MAUDE Adverse Event Report: NIHON KOHDEN CORPORATION ZM-520PA; TRANSMITTER

Model Number ZM-520PA

Device Problems Thermal Decomposition of Device (1071); Overheating of Device (1437); Temperature Problem (3022)

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

Event Date 01/30/2018

Event Type  malfunction  

Manufacturer Narrative

The nurse reported that the batteries in the transmitter were overheating but the biomedical engineer reported there was no overheating and that he kept getting sporadic readings, a "check leads" error message, and a flat line while on the simulator.There was no patient injury reported.The device was evaluated by nihon kohden, who noted that the batteries were not returned and the battery door was missing.New batteries were inserted, but overheating 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.(b)(4).

Event Description

The nurse reported that the batteries in the transmitter were overheating but the biomedical engineer reported there was no overheating and that he kept getting sporadic readings, a "check leads" error message, and a flat line while on the simulator.

Manufacturer Narrative

Investigation result: the batteries required for the investigation were not returned.In addition, the battery door was missing.When new batteries were inserted into the unit, heating could not be duplicated.Inspection of the negative contacts show resin melting at the spring which per nkc investigation on a similar incident is indicative of improper battery insertion (nkc investigation report 2016 mdr 144/complaint (b)(4)).Additionally, a review of device history found physical damage to the transmitter reported on (b)(6) 2017 in notification (b)(4) in which customer had requested part information to replace the rear battery cover.This may have contributed to damage of the battery compartment.The findings of damage to transmitter, improper insertion of the batteries, and resin melting at the spring all point toward improper handling of the device and battery.This is likely to contribute to overheating of the battery and potential burn injury to the patient.Design controls in place for the potential hazards of improper battery insertion include: spring was designed to not damage battery coating upon forcible battery insertion, structure designed to protect battery pole from contact with battery spring when inserted in reversed direction, and device designed to not cause over current in case of short-circuit damage from fall, etc.Additionally, 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-520pa 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.Additionally, to highlight the importance of correct battery insertion, technical bulletins (b)(4) issued (b)(4) 2017 and (b)(4) issued (b)(4) 2017, and (b)(4) issued (b)(4) 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 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.As the overheating could not be duplicated by the biomed or at nka, this issue is likely to have occurred due to improper insertion of the battery.The root cause is determined to be damage to the device due to user error in improper insertion of the battery.The device was in use with a patient, but there was no reported harm.

Event Description

The nurse reported that the batteries in the transmitter were overheating but the biomedical engineer reported there was no overheating and that he kept getting sporadic readings, a "check leads" error message, and a flat line while on the simulator.

Manufacturer Narrative

Details of the complaint on (b)(6) 2018, (b)(6) at (b)(6) reported that the nurses reported batteries were overheating on the transmitter zm-520pa sn: (b)(6).The biomed was unable to reproduce the overheating but was getting sporadic readings or check leads.While on a simulator, the unit kept alternating between "check leads" and a flat line.Once waveform comes up, it comes in sporadically.There were indents in the plastic indicating that the batteries had been inserted incorrectly.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.Review of device c4c history found no previously reported issues with the device after release to the customer.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 may cause 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 02/09/2017, mtbex 052 issued 04/25/2017, 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 (b)(6).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.(b)(4).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 (b)(6) or later zm-521pa - serial (b)(6) 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, #6142902694 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.

• Brand Name: ZM-520PA
• 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: 7304956
• MDR Text Key: 101267083
• Report Number: 8030229-2018-00055
• Device Sequence Number: 1
• Product Code: DRT
• UDI-Device Identifier: 04931921115077
• UDI-Public: 04931921115077
• Combination Product (y/n): N
• PMA/PMN Number: K043517
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: user facility
• Type of Report: Initial,Followup,Followup
• Report Date: 01/27/2020

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
• Device Operator: Health Professional
• Device Model Number: ZM-520PA
• Device Catalogue Number: ZM-520PA
• Device Lot Number: N/A
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 02/22/2018
• Was the Report Sent to FDA?: Yes
• Date Report Sent to FDA: 01/27/2020
• Distributor Facility Aware Date: 01/24/2020
• Device Age: 41 MO
• Event Location: Hospital
• Date Report to Manufacturer: 01/27/2020
• Initial Date Manufacturer Received: 02/28/2018
• Initial Date FDA Received: 02/28/2018
• Supplement Dates Manufacturer Received: 02/28/2018; 01/24/2020
• Supplement Dates FDA Received: 04/12/2019; 01/27/2020
• Is This a Reprocessed and Reused Single-Use Device?: No
• Removal/Correction Number: NOT APPLICABLE
• Patient Sequence Number: 1