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Manufacturer
Model
Models Covered
Medfusion 3500 syringe infusion pump. The 3500BC has a different leakage-current setup that is called out separately below. Confirm complete model, software version, electrical classification, battery chemistry, and manual applicability from the nameplate and startup information. Do not substitute Medfusion 4000 sensor or battery limits.
Manual Reference
Smiths Medical Medfusion 3000 Series Technical Service Manual, document 40-5648-51C, including the Medfusion 3500 mandatory annual maintenance and battery-maintenance sections.
Manufacturer Recommendation / AEM Status
The manufacturer requires the Medfusion 3000 Series pump to be tested annually and whenever it has been damaged or dropped. All sensor calibrations are checked during annual maintenance. The manual states that calibration is not required to maintain flow-delivery accuracy; the prescribed delivery test verifies performance. This page preserves the annual interval and OEM limits. Do not extend the interval through an AEM program without documented risk assessment and approval.
What This PM Procedure Covers
- Identity, history, cleaning, enclosure, keypad, labels, power cord, pole clamp, tubing guides, rubber feet, syringe-loading mechanism, and force-sensor seal
- Power-up, audio, LEDs, display, AC/battery transition, and self-test
- Force, syringe-size, and plunger-position sensor verification using the exact Medfusion 3500 limits
- Plunger travel, lock indicator, syringe-empty alarm, motor drive, and occlusion operation
- 50 mL delivery/travel accuracy at 300 mL/hr using the OEM syringe-specific limits
- AC leakage-current testing and battery LMD/CPI review
Required Tools and Equipment
- Current Medfusion 3000 Series Technical Service Manual, model-specific operator manual, and PM checklist
- Medfusion calibration kit with small and large calibration slugs and calibrated force gauge/bracket
- Calipers with at least 0.001-inch resolution
- New compatible 50 or 60 mL Luer-lock syringe from the OEM flow-accuracy table; change test syringes at least monthly
- Three-way stopcock for the motor-drive/occlusion test
- Electrical-safety analyzer suitable for leakage-current testing
- For optional CF verification: 0.9% saline, beaker, compatible syringe, and tubing
- Approved cleaning/disinfection materials and facility documentation system
Step-by-Step PM Procedure
1. Remove the Pump From Clinical Use
Action: Confirm no patient is connected, stop the infusion, remove the clinical syringe and tubing, label the pump as under service, and move it to a controlled work area.
Expected outcome: The pump cannot deliver medication during service testing.
2. Verify Identity and Manual Applicability
Action: Record asset tag, complete model and serial number, software version, electrical classification, battery chemistry, accessories, department, and PM due date. Confirm whether the unit is a standard 3500 or 3500BC before electrical-safety testing.
Expected outcome: The pump and CMMS record agree, and the correct revision-specific limits are established.
3. Review Service History
Action: Review prior PMs, repairs, drops, physical damage, fluid exposure, battery/runtime complaints, calibration history, delivery complaints, occlusion alarms, self-test failures, and recurring system or watchdog errors.
Expected outcome: Repeat faults and repair-triggered testing are identified before PM.
4. Clean and Dry the Pump
Action: Disconnect AC power. Apply an approved agent to a soft cloth and wipe the pump dry. Do not spray liquids into bottom openings, immerse, autoclave, gas sterilize, use organic solvents/quaternary ammonia/strong acids or bases, or apply spray oils.
Expected outcome: The pump is clean, dry, and free of residue or fluid intrusion.
5. Perform the General Inspection
Action: Inspect for cracked housing, torn keypad, damaged cord/receptacle, loose parts, damaged tubing guides, punctured force-sensor seal, loose or damaged pole clamp, unreadable serial/warning labels, and missing rubber feet. Verify smooth operation of the plunger driver, syringe release lever, syringe flange clip, and barrel clamp.
Expected outcome: All components are intact, secure, legible, and operate smoothly. Replace or repair damage before testing.
6. Verify AC Power and Power-Up
Action: With no syringe installed and the barrel clamp fully down, connect the pump to 100-240 VAC and verify the AC and charge indicators. Power on and observe audio, LEDs, battery capacity, self-test, display, and contrast. Unplug AC and verify within several seconds that the AC indicator turns off and the battery indicator flashes; then reconnect AC.
Expected outcome: Alarm beeps sound, LEDs cycle except the continuously applicable AC/battery indicators, displayed battery capacity is greater than 0%, no self-test fails, display is legible, and AC-to-battery transition is correct.
7. Check the Force Sensor
Action: Enter authorized Biomed diagnostics and display the analog sensors. With no syringe loaded, record force. Install and zero the force gauge, apply 15 lb (6.8 kg), and record the pump reading.
Expected outcome: No-load force is -0.2 to +0.2 lb; at 15 lb applied, the displayed force is 14.0 to 16.0 lb. Recalibrate and retest any out-of-specification sensor.
8. Check the Syringe-Size Sensor
Action: Load the small calibration slug in the barrel clamp without the plunger driver. Keep the clamp perpendicular and move it slightly to find the lowest reading. Repeat with the large slug.
Expected outcome: Small-slug size is 0.256-0.272 in; large-slug size is 1.244-1.260 in, inclusive. Recalibrate and retest if outside limits.
9. Check the Plunger-Position Sensor
Action: With the small slug loaded, place the plunger driver on its end with flippers open and about 0.1 lb applied; record position. Repeat with the large slug and about 0.5 lb applied.
