Nihon Kohden NKV-550-URecalls & reported problems

Summary

The FDA's MAUDE database contains 223 adverse event reports that list this exact device (DI 00843685100012), received between Jul 17, 2020 and Jun 22, 2026 — classified as 2 injuries, 221 malfunctions.

The most frequently reported specific device problem is “Defective Component” (72 reports).

1 other recall cover devices cleared under the same FDA submission (K181695, K192307); they may or may not involve this specific model.

Reports come from manufacturers, hospitals and patients and are not verified by the FDA. A report does not prove the device caused the event, and counts can't be used to compare devices or estimate failure rates. What reports can and can't tell you · How this data works · Data updated Oct 18, 2026.

Most reported problems

Recent adverse event reports

The 25 most recent of 223 reports, in the reporter's own words as published by the FDA.

• MalfunctionJun 22, 2026Defective Component

  IT WAS REPORTED THAT DURING PATIENT USE, THE GRAPHICAL USER INTERFACE (GUI) TOUCHSCREEN DISPLAYED WHITE, BLURRY LINES THAT PROGRESSIVELY WORSENED OVER TIME. DESPITE THE DISPLAY ANOMALY, THE TOUCHSCREEN REMAINED READABLE AND RESPONSIVE TO USER INPUT. THE VENTILATOR CONTINUED TO PROVIDE VENTILATION THROUGHOUT THE EVENT, AND THE PATIENT REMAINED ON THE VENTILATOR. NO PATIENT HARM WAS REPORTED.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 25577842 ↗
• MalfunctionJun 19, 2026Insufficient Device Problem Information

  A VENTILATOR-RELATED EVENT WAS REPORTED TO NKOM FROM MEDWATCH. THE VENTILATOR'S ETCO2 ALARM ACTIVATED WHILE THE PATIENT APPEARED TO BE BREATHING ABOVE THEIR NORMAL RESPIRATORY RATE. THE RESPIRATORY THERAPIST OBSERVED ABNORMAL VENTILATOR BEHAVIOR, INCLUDING INTERMITTENT TOUCHSCREEN DISPLAY MALFUNCTION ("GLITCHING") AND REPETITIVE, UNINTENDED ACTIVATION AND DEACTIVATION OF THE EXPIRATORY HOLD FUNCTION. ATTEMPTS TO CANCEL THE EXPIRATORY HOLD BY SELECTING THE ON-SCREEN "X" WERE UNSUCCESSFUL, AS THE VENTILATOR DID NOT RESPOND TO USER INPUT. DURING THE EVENT, THE PATIENT EXPERIENCED OXYGEN DESATURATION; HOWEVER, NO SERIOUS INJURY OR LASTING PATIENT HARM WAS REPORTED. THE CLINICAL TEAM PREPARED TO INITIATE MANUAL VENTILATION USING A BAG-VALVE MASK. BEFORE MANUAL VENTILATION WAS REQUIRED, THE VENTILATOR SPONTANEOUSLY RETURNED TO NORMAL OPERATION WITHOUT INTERVENTION. THE VENTILATOR WAS REPLACED WITH ANOTHER VENTILATOR. BIOMEDICAL ENGINEERING EVALUATED THE DEVICE FOLLOWING THE EVENT. FUNCTIONAL TESTING, OPERATIONAL VERIFICATION, AND EXTENDED MONITORING OF THE TOUCHSCREEN DISPLAY WERE PERFORMED. THE DEVICE PASSED ALL TESTING AND WAS FOUND TO BE OPERATING WITHIN MANUFACTURER SPECIFICATIONS. T

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 25568265 ↗
• MalfunctionJun 2, 2026Inappropriate or Unexpected Reset

