Make Plans Now to Start Your Gap Assessment
Over the many years of my career, I have noticed that standards keep changing at an ever-increasing rate. Most recently, I have been involved in four of the standards committees dedicated to IEC 60601-1, Medical electrical equipment, one of eight standards in the IEC Amendments Project. Part of our work is reflected in the recently released Ed. 3.2 of IEC 60601-1.
Medical device standards are being developed more and more rapidly and some existing standards are being updated in shorter time frames (i.e., the rules for IEC standards development has changed to allow for shorter development cycles), and national medical device regulations (including guidances) keep changing at a faster pace. As a result, it is becoming more difficult for medical device manufacturers as well as medical device consultants to keep up to date with the proliferation of changes. Ultimately, this impacts the manufacturer’s quality systems and technical documentation, increases product development cycle times, and stretches out product time to market.
This article will focus on the IEC 60601 series of medical electrical standards, and specifically on the IEC Amendments Project, a project that was completed under Sub Committee 62A (SC62A). The article provides a summary of some of the changes from the previous version of the standards impacted by the Amendments. There are literally hundreds of changes in these standards, and it would be impossible to adequately provide details on all of these changes.
But we’ll do our best in the pages that follow.
About the IEC Amendments Project
The Amendments Project under SC62A covers the general standard (IEC 60601-1) and most of the collateral standards (IEC 60601-1-XX, except for IEC 60601-1-3). (For background on the Amendments Project, refer to my previous article, “The Future of the IEC 60601 Series: An Update,” published in the In Compliance 2020 Annual Reference Guide.) Six of the standards that fall under the Amendments Project were published in July 2020, and IEC 60601-1 was published in August. IEC 60601-1-2, the remaining standard of the Project was published in September. IEC 60601-1-3 is not part of the Amendments Project. It is expected that IEC 60601-1-3 will be published around September 2021 to align with the Amendments Updates. See Table 1 for publication dates.
|Types of changes
|Edition 3.2 = 3rd ed. + A2
Medical electrical equipment
|Edition 4.1 = 4th ed. + A1
Electromagnetic disturbances – requirements & tests
|Edition 2.2 = 2nd ed. + A2
Radiation protection in diagnostic X-ray equipment
|Not Determined – In process still
|Edition 3.2 = 3rd ed. + A2
Terms & referenced standards.
Transition to IEC 62366-1.
|Edition 2.2 = 2nd ed. + A2
Alarm Systems in MEE & MES
|Edition 1.2 = 1st ed. + A2
Environmentally conscious design
No Technical Changes
|Edition 1.2 = 1st ed. + A2
Physiologic closed-loop controllers
|Edition 2.1 = 2nd ed. + A1
Home healthcare environment
|Edition 1.1 = 1st ed. + A1
Emergency medical services environment
|No Technical Changes
Table 1: Current status of IEC 60601 Amendments
It is important to understand that the particular standards of IEC 60601-2-XX / IEC/ISO 80601-2-XX have not yet been updated to align with the Amendments. If the particular standard applicable to your device has not yet been updated to align with edition 3.2 of the general standard, you can continue to use edition 3.1. However, the new versions of collateral standards (e.g., IEC60601-1-2 ed 4.1) may still apply because of new regulatory requirements (e.g. FDA CDRH).
Some particular standards in the series are likely to be updated fairly quickly, while others may take up to three or more years before they are published. This extended timeline may determine when manufacturers begin the process of transitioning from IEC 60601-1, Ed. 3.1, and the applicable collateral and particular standards to the pertinent Amendments.
The decision to transition may be impacted by additional factors such as:
- Transition dates of national certifiers such as UL, CSA, BSI;
- National regulators transition periods;
- New product being ready for market or legacy product lines;
- Regulatory approvals;
- Existing safety certifications;
- Business, regulatory, quality system strategy and impact.
Therefore, it is important for device manufacturers to initiate a full gap assessment as soon as possible to understand the consequence of the anticipated changes, as they are likely to impact design requirements, testing laboratory approvals, regulatory approvals, and more.
