Overview

The Smiths Medical Medfusion 3500 is a compact, lightweight single-syringe infusion pump designed for the administration of fluids and medications that require precisely controlled infusion rates. It is indicated for intravenous, subcutaneous, epidural, spinal, and arterial routes and is used across the full patient range, from neonatal through adult, which is why it appears so often in NICU, PICU, operating-room, and adult critical-care environments. The 3500 belongs to the long-running Medfusion 3000 Series platform that has been recognized for accurate medication delivery in critical care for well over a decade. This listing covers the pump running Software Version 6 (V6), the most fully featured software release for the platform. Two capabilities define the device clinically: PharmGuard medication safety software, which lets a facility build a drug library with programmable dose limits, and FlowSentry pressure monitoring, which provides rapid occlusion detection. Together they give the pump both the programming discipline of a smart pump and the responsiveness needed for low-rate neonatal and critical-care infusions.

Medfusion 3500 Software Versions: V3 vs V4 vs V5 vs V6

Every Medfusion 3500 looks almost the same from the outside. The software version shown on the start-up screen is what separates a Version 3 pump from a Version 6 pump, and it determines both the feature set and the pump’s FDA recall status. Here is how the versions compare for buyers.

FDA recalls of the Medfusion 3500 are corrections, not product removals. For the full history in plain English, see our Medfusion 3500 recall and software versions guide. Choose Version 3, Version 5 or Version 6 from the Software Version menu at the top of this page. Need a wireless pump? See the recertified Medfusion 4000 wireless syringe pump. Need documentation? Download the operator’s manuals and brochure from our Medfusion 3500 manuals and documentation page.

Display and User Interface

The Medfusion 3500 V6 presents programming and status information on a color display with an adjustable backlight that can be switched between bright and dim for different lighting environments. Four softkeys sit beneath the lower portion of the screen, and their function changes contextually with each menu, so the same four physical keys drive the entire programming workflow. From the main delivery screen, the softkeys open the main menu, change the dose value, open the options menu, and clear infusion volume and dose totals. Programming follows a guided, prompt-driven sequence: the clinician selects a profile and category, chooses a drug program or a manual delivery mode, loads and confirms the syringe model and size, and enters the infusion parameters. When a programmed value falls outside a configured limit, the pump displays a soft-limit advisory or, for hard limits, blocks the entry, and an out-of-range alarm prompts the clinician to confirm or correct the value. A locking option restricts changes to a running infusion, deterring inadvertent or unauthorized adjustment.

Delivery Modes, Drug Library, and Dose Error Reduction

PharmGuard is the dose-error-reduction system at the center of the 3500. A facility builds its library in PharmGuard Toolbox 2 and organizes it by profile; each profile supports up to eight categories with up to 36 drug programs each, for as many as 288 entries, plus one Quick Library for rapid setup. Each drug program can carry hard limits, which cannot be overridden, and soft limits, which warn but allow a confirmed override, across dose, rate, weight, time, and delivery mode. The pump supports an unusually broad set of delivery modes for both continuous and intermittent therapy: continuous mL/hr; dose per minute, hour, or day; weight-based dose/kg and body-surface-area dose/m² in the same time bases; and mL/kg dosing; alongside intermittent volume/time, dose/time, dose/kg/time, dose/m²/time, mL/kg/time, and intermittent volume/time. Additional delivery options include programmable bolus and loading doses, volume limits, KVO, standby, periodic callback, and a delayed start. This range lets a single pump cover everything from microgram-level neonatal vasoactive drips to weight-based critical-care boluses while keeping each program inside pharmacy-defined safety boundaries.

FlowSentry Occlusion Detection and Pressure Monitoring

FlowSentry is the 3500’s pressure-monitoring and rapid-occlusion-detection system, and it is one of the main reasons the pump is valued for low-rate work. For syringes larger than 1 mL, the user can select an occlusion limit appropriate to the line and application: Very Low at 4 psi, Low at 8 psi, Normal at 12 psi, or High at 16 psi. For 1 mL syringes, the limit is fixed at Very High, 50 psi. The pump continuously displays a pressure trend graph during delivery, which gives clinicians an earlier opportunity to intervene before a hard occlusion alarm occurs, and a post-occlusion bolus-reduction feature limits the unintended bolus that can otherwise be released when an occlusion clears. Lower occlusion limits shorten the time to alarm, which matters most at very low neonatal flow rates where a fixed high threshold could allow a long delay before an occlusion is detected. Because occlusion detection depends on a force sensor, calibration integrity is part of routine service (see the FDA section below).

