Amendment 1 to IEC 60601-1-2 is worth a careful reading by anyone involved in the design, manufacturing and/or testing of electrical medical equipment.
Daniel D. Hoolihan
Hoolihan EMC Consulting, Lindstrom, MN
In September of 2004, the International Electrotechnical Commission (IEC) released Amendment 1 to the Second Edition of IEC 60601-1-2. This Amendment was prepared by Subcommittee 62A (Common Aspects of Electrical Equipment used in Medical Practice) which is part of IEC Technical Committee 62 (Electrical Equipment in Medical Practice).
The Amendment deals primarily with equipment that complies with CISPR 11, Group 2, Class B except for the third harmonic of the fundamental frequency. In addition, that equipment has to be used by healthcare professionals, cannot be offered for sale to the general public, and can be used in domestic establishments.
The Amendment also addresses several corrections and additions to IEC 60601-1-2.
GENERAL
The official title of IEC 60601-1-2 is “Medical Electrical Equipment – Part 1-2: General Requirements for Safety – Collateral Standard: Electromagnetic Compatibility (EMC) – Requirements and Test.” The Second Edition of this standard was released in 2001 and this current Amendment was driven by comments received from users of the Second Edition.
The standard is a Collateral Standard which means that it is capable of covering a number of products in a “horizontal” fashion.
The Amendment is necessary because the changes in the Amendment could not wait until the next scheduled maintenance cycle date of the standard which is usually every 5 years.
SPECIFIC CHANGES
The first modification to the standard by the subject amendment was to delete the following paragraph in the “Introduction” portion of the standard.
This second edition allows a risk analysis to be used to determine the ESSENTIAL PERFORMANCE and safety of MEDICAL ELECTRICAL EQUIPMENT that must be examined during IMMUNITY testing and whether testing according to this standard is required for non-medical electrical equipment that is combined with MEDICAL ELECTRICAL EQUIPMENT to form a SYSTEM.
The second modification was to replace in “Terminology and Definitions” the phrase “For the purposes of this standard, the following definitions apply” with “For the purposes of this Collateral Standard, the terms and definitions given in IEC 60601-1:1998, IEC 60601-1-1:2000, IEC 60601-1-8;2003 and ISO 14971:2000 and the following apply:” Also, definition 2.210 (Essential Performance of an equipment or system) was deleted and all occurrences of “essential performance” were changed to normal font throughout the document.
Definition 2.212 – Function (of an equipment or system) was changed to “clinically significant operation that the equipment or system is intended to perform in the diagnosis, treatment, or monitoring of a patient.”
Also, two new definitions were added; 2.227 – Professional Equipment or System and 2.228 – Type A Professional Equipment or System. The former is defined as “equipment or system for use by healthcare professionals and that is not intended for sale to the general public” and the latter is defined as “professional equipment or system that complies with CISPR 11- Group 2 – Class B except for the third harmonic of the fundamental frequency of the equipment or system, in which case the third harmonic complies with the Group 2 – Class A electromagnetic radiation disturbance limit.”
In the General Requirements section of the standard, the text on Essential Performance (3.201.2) was swapped out and the new words are “either the essential performance of the equipment or system shall be identified (see Annex GGG for guidance on identifying the essential performance) or the performance of all functions of the equipment or system shall be considered essential performance for the purpose of immunity testing (see 36.202.1 j). The essential performance shall be disclosed in the accompanying documents. Compliance is checked by inspection of the accompanying documents or, if this identification is not performed, by inspection of the documents to verify that the performance of all functions of the equipment or system has been tested in accordance with 36.202.”
In section 3.201.4 on Non-Medical Electrical Equipment, the existing text has been replaced with:
“Non-medical electrical equipment that is supplied as part of a system is exempt from the EMC testing requirements of this standard, provided all of the following conditions are met (see also Annex HHH):
a) The non-medical electrical equipment complies with applicable international EMC standards.
b) Both the emissions and immunity of the non-medical electrical equipment have been determined to not adversely affect the essential performance or safety of the system.
c) The emissions of the non-medical electrical equipment have been determined to not cause the emissions of the system to exceed applicable limits.
Compliance is checked by inspection of the documents for this determination and other appropriate documents or certificates or, if this determination is not performed, by inspection of the documents to verify that the non-medical electrical equipment has been tested in accordance with this standard.”
A new subclause, 3.201.5 – General Test Conditions was added to the standard by the Amendment. It says “for EMC testing, the single fault condition requirements of the General Standard do not apply.”
