Description of Event or Problem · 1
NO EXCEL TECH EMPLOYEE WAS PRESENT AT THE TIME OF THE EVENT. PT WAS BEING MONITORED WITH EMG DEVICE DURING SURGERY ON LUMBAR SPINE. MONITORING PHYSICIAN REPORTED TO EXCEL TECH OVER THE PHONE A BURN WHERE A NEEDLE GROUND FROM THE EMG DEVICE WAS INSERTED IN THE PT'S RIGHT GASTROCNEMIUS. HE RELATED THE NATURE OF THE BURN AS "DIAMETER OF A PENCIL WITH THE NEEDLE PUNCTURE AT THE CENTER." PHYSICIAN SAID HE WOULD TAKE PICTURES OF THE BURN BUT EXCEL TECH HAS NOT YET SEEN THE PHOTOGRAPHS. EXCEL TECH FACTORY REPS WENT TO THE HOSPITAL SEPTEMBER 29TH, THE DAY AFTER THE INCIDENT OCCURRED. THE EMG MACHINE IN QUESTION WAS TAKEN TO THE BIOMEDICAL ENGINEERING LABORATORY IN THE HOSPITAL. A SIMULATION WAS DONE INSERTING THE RECORDING NEEDLES FROM A NUMBER OF CHANNELS INTO A SIDE OF BEEF. THE MFR'S REP FROM ELECTROSURGICAL DEVICE USED THE PREVIOUS DAY WERE USED SIMULTANEOUSLY. APPROX 20 MINUTES OF COMBINED HIGH VOLTAGE CUTTING AND CAUTERY WAVEFORMS WITH CONCURRENT WAVEFORM ACQUISITION WERE COMPLETED. BOTH THE EMG AND CAUTERY EQUIPMENT SEEMED TO OPERATE FINE AND NO ADVERSE OR UNEXPECTED EFFECTS WERE NOTED. IN PARTICULAR NO TISSUE BURNING WAS NOTED AT ANY OF THE EMG ELECTRODE SITES. NO MEASUREMENT EQUIPMENT WAS AVAILABLE AT THE TIME OF THE SIMULATION TO DETECT WHETHER OR NOT ANY SMALL STRAY CURRENTS WERE PRESENT IN THE EMG DEVICES OR ATTACHED CABLES AND LEADWIRES. IT WAS DECIDED THAT FURTHER INVESTIGATION IN A MORE DETAILED MANNER WAS WARRANTED. EXCEL TECH PERSONNEL BROUGHT THE UNIT BACK TO THE FACTORY BY AIRCRAFT THAT EVENING. AT THE FACTORY IT WAS NOTED THAT THE CABLES IN PARTICULAR HAD BEEN SUBJECTED TO SIGNIFICANT WEAR AND TEAR. IN PARTICULAR THE CABLES HAD BEEN TAPED TO THE FLOOR AND MAY HAVE BEEN SUBJECT TO PERSONNEL WALKING ON THEM, EQUIPMENT BEING ROLLED OVER THEM OR PULLING UP THE TAPE USING THE CABLE AS THE LIFTING MECHANISM. THE CABLE ASSEMBLY IS CONSTRUCTED FROM 8 SMALLER DIAMETER COAXIAL CABLES COMPRISED OF COPPER INNER CONDUCTOR AND SHIELD SEPARATED WITH LOW NOISE POLYESTER INSULATION. IT APPEARS EXCESSIVE COMPRESSION OR STRESS CAN CRACK THE POLYESTER INSULATION LAYER. AS A RESULT AN INTERMITTENT SHORT CIRCUIT CAN DEVELOP BETWEEN THE SIGNAL AND THE ACTIVE SHIELD DRIVE ELECTRONICS CAUSED BY THE BREAKDOWN OF THE INSULATION BARRIER. THIS WAS NOTED IN THE CABLE FROM THE HOSPITAL AND SUBSEQUENTLY HAS BEEN SIMULATED ON OTHER CABLES AT THE FACTORY. EXCEL TECH HAS WRITTEN SOFTWARE, WHICH IS AVAILABLE ON THE INTERNET IMMEDIATELY, THAT WILL CHECK THE INTEGRITY OF THE CABLE AS PART OF THE POWER ON SEQUENCE FOR THE EMG. FURTHER, THE CABLE INTEGRITY TEST MAY BE REQUESTED BY THE PHYSICIAN AT ANY TIME DURING OPERATION OF THE EMG. EXCEL TECH HAS IMMEDIATELY STARTED TO INFORM ALL USERS OF THIS CABLE (PART# W655H REV. A) OF THE POTENTIAL FOR CABLE FAILURE AND WILL REPLACE ALL CABLES WITH A SIGNIFICANTLY MORE ROBUST CABLE BEGINNING IMMEDIATELY. A COPY OF THE LETTER BEING SENT TO CO'S CUSTOMERS IS ATTACHED.