Interpretation of IEC 60601-1-2 Electromagnetic Compatibility – Requirements & tests

[karthika subramaniam]

Hi Everyone, would like to get clarified few clauses – interpretation of IEC 60601-1-2 - Electromagnetic compatibility –Requirements and tests

1. Is sub-system’s EMC/I test reports are acceptable, what is the condition of acceptability & technical consideration? For example we procure X-ray generator, X-ray tube, and x-ray detector that are IEC tested, if we change these models from one vendor to another for the same terminal specifications, should we repeat the entire SYSTEM testing? Please clarify.

2. What are the requirements applicable for EQUIPMENT and SYSTEMS specified for use only in a shielded location?

3. For example, if the attenuation by shielding material is less than 20db, will the attenuation by the room shielding material on Radiation and conducted Emission taken into account and that value is relaxed from the Radiated/conducted Emission levels that are measured?
If not, what is the rationale behind this, can anyone please explain?

4. Radiated Emission – to apply the 20db relaxation – for the equipment when installed in a shielded location. Reference to the following “note” in IEC 60601-1-2.

“It is essential that the actual RF shielding effectiveness and filter attenuation of the shielded location be verified to ensure that they meet or exceed the specified minimum values”

What is the verification methods to use the relaxation, testing is conducted in-situ with shield present otherwise how it will be done?

5. We find the following point from 4th edition of IEC,
“Specific medical environments are now clearly defined as; Emergency Medical Services Environment, Home Healthcare Environment, Professional Healthcare Facility Environment and Special Environments.
Professional healthcare environment is considered a controlled EM environment. MRI, x-ray and other medical equipment requiring shielded rooms have special label and user information detailing the use in special environments. X-ray generators operating in intermittent mode may have the quasi-peak limits relaxed by 20dB for discontinuous conducted and radiated emissions.”

Can anyone clarify on following points:
- Does it mean that the testing has to be done during X-ray firing or is it ok to test in stand by condition?
- What does it mean – “controlled EM environment”?

Please help me out

 

[Stijloor]

Re: Interpretation of IEC 60601-1-2 Electromagnetic Compatibility – Requirements & te

A Quick Bump!

Can someone help with this question? Thank you very much!

 

[Pads38]

Re: Interpretation of IEC 60601-1-2 Electromagnetic Compatibility – Requirements & te

As this hasn't attracted any answers I will try - but I must admit that I do not have experience of EMC testing an X-ray machine, or a large scale installation.

1. I would expect that EMC tests should be done on the system as a whole. Any significant change to that system may mean having to repeat tests, but I would expect that this could be a limited set of tests - perhaps only needing, say, the radiated emissions repeated. If you have EMC test results for the different modules you may be able to further reduce tests. Note that inter-connecting cables and terminations are particularly important for EMC tests.

2. For equipment specified for a shielded location - (Clause numbers from Edition 3 - 2007). The required technical information is at 5.2.2.3.

The test that is altered is the RF immunity test of 6.2.3.1
It, effectively, allows you to reduce the test level as if the shielding were in place.

3. The test level is reduced by the same amount as you specify in the required shielding effectiveness. From 5.2.2.3 the minimum effectiveness is 20dB. If your shielding does not provide 20dB it is assumed to provide 0dB - as if you have no shielding. This also applies to frequencies where your shielding is less effective.

4. The boxed Note is information that must be added to your Instruction Manual / Technical Documentation. It is an instruction for the buyer to test their shielded location.

5. I do not yet have Edition 4 but I will try and make some suggestions.

Professional healthcare environments are assumed to need lower levels for the immunity tests than mobile or home settings. This is because they are expected to have their power delivered by a robust, dedicated sub-station, which limits things like surges and EFT. Also, the floor covering is assumed to not be carpet - so the ESD test levels are reduced.
Shielded locations are 'Special locations' with the test modifications mentioned above.
I would suggest that the X-ray generator does need to be fully functional during tests, but with the 20dB reduction in limits but only if the tests are done with the quasi-peak detector (there are several types of RF receivers used for these tests - QP are one).

