CritiCare 504DX
CritiCare · Model 504DX
Advanced DOX™ SpO2 and Heart Rate monitoring - from routine, periodic spot-check measurements - to extended, continuous monitoring. With just one compact, lightweight, portable monitor, accommodate all of your patients - from neonate to adult. Unique DOX™ digital SpO2 technology for improved pulse recognition and artifact rejection. Audible and visual alarms provide instant notification. Optional printer, with user-definable report formats, enables accurate documentation of SpO2 and heart rate - short term or overnight - for graphic, tabular, and sleep summary reports. 24-hour internal memory supports Profox* Oximetry sleep study software. Built-in, rechargeable sealed lead acid battery ensures uninterrupted operation throughout patient transport or during power failure.
Key tips
- ·A no-signal/flatline alarm gets checked on the patient first, not the monitor - rule out a real clinical event before troubleshooting.
- ·Recalibrate NIBP against a reference manometer, not just a self-test pass.
- ·Reused patient cables (SpO2, ECG leads) are a common source of intermittent-fault complaints - swap the cable before the module.
Typical Failure Modes
Compiled for this model from its own documentation and established engineering knowledge for this equipment class - not from a verified service record. Confirm against the manufacturer's service manual.
No SpO2 / pulse reading or poor signal
HighSymptoms: No saturation / pulse value, "pulse search", low signal quality, implausible values.
Root cause: Worn or wrong SpO2 sensor, a damaged cable, poor site / perfusion, or motion.
Sensor / cable connector fault
MediumSymptoms: Reading drops when the cable is moved, sensor not recognised.
Root cause: Broken conductors in the sensor / extension cable, or a worn connector.
Inaccurate SpO2 vs a co-oximeter
MediumSymptoms: SpO2 consistently biased vs an arterial reference.
Root cause: Sensor degradation, or a monitor calibration / module fault.
Alarm / audio fault
MediumSymptoms: No or quiet audible alarm.
Root cause: Speaker or audio-board fault - a safety-critical failure.
Battery / power fault
MediumSymptoms: Short battery run time, will not power on.
Root cause: Aged battery.
Serviceable Parts & Consumables
Serviceable items for this model, compiled from its documentation and engineering knowledge for this equipment class. Service class and relative cost are estimates, not manufacturer figures; no part numbers are given. Confirm intervals and pricing against the manufacturer.
SpO2 sensor (reusable / disposable)
Class Frequent wear itemRel. cost $$R&R Easy
Pulse-oximetry extension cable
Class Frequent wear itemRel. cost $$R&R Easy
Battery
Class Periodic replacementRel. cost $$R&R Fairly easy
SpO2 module / board
Class Major service partRel. cost $$$R&R Moderate
Alarm speaker / audio board
Class Major service partRel. cost $$R&R Moderate
| Part | Service class | Relative cost | R&R difficulty |
|---|---|---|---|
| SpO2 sensor (reusable / disposable) | Frequent wear item | $$ | Easy |
| Pulse-oximetry extension cable | Frequent wear item | $$ | Easy |
| Battery | Periodic replacement | $$ | Fairly easy |
| SpO2 module / board | Major service part | $$$ | Moderate |
| Alarm speaker / audio board | Major service part | $$ | Moderate |
Relative cost: $ lowest · $$$$ highest service-part cost for this equipment class. Not a price.
PM Checklist
Preventive-maintenance tasks typical of this equipment class. Perform to the manufacturer's procedure and your facility's policy - this is general reference, not a schedule for this specific unit.
- ·Routine cable and lead-wire inspection for fraying/wear
- ·Battery conditioning cycle
- ·NIBP calibration check against a reference manometer
- ·ECG / SpO2 accuracy verification against a patient simulator
- ·Annual electrical safety test
Troubleshooting Approach
A starting sequence for this model, compiled from its documentation and engineering knowledge for this equipment class. Follow the manufacturer's service documentation for the actual procedure.
Symptom: No SpO2 or poor signal
- Fit a fresh, correct-size sensor on a well-perfused, still site.
- Swap the extension cable.
- Confirm the signal-quality / pleth indicator improves.
- Test the monitor with an SpO2 simulator.
- Replace the sensor / cable, or refer the monitor if the simulator also fails.
Symptom: Accuracy or alarm concern
- Compare SpO2 to a co-oximeter blood gas where clinically indicated.
- Try a known-good sensor.
- Verify against an SpO2 simulator at several saturations.
- Test the audible alarm at the set volume.
- Refer for module / audio service if it fails the simulator or alarm test.
Technical Specs
- Height
- 5.67 in
- Length
- 4.81 in
- Pulse Rate Range
- 20-300 BPM
- Weight
- 3.34 lbs
- Memory
- 24 hr
- SpO2 Range
- 0-100%
- Width
- 7 in
Typical Location
Where this class of equipment is typically deployed - general reference, not this unit's own placement record.
- ICU / CCU
- Emergency Department
- OR / PACU
- General med-surg floors
- Step-down units
- Telemetry units
Documents & Manuals
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