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Asset Type
Manufacturer
Model
What This Guide Helps With
Control-input problems caused by contamination, gloves, physical obstruction, frozen software, power instability, damaged controls, or external accessories.
Step-by-Step Troubleshooting
1. Protect the Patient and Remove Unreliable Controls From Clinical Use
If the touchscreen or rotary knob cannot reliably control the anesthesia machine during a case, transition patient care to another verified anesthesia machine or approved backup method.
Do not continue using a machine whose primary controls respond intermittently.
Expected outcome: Patient care is maintained without reliance on the affected control interface.
2. Confirm Which Controls Are Affected
Determine whether the touchscreen, rotary knob, confirmation action, or multiple controls are unresponsive. Note whether the display itself continues updating and whether alarms remain active.
Record whether the fault is constant or intermittent.
Expected outcome: The affected input method and scope of the failure are defined.
3. Inspect the Touchscreen Surface
Check for liquid, cleaning residue, adhesive film, heavy contamination, or an object pressing against the screen. Clean the external surface using approved methods.
Confirm the issue occurs with normal intended touch technique and appropriate clinical gloves when applicable.
Expected outcome: The touchscreen is clean and unobstructed. If responsiveness returns and remains stable, proceed to final verification.
4. Inspect the Rotary Knob and Surrounding Area
Check the rotary knob for visible damage, contamination, binding, impact damage, or obstruction. Confirm it rotates and actuates normally without forcing it.
Expected outcome: The knob moves normally and provides consistent input.
5. Verify Power Stability
Confirm the unit is connected to stable AC power and that there is no evidence of intermittent power loss, rebooting, dimming, or unexpected display resets.
Expected outcome: The machine has a stable power source.
6. Check for an Application or Interface Freeze
Observe whether waveform displays, clock functions, numerical values, or other screen information continue updating. If the machine is safely off patient use, perform a normal controlled restart according to approved operating procedures.
Do not enter unauthorized service modes.
Expected outcome: Normal interface response returns after an approved restart. If the problem does not recur, proceed to final verification.
7. Disconnect Nonessential External Interfaces
When appropriate for bench testing, disconnect nonessential external USB, network, data, or accessory connections that could contribute to abnormal interface behavior, while preserving required machine functions.
Expected outcome: The control interface operates normally with nonessential external connections removed, identifying an external contributor if applicable.
8. Exercise the Controls Under Bench Conditions
Using normal user-accessible functions, verify repeated touchscreen selections, rotary adjustments, confirmations, menu navigation, alarm silence/reset functions as appropriate, and transitions between screens.
Expected outcome: Controls respond consistently without missed, repeated, or unintended inputs.
9. Complete System and Functional Testing
Perform the normal system test and verify ventilation, gas controls, alarm functions, display updates, and user inputs before return to service.
Expected outcome: The machine passes system testing and all primary control inputs remain reliable.
10. Escalate Recurring or Unresolved Control Failure
If either control remains intermittent, physically damaged, frozen, or unreliable after external checks and controlled restart, remove the machine from service.
Expected outcome: The machine is routed for qualified service evaluation.
If the Problem Persists
External contamination, obstruction, power instability, and peripheral connections have been ruled out. The remaining problem may involve the touchscreen assembly, rotary encoder, internal user-interface electronics, software, communication pathways, or another service-level fault.
Remove the machine from service, label it Out of Service, and evaluate it using appropriate Drager documentation and approved test equipment. Internal control replacement, software servicing, or configuration should be performed only by qualified personnel.
Complete system testing and repeated control-input verification before return to service.
Knowing when to stop external troubleshooting and escalate is proper troubleshooting.
Clinical Use Tip
An anesthesia machine with intermittent control response should be exchanged even if the controls begin working again after manipulation or restart.
Work Order Documentation (CCR Method)
CCR = Complaint, Cause, Resolution
Complaint
What was reported by the clinical staff.
Example:
"OR staff reported the Atlan A300 touchscreen stopped responding during room setup while the rotary control remained functional."
Cause
What was observed during troubleshooting.
Example:
"Clinical Engineering found dried cleaning residue across the touchscreen surface that interfered with touch input."
Resolution
What action was taken.
Example:
"Cleaned the touchscreen using the approved method, verified repeated touch and rotary-control operation, completed the system test, and returned the machine to service."
Helpful Details to Include (If Known)
- Touchscreen, rotary knob, or both affected
- Whether display information continued updating
- Intermittent or constant behavior
- Visible contamination or damage
- AC-power status
- Restart result
- External connections removed
- Controls tested after correction
- System-test result
- Final device status
Final Thought
Control failures are safety-critical because reliable machine operation depends on predictable user input; verify simple external causes first and remove any intermittently unreliable machine from service.
That is successful troubleshooting.