| Seq | Brand | Generic | Manufacturer | Product code | Model | Catalog | Lot | PMA | 510(k) | Implant | Evaluated | Availability |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | TRANSONIC SYSTEMS TRANSIT TIME FLOWMETER | ULTRASOUND BLOOD FLOWMETER | TRANSONIC SYSTEMS, INC. | DPW | HT107P910040 | HT107 | NA | K872048 | N | Y | Y |
| Sequence | Received | Treatment | Outcome |
|---|---|---|---|
| 1 | 1996-08-30 | 0 | 1. O |
Patient 1
DURING GRAFT SURGERY AT MEDICAL CTR, A BLOOD FLOW READING WAS TAKEN USING CO'S EQUIPMENT. THE FLOWMETER WAS LEFT CONNECTED IN THE OPERATING FIELD DURING THE FOLLOWING CAUTERIZATION PROCEDURE. THERE WAS FEEDBACK OF AN UNDETERMINED NATURE THAT CAUSED A SMALL FIRE IN THE METER POWER SUPPLY. THE FIRE DEPT WAS CALLED. THE PT WAS UNHARMED.
Patient 1
9/30/96: CO HAS COMPLETED THE FAILURE ANALYSIS OF THE HT107P-91-0040 FLOWMETER WHICH WAS INVOLVED IN AN OPERATING ROOM FIRE ON 8/23/96. THE FLOWMETER WAS LEFT PLUGGED IN WHILE CAUTERY EQUIPMENT WAS IN USE, AND A SMALL FIRE OCCURRED IN THE POWER SUPPLY SECTION OF THE MOTHERBOARD. THE FAILURE WAS CAUSED BY A SHORT IN A CERAMIC CAPACITOR PLACED ACROSS A SECONDARY POWER BRIDGE RECTIFIER. THE SHORT CIRCUIT CURRENTS RESULTING FROM THIS SHORT OVERHEATED THE COPPER PC BOARD TRACING IN THE VICINITY OF THIS COMPONENT CREATING A NON-SUSTAINING FIRE. ALL INTERNAL FLOWMETER MATERIALS ARE FLAME RETARDANT. THE SPECIFIC COMPONENT AT C112B IS A CERAMIC .47 MFD. CAP, FACTORY RATED FOR 50V DC. IT CARRIES A 25V PEAK (18.6V RMS) UNDER NORMAL OPERATION OF NOMINAL LINE VOLTAGE, AND IS DESIGNED TO TAKE THE STRESS OF NORMAL OPERATION WITH A 2X SAFETY MARGIN. TWO POSSIBLE REASONS FOR THIS FAILURE CAN BE HYPOTHESIZED: 1. EMI/RFI FAILURE, FROM AN FRI SPIKE COMING INACROSS THE METER/S LINE POWER CORD: THIS METER MODEL USES ALL THE SAME POWER LINE COMPONENTS AS CO'S CURRENT HT107A MODELS WHICH PASSED EMISSIONS AND SUSCEPTIBILITY TESTING TO THE EUROPEAN EMC DIRECTIVE IN DECEMBER OF 1995. THEREFORE, A PRIMARY POWER SURGE RESPONSIBLE FOR THIS BREAKDOWN WOULD HAVE TO HAVE BEEN IN EXCESS OF THE TEST LIMITS IN THE HARMONIZED STANDARD EN50082-1. 2. RANDOM COMPONENT FAILURE DUE TO AGING: THIS IS THE FIRST SUCH FAILURE CO'S SEEN SINCE THIS COMPONENT WAS FIRST USED IN 1990. CO INSTALL 4 CAPACITORS ACROSS THE FOUR ARMS OF THE BRIDGE RECTIFIER IN EACH CHANNEL OF THE METER. CO ESTIMATES THAT CO HAS INSTALLED APPROX 10,000 SUCH CAPACITOS IN THE PAST 7 YEARS. THIS TYPE OF RANDOM BREAKDOWN WOULD DEFINITELY NOT BE TYPICAL OR SYMPTOMATIC OF A SYSTEMIC ISSUE. CONDUCTION OF AN ELECTRICAL SURGE FROM THE PT VIA CO'S PT CONNECTED FLOW-PROBE BACK INTO THE POWER LINE DIDNOT OCCUR. THE METER'S FRONT END IS EQUIPPED WITH DEFIB-PROOF TRANSFORMERS. A SURGE PASSING THROUGH THIS FRONT END WOULD FLOW OFF TO POWER LINE GROUND RATHER THAN THROUGH THIS CAPACITOR. ADDITIONALLY, THE PROBE THAT WAS CONNECTED WHEN THE FIRE OCCURRED WAS RETURNED WITH THE METER AND FOUND TO BE UNHARMED AND OPERATING NORMALLY. AT A MINIMUM, CO WOULD HAVE FOUND AN ERASED EPROM IN THE PROBE IF THE SURGE WERE INTRODUCED THROUGH THE PROBE. CO HAS REPLACED THE MOTHERBORAD, LINE TRANSFORMER AND RELATED CIRCUITRY IN THE HT107P-91-0040 AND HAS RETURNED IT TO FACILITY WITH THE UNAFFECTED FLOW PROBE. GENERIC, ACROSS-THE-BOARD, REMEDIAL ACTION DOES NOT APPEAR TO BE WARRANTED, ESPECIALLY IN LIGHT OF THE OTHER RF COMPATABILITY PROBLEMS THAT FACILITY'S ENGINEER SAID THAT THEY'D HAD WITH THE CAUTERY EQUIPMENT.