  IT WAS REPORTED THAT THE VENTILATOR UNEXPECTEDLY POWERED OFF AND THEN RESTARTED (REBOOTED) WHILE IN USE ON A PATIENT. THE REGISTERED NURSE (RN) OBSERVED THE EVENT AND IMMEDIATELY INITIATED MANUAL VENTILATION (BAGGING). WHEN THE RESPIRATORY THERAPIST (RRT) HAD ARRIVED AT THE BEDSIDE, THE VENTILATOR HAD COMPLETED ITS REBOOT SEQUENCE AND RESUMED NORMAL OPERATION. AS A PRECAUTION, THE PATIENT WAS TRANSITIONED TO AN ALTERNATE VENTILATOR. THERE WERE NO REPORTED ALARMS ASSOCIATED WITH THE EVENT. NO PATIENT HARM OR ADVERSE CLINICAL IMPACT WAS REPORTED. A REVIEW OF THE DEVICE LOGS CONFIRMED A MOMENTARY CPU RESET, WITH VENTILATION RECOVERY OCCURRING WITHIN 18 SECONDS. VENTILATION RESUMED SUCCESSFULLY USING THE PREVIOUS SETTINGS AFTER THE MOMENTARY SYSTEM RESTART. IT ALSO SHOWED THAT A 'VENTILATOR RESTARTED' ALARM MESSAGE HAD BEEN ACTIVATED.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 25364375 ↗
• MalfunctionMay 19, 2026Computer Software Problem

  IT WAS REPORTED THAT WHILE THE VENTILATOR WAS IN NON-INVASIVE VENTILATION (NIV) MODE, VENTILATION SUDDENLY STOPPED, AND THE TOUCHSCREEN WENT BLACK. AUDIBLE AND VISUAL ALARMS, INCLUDING BLINKING INDICATORS, WERE REPORTED AT THE TIME OF THE EVENT. THE RESPIRATORY THERAPIST REMOVED THE PATIENT FROM THE VENTILATOR AND PLACED THE PATIENT ON AN ALTERNATE VENTILATOR. NO PATIENT HARM WAS REPORTED AS A RESULT OF THIS EVENT. DEVICE LOG ANALYSIS SHOWED THAT THE SYSTEM DETECTED AN I2C2 COMMUNICATION ERROR, FOLLOWED BY AN ¿I2C2: RESET¿ EVENT. REVIEW OF THE BREATH LOGS INDICATED THAT VENTILATION WAS NOT INTERRUPTED DURING OR AFTER THE I2C2 RESET EVENT.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 25220091 ↗
• MalfunctionApr 29, 2026Computer Software Problem

  IT WAS REPORTED THAT THE VENTILATOR MALFUNCTIONED AFTER A USB FLASH DRIVE WAS INSERTED TO EXTRACT DATA. THE PRIMARY TOUCHSCREEN BECAME UNRESPONSIVE (FROZE), AND A BATTERY ALARM WAS TRIGGERED. A SECONDARY GRAPHICAL USER INTERFACE (GUI) THAT WAS CONNECTED AND MIRRORED THE PRIMARY GUI ALSO DISPLAYED THE SAME ISSUE. AUDIBLE AND VISUAL ALARMS WERE GENERATED. THE VENTILATOR CONTINUED TO PROVIDE VENTILATION TO THE PATIENT. AS A PRECAUTION, THE PATIENT WAS TRANSITIONED TO ANOTHER VENTILATOR. THERE WAS NO REPORTED PATIENT HARM. THE DEBUG LOGS SHOWED THAT A ¿NON-CRITICAL THREAD (BDU)¿, ¿BACKUP BATTERY FAULT¿, AND ¿EXTENDED BATTERY FAULT¿ ALARMS WERE ACTIVATED. THE BREATH LOGS INDICATE THAT THE VENTILATION CONTINUED WITHOUT INTERRUPTION.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 25037952 ↗
• MalfunctionApr 11, 2026Computer Software Problem

  IT WAS REPORTED THAT THE NKV-550 VENTILATOR WAS IN O2 THERAPY MODE WHILE IN USE ON A PATIENT WHEN THE CRITICAL ALARM LIGHT ACTIVATED AND THE DISPLAY BECAME UNRESPONSIVE. AFTER SEVERAL MINUTES, THE DEVICE STOPPED DELIVERING OXYGEN FLOW TO THE PATIENT. CLINICAL STAFF IMMEDIATELY PLACED THE PATIENT ON A NON-REBREATHER MASK WHEN THE DEVICE STOPPED DELIVERING FLOW AND SUBSEQUENTLY TRANSITIONED THE PATIENT TO ANOTHER VENTILATOR. DURING THE EVENT, THE PATIENT¿S OXYGEN SATURATION (SPO2) TEMPORARILY DECREASED TO BELOW 85% BUT RETURNED TO BASELINE FOLLOWING INTERVENTION. NO SERIOUS INJURY OR PERMANENT HARM TO THE PATIENT WAS REPORTED. THE AFFECTED VENTILATOR WAS REMOVED FROM SERVICE FOR EVALUATION.