Each of the IEC standards of the Amendments Project were concurrently voted on by CENELEC for adoption and final approval as European standards (EN Norms). These EN Norms are not currently harmonized under either the EU’s Medical Device Directive (MDD) or the EU’s Medical Device Regulation (MDR). Therefore, it will be up to the national standardization bodies (NSBs) throughout EU Member States to issue their own versions of the European equivalent standards. These delays are likely to further complicate an already challenging process for obtaining device approval under the EU’s MDR.
The Scope of Changes
We had a variety of changes between all these documents. The majority of changes fall under one of the following issues:
- Some of these changes were intended to align the standards with regulatory requirements and with the updates to ISO 14971, IEC 62366-1 and IEC 62304 to facilitate the regulatory approval process:
- IEC 60601-1, 60601-1-2, 60601-1-6 and 60601-1-10 refer to the most recent standard ISO 14971:2019 Medical devices – Application of risk management to medical devices standard.
- IEC 60601-1-6, 60601-1-8, 60601-1-10, & 60601-1-11 refer to the most recent standard IEC 62366-1:2015 + A1:2020 for Medical devices – Part 1: Application of usability engineering to medical devices. Note that IEC 60601-1 refers bibliographically to IEC 62366-1:2015 as an informative reference, not as a normative standard.
- IEC 60601-1 refers to the current IEC 62304:2006 + A1:2015. It was hoped that IEC 62304 2nd edition would have been published but that edition had issues in committee and has not yet been published. So the Amendments Project couldn’t wait any longer to align with the anticipated IEC 62304 2nd edition requirements. We will have to live with this version for now.
- Updates to key standard references – Normative references that were updated in IEC 60601-1, Ed. 3.2 include the following standards (a number of which will be discussed later in this article):
- IEC 60601-1-2:2014 + A1:2020, EM disturbances
- IEC 60601-1-3:2008 + A1:2013, Diagnostic X-ray equipment
- IEC 60601-1-6:2010 + A1:2013 +A2:2020, Usability
- IEC 60601-1-8:2006 + A1:2012 + A2:2020, Alarm systems
- IEC 60747-5-5:2007 or later, Optoelectronic devices – Photocouplers
- IEC 60825-1:2014, Safety of laser products –
Part 1: Equipment classification and requirements
- IEC 60950-1:2005 + A1:2009 +A2:2013, Information technology equipment
- IEC 62133-2, Lithium systems
- IEC 62368-1:2018, Audio/video, information and communication technology equipment
- ISO 7010:2019 Safety signs
- ISO 15223-1:2016, Medical devices— Symbols to be used with medical device labels, labelling and information to be supplied
- New or updated terms in IEC 60601-1 and some of the other standards. Some of the terms come from the regulatory standards. IEC 60601-1 has two new definitions internal to the standard itself.
- IEC 60601-1 required a significant number of clarifications, as did several other standards. The primary reason for these clarifications stemmed from:
- Safety gaps identified by WG14 decisions, many of which are published in IEC TR 60601-4-3:2018 (2nd Ed) Guidance and interpretation – Considerations of unaddressed safety aspects in the third edition of IEC 60601-1 and proposals for new requirements
- Inconsistencies within a standard
- Technical errors which generated new and updated test requirements
The following sections detail the changes of significance found in IEC 60601-1, Ed. 3.2.
Clause 8 & Annex A, Clause 8
IEC 62368-1:2018 is being used as an alternative solution for means of operator protection (MOOP) to IEC 60950-1, which was the only other option in IEC 60601-1, Ed. 3.0 and 3.1 for MOOP. (Note that one level of means of patient protection (MOPP) of IEC 60601-1 can’t always be provided by the lower level of two levels of MOOPs detailed in either IEC 60950-1 or in IEC 62368-1.)
We found some drawbacks with IEC 62368-1:2018 when we did our analysis for an alternative option to IEC 60601-1. There are areas where voltages for 2 MOOP don’t meet the requirements for 1 MOPP, so manufacturers should carefully read and evaluate the examples and extensive details included in Clause 8 of Annex A (Guidance & Rationale) to determine if they apply to a given device or component, such as switch mode power supplies.
