EBME Forums Forums Management Medical Equipment Management Multiple portable socket outlet problems

The Draeger anaesthetic machines I used to service had an IEC distribution board supplied from an seperate lead to power other equipment such as monitors. The IEC board stopped "rouge" equipment being plugged in according to the manufacturers and was seperate so that a problem with the monitor would not take out the anaesthetic machine as well. Only the correct equipment had an IEC plug put on it.
The Datex-Ohmeda machines where I now work have one mains lead and ordinary BS1363A (13Amp) sockets on the back. This worries me. I have not taken one apart as they are on contract.
I believed you should not be able to plug any old equipment in to a medical device. I thought distribution boards on medical equipment had to be covered to prevent equipment other than the intended stuff being connected or at least of a non-common type to stop the cleaners/ centifuges/laptops etc being easily plugged in. Am I right?
Does anyone know the internal connections of these Datex-Ohmeda Astheva machines?
Robert

The get out clause in the CE regs means you can manufacture for your own institution without having to have it assessed for CE marking.
This means you can modify your own kit quite legally. But cannot do it for anyone else and the kit cannot be used outside of your own institution.
Robet

2 points ;-

You can modify or manufacture anything you like and not get it CE marked as long as it's not passed on to another "organisation" (Trust or hospital, in our case) - but the risk if anything goes wrong is yours !

You don't create a "system" by using a shared mains supply. The equipment has to be connected together in a functional way (e.g. the signal lead to a printer) to constitute a system. Otherwise it would be difficult to differentiate between two items using a split mains lead and two items plugged into sockets on the same ring main

Roy,
Yes you do take responsibility - as a Trust not as a person - if you are doing your job and have done it properly, and risk assessed the project, you are safe.
The definition of a system from the MDA Device Bulletin is that a system shares a mains connection and if it is plugged in to seperate outlets even on the same ring main it is not a system. It does not have to have functional connection. So two seperate items on a distribution board are a single medical system and must be treated as such.
Robert

This is an old topic but still seems to be an issue today!

Many hospitals still allow the use of extension leads (multiple socket outlet) even though no assessment has been made to ensure what they have done will comply with 60601-1.

From Annex A of BS EN 60601-1:

Subclause 3.64 - Medical Electrical System

It is common practice for MANUFACTURERS, RESPONSIBLE ORGANISATIONS and OPERATORS to connect ME EQUIPMENT and other medical or non-medical equipment to MULTIPLE SOCKET-OUTLETS. The inclusion of such arrangements within the definition of ME SYSTEM brings them within the scope of this standard and thus allows appropriate requirements to be specified for BASIC SAFETY and ESSENTIAL PERFORMANCE.

To minimize the impairment of the safety level of this standard, the connection of a MULTIPLE SOCKET-OUTLET to the SUPPLY MAINS is subject to certain conditions. Subclause 16.9.2.1 requires that MULTIPLE SOCKET-OUTLETS are constructed to comply with the requirements from this standard applying to ME EQUIPMENT.

Clearly just plugging ME equipment into any old mains extension lead will not meet with the requirements of the standard. I have even seen portable X-ray equipment plugged into extensions! This would fail to consider the possible implications of the additional resistance affecting the line impedance, which may reduce the maximum output power of the X-ray tube and therefore affect image quality.

This is without the additional fact that most medical locations will have liquids spilled on the floor and it is unlikely the mains extension will be waterproof!

Basically all mains extensions should be banned from use with medical electrical equipment.

We probably need to distinguish between untethered "mains extension leads" of doubtful quality snaking across the floor, and the "multiple socket outlets" (strips) deliberately fixed to the rear of anaesthesia units, ultrasound machines, and the like.

Meanwhile, and out of interest, what other power supply options were available within reach of the "portable" (mobile?) x-ray unit you saw?

And lastly, yes; all this has been discussed many times before. Like here, for example.

There are a lot of devices in use in Theatre that use multiple socket outlets, anaesthesia systems and endoscopy stacks come to mind readily. An endoscopy stack could have a light source, camera system, insufflator and printer all requiring power. How do you ban the use of multiple socket outlets in these instances.

But all these things are already ME systems and will meet the requirements of IEC 60601-1. Well, at least they should! For example most endoscopy stacks have their own mains isolating transformer fitted.

The items of concern are locally sourced mains extension leads being used without any assessment with regard to IEC 60601-1. A clinical end user just bringing in a mains extension and plugging in assorted medical equipment is putting themselves and their patients at risk.

The latest edition of the Department of Health Technical Memorandum 06-01 has a nice single page poster about the subject of mains extension leads in medical locations in appendix 4.

HTM 06-01 (2017) looks like a useful document.

Perhaps it needs to be reviewed early on in "foundation" biomed training courses ... if only to "skim through" some of the (many) abbreviations involved.

For example:-

ERIC ... Estates Return Information Collection (?)
IMD ... insulation-monitoring device (previously known as a LIM)
Medical IT (isolated terra) ... meaning an isolated power supply*

Not to mention TN, TN-S and all the rest. See here for a nice .pdf about all that.

... how about it, Rob, Nigel?

Perhaps then we could all (biomeds, and "Estates") be "singing from the same hymn-sheet"; at least when it comes to electrical terminology.

By the way, it has a good section on maintenance ("Operational maintenance strategy"), too.

* And nothing to do with Information Technology!