips, Nellcor OxiMax, and Masimo sensor families), and tympanic temperature as options, so the installed configuration should be confirmed on each unit. The FM50 accepts both previous-generation and new-generation wired Avalon transducers across four front fetal sensor sockets. Philips notes that the ECG display is for signal quality only and that the monitor is not a diagnostic ECG device.

Software Versions and Platform Evolution

Avalon fetal monitor software is released by lettered revision, and the same release covers the FM20, FM30, FM40, and FM50. Release J.3 (software J.3x.xx) introduced support for the Avalon CL cableless transducer system with twin and triplet capability, the IntelliVue CL SpO₂ and NBP Pods, cableless ECG/IUP, underwater monitoring with watertight CL transducers, and patient calling. J.3 also redesigned the user interface, added maternal tympanic temperature and manual temperature entry, configurable SpO₂ recording and transmission intervals, an audible Coincidence INOP, DHCP support, data export over LAN or MIB/RS232, a configurable NBP measurement sequence, alarm reminders, and optional USB and flexible nurse call interfaces. J.3 increased trace backup memory to at least 3.5 hours, or at least 7 hours on units with mainboard hardware revision A 00.18. Release L.3 (software L.3x.xx), the current release documented in the Philips operator manual, added the Avalon CL Wide Range Pod for WLAN-based ambulatory monitoring, support for the new-generation wired transducers, IntelliVue XDS remote display support, typed notes of up to 30 characters, and an alarm mode default of All. The new-generation wired Toco+ MP transducer requires L.3x.xx. Two L.3 features, the CL Fetal & Maternal Pod and Dawes/Redman NST interpretation, are not available in the U.S. Note that a software upgrade clears stored trace memory. IPR Medical can identify the software and hardware revision installed on a specific unit before sale or service.

Power, Recorder, and Physical Configuration

The FM50 is a mains-powered bedside monitor. It runs on 100–240 VAC ±10% at 50–60 Hz, draws 1.3–0.7 A, and is Class I equipment requiring an earthed outlet; Philips advises against extension cords and multiple portable socket-outlets. Unlike the FM20 and FM30, which offer a lithium-ion battery option for in-transport monitoring, the FM40 and FM50 have no internal battery. The unit measures 16.6 x 6.9 x 14.4 inches (W x H x D) without options and weighs less than 19.5 lbs, and it starts displaying parameter labels in under 30 seconds. The front panel carries the touchscreen, the recorder paper drawer and transparent paper guide with tear-off edge, the four fetal sensor sockets, and the optional NIBP and SpO₂ sockets. The built-in thermal array recorder prints on standard Z-fold paper at 1, 2, or 3 cm/min across a 5.0-inch print width at 200 dpi, uses optical sensing of black page marks, and fast-prints stored traces at up to about 0.8 inches per second. Philips calls for cleaning the thermal printhead at each paper pack change. Operating range is 32°F to 113°F at below 95% relative humidity at 104°F, and the enclosure is rated IPX1 with the recorder drawer shut.

Trace Recovery, NST Reporting, and Cross-Channel Verification

The FM50 keeps trace data and annotations in internal backup memory so traces are not lost when paper runs out or the drawer is open. When new paper is loaded, the monitor can automatically fast-print the missed interval from the stored data, and at least one hour of recovery data is available for printout. On a LAN connection, stored data uploads to OB TraceVue or IntelliSpace Perinatal automatically when the link is restored, provided the patient has an open episode. Buffered memory retains active settings, alarm review, and stored trace data for at least eight hours without power, and the alarm review log holds 300 items. Cross-channel verification is standard: the monitor compares all monitored maternal and fetal heart rates, flags any two channels picking up the same or similar signal with a Coincidence INOP and a configurable tone, and marks the affected numerics and trace with a question mark, helping staff avoid mistaking a doubled maternal heart rate for the fetal rate. Philips still instructs users to confirm fetal life and check maternal pulse periodically. An NST timer is standard, and optional NST trace interpretation based on the 2008 NICHD guideline prints a report on the fetal strip for up to three fetal heart rates.

