ME (Medical Equipment) Systems - IEC 60601-1 Clause 16.1 Interpretation

[Eamon]

60601-1 cl. 16.1 states that the ME system shall provide:

outside the PATIENT ENVIRONMENT, the level of safety equivalent to equipment complying with their respective IEC or ISO safety standards.​

I need to understand better what "the level of safety equivalent to equipment complying with their respective ... safety standards". Is "safety" interpreted narrowly, or broadly?

Can we interpret this to mean that if a device (e.g. a battery charging device) is certified to IEC 60950, and is intended to be placed only in the operator environment as part of a medical electrical system, it will only need to comply to IEC 60950?

If "safety" is interpreted broadly, it could mean for example that 60601-1 provisions for the colour of indicator lamps (specified in cl. 7.8.1) would not apply to indicator lamps on the IEC 60950 compliant device, so an off the shelf device 60950 compliant device could include an indicator lamp that flashes red without indicating a warning, for example.

If "safety" is interpreted narrowly, it might just mean electrical safety, in which case 60601-1 cl. 7.8.1 would have to be applied to the 60950 compliant device.

Best regards

Eamon Egan

 

[Peter Selvey]

Re: ME Systems - IEC 60601-1 Clause 16.1 interpretation

For the purpose of Clause 16.1, the reference simply means establishing compliance with the appropriate product standards for non-medical devices in the system, such IEC 60950-1 for IT equipment, IEC61010-1 for lab equipment etc.

Broader safety issues should still be covered under ISO 14971 (general risk management). For example if a 950 PC outside of the patient environment controls a robotic surgical laser, there would be many safety issues to consider. But that is not the target of Clause 16, rather it just focuses a few basic items like electrical shock, mechanical injury, power fail, connectors.

 

[Eamon]

Re: ME Systems - IEC 60601-1 Clause 16.1 interpretation

Hi Peter, thanks for the reply.

The specific question is whether an off the shelf wireless power transmitter (used to charge a medical device, in non-operational mode outside the patient environment), can be specified for this purpose, certified and sold along with the medical device, on the assumption that it conforms to 60950, and does not present any unacceptable risks as determined in the RMF.

In spite of the fact that it has a status indicator which does not conform to 60601 cl. 7.8.1

If you'd like to weigh in on this more specific question, I'd very much appreciate knowing what you think.

Regards

Eamon

 

[Peter Selvey]

Re: ME Systems - IEC 60601-1 Clause 16.1 interpretation

Within the context of Clause 16, it clearly not relevant. Within the context of risk management, probably not worth mentioning either unless the nature of the indication raises some concerns about possible confusion.

I know there are people out there that like stretch the words in the standard, but the check point is consistency. Yes, a red light fails IEC 60601-1, but if you want to go down that road, where do you stop? A red light just happens to be a prominent requirement. But why borrow just this one when there are 1500 other requirements from IEC 60601-1? Who decides which IEC 60601-1 requirements to transfer to non-medical ME system components?

Standards will always have unclear wording, so it's always good to test whether an interpretation is feasible to be universally or consistently applied.

To summarise: For Clause 16.1 it is enough to have the certificates or declaration of conformity for the non-medical device. Then you can write "Pass". Other system related risks can be handled in the RM file if they are significant. But this is not linked to Clause 16.1.

 

[Eamon]

Re: ME Systems - IEC 60601-1 Clause 16.1 Interpretation

Hi Peter,

thanks again for the clarification.

It seems to me that we can distinguish two ways in which 60950 certification might be used in the context of 60601-1:

1) Where it is specifically called out as being adequate for MOOPs for test voltages, creepage & clearance (many references in part 8);

2) As one of the possible applicable standards to apply to operator safety in part 16.

The point in making this distinction is, that if one is pointing to certification of a component under part 16 (to argue, for example, that a red LED can be overlooked since it's 60950), this is necessarily done in the context of calling the whole shebang a "system". Whereas, it would not be necessary to invoke 16.1 (to more generally allow application of another safety standard) if one were just allowing a 60950 certified power module as adequate for operator protection, as allowed in part 8.

Now, it does seem counter-intuitive to turn the whole thing into a "system" just because we intend to use an off-the-shelf charging pad, but I guess if you can do this for a 60950 PC, you should just as well be able to do it for something a lot less complex like a charging pad.

- Eamon

 

[Peter Selvey]

It's good to keep in mind that one of the benefits of standards is that they standardise. We enjoy for example the benefits of USB connections based on universal standards. Doubtless many engineers think there are a few crazy overkill rules in the USB spec, but the benefits of the common construction far outweigh the occasional idiosyncrasy.

The same applies here. If I had a dollar for every time a manufacturer of a medical device complained during tests that there is no way their little red LED at the base of a device is ever going to be taken for "danger/urgent action", I'd have, well, actually, six dollars. But you get the point.

Making a strict rule for medical devices - no red for non-urgent indicators - doesn't mean every red LED is dangerous, it's just a kind of collateral damage sustained in realising the broader benefits of standardisation. And after a while most manufacturers learn not to use red, so it becomes even more efficient.

But we don't want extend that to support equipment in an ME system: that would an unacceptable level of destruction in the name of standardisation.

The switch in 8.2.1 allows the manufacturer to decide if a battery charger is part of the ME equipment or an ME system. The first option bans a red LED while the second would allow it - this seems illogical for the individual case, but makes sense in the broader context of standardisation.

 

[Eamon]

Hi again Peter,

Thanks a lot for the reference to 8.2.1. Although it makes sense logically, I didn't know that the option of "turning the whole thing into a system" was given as an explicit option in the case of a non-ME power supply.

Eamon