TÜV Product Service Ltd © Open Day 24 June 2010Norman Richardson 1 ` TÜV Product Service Ltd Medical and Health Services Open Day 24 June 2010 Electrical

TÜV Product Service Ltd © Open Day 24 June 2010Norman Richardson

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TÜV Product Service LtdMedical and Health Services

Open Day 24 June 2010

Electrical Safety Testing of Active Medical Devices – New challenges. IEC 60601-1:2005


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IEC 60601-1:2005 The 3rd Edition

1. 60601-1:2005. Background and what went into it2. 60601-1:2005. The major changes3. Update on the collaterals 4. The technical challenges5. The timing and implementation challenges6. The cost challenges


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IEC 60601-1:2005 The 3rd Edition

IEC 60601-1:2005

3rd Edition

‘The General Safety Document’


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Background



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IEC 60601-1 3rd Edition

Background.

1st Edition 1977. Formed from an amalgamation of national requirements but mainly from the UK and Germany (HTM8 and VDE 0750). This was a ground-breaking document for which the main UK participant was awarded an OBE. This edition lasted until 1988.

2nd Edition 1988. More in-depth with greater emphasis on creepage and clearance distances and insulation tests. With the later Amendments 1 and 2, this document is still valid and will continue to be so until June 2012. 128 pages plus 40 pages of guidance and rationale.


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Background.

3rd Edition 2005. Massive document of 200 pages PLUS 180 pages of guidance and rationale.

Met with horror and disbelief at first.

Much opposition to it becoming a harmonised standard but it was harmonised anyway.


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What went into the 3rd Edition?

• The contents of the 1st Edition and the 2nd Ed + Amdts 1 & 2• Some alarm requirements from other mainly medical stds• WG 14 Recommendations 1 to 56• Large parts of IEC 60950 (IT equipment)• Requirements for Expected Service Life (a ‘one-liner’ with big

implications)


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What went into the 3rd Edition? (contd)

• UL national deviations• 60601-1 Medical Systems• 60601-1-4 PEMS• Risk Management requirements• Essential Performance (in concept but see Particular Stds)• Mechanical safety requirements from a variety of sources


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• New clause numbering. (Now 17 clauses instead of 59)• Clause 4. New Single Fault Conditions. New major

requirement for a Risk Management (RM) file to ISO 14971. There are over a hundred references to the RM file in the standard and manufacturers must ensure that the questions posed are answered in the RM file. Therefore in reality there must be an RM file tailored to the GSD.(example: 8.6.3 PE of moving parts. Requirement, blah blah blah. Compliance is checked by.........inspection of the RM file)

• Essential Performance. The risk must be assessed of the loss of the primary intention of the equipment or critical aspects of its performance.


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Examples of Essential Performance

Essential performance - a high speed tutorial

Each item of equipment has a primary intention, a ventilator must ventilate, a defibrillator must defibrillate and an X-ray system must produce an image. This is their Essential Performance

In addition, in any specific application, one or some of the pure performance aspects of a product may be critical to the safe and effective operation of the equipment. They are not nice-to-have features, they are ESSENTIAL.

For many attributes which in general are probably pure performance, one can think of an item of equipment for which the attribute is critical, examples:


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Examples of Essential Performance

...and so on

‘Pure’ safety But critical in.......

Fast operation Interventional MRI

Quiet Baby incubator, audiometer

High definition Ophthalmological ultrasound

Comfortable patient support Conscious neurosurgery, dentistry

Quick set-up Emergency ventilator, stretcher

Nice display colours Doppler colour flowmetry


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Essential performance - examples

Some more general examples of essential performance (but still somewhat equipment specific):

•Does not switch to full output power•Does deliver correct output

• Makes a correct diagnosis (or a very detailed diagnosis but not an underdiagnosis)•Does not overpump•Has adequate bandwidth to show abnormalities•Questions unusual operations•Operates smoothly (hoists, treadmills, ergometers)


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New requirements on a clause by clause basis

• Clause 5. General Requirements for testing..... and Clause 6. ClassificationNo significant changes

• Clause 7. Identification, marking and documents. No significant changes, but see EN 980:2008 and new requirement in MDD to have IfUs as controlled docs.

• Clause 8. Protection against electrical hazards.This is where substantial new material appears. 8.2.1 Connection to a separate power source clarified


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New requirements on a clause by clause basis8.5 New concepts of MOP, MOOP and MOPP with Means of

Patient Protection (MOPP) being more rigorous than Means of Operator Protection (MOOP). MOOP comes from 60950. There are detailed and complex tables for determining test voltages and C&C distances.(These replace A-a1/k and B-a/e which have GONE)

8.7.1 and 8.7.3. Touch Current rather than Enc Leakage Current, Earth Leakage currents of 5mA (NC) or 10mA (SFC). 10x earlier values now allowed BUT it can flow only down the Earth wire and must NOT be available on the enclosure. This enables the possible use of more ‘commercial’ power supplies. ELC now taken out of leakage current table (Table 3 page 86)


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8.7.4.7 h) New leakage current concept for multiple APs of same type connected together (total Patient Leakage current).

8.9 C&C MOPPs based on earlier editions and MOOPs based on 60950 (less stringent). Complex tables need to be studied for the applicable values in any particular case.Added concepts: Altitude of operation needs to be taken into account. Additional insulation classifications (CTI, I, II, IIIa & IIIb). Overvoltage categories extended (‘cleanliness’ of supply). Degrees of pollution extended (reminiscent of 61010).Insulating compound taken into consideration (‘potting’ and encapsulation)


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New requirements on a clause by clause basis• Clause 9. Mechanical hazards

The hugely expanded requirements can broadly be considered in two categories.

