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Asset Type
Continuous Renal Replacement Therapy (CRRT)
Manufacturer
Model
What This Guide Helps With
User-interface controls stop responding, on-screen guidance freezes, or display updates become unreliable because of external, power, software, or service-level problems.
Step-by-Step Troubleshooting
1. Protect the Patient and Assess Therapy Status
If the touchscreen, rotary control, or on-screen guidance becomes unreliable during active therapy, do not continue relying on the system merely because pumps appear to be operating.
Follow clinical procedures for maintaining or transferring therapy to another verified system.
Expected outcome: Patient therapy and monitoring do not depend on an unreliable user interface.
2. Confirm Which Interface Function Has Failed
Determine whether the problem involves:
- Touch input only
- Rotary control only
- Display updates
- On-screen guidance
- Multiple interface controls
- The entire system appearing frozen
Note whether alarms remain audible and whether displayed values continue to update.
Expected outcome: The failure is narrowed to a specific control or broader user-interface condition.
3. Check for Physical Screen Interference
Inspect the touchscreen for:
- Moisture
- Cleaning residue
- Protective material interfering with contact
- Dirt or contamination
- Cracks or impact damage
- Objects resting against the screen
Clean the external surface only using approved methods.
Expected outcome: The screen surface is clean, dry, intact, and unobstructed. If normal touch response returns, the issue is resolved after functional verification.
4. Inspect the Rotary Control Externally
Check whether the rotary control moves normally and is free from physical binding, contamination, or obvious mechanical damage.
Do not pull, pry, lubricate, or disassemble the control.
Expected outcome: The rotary control operates mechanically without sticking or damage. If an external obstruction is corrected and input returns, continue to final verification.
5. Confirm Stable AC Power
Inspect the power cord and device inlet and verify that the unit has a reliable AC power source.
Intermittent power conditions can create symptoms that resemble a frozen display or incomplete software response.
Expected outcome: AC power is stable and external power connections are secure.
6. Remove Nonessential External Connections
When the device is not supporting a patient, disconnect nonessential external communication or peripheral connections that are not needed for basic operation.
Observe whether the interface becomes responsive after a controlled restart.
Expected outcome: The PrisMax operates normally with unnecessary peripherals removed. If so, reconnect items individually to identify the external source.
7. Perform a Controlled Restart When Clinically Safe
Only after therapy has been safely discontinued or transferred, perform a normal shutdown and restart.
Do not cycle power on an actively relied-upon treatment merely to test the interface.
Observe the startup process for freezes, delayed response, or recurring messages.
Expected outcome: The touchscreen, rotary control, and on-screen guidance operate normally following restart. If the failure does not recur during repeated checks, proceed to final verification.
8. Check Whether the Failure Is Reproducible
Navigate through normal non-patient setup functions and verify consistent response from both the touchscreen and rotary control.
Determine whether freezing occurs only on a specific screen, after a particular external connection, or randomly.
Do not enter unauthorized service menus or change protected configuration settings.
Expected outcome: User-interface operation remains stable across normal permitted functions. Recurrent freezing indicates the device should not be returned to service.
9. Perform Final Functional Verification
Verify:
- Touch input works across normal operator screens
- Rotary input is responsive and consistent
- Displayed information updates normally
- On-screen guidance advances appropriately
- Audible and visual alarm presentation remains functional
- The system completes normal startup without freezing
Complete any manufacturer-required post-service checks appropriate to the work performed.
Expected outcome: All interface functions are responsive and repeatable. The PrisMax may be returned to service only when reliable control and display operation are confirmed.
10. Escalate Persistent or Intermittent Freezing
If the touchscreen, rotary control, or user-interface software continues to freeze after external checks and a controlled restart, remove the unit from service.
Intermittent control failure is sufficient reason for escalation even if the unit later appears normal.
Do not perform internal display repair, controller-board troubleshooting, or unauthorized software changes.
Expected outcome: The affected unit is routed for qualified service evaluation rather than returned with an unresolved intermittent fault.
If the Problem Persists
Common external causes have been ruled out. Remaining possibilities may involve the display assembly, input controls, internal communication, software, processing electronics, power distribution, or other service-level functions.
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 or configured only by qualified personnel
After repair, verify all user-interface controls, displays, alarms, startup functions, and any manufacturer-required safety tests before return to clinical use.
Knowing when an intermittent control problem makes a CRRT system unsuitable for service is proper troubleshooting.
Clinical Use Tip
A functioning fluid circuit does not make the system safe to continue using if clinicians cannot reliably view status, respond to alarms, or control therapy.
Work Order Documentation (CCR Method)
CCR = Complaint, Cause, Resolution
Complaint
What was reported by the clinical staff.
Example:
"Clinical staff reported that the PrisMax touchscreen intermittently stopped responding during setup while the rotary control remained functional."
Cause
What was observed during troubleshooting.
Example:
"Clinical Engineering found dried cleaning residue on the touchscreen surface that interfered with consistent touch response."
Resolution
What action was taken.
Example:
"Clinical Engineering cleaned the screen using the approved method, verified reliable touch and rotary-control operation through repeated setup checks, and returned the unit to service."
Helpful Details to Include (If Known)
- Whether therapy was active when the problem occurred
- Touchscreen, rotary control, or both affected
- Whether displayed values continued updating
- Alarm audio behavior
- Screen contamination or physical damage
- AC power status
- External peripherals connected
- Whether a controlled restart restored operation
- Whether the freeze was reproducible
- Final device status
Final Thought
Unreliable controls or guidance can make an otherwise operating CRRT system unsafe. Rule out screen contamination, physical interference, power, and external connections first, then escalate recurring freezes and document the final functional verification clearly.
That is successful troubleshooting.