MRI's and Article 517.13

[mc5w]

Re: MRI's and Article 517.13

Hitachi allows 120 VAC lighting but it has to be incandescent. Ballasts and electric discharge bulbs create too much electrical noise.

You are right about the MRI room having to be grounded as a single isolated ground appliance. The equipment ground has to be isolated from the supply conduits so as to keep the system from picking up radio stations. I misses a date on getting WQMX-FM out of a public address system.

 

[iwire]

Re: MRI's and Article 517.13

Originally posted by mc5w:
Hitachi allows 120 VAC lighting but it has to be incandescent. Ballasts and electric discharge bulbs create too much electrical noise.

I am not sure discharge lamps would work in such a strong magnetic field.

 

[physis]

Re: MRI's and Article 517.13

The lamps would fine.

 

[iwire]

Re: MRI's and Article 517.13

Sam this is as much of a question as a statement.

It is my understanding discharge lighting relies on a plasma arc.

I believe that arc would be acted on by the magnetic field.

Essentially 'pulling' the arc against the envelope, I imagine at the least this would shorten the life expectancy of the lamps if they even light up.

But I am really over my head here and am interested if I have any of this right.

 

[physis]

Re: MRI's and Article 517.13

Plasma is ionic and therefor will respond to a magnetic field.

 

[iwire]

Re: MRI's and Article 517.13

Originally posted by physis:
But You'll have a very hard time pulling the plasma through the glass tube.

Well that would be cool but I did not expect that.

 

[physis]

Re: MRI's and Article 517.13

Come on Bob, you thought there'd be plasma everywhere, all over the place.

For fun, after I read your other post I took a magnet from a hard drive (strongest magnet pound for pound I've ever encountered, that's why I keep them) over to my kitchen fluoro's, nothin'.

I kind of have some kind of intuitive idea that it might have a meaningful effect, but I can't think of anything that would be a bother. Without putting a field source in very close proximity.

 

[iwire]

Re: MRI's and Article 517.13

Actually I had metal halide lamps in mind.

 

[physis]

Re: MRI's and Article 517.13

I see, you're saying the arc might lay against the tube and be concentrated on the coating.

If I'm thinking of this correctly, the ionized gas carrying electrons will actually be electrically and magnetically neutral. And wont be effected by a magnetic field.

And I also think that if the gas is ionically homogenous that the only difference would be a microscopic difference in pressure on opposing sides.

But I'm getting a tad out of my element too now And would be interested in hearing from someone who could pick up from there.

 

[physis]

Re: MRI's and Article 517.13

I don't really know how those are built but I would guess that they work similarly.

Edit: Missing word Error B.

[ June 04, 2005, 08:44 PM: Message edited by: physis ]

 

[pierre]

Re: MRI's and Article 517.13

In reading the handbook for NFPA 99 Health Care Facilities, on page 52, Exhibit 3.7 shows and states: "An MRI (magnetic resonance imaging) unit, one of the many kinds of patient care apparatus."
"The term patient care vicinity more accurately conveys the intended meaning of a place where patients are actually cared for."
MHO - this is a patient care vicinity.

 

[charlie b]

Re: MRI's and Article 517.13

Originally posted by iwire: Do they examine patients in the MRI room? Yes or no? In my opinion it is that simple.

I have been out of touch for some time, and am coming into this one late. Also, I do not yet have my code books with me (I?m in the process of moving). So my opinion is based on, well, opinion, and not on code citations.

I have disagreed with jwelectric on other issues, but I agree with him here. An exam room that contains an MRI machine is not, by definition, a ?patient care area,? despite my use (in this very sentence) of the word ?exam.? Let us not get the English Language confused with code language.

A patient is not ?examined? by an MRI any more than a passenger is ?examined? by the metal detector that he passes through in the airport. There is nothing "medical" about the process of using an MRI to obtain an image. The process is not run by a person with medical knowledge, but rather by a person with expertise in operating the equipment. The medical part comes into play when a doctor reviews the scanned image, and the patient is not present when that happens.

The reason that there are special rules for a ?patient care area? is to make sure the doctors and nurses have enough power connections (from both the normal and critical branches) to operate the types of equipment they may need when performing a hands-on examination of a patient, or when responding to a medical emergency.

 

[charlie b]

Re: MRI's and Article 517.13

Originally posted by pierre: In reading the handbook for NFPA 99 Health Care Facilities, on page 52, Exhibit 3.7 shows and states: "An MRI (magnetic resonance imaging) unit, one of the many kinds of patient care apparatus." "The term patient care vicinity more accurately conveys the intended meaning of a place where patients are actually cared for."

I think this is another example of relying too heavily on the common, conversational, meaning of words. The notion of an MRI being a ?patient care apparatus? does not cause its room to become a ?patient care area,? as defined in the NEC. Also, a patient is not ?actually cared for? in an MRI room.

 

[iwire]

Re: MRI's and Article 517.13

Well I am not convinced.

If I walk through a metal detector I am being examined.

If I walk by a security camera I might be examined.

Patient Care Area. Any portion of a health care facility wherein patients are intended to be examined or treated. Areas of a health care facility in which patient care is administered are classified as general care areas or critical care areas, either of which may be classified as a wet location. The governing body of the facility designates these areas in accordance with the type of patient care anticipated and with the following definitions of the area classification.

It does not specify a doctor must be examining me or that that an examine must include physical contact.

The reason that there are special rules for a ?patient care area? is to make sure the doctors and nurses have enough power connections (from both the normal and critical branches) to operate the types of equipment they may need when performing a hands-on examination of a patient, or when responding to a medical emergency

That may be true to some extent but the rules also require redundant grounding in patient care areas. Which is what the OP was asking about.

Ultimately it will be up the the AHJ to decide.