In many cases, working voltages that are above 354Vdc/250Vrms become problematic for double insulation for 2 MOOP for air clearance for IEC 62368-1:2018 as it may not necessarily meet the needed 1 MOPP for air clearance. Similar to IEC 62368-1, IEC60950-1:05, A1:09, A2:13 working voltages that are above 707Vdc/500Vrms in many cases become problematic for double insulation for 2 MOOP for air clearance as it may not necessarily meet the needed 1 MOPP for air clearance. Adding in IEC 62368-1 was not originally part of IEC 60601-1, Ed. 3.2 but was inserted into the project given the anticipated shortage of IEC 60950-1 certified power supplies in the near future.
If you can’t you use an IEC 62368-1 switch mode power supply, here are some other options:
- Substitute an IEC 60601-1 and IEC 60601-1-2 compliant power supply. This is our recommendation to clients anticipating FDA review and since reviewers may have concerns about the use of a power supply intended for ITE applications.
- Look at the isolation in your overall device/system and determine if you can add additional isolation that will get you the isolation needed. This may mean a redesign and additional testing, and could add cost and testing time.
Another piece of the puzzle is that EN 60950-1 (the CENELEC equivalent of IEC 60950-1) will be withdrawn as of 12/20/2020, and will no longer qualify as a harmonized standard under the EU’s Low Voltage Directive (LVD). Therefore, EN 62368-1 is probably the best alternative as it remains a harmonized standard under the LVD, and it enables you to use an ITE type (non-medical) power supply for MOOP.
The changes also relate to other components that provide MOOP isolation on the mains side of power isolation of medical devices, as well as system requirements related to monitors, keyboards, computers, printers, etc. The updates to IEC 60601-1, Ed. 3.2 reflect these considerations.
Alarms and Indicators (Table 2)
The revised Table 2 of the standard represents a significant improvement over that found in the prior edition of the standard. This updated table was generated by the Joint Working Group on Alarms IECSC62A JWG2 (the Committee which also developed the alarm system standard IEC 60601-1-8). The revised table shows much more clearly and precisely what is expected for indicators (warnings & cautions) and alarms. The most significant change is the addition of more detailed specifications regarding alarms. This is especially important since it may encourage the inclusion of alarm systems that conform with the requirements of IEC 60601-1-8 in the design of medical devices (new and existing).
Detachable Power Cords (Clause 8.6.4)
Prior to the release of the updated edition of IEC 60601-1, testing laboratories were required to use a 3 meter power cord consistent with the requirements of Clause 18.104.22.168 and Table 17 in cases where a device manufacturer neither provided nor specified one. But testing laboratories don’t typically stock power cords, so this requirement wasn’t always tested consistent with the requirements. The updated edition of the standard now includes new requirements that specify that testing to be carried out “using a DETACHABLE POWER SUPPLY CORD as provided or specified (length and cross-sectional area) by the MANUFACTURER.” This means that device manufacturers may either provide samples of all variations of power cords intended for use with their device or specify in their IFU the length and cross-sectional area of each power cord. Providing cord samples to the test lab for this requirement can add time to testing and increase the cost.
Conductive Coating (New Clause 22.214.171.124)
A new requirement was added to the standard, even though most test houses have applied this requirement for many years. The requirement involves confirmation that flaking or peeling of conductive coatings doesn’t reduce spacings. If compliance can’t be verified by an examination of construction and available data, the appropriate testing of the coating must be conducted. UL 746C has always served as the default standard for such testing, but the updated IEC 60601-1 now includes references to UL 746C as well as ISO 2409 and ISO 4624.
IEC 62133-2 for Secondary (Rechargeable) Lithium Batteries (Clause 126.96.36.199)
IEC 62133-2 has been added as an alternative to the older IEC 62133 standard. But if your testing lab/regulator (i.e., EU Notified Body) or customer expects you to meet the newer IEC 62133-2 standard, you’ll need to retest in order to obtain a new test report and CB certificate. The implication is increased test costs, additional test samples, project delays and potential redesign of batteries/battery packs to meet the new requirements. The two standards (IEC 62133 vs IEC 62133-2) don’t have identical tests between them.