Software Versions and Platform Evolution

The Medfusion 3500 shipped across several software versions, identified on screen at power-up, and the version matters because it governs both available features and the device’s correction status. Versions 3, 4, 5, and 6 were all fielded, with each release refining PharmGuard behavior, alarm handling, and delivery logic. Version 6 (V6) is the most fully featured release and is the configuration covered by this listing; the OEM operator’s manual referenced here is the V6 manual, and configuration on V6 is performed with PharmGuard Toolbox 2, Version 3 or higher. Importantly, several issues identified in software versions earlier than v6.0.0 — including delivery during a motor-not-running alarm, infusions restarting with incorrect parameters, screen lock, and incorrect recall of last settings — were corrected by Smiths Medical in v6.0.0, which is part of why a V6 unit is generally preferable to an earlier-version pump. Even so, V6 itself has been the subject of corrections, so confirming the exact sub-version and its current correction status is essential before clinical use. IPR Medical can help identify the software version reported by a specific pump and advise on bringing it to a current, validated release.

Battery and Power Operation

The Medfusion 3500 runs on an internal rechargeable nickel-metal-hydride (NiMH) battery or on AC mains power, with an optional external DC supply for transport applications. On AC, it accepts 100 to 240 VAC at 50/60 Hz, drawing about 30 VA, and the optional DC input operates from 6 to 14 VDC at roughly 7 watts. A fully charged battery will run the pump for at least six hours at a continuous rate of 5 mL/hr with a 60 mL syringe at room temperature; runtime varies with rate, syringe size, and battery age. Battery service life is rated at 500 full discharge/charge cycles or two years, whichever comes first, so a pump arriving from the secondary market should be evaluated for battery health and, in many cases, fitted with a fresh pack. The on-screen battery indicator and a set of battery alarms (low, damaged, or not working) help staff manage charge state, but because depleted-battery and related alarm behavior have been addressed in FDA corrections, battery condition and software status should be verified together during incoming inspection.

Configuration Management and Connectivity

The Medfusion 3500 is a stand-alone pump rather than a wirelessly networked, EMR-integrated smart pump. Its drug libraries and configurations are built and managed off-pump in PharmGuard Toolbox 2 and then transferred to the device through an infrared or RS-232 connection using the OEM converter box, and a cloning block allows a validated configuration to be copied from one pump to another. This model fits facilities that want pharmacy-governed drug libraries and standardized configurations without the infrastructure of a fully connected infusion system. Because configuration is centralized in Toolbox 2, a fleet can be kept consistent: a pharmacy publishes a profile, and each pump receives the same categories, drug programs, and limits. When acquiring or redeploying 3500 pumps, it is worth confirming the Toolbox version in use, the profile and configuration currently loaded, and whether the converter box and cloning hardware are on hand, since these determine how readily a unit can be brought in line with an existing library. IPR Medical can advise on the configuration accessories required for a given workflow.

FDA Device Corrections and Safety Bulletins

The Medfusion 3500 has an extensive FDA correction history that buyers and biomedical teams should review, including several Class I actions (the most serious classification). A Class I correction initiated in June 2020 (FDA recall Z-2735-2020) addressed Software Version 6.0 specifically: inaccurate delivery could occur following an interrupted bolus or loading dose if a specific sequence of events occurred. A Class I correction initiated in April 2022 (FDA recall Z-1272-2022) addressed multiple Model 3500 issues with the potential for therapy interruption or over-infusion, including primary audible alarm behavior, unanticipated depleted-battery alarms, a time-base alarm, intermittent-volume-over-time infusions continuing after a system failure, clearing of program-volume-delivered totals, false low-rate alarms, and a network port issue. A further Class I correction initiated in December 2023 (FDA recall Z-0863-2024) enumerated issues present in software versions earlier than v6.0.0 — such as delivery during a motor-not-running alarm and infusions restarting with incorrect parameters — which Smiths Medical had corrected in v6.0.0. On the Class II side, an August 2023 action (FDA recall Z-0076-2024) covering V3 through V6 warned that a force sensor in the occlusion detector may drift out of calibration, leading to longer occlusion-detection times, false occlusion alarms, or a System Failure Alarm; and a 2017 action (FDA recall Z-0314-2018) addressed a syringe barrel-clamp mechanism that could loosen and trigger an “Invalid Syringe Size” alarm. The recall classifications and dates above are taken from FDA’s openFDA enforcement records.

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

Medfusion 3500 Guides from IPR Medical

• Medfusion 3500 Recall and Software Versions – what the FDA recalls cover, which versions are affected, and how to check your pumps
• Medfusion 3500 Manuals and Documentation – download the operator’s manuals and brochure, and find the manual that matches your pump
• Medfusion 3500 Repair: The Most Common Problems and How to Prevent Them – the failures we see most often, what causes them, and a maintenance checklist to avoid them
• The Top 10 IV Pumps: A Comprehensive Guide – how the Medfusion 3500 compares with other widely used infusion pumps

Medfusion 3500 FAQ

What is the difference between Medfusion 3500 Version 3, 4, 5 and 6?

