ZM-531PA

Description of Event or Problem

THE CUSTOMER REPORTED THAT LEAD 1 WAVEFORM IS INVERTED ON THIS TRANSMITTER. THE UNIT WAS NOT IN PATIENT USE AT THE TIME.

Additional Manufacturer Narrative

THE CUSTOMER REPORTED THAT LEAD 1 WAVEFORM IS INVERTED ON THIS TRANSMITTER. ACCORDING TO THE CUSTOMER, THE UNIT WAS CONNECTED TO A SIMULATOR AND THE DEVICE PRODUCED AN INVERTED WAVEFORM. THE UNIT WAS NOT IN PATIENT USE AT THE TIME. 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. THE FOLLOWING FIELD CONTAINS NO INFORMATION (NI), AS ATTEMPTS TO OBTAIN THE INFORMATION WERE MADE, BUT NOT PROVIDED: D10 ATTEMPT # 1: 05/07/2026 EMAILED THE CUSTOMER VIA MICROSOFT OUTLOOK FOR THE INFORMATION IN THE NI LIST ABOVE: NO REPLY WAS RECEIVED. ATTEMPT # 2: 05/12/2026 I CALLED (B)(6) TO ASK FOR MODEL AND SERIAL NUMBERS OF ANY DEVICES THE REPORTED DEVICE WAS CONNECTED OR RELATED TO. A MESSAGE WAS LEFT FOR (B)(6) TO CALL ME BACK WITH THIS INFORMATION. ATTEMPT # 3: 05/15/2026 I CALLED (B)(6) TO ASK FOR MODEL AND SERIAL NUMBERS OF ANY DEVICES THE REPORTED DEVICE WAS CONNECTED OR RELATED TO. A MESSAGE WAS LEFT FOR (B)(6) TO CALL ME BACK WITH THIS INFORMATION.