I would suggest that you have a look at the 'Particular' standards for any that may be relevant. They often have modifications to the EMC tests to suit different device types.
This might include:
60601-2-7
60601-2-8
60601-2-15
60601-2-28
60601-2-32
60601-2-43
60601-2-44
60601-2-45

Also:
60601-1-3
61262 series

I think that this is an instance where working with your chosen test house could be very beneficial. For that, I would recommend that you choose a very experienced test house - one that has experience of testing large installations as well as single devices. It may seem expensive - but could save you time and money in the longer term

Most EMC test houses offer 'consultancy' services as well as testing. Involving them, as early in the project as possible, would probably be a very good idea.

 

[gpkaran]

Re: Interpretation of IEC 60601-1-2 Electromagnetic Compatibility – Requirements & te

1. Is sub-system’s EMC/I test reports are acceptable, what is the condition of acceptability & technical consideration? For example we procure X-ray generator, X-ray tube, and x-ray detector that are IEC tested, if we change these models from one vendor to another for the same terminal specifications, should we repeat the entire SYSTEM testing? [/COLOR] Please clarify.

Yes conditionally.
# Lets assumed: Your DR system powered with 3-phase (Generator) and the detector power tapped with the same 3-phase line.
- Change of generator : Yes, to perform all the tests(Since its main part of your system)
- Change of detector : Yes, to perform all the tests(Onl
- Change of X-Ray tube : No, to perform RE and RS (Input power related test not required, its connected with Generator’s HT cable)

Note: To avoid the multiple testing in (EMI/C), lets freez the product configuration like listed below, to test only highest configuration highlighted in yellow, and give justification, why it’s not being tested others.

Refer the attachment: DR Configuration.

For IEC 60601-1 Testing, test with highest configurations, and to add other manufactures (X-ray tube, Detector) details in the critical pats list (Alternate), so to minimize the testing for tube and detector inclusion on later stage).

5. We find the following point from 4th edition of IEC,
“Specific medical environments are now clearly defined as; Emergency Medical Services Environment, Home Healthcare Environment, Professional Healthcare Facility Environment and Special Environments.
Professional healthcare environment is considered a controlled EM environment. MRI, x-ray and other medical equipment requiring shielded rooms have special label and user information detailing the use in special environments. X-ray generators operating in intermittent mode may have the quasi-peak limits relaxed by 20dB for discontinuous conducted and radiated emissions.”

• Most of the DR system X-Ray Generator (Floor/Ceiling mount) will be tested with stand by condition only, but your mechanics (i.e tube supporting floor/ceiling) will be tested full functional movements if its motorized.(RE CISPR 11, Class A (Limits 40/47db)

• Note: If you are using IEC/CE certified generator in DR system, make sure the tests recommendation (stand by or intermittent) its mention in User/service manual or get the test report.

• Intermittent mode is nothing like x- ray exposure, will consumes high load at short interval (e.g 50kW Generator, Intermittent/Momentary current 100A) then you can test with the mode, in that case the RE test qp level (20db) tolerance is applicable.

Can anyone clarify on following points:
- Does it mean that the testing has to be done during X-ray firing or is it ok to test in stand by condition?

Note: DR system recommended to test in standby mode.

- What does it mean – “controlled EM environment”?
• The ability of an equipment or system to function satisfactorily in its electromagnetic environment without introducing intolerable electromagnetic disturbances to anything in that environment
• Equipment used in hospital’s mains power been isolated from the public low voltage power supply network.
• Simply says, the equipment used in the controlled environment should not affect the other near by devices/equipment. (e.g Lead shielded room for X-Ray, RF shield for MRI)


Assumed : your x-ray components already certified by CE mark, in that scenario, below listed std to comply for your DR system

EN 60601-1:2006/A1:2013 (safety)
EN 60601-1-2:2007/AC:2010 (EMI/EMC)*
EN 60601-1-6:2010
EN 60601-1-8:2007/AC:2010 (Does your DR system contains any alarm/alerts then applicable otherwise not)

Product specific std.
EN 60601-1-3:2008/AC:2010
EN 60601-2-54:2009


EN 60601-1-2:2015 (EMI/EMC)*, 4th Edition, If you place device/equipment in EU Market after December 2018, it's applicable.

Make sure EMI/EMC 4th edition is requires or not, the reason most of current x-ray components (X-ray tube, generator, detector) been tested with 3rd edition only.