Expected outcome: Small-slug position is 0.680-0.720 in; large-slug position is 4.680-4.720 in, inclusive. Recalibrate and retest if outside limits.
10. Perform the Plunger-Travel and Syringe-Empty Test
Action: Exit Biomed mode. Load a new air-filled 50 or 60 mL syringe, select mL/hr, set 20 mL/hr, clear total infused, and start. Verify the three green infusion indicators sequence right-to-left through at least 0.033 mL. Check Lock/Unlock indication, change to the maximum available rate, and run the full syringe length.
Expected outcome: Indicators sequence correctly, lock indication responds, the drive travels smoothly, and at syringe end the Syringe Empty alarm, red alarm indicator, and audible alarm operate correctly.
11. Perform the Motor-Drive and Occlusion Operational Test
Action: Connect a three-way stopcock to an air-filled 50 or 60 mL Luer-lock syringe containing approximately 30 mL of air. Run at the maximum displayed mL/hr rate, prime at least 0.2 mL, close the stopcock, select the High occlusion limit, disable rapid occlusion detection if that option is available, and begin delivery.
Expected outcome: The pump operates until an occlusion alarm occurs. Open the stopcock to release pressure before removing the syringe. Any other alarm requires investigation.
12. Perform the Flow-Delivery Accuracy Test
Action: Select the installed syringe manufacturer, load a new air-filled listed syringe, set 300 mL/hr and a 50 mL volume limit, prime at least 0.2 mL, and measure from outside the syringe flange to inside the plunger. Record start position. Deliver 50 mL in approximately 10 minutes, stop/silence, record end position, and subtract end from start.
Expected outcome: Travel is within the range for the selected syringe: B Braun Perfusor 50 mL 3.146-3.275 in; B Braun Omnifix 50 mL 3.146-3.275 in; BD 60 mL 3.473-3.615 in; Fresenius 50 mL 2.904-3.023 in; Monoject 60 mL 3.473-3.615 in; Terumo 60 mL 2.901-3.020 in.
13. Review Battery Status
Action: In Biomed diagnostics, record battery chemistry, charge level, Last Measured Discharge (LMD), Capacity Inaccurate (CPI) count, voltage, current, and temperature as available.
Expected outcome: Replace the battery when LMD is below 1600 mAh. Recalibrate when CPI is 0x80 hexadecimal (128 decimal) or higher. Recharge a stored battery pack after four months, or an installed pack after two months without charging. Follow the complete OEM charge/discharge procedure when calibration is required.
14. Set the PM Date and Restore the Pump
Action: Set/view the PM date appropriate to the installed software, restore authorized configuration, verify date/time, reconnect approved accessories, fully recharge if needed, clean the exterior, and document results, equipment IDs, parts, and disposition.
Expected outcome: No test configuration remains, the PM reminder is correct for facility policy, and the pump is either returned to service or clearly removed from service.
Electrical Safety Testing
The standard Medfusion 3500 is listed as Safety Class II, Type CF. Connect the AC cord to the safety analyzer, power on, and contact either the plunger-driver tube or center post of the DC input jack. Normal-condition line/enclosure leakage must be less than 100 µA. The optional CF verification uses saline-filled tubing in contact with a 0.9% saline beaker and requires less than 10 µA in the normal setting. The Class II design does not require open-ground testing or a ground-resistance test.
For a nameplate-confirmed 3500BC, follow its dedicated setup: enclosure leakage at the DC-input center post and earth leakage through the functional-earth conductor must each be less than 100 µA in the normal setting; optional CF leakage must be less than 10 µA in normal and reversed settings. The functional earth is not protective earth, so ground-resistance testing is neither possible nor required.
Pass / Fail Criteria
PM Pass Criteria
- Correct identity/manual established; cleaning, housing, keypad, cord, labels, feet, pole clamp, tubing guides, force-sensor seal, and syringe-loading mechanics pass
- Power-up, audio, LEDs, display, battery capacity, self-test, and AC/battery transition pass
- Force sensor: -0.2 to +0.2 lb unloaded and 14.0 to 16.0 lb with 15 lb applied
- Small/large size readings: 0.256-0.272 in and 1.244-1.260 in; small/large position readings: 0.680-0.720 in and 4.680-4.720 in
- Plunger travel, lock, syringe-empty alarm, motor drive, and occlusion operation pass
- Measured 50 mL syringe travel is within the listed manufacturer-specific range
- Normal-condition leakage is below 100 µA; optional CF verification is below 10 µA
- Battery is replaced if LMD is below 1600 mAh and recalibrated if CPI is 0x80 or higher
Remove From Service Criteria
- Cracked/wet housing, torn keypad, damaged cord, punctured seal, loose part, missing safety component, or binding syringe mechanism
- Self-test, alarm, indicator, display, power transition, plunger travel, syringe-empty, motor-drive, or occlusion test fails
- Any sensor remains outside its stated limit after authorized calibration
- Flow-delivery travel or leakage current is outside the OEM limit
- Battery cannot meet the listed replacement/calibration criteria or any unresolved condition could affect delivery or patient safety
Copy/Paste CMMS Work Order Procedure
Use the current model- and software-specific OEM documentation and trained biomedical personnel. Do not perform testing on a patient, do not substitute Medfusion 4000 limits, and never return an incompletely tested or failed pump to clinical use.