Damage to the patient or user by movement of the equipment. Hazards such as crushing (all body parts mentioned plus the clearances which need to be allowed), cutting, entanglement, stabbing, abrasion, falling and so on.Instability and damage due to pressure are included.Damage to the patient or user by failure of a suspension or support means. Required safety factors of such means are given.


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• Clause 10. Unwanted or excessive radiation.Generally the same as before. Reliance is placed on the manufacturer’s RM file.

• Clause 11. Excessive temperatures.Significant changes in the direction of more relaxed requirements (ie higher temperatures permissible) BUT any temp in excess of 41 C (the traditional value) must be justified, is material dependent and must feature in the RM file.


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• Clause 13. Hazardous situations and fault conditionsMany new examples of SFCs. Motor locking, cooling failure, detachment of wires and connectors, blocking of filters and so on (see also Part 2s). Heavy dependence on RM file.

• Clause 14 PEMS. This former collateral (60601-1-4) now incorporated into the GSD.


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• Clause 15. Construction.Where access for servicing is needed, it shall be provided.Numerous requirements for the strength of the equipment against dropping, pushing, impacting and rough handling.

• Clause 16. Systems. The former collateral standard 60601-1-1 is now incorporated into the GSD. Multiple socket outlets now allowed.


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The collaterals



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The collaterals

Collateral standards• 60601-1-1 Systems. Now part of the main standard.• EMC 60601-1-2:2007, generally as before but the

requirements can be modified by the mfr’s RM file.• 60601-1-3:2008 Radiation protection in diag X-ray equipment• 60601-1-4: PEMS. Now incorporated into the main standard.• 60601-1-6:2007 Usability. Not a pass/fail standard but a

design guideline. This is an assessment of the ergonomics of the design. The manufacturer is expected to be able to show that ‘Usability’ factors have been considered in design. For post design appraisal, TÜV is able to have the equipment assessed by a panel of expert and lay users and prepare a report on the Usability.)


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The collaterals

Collateral standards

• 60601-1-8:2006 Alarm systems (frequently overwritten by the particular standard)

• 60601-1-9:2007 Requirements for environmentally conscious design

• 60601-1-10:2007 Development of physiologic closed loop controllers

• 60601-1-11: Home health care (in development, FDIS Feb 2010)


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The technical challenges



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Designers, manufacturers and test houses have put off any involvement with the 3rdEdition as long as possible. There was hope that the standard would not be harmonised but it was.

Another reason is that (TÜV has found) the testing time and the testing costs are about 70% greater than the 2nd Edition.


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Apart from the increase in the number of tests, the new mechanical tests where applicable and the complexity of the standard, there is also a RM file to assess and test parameters to adjust in the light of the RM file.

A number of the superficially similar requirements have detail changes and therefore do not map directly across from 2nd to 3rd Eds


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The technical challenges 2

Are there any advantages to the 3rd Ed?

In general power supplies approved to 60950 can be used and more substantial filters are allowed to help with EMC compliance.

Battery circuits and charging arrangements have been clarified

In the test voltage tables, it is now acceptable to interpolate between values.


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The technical challenges 2

Are there any advantages to the 3rd Ed?

Mechanical safety covered.

Detailed and explicit Guidance and Rationale (in line with recent IEC standards policy)

Note: Parts of previous versions of 60601-1 have been inappropriately used for routine production testing and testing following servicing or repair. The 3rd Ed is even less suitable for these applications.

Now covered by a specific standard, IEC 62353.


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Timing and implementation



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Timing and implementation

Among many other things, the clause numbering in the 3rd Ed is different.

Therefore a Part 2 standard intended to relate to the 2nd Ed cannot be used with the 3rd Ed.

Testing of products for which there is a Part 2 must be done to the 2nd Ed until a “3rd Ed” Part 2 becomes available. Only about half a dozen 3rd Ed Part 2s are available out of about 40 Part 2s.

Transition time will depend on the availability of Part 2s. In general the 2nd Ed will stay valid until June 2012 (June 2013 in the USA). If a particular Part 2 standard is still not available by June 2012, the 2nd Ed will remain valid for longer.


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The cost challenges



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The cost challenges

3rd Ed testing is about 70% more expensive than 2nd Ed.

What do manufacturers do if their product has been successfully tested to the 2nd Ed? TÜV offers ‘delta’ testing.

That is, not testing the 2nd Ed aspects which have already been done but only testing the 3rd Ed additions.

This keeps costs down a bit and shortens the testing time a bit but this is not entirely straightforward.

Why? Because many of the apparently similar requirements have detail changes and therefore do not map across from 2nd to 3rd Eds. Nevertheless it does save testing time as TÜV has carried out a very careful clause by clause equivalence appraisal.


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The cost challenges

What else can our clients do to keep costs down?

Prepare an insulation diagram so we don’t need to do it at increased cost. Use certified major components. Provide all the supporting documentation and certification required. Provide test reports of earlier tests (the previous model) if applicable.

Do prepare a relevant Risk Management file. TÜV can provide you with a checklist for the elements you need for the 3rd Ed.


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Questions

Any questions?


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TÜV Product Service LtdOctagon House Concorde Way Email: [email protected] North Tel: +44 (0) 1489 558 217Fareham, Hampshire Fax: +44 (0) 1489 570 686PO15 5RL, UK Website: www.tuvps.co.uk

ThankYou

http://www.tuvps.co.uk/

Norman Richardson – Medical & Health Services

Documents

TÜV Product Service Ltd © Open Day 24 June 2010Norman Richardson 1 ` TÜV Product Service Ltd Medical and Health Services Open Day 24 June 2010 Electrical