  Patient problems: Low Oxygen Saturation

  MAUDE report 24852535 ↗
• MalfunctionApr 2, 2026Inappropriate or Unexpected Reset

  THE EVENT OCCURRED DURING PATIENT USE, THE REPORTER STATED THAT THE NKV-550 VENTILATOR SHUT DOWN WITHOUT EXTERNAL INTERVENTION AND TRIGGERED AUDIBLE AND VISUAL ALARMS. THE VENTILATOR SPONTANEOUSLY RESTARTED AND RESUMED VENTILATING THE PATIENT. AS A PRECAUTION, THE PATIENT WAS SUBSEQUENTLY PLACED ON ANOTHER VENTILATOR. NO PATIENT INJURY OR SERIOUS HARM WAS REPORTED. A REVIEW OF THE DEVICE LOGS CONFIRMED A MOMENTARY CPU RESET, WITH VENTILATION RECOVERY OCCURRING WITHIN 20 SECONDS. BY DESIGN, AUDIBLE AND VISUAL ALARMS ARE ANNUNCIATED WHEN THE MOMENTARY SYSTEM RESTART OCCURS.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 24766874 ↗
• MalfunctionApr 2, 2026Computer Software Problem

  THE CUSTOMER REPORTED THAT DURING PATIENT USE, THE VENTILATOR EMITTED A CONTINUOUS AUDIBLE ALARM, CAUSING PATIENT DISCOMFORT. UPON ASSESSMENT, THE VENTILATOR SCREEN WAS OBSERVED TO BE DARKENED, UNRESPONSIVE TO TOUCHSCREEN AND BUTTON COMMANDS, WHILE THE AUDIBLE ALARM CONTINUED. MANUAL VENTILATION WAS INITIATED AND THEN DISCONTINUED ONCE THE PATIENT WAS CONNECTED TO A TRANSPORT VENTILATOR. THE PATIENT WAS SUBSEQUENTLY PLACED ON ANOTHER NIHON KOHDEN BRAND VENTILATOR AND ACHIEVED CLINICAL STABILIZATION. NO PATIENT HARM WAS REPORTED. AFTER THE PATIENT WAS REMOVED FROM THE AFFECTED VENTILATOR, THE UNIT WAS POWERED OFF USING THE ON/OFF BUTTON, WHICH STOPPED THE AUDIBLE ALARM. THE DEVICE WAS NOT RETURNED TO PATIENT USE AND WAS SENT TO CLINICAL ENGINEERING FOR FURTHER TECHNICAL EVALUATION.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 24766856 ↗
• MalfunctionMar 16, 2026Inappropriate or Unexpected Reset

  IT WAS REPORTED THAT DURING PATIENT USE, THE VENTILATOR REBOOTED AND DISPLAYED THE ERROR MESSAGE: ¿UNIT RESTARTED, CHECK SETTINGS, CHECK APPS ACTIVATED.¿ FOLLOWING THE REBOOT, THE VENTILATOR RESUMED VENTILATING THE PATIENT. AS A PRECAUTION, CLINICAL STAFF TRANSFERRED THE PATIENT TO ANOTHER VENTILATOR AND REMOVED THE AFFECTED DEVICE FROM SERVICE. THERE WAS NO PATIENT HARM REPORTED AS A RESULT OF THE EVENT. THE REPORTING HOSPITAL DECLINED TO PROVIDE PATIENT DEMOGRAPHIC INFORMATION. A REVIEW OF THE DEVICE LOGS CONFIRMED A MOMENTARY CPU RESET, WITH VENTILATION RECOVERY OCCURRING WITHIN 15 SECONDS. BY DESIGN, AUDIBLE AND VISUAL ALARMS ARE ANNUNCIATED WHEN THE MOMENTARY SYSTEM RESTART OCCURS.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 24611714 ↗
• MalfunctionMar 16, 2026Inappropriate or Unexpected Reset

