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Manufacturer
Model
What This Guide Helps With
Addresses incorrect fluid-level or optical detection caused by disposable placement, contamination, foam, tubing position, damaged disposables, or sensor-related faults.
Step-by-Step Troubleshooting
1. Protect the Patient and Maintain Continuity of Care
Do not continue processing if the system cannot reliably determine blood or fluid level. Establish an alternate blood-management plan before troubleshooting.
Expected outcome: Patient care continues safely without relying on uncertain level detection.
2. Record the Exact Indication and Operating Condition
Document the displayed message or abnormal level behavior and note whether it occurs at startup, during filling, processing, washing, or empty conditions.
Compare the indicated state with the visible condition of the disposable.
Expected outcome: The discrepancy is clearly defined and can be correlated with a particular disposable or operating state.
3. Inspect Reservoir and Bowl Installation
Verify the reservoir, bowl, and associated disposable components are seated in the correct accessible positions without tilting, incomplete insertion, or interference.
Expected outcome: Disposable components are physically positioned as intended. If reseating corrects the indication, troubleshooting can stop after verification.
4. Inspect Sensor Viewing Areas for Contamination
Examine externally accessible optical or level-sensing windows and adjacent disposable surfaces for blood residue, condensation, labels, tape, debris, or other material that could obstruct sensing.
Clean only according to approved manufacturer and facility procedures.
Expected outcome: Sensor viewing areas are clean and unobstructed.
5. Inspect the Disposable for Clouding, Damage, or Deformation
Look for scratches, discoloration, deformation, trapped material, or damage in areas where the system observes fluid levels.
Do not modify the disposable.
Expected outcome: The disposable presents a clear and properly positioned sensing surface.
6. Check for Foam, Bubbles, or Irregular Fluid Conditions
Observe whether excessive foam, air, or unusual fluid distribution is present near the level-sensing area. These conditions can alter optical detection even when the sensor hardware is functioning.
Address the underlying external fluid-path cause rather than altering system calibration.
Expected outcome: The fluid interface appears stable and consistent with normal processing conditions.
7. Verify Tubing and Flow Conditions
Confirm tubing is not kinked, obstructed, or incorrectly routed in a way that causes abnormal reservoir or bowl filling.
Expected outcome: Fluid moves predictably through the disposable path without abnormal filling patterns.
8. Test With a Known-Good Compatible Disposable
If practical, use a known-good compatible processing set or relevant disposable component to determine whether the indication follows the original set.
Expected outcome: Correct level detection with a known-good disposable indicates the original disposable was the likely cause.
9. Perform Functional Verification
Under nonpatient conditions, observe level indications through an appropriate operational sequence. Verify displayed status agrees with the actual disposable condition.
Do not enter unauthorized calibration or sensor-adjustment modes.
Expected outcome: Level and optical indications remain accurate and stable. Troubleshooting can stop if repeated verification is successful.
10. Remove From Service if Detection Remains Incorrect
If correct disposable positioning, clean sensing areas, normal fluid conditions, and known-good components do not restore reliable detection, remove the system from service.
Expected outcome: Equipment with unreliable fluid-level detection is labeled Out of Service and referred for bench evaluation.
If the Problem Persists
Disposable alignment, contamination, foam, tubing, and optical-path obstruction have been ruled out. The remaining condition may involve sensing hardware, internal alignment, electronics, calibration, or another service-level fault.
The device should be:
- Removed from service
- Labeled Out of Service
- Sent for repair or bench evaluation
- Evaluated using appropriate manufacturer documentation and approved test equipment
- Repaired, calibrated, or configured only by qualified personnel
Any calibration should be performed only when manufacturer procedures and approved equipment specifically require it. Complete appropriate return-to-service testing afterward. Knowing when to stop external troubleshooting is proper troubleshooting.
Clinical Use Tip
Do not dismiss a level-sensor indication simply because the visible fluid level appears acceptable; reliable automated detection must also be verified.
Work Order Documentation (CCR Method)
CCR = Complaint, Cause, Resolution
Complaint
What was reported by the clinical staff.
Example:
"OR staff reported repeated bowl-level indications even though the disposable appeared to be filling normally."
Cause
What was observed during troubleshooting.
Example:
"Clinical Engineering found dried residue on an accessible optical sensing surface adjacent to the bowl."
Resolution
What action was taken.
Example:
"The surface was cleaned using approved methods, and repeated functional testing confirmed stable level detection through the test cycle."
Helpful Details to Include (If Known)
- Exact displayed indication
- Processing stage when it occurred
- Visible reservoir or bowl level
- Disposable seating
- Sensor-window condition
- Foam or bubbles observed
- Known-good disposable test
- Cleaning performed
- Indication before and after correction
- Final device status
- Exact displayed indication
- Processing stage when it occurred
- Visible reservoir or bowl level
- Disposable seating
- Sensor-window condition
- Foam or bubbles observed
- Known-good disposable test
- Cleaning performed
- Indication before and after correction
- Final device status
Final Thought
Level-detection problems require comparison between the system indication and the actual disposable condition, followed by careful checks of seating, visibility, flow, and contamination before internal sensing problems are assumed.
That is successful troubleshooting.