The Amendment then jumps to Clause 6 on “Identification, Marking and Documents.” In this clause, it adds a new warning to be used in the instructions for use for Type A Professional Equipment or System. The warning is as follows: “This equipment/system is intended for use by healthcare professionals only. This equipment/system may cause radio interference or may disrupt the operation of nearby equipment. It may be necessary to take mitigation measures, such as reorienting or relocating the equipment/system or shielding the location.” Furthermore, the Amendment modifies in clause 6.8.3.201 – Technical Description, the instructions relative to Table 201 to include Type A Professional Equipment and Systems. The Amendment adds a seventh requirement applicable to all equipment and systems under clause 6.8.3.201; it is that “the performance of the equipment or system that was determined to be essential performance.”
The Amendment also modifies clause h) under 6.8.3.201 – Technical Description. This clause covers “requirements applicable to large, permanently-installed equipment and systems.” It corrects a typo in the second edition which refers to 36.202.3 b) 1) when it should refer to 36.202.3 b) 9). It should be noted that 36.202.3 b) 9) states that “large, permanently-installed equipment and systems that are constructed in such a way that simulated operation of sub-systems is not feasible are exempt from the testing requirements specified by IEC 61000-4-3.” However, “9)” does place some alternate requirements on the large systems to assure some immunity to radiated radio frequency (RF) electromagnetic fields.
Continuing to modify 6.8.3.201, the Amendment deletes the words “by a risk analysis” from the title of clause i) (Requirements applicable to equipment and systems found by a risk analysis to have no essential performance). It also deletes the same phrase from clauses i) 1) and i) 2).
Continuing on, the Amendment adds a new clause j) to 6.8.3.201. The new clause is entitled “Requirements Applicable to Type A Professional Equipment and Systems.” The words in the new clause are “For Type A Professional Equipment and Systems intended for use in domestic establishments or connection to the Public Mains Network (see 36.201.1 a) 6)), the accompanying documents shall include a justification for not complying with the CISPR 11 – Group 2 – Class B electromagnetic radiation disturbance limit at the third harmonic of the fundamental frequency of the equipment or system. This justification shall be based on significant physical, technological, or physiological limitations that prevent compliance. The accompanying documents shall also include a justification why the equipment or system needs to be used in domestic establishments or connected to the public mains network.”
The Amendment modifies Table 201 in the standard to include Type A Professional Equipment or System. Table 201 is entitled “Guidance and Manufacturer’s Declaration – Electromagnetic Emissions – for All Equipment and Systems (See 6.8.3.201 a) 3)).”
The Amendment also modifies Figure 201 to include Type A Professional Equipment or System. Figure 201 is the “Instructions for Completing Table 201 for CISPR 11 Equipment and Systems (see 6.8.3.201 a) 3)).”
Figure 202 does not escape the Amendment, it too gets modified to reflect the changes in Table 201. The title of Figure 202 is “Instructions for Completing Table 201 for CISPR 14 and CISPR 15 Equipment (see 6.8.3.201 a) 3)).”
Table 202 – Guidance and Manufacturer’s Declaration – Electromagnetic Immunity – for All Equipment and Systems (see 6.8.3.201 a) 6)) gets a minor change from the Amendment. It changes the Surge matrix value to read “line(s) to line(s)” instead of “differential” and it changes “common mode” to “line(s) to earth.”
The Amendment modifies Clause 36.201.1 – Protection of Radio Services – to include “requirements” for Type A Professional Equipment and Systems. It also corrects a typo from the second edition in 36.201.1 b) – Tests – where the second edition only referred to clauses 1) and 2). The Amendment correctly references clauses 1), 2) and 3) which includes patient-coupled cables; sub-systems; and large, permanently-installed equipment and systems; respectively. The Amendment also corrects the footnote on page 33 to read “CISPR 11:2003” instead of “CISPR 11:1997.”
Under clause 36.202.1 – General, the Amendment replaces existing words under d) – Non-Medical Electrical Equipment with the following:
Non-medical electrical equipment that is supplied as part of a system is exempt from the immunity testing requirements of this standard, provided all of the following conditions are met (see also Annex HHH):
- the non-medical electrical equipment complies with applicable international immunity standards (such as CISPR 24 for ITE and IEC 61326-1 for Measurement, Control and Laboratory Equipment).
- Both the emissions and immunity of non-medical electrical equipment used in as system have been determined not to adversely affect the essential performance or safety of the system.
Again, under Clause 36.202.1 – General, the Amendment exchanges the existing words in h) – Testing of Normally Non-Observable Functions with the following: “If a function associated with essential performance (e.g. high priority and medium priority alarm conditions) cannot normally be observed or verified during the test, a method shall be provided (e.g. display of internal parameters) for determining compliance. The use of special software or hardware may be needed.”