Considering what is at stake I would opt for the safer interpretation.

 

[iwire]

Re: MRI's and Article 517.13

Originally posted by charlie b:
Also, a patient is not ?actually cared for? in an MRI room.

No?

Many times IVs are administered, then of course many patients have adverse reactions to the confined space and need attention.

IMHO this room should be considered a patient care area.

Here is the FPN after the patient care area definition

FPN:Business offices, corridors, lounges, day rooms, dining rooms, or similar areas typically are not classified as patient care areas.

To me those area are obviously not patient care areas.

If the NFPA thought that those areas which are obviously not patient care areas need to be included in an FPN I would think the FPN would also point out areas that are not so obvious such as MRI and Xray rooms.

IMO the reason those rooms are not in the FPN is that the NFPA considers those rooms patient care areas worthy of redundant grounding.

Which as it turns out can not be achieved in the MRI room anyway.

 

[jwelectric]

Re: MRI's and Article 517.13

I admit that my knowledge about health care facilities is not what it should be but I am working on this to get a better understanding of the code intent.

Dave?s post was addressing 517.13 Grounding of Receptacles and Fixed Electric Equipment in Patient Care Areas so I looked at the definition of Patient Care Areas as outlined in 517.02 of the 2005 cycle of the code.

As defined there are two types of Patient Care Areas and either or both can be a wet location.
When looking at the definition we see that in a General Care Areas there are some areas in which it is intended that the patient will come in contact with ordinary appliances such as a nurse call system, electrical beds, examining lamps, telephone, and entertainment devices. In such areas, it may also be intended that patients be connected to electromedical devices (such as heating pads, electrocardiographs, drainage pumps, monitors, otoscopes, ophthalmoscopes, intravenous lines, etc.).
Take not what is outlined above.

Then we have the Critical Care Areas. Those special care units, intensive care units, coronary care units, angiography laboratories, cardiac catheterization laboratories, delivery rooms, operating rooms, and similar areas in which patients are intended to be subjected to invasive procedures and connected to line-operated, electromedical devices.

By reading these definitions it is clear that there is a difference between a General and Critical care area but both are Patient Care Areas. In the Critical Care Area the CMP was sure to point out every room that applied to that portion of the Critical Area definition.

The CMP also added a part to 517 that clearly describes what an X-ray room is and the criteria is for wiring one. The only reference I can find in Part V that would lead me to believe that the X-ray room is an exam room is the reference found in 517.78 Guarding and Grounding. Part (C) where it states ?shall be grounded in the manner specified in Article 250, as modified by 517.13(A) and 517.13(B).?

Therefore I stand on my belief, until proven different, that a MRI or X-ray room is not a Patient Care Area
This belief is based on the fact that in a General Care Area it states ordinary appliances and a Critical Care Area we are trying to save a life. In a MRI or X-ray room we are taking pictures and not treating the patient.

 

[physis]

Re: MRI's and Article 517.13

By Charlie B.

A patient is not ?examined? by an MRI any more than a passenger is ?examined? by the metal detector that he passes through in the airport.

I think this is both symantics and not true. I agree that we need to deliniate between NEC English and real English and it could be made much less difficult if they'd put a few words in article 100.

There is nothing "medical" about the process of using an MRI to obtain an image. The process is not run by a person with medical knowledge, but rather by a person with expertise in operating the equipment. The medical part comes into play when a doctor reviews the scanned image, and the patient is not present when that happens.

Coincidently, my girlfriend's brother had been an MRI "operator" for many years. I don't know whether he's an MD, I don't believe he is. But he had to be certified. That certification did require extensive medical knowledge. He did operate the equipment and interpret the MRI results. He is easily as well trained as a nurse. I can't be sure just much medical knowledge is required though.

Either way, everything associated with MRI is "completely" medical.

Edit: I sound kind of arguementative here. Din't mean to Charlie.

[ June 06, 2005, 02:25 AM: Message edited by: physis ]

 

[roger]

Re: MRI's and Article 517.13

Originally posted by mc5w:
The entire interior of the room was shielded from outside interference with sheet steel.

This would have been aluminum.

It is really a moot point as to whether it is a "Patient Care Area" or not.

The metal within an MRI shielding envelope (the room is completely wrapped in copper or aluminum) is isolated through RF filters and a common ground post is provided for the insulated EGC through this envelope but makes no contact to other metals from inside to out.

There is a nonmetallic connection (we usually use Carflex) to tie the systems together keeping the metal inside and out isolated from one another.

Bob check your PM's


Roger

[ June 05, 2005, 03:21 PM: Message edited by: roger ]

 

[rick hart]

Re: MRI's and Article 517.13

If the patient is to come in contact with bedside electrical equipment for the purpose of continuation of their care, those outlets must have the provisions of 517.13 applied as any patient care area. There are rare instances that do require auxiliary equipment to follow the patient into an MRI, and they must not be ferrous.
I can see where design provisions of an MRI and NO patient care receptacles are installed in the MRI and other diagnostic (medical examination) procedures are used instead- CT.

As far as this being an oversight- no. NEC is not a design manual for every occupancy. If you install something under the NEC, it must comply with the appropriate sections. Patient care receptacles are installed, they must comply. A pet grooming salon is not specifically mentioned in NEC but the things installed are. It is up to the field personnel to comply with NEC unless engineering supervision allows and assumes the liability. I would hope that an MRI would have a Professional Engineer stamp the design.

 

[roger]

Re: MRI's and Article 517.13

Originally posted by roger:

Originally posted by mc5w:
The entire interior of the room was shielded from outside interference with sheet steel.

This would have been aluminum.

Mc5w, I have to retract that statement, steel can be used.

It's just that I have never been involved in an istallation that uses anything besides Aluminum or Copper.

Roger