IEC TR 60601-4-3:2015 Guidance & interpretation of IEC 60601-1, 3^rd ed. Published

This post discusses the recently published Guidance IEC TR 60601-4-3:2015 that issues interpretations of IEC 60601-1, 3rd ed. and edition 3.1.

The technical report tiled IEC TR 60601-4-3:2015 Guidance & interpretation – Considerations of unaddressed safety aspects in the 3^rd ed of IEC 60601-1 & proposal for new requirements was released April 2015.  It deals with recommendations and interpretations of the IEC 60601-1, 3^rd ed. and edition 3.1 (or 3^rd ed. + A1).  IEC Subcommittee (SC) 62A established a process under which Working Group (WG) 14 would develop recommendations regarding problems of interpretation or application of IEC 60601-1.  I am a member of this WG.  Many of the WG14 experts are employed by test laboratories and manufacturers and have many years experience applying IEC 60601-1 to MEDICAL ELECTRICAL EQUIPMENT.  The one thing to be crystal clear about is in the INTRODUCTION of the document it says:

“While the National Committee members of SC 62A nominate these experts, their recommendations were not to be formally adopted through any official voting procedure. To reinforce this process, the Subcommittee specifically directed that the following note appear on every page of the resulting informational circular:

IMPORTANT NOTE: Per the 62A decision at Sydney…, the 62A Secretary is circulating this recommendation,…regarding problems of interpretation or application of IEC 60601-1 to all P-Member NCs.

This recommendation/interpretation is the result of considerations by a group of nominated experts and has not been formally adopted through any National Committee voting procedure. Distribution is only for information.

The INTRODUCTION of this Technical Report goes on to say:

“This technical report is intended to convey the results of WG 14’s work to interested parties such as MANUFACTURERS and test laboratories while retaining the informative nature of the material.

This first edition of IEC TR 60601-4-3 contains 93 recommendations, numbered 101 to 193. All these recommendations are based upon IEC 60601-1:2005 and IEC 60601-1:2005/AMD1:2012.

The numbering starts with 101 instead of just 1 to ensure that these WG 14 recommendations (101 to 193) will not accidentally be confused with previous issued WG 14 recommendations 1 to 63, which are based on the second edition of IEC 60601-1 and published in IEC TR 62296.”

The other purpose of this document is that these recommendations may be potential sources for some of the changes to the IEC 60601-1 standard when it is up for it’s next round of changes.  The standards committees, working groups, and maintenance committees for IEC 60601-1 and it’s collateral standards (IEC 60601-1-XX) are in discussion if the next revision will start late this year or early next year.  There is a meeting of all the TC 62 (& SC62A – D) committees in Kobe Japan in Nov 2015 that will discuss this and probably have a formal vote to decide on the fate of the next revision of IEC 60601-1.  I plan to be at these meetings and involved in the discussions and decisions. If this vote is positive the earliest the changes would occur is sometime in 2019.  Stay tuned for more updates on the potential changes to the IEC 60601-1 standards and it’s related collateral standards.

As there are 93 recommendations sheets I will not note all of them in the below list but a sampling showing a cross section of the ones that draw my attention.  You can see from the list below that many of these were not addressed fully in the standard and this is the start of the resolution to these issues. Many of test houses use this document as their interpretations that they rely on until these decisions are finalized by being adopted into the next revision of the applicable standard (primarily IEC 60601-1).  But realize as the boxed text says these are not formalized so your test lab may not rely on them.  I would suggest that you check first with your Test Lab on the specific issues before assuming they are their interpretations.  You don’t want to use these and find out at the end of your test project that your lab doesn’t agree to the perspective on one or more of these recommendation sheets.  I would hate to see you redesign a product to find out the solution doesn’t meet the requirements for your lab.  As mentioned many labs do accept these but with added text box please be diligent and check first:

3.2.101             Total PATIENT LEAKAGE CURRENT of a ME SYSTEM

3.2.102             Pollution degree for MOPP

3.2.103             Transients on d.c. mains

3.2.104             Altitude factor for DEFIBRILLATION-PROOF APPLIED PARTS

3.2.105             Defibrillation energy protection for MOOP / MOPP

3.2.106             Overvoltage categories III and IV

3.2.107             Pollution degree related to different micro/macro environments

3.2.108             Warnings versus ALARM SIGNALS

3.2.109             Single Y1 capacitor for MOPP

3.2.111             CREEPAGE DISTANCE and AIR CLEARANCE for dental equipment

3.2.112             Short circuiting of one constituent part of DOUBLE INSULATION

3.2.113             Instability in transport position

3.2.116             Instability excluding transport position

3.2.119             Test equipment for recurrent tests according to IEC 62353 testing used within IEC 60601-1 type approval testing

3.2.124             WORKING VOLTAGE measurement

3.2.125             Defibrillation test

3.2.127             PERMANENTLY INSTALLED ME EQUIPMENT in the HOME HEALTHCARE ENVIRONMENT

3.2.129             Push buttons

3.2.132             Eye-verification of tester before legibility test

3.2.125             Labeling: spare parts vs. detachable parts vs. ACCESSORIES

3.2.144             Impedance of a PROTECTIVE EARTH CONDUCTOR within a DETACHABLE POWER SUPPLY CORD

3.2.149             Expected voltage on SIP/SOPs

3.2.151             COMPONENT WITH HIGH-INTEGRITY CHARACTERISTICS

3.2.153             Critical components

3.2.166             Keep dry and umbrella symbol

3.2.167             MOBILE and STATIONARY ME EQUIPMENT with wheels

3.2.175             Biocompatibility for quasi APPLIED PARTS

3.2.182             Chargers for ME EQUIPMENT used at home

3.2.186             Rationale for IP2X

3.2.187             Battery – limited power

3.2.191             The SIP/SOP pin to earth TOUCH CURRENT

3.2.193             MAINS VOLTAGE on APPLIED PART

This is a great resource to have throughout your design process and through the testing and beyond.  Always have it available so you can leverage the knowledge of these WG14 experts, including myself.  You can purchase this document from IEC, AAMI, and many other sources.  Go to http://www.eisnersafety.com/links/ to find a listing of standards Sales Organizations and also Standards Organizations.

We are in the process of setting up a standards reconnaissance service where we monitor the MEDICAL ELECTRICAL EQUIPMENT and HOME USE MEDICAL ELECTRICAL standards of your choice.  If you are interested in this service please contact Leo Eisner at Leo@EisnerSafety.com or 503-244-6151.  We would be happy to discuss what we can do for your organization as Leo is on many of the standards committees that these standards are involved with.  Below is a summary of my involvement in these committees.

Leo is a co-chair of the U.S. TAG (technical advisory group) for IEC/SC 62D, a member of the US TAG for TC 62 (Electrical Equipment in Medical Practice), SC 62A (Common Aspects of Electrical Equipment Used in Medical Practice) and SC 62D (Electromedical equipment).  He is the convener of SC62D JWG9 “Lens removal and vitrectomy devices for ophthalmic surgery”.  Leo is a member of the TC 62/SC 62A/WG 14 (Testing to General Safety Standard – The Working Group is chartered to develop recommendations regarding interpretation & application of IEC 60601-1 to testing of medical electrical equipment, and to deal with general testing requirements not assigned to other maintenance teams.)  To support the increase in demand for medical device Home Use and Wearables Leo is a member of the AAMI committee for Home Use Medical Devices and the US TAG for Active Assisted Living Syc (System Committee for all devices in various categories for the elderly which includes the home use medical device industry).