  IT WAS REPORTED THAT ON (B)(6) 2026 AT 06:49:04, THE NKV-550 VENTILATOR UNEXPECTEDLY POWERED DOWN. A CRITICAL RED VISUAL ALARM BEGAN FLASHING AND THE VENTILATOR CEASED DELIVERING MECHANICAL BREATHS. ABSENCE OF VENTILATION WAS CONFIRMED VIA WAVEFORM CAPNOGRAPHY ON THE PATIENT MONITOR. AT 06:49:28, THE VENTILATOR BEGAN TO POWER BACK ON. BY 06:49:50, THE PATIENT WAS BEING MANUALLY VENTILATED BY A RESPIRATORY THERAPIST AT THE BEDSIDE. AT APPROXIMATELY 06:50:00, THE VENTILATOR COMPLETED THE POWER-ON SEQUENCE. DURING THE EVENT, THE PATIENT BECAME BRADYCARDIC TEMPORARILY. AT APPROXIMATELY 06:56:00, THE PATIENT WAS PLACED ON A REPLACEMENT VENTILATOR, AND VITAL SIGNS WERE REPORTED TO BE STABLE. A REVIEW OF THE DEVICE LOGS CONFIRMED THAT A MOMENTARY CPU RESET OCCURRED, WITH VENTILATION RECOVERY OCCURRING WITHIN 16 SECONDS. BY DESIGN, AUDIBLE AND VISUAL ALARMS ARE ANNUNCIATED DURING A MOMENTARY SYSTEM RESTART.

  Patient problems: Bradycardia

  MAUDE report 24611684 ↗
• MalfunctionFeb 13, 2026Inappropriate or Unexpected Reset

  IT WAS REPORTED THAT DURING PATIENT USE, THE VENTILATOR TRIGGERED A HIGH-PRIORITY ALARM, AFTER WHICH THE TOUCHSCREEN ON THE GRAPHIC USER INTERFACE WENT BLACK. THE PATIENT WAS REMOVED FROM THE VENTILATOR AND MANUALLY VENTILATED. UPON DISCONNECTION FROM THE PATIENT, THE VENTILATOR WAS OBSERVED TO BE CONTINUOUSLY VENTILATING. WHEN THE RESPIRATORY THERAPIST ARRIVED IN THE ROOM, THE VENTILATOR WAS REBOOTING AND DISPLAYING THE START-UP SCREEN. ONCE THE MAIN SCREEN APPEARED, IT DISPLAYED THE MESSAGE ¿UNIT RESTARTED, CHECK SETTINGS, CHECK APPS.¿ UNDER THE QUESTION ICON, THE MESSAGE STATED, ¿THE VENTILATOR HAS RESTARTED WITHOUT USER INTERVENTION.¿ THE PATIENT WAS PLACED ON ANOTHER VENTILATOR. THERE WAS NO PATIENT HARM, AS VITAL SIGNS REMAINED UNCHANGED. NO PATIENT DEMOGRAPHIC INFORMATION WAS PROVIDED BY THE HOSPITAL. A REVIEW OF THE DEVICE LOGS CONFIRMED A MOMENTARY CPU RESET, WITH VENTILATION RECOVERY OCCURRING WITHIN 17 SECONDS. BY DESIGN, AUDIBLE AND VISUAL ALARMS ARE ANNUNCIATED WHEN THE MOMENTARY SYSTEM RESTART OCCURS.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 24338902 ↗
• MalfunctionFeb 13, 2026Inappropriate or Unexpected Reset

