Electrical Safety Testing of Active Medical Devices

TÜV Product Service Ltd © 60601-1 3rd Edition Norman Richardson1

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Electrical Safety Testing of

Active Medical Devices –

New challenges. IEC 60601-1:2005

Presented by Norman Richardson

Senior Medical Device Specialist


IEC 60601-1:2005 The 3rd Edition

1. 60601-1:2005. Background and what went into it

2. 60601-1:2005. The major changes

3. Update on the collaterals

4. The technical challenges

5. The timing and implementation challenges

6. The cost challenges

TÜV Product Service Ltd © 60601-1 3rd Edition Norman Richardson

IEC 60601-1:2005 The 3rd Edition

IEC 60601-1:2005

3rd Edition

„The General Safety Document‟

3


Background








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.

5



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.

6



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)

7



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:11


Examples of Essential Performance

...and so on

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‘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


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. Classification

No 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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8.5 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) 15




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)16




• 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 conditions

Many 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.

20


The collaterals








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.)

22


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)

23


The technical challenges









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.

27


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.

28


Timing and implementation








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.

30


The cost challenges








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.

32


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.

33


Questions

Any questions?

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TÜV Product Service LtdOctagon House

Concorde Way Email: [email protected]

Segensworth North Tel: +44 (0) 1489 558 217

Fareham, Hampshire Fax: +44 (0) 1489 570 686

PO15 5RL, UK Website: www.tuvps.co.uk

Thank

You

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

Norman Richardson – Medical & Health Services

Documents

Electrical Safety Testing of Active Medical Devices