 

[karthika subramaniam]

Re: Interpretation of IEC 60601-1-2 Electromagnetic Compatibility – Requirements & te

Thank so much for the responses..

Posting few more questions, pl help me out.....

IEC 60601-1-2, 4th edition:
IEC 60601-1-2, 4th edition has established new “Environments” as a guide for manufacturers and developers to consider during development of their products. Each “Environment” identifies locations where devices and systems could be used, and how EMC/I in those locations could impact the performance of their devices.

Extract from 4th edn of IEC 60601-1-2:
There are special conditions, due to INTENDED USE or SPECIAL ENVIRONMENTS, where one or more of the EM phenomena are expected to have lower EM DISTURBANCE levels;
Examples:
1. Examples of when this might be appropriate include ME EQUIPMENT and ME SYSTEMS in the vicinity of SHORT-WAVE THERAPY EQUIPMENT (diathermy) and PERMANENTLY INSTALLED computed tomography ME SYSTEMS within an X-ray shielded room with air conditioning (controlled temperature and humidity).
2. An example of mitigation's (special conditions) for two different phenomena offered by one INTENDED USE is an oncology system with an electron accelerator. The shielding effectiveness of the bunker provides mitigation for radiated RF and the limited movement of the PATIENT during treatment would be an INTENDED USE consideration for ESD.

Particular standard:
If the particular ME equipment is intended to be used in a special environment and the electromagnetic characteristics of that environment are known, appropriate test levels and methods should be specified in the particular standards. Based on special environment not only immunity test levels, Radiated emission test requirements also to be specified.

In the view of above, the particular standard IEC 60601-2-68 released after 4th IEC 60601-1-2, specified the test methods for Radiated Emission and Radiated Immunity in Clause 201.17– as the equipment is specified for use ONLY in shielded location:
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The site(s) used for measurements shall be typical of those generally used for the installation of EBEs; they may be those of RESPONSIBLE ORGANIZATIONS or of the MANUFACTURER. Any allowances made shall be justified and included in the ACCOMPANYING DOCUMENTS. The requirements for compliance shall be those applying to PERMANENTLY INSTALLED ME EQUIPMENT.

201.17102 Radio-frequency EMISSIONS
For radio-frequency EMISSIONS, the attenuation of ELECTROMAGNETIC DISTURBANCES by structures within the bounds of the exterior walls from which measurements are made at a distance shall be regarded as though this attenuation were due to the inherent attenuation of the ME EQUIPMENT. Compliance is checked by measurements, made in accordance with IEC 60601-1-2, at 30 m from the exterior walls of the building containing the location in which the ME EQUIPMENT has been installed.

201.17103 IMMUNITY to radio-frequency electromagnetic fields
For IMMUNITY to radio-frequency electromagnetic fields, the attenuation provided by the structural protection against IONIZING RADIATION shall be regarded as though this were due to the inherent attenuation of the ME EQUIPMENT. Compliance is checked by tests made in accordance with IEC 60601-1-2. The test antenna
shall be placed at 3 m from the outside of the structural protection against IONIZING RADIATION.

Attached the test method

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But there are other particular standards – Radiotherapy Equipment's(Oncology) as below, where the equipment is intended to be used ONLY in shielded location still remains unchanged, as below:
1. IEC 60601-2-11 – Gamma Beam Therapy
2. IEC 60601-2-17 – High Dose Rate Brachytherapy
3. IEC 60601-2-29 – Radiotherapy Simulator
4. IEC 60601-2-45 – Digital Mammography

Following are the queries:
1. Though the 4th edn states that Manufactures has to define the test levels – special environments. NB gets convinced only if stated in standard. Particular standard always takes priority over collateral standard. But the above listed particular standards does not contain information – SHIELDED ROOM for Radiated Emission and Radiated Immunity Test.

In that case – how we can define Test Method based on intended use location/environment – Radiated Emission and Radiated Immunity, please suggest?

2. IEC 60601-2-68, 201.17.103 IMMUNITY to radio-frequency electromagnetic fields: Compliance is checked by measurements, made in accordance with IEC 60601-1-2, at 30 m from the exterior walls of the building containing the location in which the ME EQUIPMENT has been installed.

In most cases feasibility of getting 30m distance from the exterior wall is a challenge ? Can you advise any alternative?

Thank you very much!