MAUDE Adverse Event Report: NIHON KOHDEN CORPORATION ZM-531PA; TELEMETRY TRANSMITTER

Model Number	ZM-531PA
Medical Device Problem Codes	Incorrect, Inadequate or Imprecise Result or Readings (1535); Output Problem (3005)
Health Effect - Clinical Code	No Clinical Signs, Symptoms or Conditions (4582)
Date of Event	03/19/2026
Type of Reportable Event	Malfunction
Event or Problem Description
The biomedical engineer (bme) reported that the zm transmitter gave incorrect heart rate (hr) waveforms.When he tested the zm device on a simulator that was set to 60 bpm, the device showed 30 to 80 bpm.No patient harm was reported.
Additional Manufacturer Narrative
The biomedical engineer (bme) reported that the zm transmitter gave incorrect heart rate (hr) waveforms.He tried new leads, but the issue persisted.When he tested the zm device on a simulator that was set to 60 bpm, the device showed 30 to 80 bpm.He confirmed the simulator worked properly when testing a different zm device.No patient harm was reported.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 Manufacturer Narrative
Details of complaint: the biomedical engineer (bme) reported that the zm transmitter gave incorrect heart rate (hr) waveforms.He tried new leads, but the issue persisted.When he tested the zm device on a simulator that was set to 60 bpm, the device showed 30 to 80 bpm.He confirmed the simulator worked properly when testing a different zm device.No patient harm was reported.Investigation summary: the complaint device was returned to nihon kohden for evaluation.During the evaluation, signs of previous moisture exposure and residue in the ecg socket were found.During testing, the reported issue could not be reproduced.As such, a definitive root cause cannot be established.Previous fluid exposure or residue in the ecg socket may have caused or contributed to the observed issue at the time of reporting.Parts were replaced as part of preventative maintenance.A review of the device's complaint history by serial number reveals no similar issues.Nk will continue to trend and monitor the reported issue.Additional information: b4 date of this report g3 date received by manufacturer g6 type of report h2 if follow-up, what type? h3 device evaluated by manufacturer? h6 event problem and evaluation codes h11 additional manufacturer narrative.
Event or Problem Description
The biomedical engineer (bme) reported that the zm transmitter gave incorrect heart rate (hr) waveforms.When he tested the zm device on a simulator that was set to 60 bpm, the device showed 30 to 80 bpm.No patient harm was reported.

• Brand Name: ZM-531PA
• Common Device Name: TELEMETRY TRANSMITTER
• 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: 24832014
• Report Number: 8030229-2026-06468
• Device Sequence Number: 9168565
• Product Code: DRT
• UDI-Device Identifier: 04931921115107
• UDI-Public: (01)04931921115107
• Combination Product (Y/N): N
• Initial Reporter State: OH
• Initial Reporter Country: US
• PMA/510(K) Number: K043517
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Serviced by Third Party (Y/N): N
• Reporter Type: Manufacturer
• Report Source: User Facility
• Initial Reporter Occupation: Biomedical Engineer
• Type of Report: Initial,Followup
• Report Date (Section B): 05/11/2026

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: ZM-531PA
• Device Catalogue Number: ZM-531PA
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 04/06/2026
• Is the Reporter a Health Professional?: Yes
• Type of Report(Section G): Thirty-Day
• Initial Date Received by Manufacturer: 03/19/2026
• Supplement Date Received by Manufacturer: 05/07/2026
• Initial Report FDA Received Date: 04/09/2026
• Supplement Report FDA Received Date: 05/11/2026
• Was Device Evaluated by Manufacturer? (Y/N): Yes
• Date Device Manufactured: 01/15/2025
• 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
• Patient Sex: Unknown