The version refers to the software generation the pump runs. Version 6 is the most fully featured release and is configured with PharmGuard Toolbox 2 (Version 3 or higher). Pumps running the newest Version 6 software have the issues from the FDA recalls resolved, while Versions 3, 4 and 5 are covered by a 2024 Class I recall.

How do I check which software version a Medfusion 3500 is running?

Power the pump on and watch the start-up self-test screen. It shows the installed software version, for example “Version V6.0.3,” along with configuration details. Record the version and serial number for every pump in your fleet.

Has the Medfusion 3500 been recalled?

Yes. The Medfusion 3500 has several FDA Class I recalls tied to older software: a 2024 recall (Z-0863-2024) covering software v3.x, v4.x and v5.0.0, and recalls in 2020 (Z-2735-2020) and 2022 (Z-1272-2022) covering Version 6 pumps on v6.0.0 and v6.0.1. These are corrections, not product removals. The manufacturer asked users to keep the newest software installed and to have backup pumps available. Read our recall guide for details.

Does the pump come with a drug library installed?

For questions about PharmGuard and drug libraries, please contact our team for details.

Which syringes are compatible with the Medfusion 3500?

The Medfusion 3500 accepts 1 to 60 mL syringes from five major syringe manufacturers. The compatible brands and sizes are listed in the operator’s manual on the Docs tab and on our Medfusion 3500 manuals page. Contact us if you need to confirm the syringes your facility uses.

What does “recertified” mean at IPR Medical?

A recertified (refurbished) pump has been evaluated, repaired as needed and performance-tested by our in-house technicians at our ISO 9001:2015-certified facility in Tustin, California, before it ships.

What warranty and shipping options are included?

This pump includes a power cord and a 1-year IPR Medical warranty, and extended warranties are available. Accessories, including the pole clamp, are sold separately. We ship by FedEx and UPS throughout the United States and Canada.

Can IPR Medical repair or service my existing Medfusion 3500 pumps?

Yes. We repair, maintain and calibrate Medfusion 3500 pumps in-house, from Version 3 through Version 6. U.S. customers can request a free shipping label, you approve the estimate before any work begins, and repairs carry a 90-day warranty. Version 5 pumps can be sent in for a board inspection to see whether they qualify for the newest Version 6 software.

IPR Medical — Buy, Sell, Repair, and Parts

IPR Medical is a secondary-market specialist in infusion and syringe-pump platforms, and the Medfusion 3500 is a device the company actively supports. IPR buys surplus and decommissioned 3500 pumps, sells inspected and tested units, performs repair and functional verification, and stocks the parts and accessories that keep a fleet running — including administration sets, batteries, pole clamps, lockboxes, and the configuration accessories used with PharmGuard Toolbox 2. Because the 3500 has both a software-version dimension and an active FDA correction history, IPR can help confirm the version a given pump reports, advise on correction status, and verify occlusion-detector calibration and barrel-clamp integrity as part of service. Whether you need a patient-ready unit, a replacement part, repair turnaround on a pump already in your fleet, or a path to sell equipment you no longer use, IPR can help. Reach out to confirm current availability, request a quote, or discuss servicing a specific unit.

IPR Medical buys, sells, repairs, and stocks parts for the Smiths Medical Medfusion 3500 Syringe Pump in Versions 3, 5 and 6. Contact IPR Medical at 855-477-8866 or cs@iprmed.com with service or software questions.

More questions

What is included with a recertified Medfusion 3500?
The pump includes a power cord and a 1-year IPR Medical warranty, and extended warranties are available. Accessories, including the pole clamp, are sold separately, and the buyer should confirm compatibility with existing systems. Orders ship by FedEx and UPS throughout the United States and Canada.

Why choose Version 6 over Version 3, 4, or 5?
Version 6 is the most fully featured software release for the 3500. Issues found in versions earlier than v6.0.0 were corrected by Smiths Medical in v6.0.0, and the current V6.0.3 release resolves the issues from the 2020 and 2022 Class I recalls. Versions 3, 4, and 5 are covered by a 2024 Class I recall.

Does the Medfusion 3500 come with a PharmGuard drug library?
For PharmGuard and drug library questions on the Medfusion 3500, please contact our team directly at (855) 477-8866 or cs@iprmed.com, Monday through Friday, 7:00 AM to 4:30 PM Pacific. We can talk through your facility’s configuration before you order.

Can IPR Medical service our existing Medfusion 3500 pumps?
Yes. IPR Medical repairs, maintains, and calibrates Medfusion 3500 pumps in-house, from Version 3 through Version 6. U.S. customers can request a free shipping label, approve the estimate before any work begins, and receive a 90-day repair warranty. Call (855) 477-8866 with questions about a specific pump.

Repair service: IPR Medical also repairs Medfusion pumps in house, with a free shipping label, a free evaluation and a 90-day repair warranty. See Medfusion pump repair.

Trademark Notice: Smiths Medical, 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 Smiths Medical.