MAUDE Adverse Event Report: NIHON KOHDEN CORPORATION NEUROMASTER; NEURAL FUNCTION MEASURING SYSTEM

Model Number	MEE-2000A-LT
Medical Device Problem Code	Output Problem (3005)
Health Effect - Clinical Code	No Clinical Signs, Symptoms or Conditions (4582)
Date of Event	03/13/2025
Type of Reportable Event	Malfunction
Additional Manufacturer Narrative
The customer reported that the neuro work bench with a mee 2000a stimulator froze during a procedure.The customer reported that the wireless internet dropped, which caused a vpn loss and this made the device(s) freeze.The customer rebooted the device(s) and after the reboot, the neuro work bench (nwb) including mee 2000a stimulator system was able to open and they were able to finish the exam without further issues.No patient harm was reported.Note: the mee system measures and displays electric, auditory, and visual evoked potentials (ep), electroencephalograms (eeg), and electromyographs (emg).Nihon kohden continues to investigate the reported event.Nihon kohden will submit a supplemental report in accordance with 21 cfr section 803.56 when additional information becomes available.Additional device information: d10 concomitant medical device: the following device(s) were used in conjunction with the mee-2000a-lt: pc: model#: a/dell-5520 - lt, serial#: (b)(6), device manufacturer data: 08/10/2023, unique device identifier (udi): na, returned to manufacturer: na.
Event or Problem Description
The customer reported that the neuro work bench with a mee 2000a stimulator froze during a procedure.The customer reported that the wireless internet dropped, which caused a vpn loss and this made the device(s) freeze.The customer rebooted the device(s) and after the reboot, the neuro work bench (nwb) including mee 2000a stimulator system was able to open and they were able to finish the exam without further issues.No patient harm was reported.Note: the mee system measures and displays electric, auditory, and visual evoked potentials (ep), electroencephalograms (eeg), and electromyographs (emg).
Event or Problem Description
The eeg technician reported that neuro work bench (nwb), as well as the mee 2000a stimulator froze during a procedure.The wireless connection dropped, which caused the vpn to disconnect.No patient harm was reported.
Additional Manufacturer Narrative
Details of complaint: the eeg technician reported that neuro work bench (nwb), as well as the mee 2000a stimulator froze during a procedure.The wireless connection dropped, which caused the vpn to disconnect.After rebooting the eeg system, they were able to open and finish the exam without issue.No patient harm was reported.Note: the mee system measures and displays electric, auditory, and visual evoked potentials (ep), electroencephalograms (eeg), and electromyographs (emg).Investigation summary: the system logs were sent in for review.However, nk was unable to confirm the reported incident.A definitive root cause was not determined, due to limited information.The issue possibly stemmed from the facility's network issues, due to possible wireless and/or vpn connectivity issues at the offsite location.After the system was rebooted, the issue was resolved.The customer was notified that we did not find anything remarkable, during the review of the logs, that would help us determine a cause.Since contact was last made with the customer, no further issues related to this incident have been reported to date.Trending for similar issues and devices will continue to be monitored by nk.Additional device information: d10 concomitant medical device: the following device was connected to and supports the software needed to run the mee-2000a-lt: pc: model #: a/dell-5520 - lt.Serial #: (b)(6).Device manufacturer data: 08/10/2023.Returned to manufacturer: na.Additional information: b4 date of this report g3 date received by manufacturer g6 type of report h2 if follow-up, what type? h6 event problem and evaluation codes h11 additional manufacturer narrative.

• Brand Name: NEUROMASTER
• Common Device Name: NEURAL FUNCTION MEASURING SYSTEM
• Manufacturer (Section D): NIHON KOHDEN CORPORATION; attn: shama mooman; 1-31-4 nishiochia; shinjuku-ku, tokyo 161-8 560; JA 161-8560
• Manufacturer (Section G): NIHON KOHDEN TOMIOKA CORPORATION; attn: shama mooman; 1-1 tajino; tomioka city, gunma 370-2 314; JA 370-2314
• Manufacturer Contact: shama mooman ; seibu bldg 2, 4th floor 1-11-2; kusunokidai tokorozawa, saitama 359-8-580 ; JA 359-8580
• MDR Report Key: 21810867
• Report Number: 8030229-2025-04856
• Device Sequence Number: 15345687
• Product Code: GWF
• UDI-Device Identifier: 00841983103629
• UDI-Public: (01)00841983103629
• Combination Product (Y/N): N
• Initial Reporter State: TN
• Initial Reporter Country: US
• PMA/510(K) Number: K142624
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Serviced by Third Party (Y/N): N
• Reporter Type: Manufacturer
• Report Source: Health Professional,User Facility
• Initial Reporter Occupation: Other Health Care Professional
• Type of Report: Initial,Followup
• Report Date (Section B): 07/10/2025

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Is this an Adverse Event Report?: No
• Is this a Product Problem Report?: Yes
• Operator of Device: Health Professional
• Device Model Number: MEE-2000A-LT
• Device Catalogue Number: MEE-2000A-LT
• Was Device Available for Evaluation?: No
• Is the Reporter a Health Professional?: Yes
• Type of Report(Section G): Thirty-Day
• Initial Date Received by Manufacturer: 03/19/2025
• Supplement Date Received by Manufacturer: 06/30/2025
• Initial Report FDA Received Date: 04/09/2025
• Supplement Report FDA Received Date: 07/10/2025
• Was Device Evaluated by Manufacturer? (Y/N): No
• Date Device Manufactured: 08/10/2023
• Is the Device Labeled for Single Use? (Y/N): No
• Is This a Single-Use Device that was Reprocessed and Reused on a Patient? (Y/N): No
• Usage of Device: Reuse
• Patient Sequence Number: 1
• Concomitant Medical Products and Therapy/Usage Dates: A/DELL-5520-LT COMPUTER; A/DELL-5520-LT COMPUTER
• Patient Sex: Unknown