n
In the last few years, the control over elec-
tronic medical devices has exploded. From
GMP Annex 11, which calls for as much as
code review of a microcontroller when the
code is proprietary, all the way to the third edi-
tion of EN60601-1 – a safety standard for med-
ical devices and systems which governs the
way that medical devices must be electrically
protected. Much focus has been given to Annex
11 and the computerized aspect of an embedded
system. Standards raise expectations of creating
uniform rules and transparency within their
scope of application, and in view of this global-
ized world, it would not have been amiss to ex-
pect the same from the third edition of the
EN60601-1 standard. Even after years of prepa-
ration, astonishing differences still exist thirty-
five years after IEC/UL 60601 was first published.
While the USA gave itself an additional year
of grace, enforcing the new UL60601-1 on
July 1, 2013, Europe spared no time and re-
placed the outdated second version from 1995
with the third version on July 1, 2012. Further
complicating the transition, the new standard
applies to all devices launched onto the Euro-
pean market, even new products with old de-
signs, while the same standard in the USA was
only applied to newly developed products. The
Canadians took the middle road with the
CAN/CSA standard by enforcing the standard
on the same date as in Europe, but applying it
only to newly developed products like in the
USA. Medical devices often have product life-
times of five to ten years, so this constituted a
costly drawback for European manufacturers –
not only because they had to retrofit new com-
ponents to old designs, but also due to the
high additional costs of certifying their new
products. This grey zone, which will last years,
is a heavy burden particularly on small compa-
nies now faced with the decision to take current
products from the market prematurely while
their competitors from the USA are allowed to
continue selling their old products.
The situation is even less clear for devices that
fall under the EN/UL 60601-1 2nd edition
standard. The third edition is only mandatory
for these products once the second edition no
longer holds sway for 60601-1 2nd edition
products – which may indeed come later. Some
countries will not or at least have not yet en-
forced the third edition, and their products are
still certified according to the second edition.
Medical engineering products will literally be
subject to double standards for years to come.
Virtually nothing has changed in technical
specifications for insulation while risk man-
agement has gained focus as a major area of
innovation. Similar to Annex 11, in the 60601-
1 3rd edition, medical device manufacturers
will be required to document their risk man-
agement process as based on the ISO 14971
model. Specific processes will have to be ob-
served and documented, alongside compliance
with fundamental technical standards. In pre-
vious versions of 60601-1, devices were allowed
to break during testing as long as this did not
pose a risk to patient or operator health, but
the third edition requires that the system keeps
its essential functionality. This has to be docu-
mented in a risk management file or RMF,
which will also require far more contact be-
tween the manufacturer and testing authority
throughout the development process – espe-
cially as results from the testing process have
EN60601-1 third edition:
a standard with many faces
P
OWER
M
ODULES
By Matthew Dauterive,
Recom
This article takes a look
at the third edition of
EN60601-1 governing how
the peripherals of a medical
embedded system must be
connected. It sheds light on
the differences from the
previous version and describes
exactly how power module
manufacturers have
addressed the discrepancies.
April 2014
16
Figure 1. Block dia-
gram of a medical
device for direct
patient contact with
a reinforced isolated
DC/DC converter
as the second isola-
tion barrier.