IEC 60747-5-5:2007 or later for Optoelectronic devices, Photocouplers (Clause 188.8.131.52)
An added requirement in Clause 184.108.40.206 (MOPP) recognizes that opto-couplers found compliant with IEC 60747-5-5:2007 or later editions are considered acceptable, assuming that their dielectric voltage withstand are acceptable for the given application, and that the air clearance and creepage distances at the outside of the opto-coupler meet the requirements. Opto-couplers complying with IEC 60747-5-5:2007 or later are considered equivalent to the requirements of solid insulation (Clause 8.8.2) and insulating compounds (Clause 8.9.3).
Small Spacings (Clause 8.9.4 and Figure 23)
Not all testing laboratories are involved in the development of the interpretations (WG14). So they may be unaware of the change to the minimum X mm away vs. the 1 mm gap in some of the creepage and air-clearance limits illustrated in Figures 23–25 and 27–31 of the standard. These changes could have impact primarily on PCB layouts and their spacings. For example, Figure 1 (Figure 23 in the standard) shows X mm (underlined), while Ed. 3.1 uses 1 mm.
Figure 23 was the only one in the series of figures in the standard that had a 1 mm instead of X mm in the figure when the previous update was made. The X mm rules in Clause 8.9.4 had to be updated slightly to align properly but have been in the standard since Ed. 3.1.
As detailed in IEC 60601-1, essential performance requirements are directly connected to risk analysis. So certification to IEC 60601-1 is based in part on demonstrating compliance with the requirements of ISO 14971, the standard addressing risk management issues. There are no significant changes to risk management within IEC 60601-1, Ed. 3.2, but many of the ISO 14971:2019 terms that are referenced in the standard have been updated. These updates may necessitate updating the content of your risk management files in advance of resubmitting devices for testing.
Other Changes in Standards in the Amendment Project
Changes of significance for IEC 60601-1-2, Ed. 4.1
Conducted emissions (CISPR 11) now test at minimum and maximum rated voltage versus the single voltage test previously used. Note that this change may affect RF emission levels.
New tests Table 11, Clause 8.11 immunity to proximity magnetic fields. Two of the three tests per Clause 8.11 (134.2 kHz @ 65A/m and 3.56Mhz @ 7.5A/m) are from the AIM 7351731 standard. The third test (30kHz @ 8A/m) is for the home healthcare environment (radiant cooktops).
The Guidance section on the application of risk management with regard to electromagnetic disturbances has been totally rewritten to clarify risk management references in the standard.
Changes of significance for IEC 60601-1-8, Ed. 2.2
Clause 220.127.116.11 references Annex G – new sound files. These are new, optional audio sound files for alarms in addition to the previously listed sound files. The Alarms committee is considering making Annex G mandatory in the next revision of 60601-1-8.
Clause 18.104.22.168 – The test set-up and configuration has been changed to correct references to figures and tables in ISO 3744. This means test source and locations (based on figures) will change. Therefore, the test results may vary from past results.
Added new distributed Alarm systems requirements in Clause 6.11.1.
I’m continually being asked by manufacturers about the expected timeline for the adoption of these standards by national regulators. Each of the standards in the Amendments Project includes a recommendation for a three-year transitional period from the date of each standard’s publication. I checked with the Standards and Conformity Assessment program of the U.S. Food and Drug Administration’s CDRH, and they confirmed that internal discussions are already underway regarding the recognition and transition period for these standards. They are anticipating adopting the three-year transition period recommended in the standards in the Fall of 2020.
What is not clear is how long it will take the FDA to “recognize” the particular standards (IEC 60601-2-XX & IEC/ISO 80601-2-XX) once they are aligned with the Amendments Project. I recommend that device manufacturers take a “state of the art” approach and apply the latest version of each standard when designing their devices, recognizing at the same time that this approach has limitations in cases where regulatory authorities have requirements that reference earlier editions of a given standard (i.e., MDD Harmonized Standards) and insist on using these outdated standards.
The goal of the Amendments Project was to make the more immediately needed changes to the IEC 60601-1 series of standards in advance of efforts to develop a 4th Edition of the standard, expected to begin by about 2025. We believe that the work of the Amendments Project will help clarify many important issues around the current use of IEC 60601-1 and its collateral standards, and make it easier to use the standard in the near term. At the same time, the changes are likely to result in some additional work, as device manufacturers will need to conduct a gap assessment and review their documents and systems to determine what needs to be updated before they resubmit to their test laboratories and regulators to meet these revised requirements.