  IT WAS REPORTED THAT DURING PATIENT USE, THE VENTILATOR¿S GRAPHICAL USER INTERFACE (GUI) BECAME NONRESPONSIVE TO TOUCH. THE VENTILATOR CONTINUED TO DELIVER VENTILATION TO THE PATIENT, AND NO AUDIBLE OR VISUAL ALARMS WERE REPORTED. AS A PRECAUTION, THE PATIENT WAS TRANSFERRED TO ANOTHER VENTILATOR. NO PATIENT HARM WAS REPORTED. THE HOSPITAL STATED THAT PATIENT DEMOGRAPHICS WOULD NOT BE PROVIDED PER FACILITY POLICY.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 24338892 ↗
• MalfunctionFeb 13, 2026Inappropriate or Unexpected Reset

  IT WAS REPORTED THAT DURING PATIENT USE, THE VENTILATOR HAD A MOMENTARY SYSTEM RESTART. WHILE THE VENTILATOR WAS NOT OPERATING, THE PATIENT WAS MANUALLY VENTILATED. THE PATIENT WAS PLACED ON ANOTHER VENTILATOR. NO PATIENT HARM WAS REPORTED. DEVICE LOG REVIEW CONFIRMED A MOMENTARY CPU RESET, WITH VENTILATION RECOVERY OCCURRING WITHIN 19 SECONDS. BY DESIGN, AUDIBLE AND VISUAL ALARMS ARE ANNUNCIATED WHEN THE MOMENTARY SYSTEM RESTART OCCURS.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 24338876 ↗
• MalfunctionFeb 13, 2026Inappropriate or Unexpected Reset

  IT WAS REPORTED THAT DURING PATIENT USE, THE VENTILATOR HAD A MOMENTARY SYSTEM RESTART. THERE WAS NO PATIENT HARM REPORTED. THE HOSPITAL COULD NOT PROVIDE ANY MORE INFORMATION. DEVICE LOG REVIEW CONFIRMED A MOMENTARY CPU RESET, WITH VENTILATION RECOVERY OCCURRING WITHIN 19 SECONDS. BY DESIGN, AUDIBLE AND VISUAL ALARMS ARE ANNUNCIATED WHEN THE MOMENTARY SYSTEM RESTART OCCURS.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 24338872 ↗
• MalfunctionFeb 13, 2026Inappropriate or Unexpected Reset

  IT WAS REPORTED THAT DURING PATIENT USE, THE VENTILATOR HAD A MOMENTARY SYSTEM RESTART. DURING THE EVENT, THE PATIENT'S OXYGEN SATURATION DECREASED AND REQUIRED SOME MANUAL VENTILATION TO RECOVER; NO SERIOUS HARM OCCURRED. THE PATIENT WAS PLACED ON ANOTHER VENTILATOR. IT IS UNKNOWN WHETHER ANY AUDIBLE OR VISUAL ALARMS OCCURRED AT THE TIME OF THE EVENT. NO SERIOUS PATIENT HARM WAS REPORTED. DEVICE LOG REVIEW CONFIRMED A MOMENTARY CPU RESET, WITH VENTILATION RECOVERY OCCURRING WITHIN 17 SECONDS. BY DESIGN, AUDIBLE AND VISUAL ALARMS ARE ANNUNCIATED WHEN THE MOMENTARY SYSTEM RESTART OCCURS.

  Patient problems: Low Oxygen Saturation

  MAUDE report 24338856 ↗
• MalfunctionFeb 13, 2026Inappropriate or Unexpected Reset

  IT WAS REPORTED THAT DURING PATIENT USE, THE VENTILATOR HAD A MOMENTARY SYSTEM RESTART. THERE WAS NO PATIENT HARM REPORTED. THE HOSPITAL COULD NOT PROVIDE ANY MORE INFORMATION. DEVICE LOG REVIEW CONFIRMED A MOMENTARY CPU RESET, WITH VENTILATION RECOVERY OCCURRING WITHIN 18 SECONDS. BY DESIGN, AUDIBLE AND VISUAL ALARMS ARE ANNUNCIATED WHEN THE MOMENTARY SYSTEM RESTART OCCURS.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 24338830 ↗
• MalfunctionFeb 13, 2026Inappropriate or Unexpected Reset

