Medical Device on/off switch symbolization

[Constantijn]

Hello everyone.

I am new to this forum and have a question regarding a on/off switch for a medical device.
We are developing an ENT treatment unit and I would like to know how I have to read the text under Clause 7.4.1 of the IEC60601.
Our ENT unit is a fixed unit with a detachable power cord, a mains inlet coupler and a mains rocker switch adjacent to it.
Normally this switch will be not used by the user because it is located on the back of the unit. On the front of the unit we also have a rocker switch which shuts down the controls of the unit.
Due to some redesign we want to perform, we want to get rid of the rocker switch on front of the unit and replace it with a more sophisticated switch.
The one we have in mind is a push button non-latching switch which has to activate a relay and sequentially powers up the system.

The question for now is: should I see this switch according to the above mentioned clause as a momentary switch (so it should be carrying symbol 5011 of the IEC60417) or as a switch with a bistable function (carrying symbol 5010 of the IEC60417)?

Any help is appreciated.

 

[Jen Kirley]

A quick bump...

Can anyone help?

 

[Pads38]

I would suggest that it would be 5011 - momentary action.

But - if you look at 7.4.1 it says symbol 5011 OR light OR other non-ambiguous means.

I do not think there would be any problem with using the symbol AND a light (or other means). Perhaps a display panel springing to life would be sufficiently clear.

Ultimately, if this is significant to your design, this aspect (the clear and non-ambiguous meaning of the switch) could be verified by Usability testing.

And welcome to the forums.

 

[Constantijn]

Thanks for your reply.
I think we can explain the function of the switch when our LCD jumps on.

But, regarding the symbol 5011.. I'm not every day working in a hospital environment, but I can't remember that I've seen this symbol before nor on any Medical Device. As a matter of fact, I think that if I did see symbol 5011 on a switch, I would actually not know the meaning of that switch... Is it a commonly used symbol?
I would rather go for a symbol like IEC 5009,(line partially within a broken circle), which indicates a sleep mode or low power state. Am I allowed to use that symbol?(perhaps in combination with the LCD screen which jumps on?)

 

[Pads38]

Re-reading the text alongside the symbols I now realise 5011 would not be right. (It is "Push and Hold for On").

I think that you may have the choice between using the "...other non-ambiguous means..." or another symbol. I would agree that symbol 5009 is more widely used (and recognised). However, it is not one of the symbols shown in Annex D of 60601.

Also, 5009 specifically means "On/Standby"; does your device function like that?

 

[Constantijn]

We are still developing, we have planned a solid rocker switch adjacent to our mains inlet power cable which shuts off the power to the complete device.
However, because our device will incorporate a controller and an LCD screen (and probably a user PC), we would also like for the user at the end of the day to be able to shut the device partially (controller, LCD screen and PC) down using the pushbutton on the front.

Reading my reply whilst typing it, I realize I should call this a standby mode..
Or an idle mode? Is there a difference between standby and idle? Because English is not my native language, it makes the explanation of some definitions of the 60601 sometimes a bit difficult.

It's very typical that the 60601 does not mention anything about idle nor standby switches at all.
Anyway, I think when I use the 5009 symbol (or probably even the written text "on/off") on this switch, I would comply with the 60601 line which is stating "...other non-ambiguous means...".

Thank you for thinking with me.