Page 10
www.us-tech.com
TechWaTch Dealing With A Different Medical Safety Standard By the staff of RECOM Electronic GmbH, Dreieich, Germany T
he third edition of the EN60601-1 safety standard for medical devices and systems
has been in force in Europe since mid-2012, and has resulted in disharmony with power module man- ufacturers. This newest version of the medical safety standard was not nearly as uniform as it might have been, and those power module manu- facturers have been forced to cope. Standards are developed to provide uniform rules for manufacturers, and the expectations were high regarding the third edition of the EN60601-1 standard. But even after years of preparation, the third edition brought dramatic differences from the first edition of the standard, from 35 years earlier. Regarding the latest version of
the standard, the United States en- joyed an additional year of grace compared to Europe, enforcing the new edition of the UL60601-1 stan- dard on July 1, 2013, while Europe replaced the old second (from 1995) version of the standard with the third version exactly one year earli- er. There were differences in applica- tion of the standard as well. The new standard applies to all devices launched onto the European market, even new products with old designs.
In the US, the new standard only ap- plies to newly developed products. Canada took a middle road with their CAN/CSA standard. It was put into service at the same time as Europe, but applies only to newly developed products as in the US. Medical devices often linger in
product ranges for five to 10 years, so this last point in particular consti- tutes a costly drawback for European manufacturers — not only because they had to retrofit new components to old designs, but also due to the high additional costs of certifying their new products. This gray zone of longer lasting years is a heavy bur- den on smaller companies in particu- lar, which often face the decision of taking current products from the market early while their competitors from the US are allowed to keep sell- ing older products. The situation is even less clear
for devices that fall under the EN/UL 60601-2 standard. The third edition is only mandatory for these products once the second edition no longer ap- plies for 60601-2 products, which may indeed come later. Some countries haven’t yet enforced the third edition of the standard, and their products are still certified according to the sec- ond edition. Medical engineering
products will literally be subject to double standards for years to come.
While virtually nothing has
changed in technical specifications for insulation, risk management has gained focus as a major area of inno- vation. Medical device manufactur- ers will be required to document their risk management process as
The new standard (EN60601-1) applies to all devices launched
onto the European market, even new products with old designs. In the US, the new standard only applies to newly developed products.
based on the ISO 14971 model. Spe- cific processes will have to be ob- served and documented, alongside compliance with fundamental techni- cal standards. As an example, according to the
IR Vacuum Reflow Soldering/RTA over 400 worldwide/over 100 in USA
IR Vacuum Reflow
Table Top System
450˚C / 700˚C
450˚C 1100˚C
second edition, devices were allowed to break during testing as long as this didn’t pose a risk to patient or operator health; the third edition re- quires that the system maintains its essential functionality. This must be documented in a risk management file (RMF), which will also require far more contact between the manu- facturer and testing authority throughout the development process, especially as results from the testing process must be included in the RMF document.
Separating Patients and Operators
Devices which will have contact
Fast ramping quartz tube Furnace
SiC power devices
with a patient must have proper means of patient protection (MOPP). These devices require two isolation barriers for electrical safety, an im- portant requirement in power mod- ules. The first barrier on the supply side has been implemented in a med- ical power supply unit (PSU). Rein- forced isolated DC/DC converters provide the second isolation barrier between the medical electronics and diagnostics tools, such as endoscopes and ECG electrodes, to double the safety for patients. One key feature of the third edi-
Hot Plates/Chucks 450˚C IGBT/DCB prozessing
Hybrid Diebonder, dispenser, tester, repair
Direct IR heating
Email:
ATV@bsetplasmas.com Antioch, CA, USA Phone: 925-755-2300
www.bsetplasmas.com/atv.html www.atv-tech.com
Diamond Scribers 200 mm ø
MEMS cap/package lid sealing with Getter activation
tion of the EN60601-1 standard is that it separates operator protection or how electronic devices provide means of op- erator protection (MOOP). In theory, clearance and creepage distances as defined in the EN60950-1 standard for electronic equipment are enough for devices that will not have patient con- tact and intended for providing proper MOOP.
But the requirements for very
low operating current must also be met according to EN60601-1, so elec- tronic manufacturers are generally wise to choose medically isolated con- verter modules in any devices or products with MOOP requirements. As a leading DC/DC converter
manufacturer, RECOM supplies a broad range of medical converter modules certified according to the third edition of the EN60601-1 stan- dard with double MOPP for direct patient contact such as our RxxP, RxxP2, RV, REC3.5, and REC6 (1, 2, 3.5, and 6 W) lines. Transformer clearance and
creep age distances in these rein- forced isolated converters must be three times the size as those used in industrial settings. So far, this has been implemented with primary and secondary windings on opposite sides of a toroidal core separated by a par- tition wall in the middle. That takes care of the isolation issue, but the magnetic fields would not overlap due to the spatial separation be- tween the two windings. An unpleas- ant side effect would be a decrease in efficiency in the two transformers re- sulting in increased heat losses. RECOM’s engineers have devel-
oped a small transformer with pri- mary and secondary windings inter- locked in such a way as to ensure vir- tually optimal overlapping magnetic fields despite the creepage and clear- ance distances required for rein- forced isolation. The new converters achieve 15 percent to 20 percent more output than earlier designs in the same casing due to quasi-reso- nant circuit topology, and are also approved for ambient temperatures to +85°C, or around 15°C higher than most transformers with conventional toroidal-core transformers, due to the low heat loss. Depending upon the transformer type, isolation ca- pacitance values were reduced to 1.5 pF, ensuring lower leakage current as required for medical electronics applications. From this new transformer de-
sign, a complete generation of highly isolated converters for medical appli- cations has emerged, useful for such programming devices as pacemak- ers, blood gas analyzers, and oxime- ters. The RxxP and RxxP2 series cov- er the 1 and 2W classes, and are available in SIP7 casings. The 2W version is available as an RV series in DIP24 casings for pin compatibili- ty with legacy designs. The REC3.5 and REC6 series both provide 3.5 and 6 Watts, respectively, and also come in a DIP24 casing. The models quoted are available with isolation voltages to 8 and 10kVDC. Apart from these reinforced iso-
lated converters, there are many oth- er product lines in the RECOM range approved for medical applications without patient contact (MOOP), in- cluding regulated and unregulated SMD converters with power ratings from 0.25 to 2W (the RxS family) as well as a wide variety of different
converters to 6W. Contact: RECOM Electronic
GmbH, Otto-Hann-Strasse 60, 63303 Dreieich, Germany % +49 (0)6103-30007-0 fax: +49 (0)6103-30007-62 E-mail:
info@recom-electronic.com Web:
www.recom-electronic.com r
September, 2013
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100