  IT WAS REPORTED THAT DURING PATIENT USE, THE VENTILATOR DISPLAYED THE FOLLOWING ALARMS: ¿BACKUP BATTERY FAULT¿ AND ¿NON-CRITICAL THREAD FAILURE (BDU).¿ PATIENT VENTILATION WAS NOT AFFECTED. THE PATIENT WAS REMOVED FROM THE VENTILATOR AND PLACED ON ANOTHER NKV-550 VENTILATOR. THERE WAS NO PATIENT HARM. PATIENT DEMOGRAPHICS WILL NOT BE SHARED IN ACCORDANCE WITH HOSPITAL POLICY.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 24338810 ↗
• MalfunctionFeb 13, 2026Appropriate Device Problem Term/Code Not Available

  IT WAS REPORTED THAT AFTER RETAPING THE PATIENT'S ENDOTRACHEAL TUBE, THE USER MANUALLY VENTILATED THE PATIENT AND TRANSITIONED THE PATIENT TO THE NKV-550 VENTILATOR. ALTHOUGH THE VENTILATOR DELIVERED VENTILATION, TIDAL VOLUMES DECREASED TO APPROXIMATELY 2 CC/KG, AND ALARMS WERE TRIGGERED FOR LOW TIDAL VOLUME (CC/KG) AND LOSS OF ETCO2. THE PATIENT LOST VITAL SIGNS, AND MANUAL VENTILATION WAS INITIATED. THE PATIENT THEN STABILIZED. THE PATIENT WAS TRANSITIONED TO ANOTHER VENTILATOR, AND VENTILATION WAS SUCCESSFULLY MAINTAINED. THE USER REPORTED THERE WAS NO HARM OR SERIOUS INJURY TO THE PATIENT. THE RESPIRATORY THERAPIST PERFORMED TROUBLESHOOTING AT THE BEDSIDE, INCLUDING A CALIBRATION ATTEMPT. THE CIRCUIT CHECK PASSED; HOWEVER, THE DEVICE CHECK FAILED DURING THE SAFETY VALVE TEST AND DISPLAYED THE MESSAGE, 'SYSTEM FAILURE ¿ MAKE SURE SAFETY VALVE IS INSTALLED CORRECTLY.' FOLLOWING THE REMOVAL OF THE VENTILATOR FROM THE PATIENT'S ROOM, A BIOMEDICAL ENGINEER CONDUCTED MULTIPLE OPERATIONAL CHECKS, ALL OF WHICH PASSED. AFTER THE DEVICE WAS RETURNED TO NIHON KOHDEN ORANGEMED, IT UNDERWENT COMPREHENSIVE FUNCTIONAL AND PERFORMANCE TESTING. THE DEVICE SUCCESSFULLY PASSED ALL APPLICABLE TEST

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 24333864 ↗
• MalfunctionFeb 4, 2026Defective Component

  DURING PATIENT USE, THE DOCTOR INCREASED THE VENTILATOR RESPIRATORY RATE FROM 12 TO 22 BREATHS PER MINUTE. FOLLOWING THIS ADJUSTMENT, THE VENTILATOR DISPLAYED AN INTERNAL O2 SENSOR FAULT ALERT AND AN AUDIBLE LOW-PRESSURE ALARM. THE PATIENT WAS TRANSFERRED TO ANOTHER VENTILATOR. NO PATIENT HARM WAS REPORTED. AFTER REMOVAL FROM PATIENT USE, THE USER OBSERVED CONTINUOUS GAS FLOW EXITING THE INSPIRATORY PORT WHILE THE VENTILATOR WAS IN THE STANDBY MODE. DURING TROUBLESHOOTING, THE O2 VALVE CALIBRATION FAILED. NO LEAKS WERE IDENTIFIED IN THE REGULATORS OR PSOLS. THE O2 SENSOR PASSED TESTING, AND THE MANUAL INSPIRATORY-SIDE LEAK TEST ALSO PASSED.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 24264554 ↗
• MalfunctionFeb 4, 2026Defective Component