Network and OB Information System Integration

The FM50 connects to Philips OB TraceVue and IntelliSpace Perinatal, the Philips obstetrical surveillance and information management systems, through the optional LAN/RS232 system interface in rear slot 01. LAN connection requires OB TraceVue revision E.00.00 or later or IntelliSpace Perinatal revision H.0 or later, and the network port is 100Base-TX on an RJ45 connector with basic isolation. The monitor supports both BOOTP and DHCP addressing. While connected over LAN, the monitor takes its date and time from the OB system, including daylight saving changes, and local date and time settings are locked. When a LAN connection to the OB system is active, the RS232 port can serve a second system, such as an EMR, on a read-only basis; that system can read output data but cannot change ADT data or monitor settings. Measurement data export is also available over LAN or the optional MIB/RS232 interface, although Philips notes that compatibility with third-party obstetrical systems has not been verified and must be validated before clinical use. For cableless monitoring, the rear telemetry interface accepts up to two Avalon CL base stations or one Avalon CTS system.

FDA Device Corrections and Safety Bulletins

Two FDA-classified corrections have named the Avalon FM50 directly, and both are now terminated. In November 2009, Philips issued an Urgent Medical Device Recall notice with an Instructions for Use addendum covering the Avalon FM20, FM30, FM40, and FM50, including all FM50 serial numbers (FM50 recall Z-0552-2010, Class II), after complaints of inaccurate ultrasound-derived fetal heart rate readings. Philips stated that the inaccuracies reflected known limitations of ultrasound FHR monitoring but occurred more frequently than with the previous Series 50 monitors; the correction was a labeling addendum explaining these phenomena and the differences from Series 50 displays. In October 2014, Philips issued an Urgent Medical Device Correction for FM20, FM30, and FM50 monitors running software revision J.30.58 (FM50 recall Z-0105-2015, Class II): with NBP in time-synchronized automatic or sequence mode, the automatic NBP series could stop, and the root cause was a software design change. Philips corrected it with a no-charge software upgrade. Separately, in May 2024 Philips issued an Urgent Medical Device Correction for the 867246 Avalon ultrasound transducer used with the FM50 (Z-2239-2024, Class II, listed as ongoing by FDA): transducers with transducer software L.01.04 can produce inaccurate fetal heart rates when monitoring multiples and must be used only for singletons.

Because FDA device corrections and safety communications may be updated or expanded after the date of this listing, IPR Medical recommends that facilities also check the FDA’s official resources directly to ensure they have the most current information.

FDA resources for further review:
FDA Medical Device Recalls Database  |
FDA Medical Device Safety

IPR Medical — Buy, Sell, Repair, and Parts

IPR Medical supports the Avalon FM50 across its full service life. We sell tested FM50 monitors configured to your requirements, including triplet capability, NIBP and SpO₂ options, and the LAN/RS232 system interface for OB TraceVue or IntelliSpace Perinatal. Our technicians repair FM50 monitors in-house, covering touchscreen displays, thermal recorders, fetal sensor sockets, interface boards, and power supplies, and they perform the electrical safety checks, performance assurance, and NIBP calibration that Philips calls for at least once every two years. Before a unit ships, we confirm the installed software and mainboard revision so you know whether it supports new-generation transducers and extended trace memory, and whether the J.30.58 NBP issue applies. We also stock wired and cableless Avalon transducers, Avalon CL base stations, DECG and IUP accessories, belts, NIBP cuffs, SpO₂ sensors, and fetal recorder paper. If your facility is retiring or consolidating fetal monitors, IPR Medical buys used FM50 units and Avalon transducers.

IPR Medical buys, sells, repairs, and stocks parts for the Philips Avalon FM50 Fetal Monitor. Contact IPR Medical at 855-477-8866 or cs@iprmed.com with service or software questions.

Trademark Notice: Philips, Masimo, Nellcor, and all other brand names, model names, and part numbers shown are trademarks of their respective owners and are used on this page only to identify the original manufacturer’s equipment offered here, consistent with nominative fair use. This listing is offered by IPR Medical, an ISO 9001:2015-certified independent service organization, and is not sponsored by, affiliated with, or endorsed by Philips, Masimo, or Nellcor.