Still in 36.202.1, the Amendment replaces the ninth and tenth dashes under j) – Compliance Criteria with the following:
- noise on a waveform in which the noise would interfere with diagnosis, treatment, or monitoring;
- artifact or distortion in an image in which the artifact would interfere with diagnosis, treatment, or monitoring;
Moving on to 36.202.3 – Radiated RF Electromagnetic Fields – the Amendment replaces existing words in b) – Tests – 7) – Test Conditions for equipment and systems with a receiving section for RF electromagnetic energy – with the following words:
“The receiving section of the equipment or system shall be tuned to the preferred frequency of reception. If the receiving section of the equipment or system has no preferred frequency of reception, the receiving section of the equipment or system shall be tuned to the center of the frequency range from which the frequency of reception can be selected, except for spread spectrum receivers, which shall be allowed to operate normally.”
On page 41 of the standard, the Amendment replaces the word “ground” with the word “earth” in clause 36.205.5 – Surges, under a) Requirements. Also, under b) – Tests it replaces the word “ground” with the word “earth” and the word “grounded” with “earthed.”
In clause 36.206.6 – Conducted Disturbances, Induced by RF Fields – the same words are inserted under b) – Tests – 9) – Test Conditions for equipment and systems with a receiving section for RF electromagnetic energy – as were inserted under 36.202.3 – b) – 7) – See the above paragraph.
Changes are made to Annex AAA – General Guidance and Rationale by the Amendment. The first one is to add the following words to further explain subclause 2.212 (Function of an equipment or system); “in this definition, ‘intended’ means intended by the manufacturer of the equipment or system and relates to the intended use/intended purpose of the equipment or system.”
Continuing in Annex AAA, the Amendment adds a new paragraph further explaining subclause 2.225 (Public Mains Network). The new paragraph is “Equipment and systems are not connected to the public mains network if they are used in locations, e.g. hospitals, in which the mains connection is isolated from the public low-voltage power supply network by transformers or substations.” The Amendment also modifies explanations of 2.227 (Professional Equipment or System), it deletes the heading “subclause 3.201.2” and its accompanying rationale, and it deletes the heading “subclause 3.201.4” and its accompanying rationale. It also adds a subclause 3.201.5 which explains single fault conditions and EMC performance. It also adds two additional subclauses explaining Type A Professional Equipment and Systems; subclause 6.8.2.201 d) and subclause 6.8.3201 j).
Still in Annex AAA, the Amendment adds a new paragraph to subclause 36.201.1 a) 1) which reads “equipment and systems that are classified according to CISPR 11 do not need to tested according to CISPR 14-1.”
The Amendment also adds a new subclause explanation on page 56 of the second revision of the standard; it is subclause 36.201.1 a) 6) and it addresses the details of the allowance for the third harmonic of the fundamental frequency for electromagnetic disturbance for Type A Professional Equipment, for example, RF therapeutic equipment for physiotherapy operating at short-wave or UHF ISM frequencies.
Also added to 36.202.1 a) is the following paragraph: “The immunity test levels in this collateral standard were selected to represent the normal-use environment and therefore to be appropriate for an EMC immunity standard, rather than for a safety standard. Test levels for a safety standard would be significantly higher. (See IEC 61000-1-2.)
It deletes the phrase “Consideration should be given to ISO 14971 and IEC 60601-1-4 for this risk analysis” in subclause 36.202.1 d) on page 57. It replaces an existing second paragraph in sublcause 36.202.1 h) which addresses high priority and medium priority alarm systems. It makes some minor wording changes to 36.202.1 j) on page 60. Then, it replaces the last paragraph of “j)” with the following paragraph: Subclause 36.202.1 j) requires that equipment and systems remain safe under the test conditions of 36.202. The safety criteria to be monitored during immunity testing should be identified prior to the test.”
In Annex BBB, the Amendment changes “differential mode” to “line(s) to line(s)” and “common mode” to “line(s) to earth.” It also replaces Table BBB.5 – Example (1) Test, Immunity, and Compliance levels – in its entirety with a new table.
It modifies Annex CCC by replacing “spark erosion equipment” with “electro-discharge machining and arc welding equipment” and replaces “CISPR 11:1997” with “CISPR 11:2003” in the footnotes. It replaces the existing first paragraph of CCC.3 – Division into Classes – with a paragraph that addresses the “third harmonic of the fundamental frequency” issue.