  THIS VENTILATOR HAS BEEN EXPERIENCING AN ISSUE IN WHICH THE GRAPHICAL USER INTERFACE (GUI) INTERMITTENTLY BECOMES NON-RESPONSIVE TO TOUCH INPUT DURING PATIENT USE. THE DEVICE WAS EVALUATED AND FOUND TO BE FUNCTIONING PROPERLY; HOWEVER, UPON SUBSEQUENT USE WITH OTHER PATIENTS, THE GUI AGAIN BECAME NON-RESPONSIVE TO TOUCH. THIS ISSUE OCCURRED MULTIPLE TIMES ACROSS DIFFERENT PATIENTS. DURING EACH EVENT, THE VENTILATOR CONTINUED TO PROVIDE VENTILATION. AS A PRECAUTION, EACH PATIENT WAS TRANSFERRED TO ANOTHER VENTILATOR. NO PATIENT HARM WAS REPORTED. NO PATIENT DEMOGRAPHICS WILL BE SHARED.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 24264553 ↗
• MalfunctionJan 23, 2026Computer Software Problem

  IT WAS REPORTED THAT WHILE THE VENTILATOR WAS IN USE ON A PATIENT, THE GRAPHIC USER INTERFACE (GUI) SCREEN SPONTANEOUSLY WENT BLACK. THE VENTILATOR CONTINUED TO FUNCTION AND PROVIDE VENTILATION DURING THE EVENT. CLINICAL STAFF PERFORMED TROUBLESHOOTING BY ADJUSTING THE SCREEN BRIGHTNESS, AFTER WHICH THE DISPLAY RESUMED NORMAL OPERATION. THE GUI STAYED BLACK FOR ABOUT 30-40 MINUTES. NO ALARMS WERE REPORTED. AS A PRECAUTION, THE PATIENT WAS PLACED ON ANOTHER VENTILATOR. THERE WAS NO PATIENT HARM; THE PATIENT¿S VITAL SIGNS REMAINED STABLE, AND NO CHANGES IN THE PATIENT¿S CLINICAL CONDITION WERE OBSERVED. THE REPORTING FACILITY WAS UNABLE TO PROVIDE PATIENT DEMOGRAPHIC INFORMATION.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 24163717 ↗
• MalfunctionJan 16, 2026Incorrect Measurement

  THE FOLLOWING WAS REPORTED THROUGH ANVISA."THE EQUIPMENT SHOWED AN INACCURATE VOLUME READING, EVEN AFTER ADJUSTMENTS RELATED TO THE PATIENT¿S CLINICAL CONDITION AND THE EQUIPMENT ITSELF. AFTER REPLACING THE EQUIPMENT, VENTILATION IMPROVED. IT HAS A CALIBRATION LABEL VALID THROUGH (B)(6) 2025. THE EQUIPMENT WAS ACQUIRED AND PUT INTO USE IN (B)(6) 2025." NKOM FOLLOWED UP WITH THE INITIAL REPORTER AND RECEIVED THE FOLLOWING CLARIFICATION OF THE EVENT. "IT WAS REPORTED THROUGH THE FACILITY¿S TECHNOVIGILANCE SERVICE THAT AN NKV-550 VENTILATOR DISPLAYED INACCURATE TIDAL VOLUME READINGS DURING USE ON AN EXTREMELY CRITICAL PATIENT WITH ACUTE RESPIRATORY DISTRESS SYNDROME (ARDS). THE PATIENT REQUIRED HIGH VENTILATORY PARAMETERS AND CONTINUOUS MONITORING OF INSPIRATORY PRESSURES AND TIDAL VOLUME DUE TO SEVERE RESPIRATORY ACIDOSIS AND ELEVATED PACO2. DESPITE VERIFICATION THAT THE BREATHING CIRCUIT WAS CORRECTLY ASSEMBLED AND FREE OF LEAKS, THE VENTILATOR CONTINUED TO SHOW INACCURATE VOLUME MEASUREMENTS. THE CLINICAL STAFF REPLACED THE VENTILATOR WHILE MAINTAINING THE SAME CIRCUIT AND VENTILATOR SETTINGS, AFTER WHICH A DIFFERENCE OF GREATER THAN 60 ML IN TIDAL VOLUME WAS OBSERVED AND THE PATIE

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 24096243 ↗
• MalfunctionJan 14, 2026Application Program Freezes or Fails to Launch

