MAUDE Adverse Event Report: NIHON KOHDEN CORPORATION ZM-521PA; TRANSMITTER

Model Number ZM-521PA

Device Problems Overheating of Device (1437); Temperature Problem (3022)

Patient Problem No Known Impact Or Consequence To Patient (2692)

Event Date 12/31/2018

Event Type  malfunction  

Manufacturer Narrative

The customer sent the unit in and it is currently awaiting evaluation.They were provided with an exchange to resolve the issue.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 if additional information becomes available.

Event Description

The biomedical engineer reported that the transmitter overheated.The heat melted 2 plastic notches in the battery well.

Manufacturer Narrative

Additional manufacturer narrative: the failed transmitter was sent in for evaluation.The batteries required for this investigation were not returned.In addition the battery door was missing upon return of the device.New batteries were inserted into the unit and heating could not be duplicated.Inspection of the negative contacts shows resin melting at the spring, which per an nkc investigation on a similar incident, is indicative of improper battery insertion (nkc investigation report 2016 mdr 44/complaint (b)(4).

Manufacturer Narrative

Details of the complaint: on 12/31/2018, (b)(6) hospital reported the transmitter (zm-521pa sn: (b)(6)) was overheating.There was damage on the lower right side of the negative terminal, and the heat melted the 2 plastic notches in the battery well.Service requested/performed: exchange.Investigation result: per nkc dhr, the unit has had no history of ncmr, deviation, or capa during manufacturing of the device.The device has not been refurbished and there were no discrepancies or unusual findings before device release that might relate to the reported issue.The device was delivered to (b)(6) hospital on 08/17/2016.A review of device history found no previously reported issues with the device.Qe evaluation of the device at nka was unable to duplicate the overheating upon proper insertion of the battery.The batteries required for the investigation were not returned.Inspection of the negative contacts show dents in the plastic above the spring which per nkc investigation performed under irc-nka300097945 on a similar incident is indicative of incorrect battery insertion.The incorrect insertion of the battery causes the battery terminal spring to break the coating of the battery, leading to a short circuit.Measures to educate the customer on proper use of the batteries, including the recommended batteries, correct direction and insertion of battery, and on checking battery condition before use are addressed in the zm-520/530 series operator's manual.Customer is also advised to not allow the transmitter to continuously contact the patient's skin directly, as the transmitter heats up by 2 or 3 degrees c during normal operation, which may cause low temperature burn to the patient.Possible gradual deterioration of the transmitter battery compartment should be detected upon performance of the recommended maintenance check every six months, in which the customer is advised to ensure that the battery cover, springs, and terminals in the battery compartment are not damaged or corroded.To highlight the importance of correct battery insertion, technical bulletins mtbex 047 issued 02/09/17, mtbex 052 issued 04/25/17, and mtbex 067 issued 03/2018 were created which reiterate the recommendation of the operator's manual.Mtbex 047 provides step by step instructions on how to properly insert the battery and mtbex 052 and mtbex 067 provides examples of correct and incorrect battery placement.Importance of proper battery insertion is also addressed through the zm telemeters skills lab offered at nk university.Design considerations for the potential hazards of improper battery insertion/short circuit include (1) spring was designed to not damage battery coating upon forcible battery insertion (2) structure designed to protect battery pole from contact with battery spring when inserted in reversed direction (3) device designed to not cause overcurrent in case of short-circuit damage from fall, etc.The root cause is determined to be transmitter design did not foresee possibility of short circuit from incorrect insertion of the battery.Nkc conducted a test study to monitor temperature of the transmitter upon incorrect insertion of the battery.The results confirmed that the temperature at the exterior is at an acceptable level and has cleared safety standard iec 60601-1.Per hha (b)(4), there have been a total of 132 "overheated" related calls life-to-date until 03/07/2019.The total number of devices in distribution is 7,997 for the zm-520 series and 17,515 for the zm-530 series.The complaint rate is 0.52%.There have been no injuries or adverse patient events reported in association with the use of this device due to incorrect insertion of a battery.Assessment determined that in a worst case scenario, the probability of harm is "unlikely or remote" as the maximum exterior temperature (42.6 c) is below the minimum temperature (44 c) that can cause a burn after prolonged (greater than 5 hours) skin exposure.A new design change has been introduced to the transmitter rear case which would add an insulating sheet to prevent short circuit of the battery caused by incorrect battery insertion.The design change has been applied to the following serial numbers: zm-520pa - serial 3412 or later zm-521pa - serial 5336 or later zm-530pa - serial (b)(6) or later zm-531pa - serial (b)(6) or later additionally, for transmitters with serial numbers prior to the implementation range, the updated part (#6142902693 for zm-520 series, # (b)(6) for zm-530 series) is available for rear case repair.Investigation conclusion: the root cause is determined to be transmitter design did not foresee possibility of short circuit from incorrect insertion of the battery.Assessment determined that in a worst case scenario, the probability of harm is "unlikely or remote" as the maximum exterior temperature (42.6 c) is below the minimum temperature (44 c) that can cause a burn after prolonged (greater than 5 hours) skin exposure.A new design change has been introduced to the transmitter rear case which would add an insulating sheet to prevent short circuit of the battery caused by incorrect battery insertion.

Event Description

The biomedical engineer reported that the transmitter overheated.The heat melted 2 plastic notches in the battery well.

• Brand Name: ZM-521PA
• Type of Device: TRANSMITTER
• Manufacturer (Section D): NIHON KOHDEN CORPORATION; 1-31-4 nishiochia, shinjuku-ku; attn: shama mooman; tokyo, 161-8 560; JA 161-8560
• MDR Report Key: 8278933
• MDR Text Key: 134183727
• Report Number: 8030229-2019-00033
• Device Sequence Number: 1
• Product Code: DRT
• UDI-Device Identifier: 04931921115084
• UDI-Public: 4931921115084
• Combination Product (y/n): N
• PMA/PMN Number: K043517
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: health professional,user faci
• Type of Report: Initial,Followup,Followup
• Report Date: 01/23/2020

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 01/25/2019
• Is this an Adverse Event Report?: No
• Is this a Product Problem Report?: Yes
• Device Operator: Health Professional
• Device Model Number: ZM-521PA
• Device Catalogue Number: ZM-521PA
• Device Lot Number: NOT APPLICABLE
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 01/04/2019
• Was the Report Sent to FDA?: Yes
• Date Report Sent to FDA: 01/23/2020
• Distributor Facility Aware Date: 01/22/2020
• Device Age: 38 MO
• Event Location: Hospital
• Date Report to Manufacturer: 01/23/2020
• Date Manufacturer Received: 01/22/2020
• Is This a Reprocessed and Reused Single-Use Device?: No
• Removal/Correction Number: NOT APPLICABLE
• Patient Sequence Number: 1