In Annex FFF, it adds the following reference – “IEC 60601-1-8:2003, Medical Electrical Equipment – Part 1-8: General Requirements for Safety – Collateral Standard: General Requirements, Tests, and Guidance for Alarm Systems in Medical Electrical Equipment and Medical Electrical Systems.”
For Annex GGG, the Amendment simply states that “Definition and identification of essential performance are under consideration. In the interim, see the draft third edition of IEC 60601-1 for further information on essential performance concepts.
Annex HHH is an all-new informative annex that addresses “Guidance for determining if non-medical electrical equipment used in a system is exempt from the EMC testing requirements of this standard.” It provides basic guidance to do just that including a flowchart in Figure HHH.1 to assist the reader of the standard.
The Amendment adds CISPR 11: 2003 to the bibliography and it replaces “IEC/TS 61000-1-2” with “IEC/TS 61000-1-2:2001.”
Finally, it adds an Index of Defined Terms on page 94 of the standard; the index includes 73 defined terms and their origin.
CONCLUSION
The Amendment 1 to IEC 60601-1-2 is a major amendment to the second edition of the standard. It is worth a careful reading by individuals involved in the design, manufacturing and/or testing of electrical medical equipment.
INTERNATIONAL STANDARDS
Several International standards involving EMC and Safety are referenced in Amendment 1 to the Second Edition of IEC 60601-1-2. A brief explanation of these referenced standards is found below.
CISPR is an abbreviation for Comite International Special des Perturbations Radioelectriques or the International Special Committee on Radio Interference.
IEC is an abbreviation for International Electrotechnical Commission; a standards organization headquartered in Geneva, Switzerland.
The latest edition of CISPR 11 is Edition 4.1 released in June of 2004, It is titled “Industrial, Scientific and Medical (ISM) Radio-Frequency Equipment – Electromagnetic Disturbance Characteristics – Limits and Methods of Measurement.” Within CISPR 11, Group 2 ISM equipment is defined to be “all ISM equipment in which radio-frequency energy is intentionally generated and/or used in the form of electromagnetic radiation for the treatment of material, and EDM and arc welding equipment.” Furthermore, Class B equipment in CISPR 11 is defined to be “equipment suitable for use in domestic establishments and in establishments directly connected to a low-voltage power supply network which supplies buildings used for domestic purposes.”
CISPR 14-1 is entitled “Electromagnetic Compatibility – Requirements for Household Appliances, Electric Tools, and Similar Apparatus – Part 1: Emission.”
CISPR 15 covers “Limits and Methods of Measurement of Radio Disturbance Characteristics of Electrical Lighting and Similar Equipment.”
CISPR 24 is a standard for the immunity characteristics of Information Technology Equipment (ITE) which covers both limits and methods of measurement.
IEC 60601-1:1998 is entitled “Medical Electrical Equipment – Part 1: General Requirements for Safety.”
IEC 60601-1-1:2000 is entitled “Medical Electrical Equipment – Part 1: General Requirements for Safety – 1. Collateral Standard: Safety Requirements for Medical Electrical Systems.”
The latest edition of IEC 60601-1-2 is Edition 2.1 released in November of 2004. It is entitled “Medical Electrical Equipment – Part 1: General Requirements for Safety – 2. Collateral Standard: Electromagnetic Compatibility – Requirements and Tests.”
IEC 60601-1-4 covers “Medical Electrical Equipment – Part 1: General Requirements for Safety – 4. Collateral Standard: Programmable Electrical Medical Systems.”
IEC 60601-1-8 is titled “Medical Electrical Equipment – Part 1: General Requirements for Safety – 8. Collateral Standard: General Requirements, Tests, and Guidance for Alarm Systems in Medical Electrical Equipment and Medical Electrical Systems.”
IEC 61326-1 covers “Electrical Equipment for Measurement, Control, and Laboratory Use – EMC Requirements – Part 1: General Requirements.”
IEC/TS 61000-1-2 is titled “EMC – Part 1-2: General – Methodology for the Achievement of the Functional Safety of Electrical and Electronic Equipment with Regard to Electromagnetic Phenomena.”
Daniel D. Hoolihan is past president of the IEEE EMC Society. He has been a member of the Board of Directors of the EMC Society since 1987 and has held several leadership positions in the society. Dan is also active on the ANSI Accredited Standards Committee on EMC, C63 as chairman of the Subcommittee 6 on Laboratory Accreditation and Subcommittee 8 on EMC and Medical Devices. He served as the vice president of the Minnesota operation of TÜV Product Service, Inc. from 1994 to 1999. He can be reached at hoolihan@emcxpert.com or visit www.1klic.com/199.