  IT WAS REPORTED THAT WHILE THE VENTILATOR WAS IN USE, THE DISPLAY SCREEN BECAME FROZEN WITH A CONTINUOUS AUDIBLE ALARM SOUNDING. AT THE TIME OF THE EVENT, THE VENTILATOR WAS NOT VENTILATING BECAUSE THE PATIENT WAS IN SPONTANEOUS BREATHING MODE. DUE TO THE FROZEN TOUCHSCREEN, CLINICAL STAFF WERE UNABLE TO CHANGE PARAMETERS ON THE DEVICE. THE PATIENT WAS TRANSFERRED TO ANOTHER VENTILATOR. NO PATIENT HARM WAS REPORTED. THE LOGS CONFIRMED THAT A CRITICAL THREAD FAILURE OCCURRED.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 24075027 ↗
• MalfunctionJan 6, 2026Defective Component

  IT WAS REPORTED THAT THE MIDDLE PORTION OF THE VENTILATOR TOUCHSCREEN BECAME INTERMITTENTLY UNRESPONSIVE TO TOUCH. THE ISSUE OCCURRED ON TWO OCCASIONS WITH THE SAME DEVICE. DURING THE FIRST OCCURRENCE, THE PATIENT HAD BEEN EXTUBATED, AND THE RESPIRATORY THERAPIST ATTEMPTED TO PLACE THE VENTILATOR IN STANDBY BUT WAS UNABLE TO DO SO BECAUSE THE TOUCHSCREEN WAS UNRESPONSIVE. AFTER A SHORT PERIOD, THE THERAPIST WAS ABLE TO TURN OFF THE DEVICE. FOLLOWING THIS EVENT, A TOUCHSCREEN CALIBRATION WAS PERFORMED, WHICH PASSED, AND THE VENTILATOR WAS RETURNED TO SERVICE. DURING THE SECOND OCCURRENCE, THE DEVICE WAS PLACED ON ANOTHER PATIENT, AND STAFF ATTEMPTED TO EXIT THE SCREEN LOCK MODE BUT WERE UNABLE TO BECAUSE THE TOUCHSCREEN DID NOT REGISTER TOUCH INPUT. THE VENTILATOR CONTINUED TO VENTILATE THE PATIENT. NO PATIENT HARM WAS REPORTED. FOLLOWING THESE EVENTS, TOUCHSCREEN CALIBRATION WAS PERFORMED TWICE. AFTERWARD, THE DEVICE FUNCTIONED NORMALLY, BUT INTERMITTENT TOUCHSCREEN SENSITIVITY ISSUES PERSISTED. THE REPORTING HOSPITAL WILL NOT PROVIDE PATIENT DEMOGRAPHICS.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 23980633 ↗
• MalfunctionJan 6, 2026Inappropriate or Unexpected Reset

  IT WAS REPORTED BY HOSPITAL STAFF THAT THE VENTILATOR UNEXPECTEDLY RESTARTED DURING PATIENT USE. FOLLOWING THE RESTART, THE DEVICE RESUMED OPERATION WITH THE SAME SETTINGS AS BEFORE AND CONTINUED VENTILATING THE PATIENT NORMALLY. AS A PRECAUTION, THE HOSPITAL PLACED THE PATIENT ON ANOTHER VENTILATOR THE FOLLOWING DAY. NO PATIENT HARM WAS REPORTED. THE REPORTING HOSPITAL DECLINED TO PROVIDE PATIENT INFORMATION. THE LOGS CONFIRMED THAT IT WAS A MOMENTARY CPU RESET, WITH VENTILATION RECOVERY OCCURRING WITHIN 16 SECONDS.

  Patient problems: Insufficient Information

  MAUDE report 23980625 ↗

Recalls under the same FDA submission

These recalls involve devices cleared under K181695, K192307. One submission often covers many models, so check the product and lot details in each record.

• Z-2435-2021 · Jul 20, 2021 · Terminated
  Nihon Kohden NKV-550 Ventilator, REF: NKV-550-U, CE 0344, UDI: (01) 00843685100012 The Nihon Kohden NKV-550 Series Ventilator System is intended to provide continuous ventilation