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MRI LED lights dimmer control replacement - wow! #219087
01/18/18 11:41 PM
01/18/18 11:41 PM
Potseal  Offline OP
Member
Joined: Feb 2013
Posts: 264
Saskatchewan
I got a call last week to check out a problem with lighting in an MRI suite. There are two separate LED lighting circuits in the room with the MRI. One set of lights was working and the other set was "off" and the switch/dimmer control failed to turn them "on". After a few minutes of troubleshooting it appeared the problem was at the switch/dimmer control. I got lucky and after momentarily removing one of the wires at the back of the control the lights turned "on". Didn't solve the problem since the switch/dimmer control couldn't turn the lights "off". For the moment, having the lights permanently "on" is better than "off". My boss looked at what it would cost to buy a replacement control. He was a little shocked to find out it would be $1300. So what makes this control so special?

After reading about the product and how it's designed for the MRI suite I assume it's all about the R&D that goes into making a lighting system that works with little maintenance and minimal interference with the imaging. A few years back there was a MRI suite renovation that I worked on and heard about how the maintenance staff had to routinely change the incandescent bulbs nearest the MRI because the magnet would damage the filaments. We upgraded the lights to LED but apparently there was imaging problems after. Could it have been due to dimmer control interference? I do not recall that the LEDs and control we used were designed specifically for an MRI suite.

The documentation for the expensive dimmer control for the MRI suite I was working in last week describes how a typical LED dimmer, that uses PWM to vary the light output, creates a square wave which can cause interference with the MRI's imaging results. The expensive MRI designed dimmer apparently creates a trapezoid wave which supposedly minimizes interference with the image quality. But is it worth $1300? Apparently this manufacturer claims that 3rd party 0-10V dimming control will work but only if you buy a special module to interface the 3rd party dimmer and their proprietary dimming system. I can only imagine how much that would cost.

At the end of the day I guess you can look at the big picture and start adding up how expensive MRI's are to install and operate and then the $1300 dimmer control doesn't look very expensive. On the other hand it's a publicly funded system that is always trying to find money so any time you can save a dollar...some administrator with zero accountability will find another way to waste two smile

Last edited by Potseal; 01/18/18 11:44 PM.

A malfunction at the junction
--------------------------------------
Dwayne
Work Gear for Electricians and the Trades
Re: MRI LED lights dimmer control replacement - wow! [Re: Potseal] #219088
01/19/18 07:05 AM
01/19/18 07:05 AM
A
andey  Offline
Member
Joined: Aug 2008
Posts: 46
germany
In a sensitive environment like a hospital or MRI suite, I would strongly recomment to swap such parts 1:1.
Somebody must have checked their usability for this environment before, maybe even wrote a risk assessment for it.
If you put in a 50$ dimmer, you take over the responsibility, if problems develop.

When you start thinking about the money burnt and mis-used in medical care, (as in many many other fields) you will not get any more nights sleep. I try not to think about it.

I used to work in medical electronics engineering for a short time and sometimes heard the sentence "money doesnt play a role". Thats one reason why I didnt stick with medical.

Last edited by andey; 01/19/18 07:07 AM.
Re: MRI LED lights dimmer control replacement - wow! [Re: Potseal] #219089
01/19/18 12:37 PM
01/19/18 12:37 PM
G
ghost307  Offline
Member
Joined: May 2005
Posts: 943
Chicago Illinois USA
Those types of installation are very tricky as they are sensitive to stuff we would never think of.
Even the light fixtures have to be designed specifically for the MRI suite.

I'd ask why things cost so much (for my own education); but I'd still put it in (for my own peace of mind).
You may save a few dollars now; but what will it end up costing if the MRI misses something in a patient and the lawyers trace it back to someone trying to save a buck or two.


Ghost307
Re: MRI LED lights dimmer control replacement - wow! [Re: Potseal] #219090
01/19/18 07:19 PM
01/19/18 07:19 PM
HotLine1  Online Content

Member
Joined: Apr 2002
Posts: 6,964
Brick, NJ USA
Potseal:

As Ghost said, think of the possible liability you, your boss, the company may face. You may want to look at the original plans and specs for the MRI suite, and replace with the exact same items. If the plans/specs are not available, think about contacting the MRI mfg., for assistance.

The personal injury/medical malpractice lawyers here, in the event of an incident would be lined up.


John
Re: MRI LED lights dimmer control replacement - wow! [Re: andey] #219092
01/19/18 09:52 PM
01/19/18 09:52 PM
Potseal  Offline OP
Member
Joined: Feb 2013
Posts: 264
Saskatchewan
Originally Posted by andey
In a sensitive environment like a hospital or MRI suite, I would strongly recomment to swap such parts 1:1.
Somebody must have checked their usability for this environment before, maybe even wrote a risk assessment for it.
If you put in a 50$ dimmer, you take over the responsibility, if problems develop.

When you start thinking about the money burnt and mis-used in medical care, (as in many many other fields) you will not get any more nights sleep. I try not to think about it.

I used to work in medical electronics engineering for a short time and sometimes heard the sentence "money doesnt play a role". Thats one reason why I didnt stick with medical.


Nobody's thinking of trying a standard $50 dimmer. As I mentioned above, I read the manufacturer's documentation and it explains the difference in how their MRI dimmer works vs a standard dimmer. But is it worth $1300? I really doubt it. Unfortunately in the health care system we often find ourselves in this position, for many reasons, where you have no choice.

In less critical areas we don't always follow that route. For example, I have had circuit boards go on automatic door openers and have replaced them with general purpose circuit boards that can be programmed to do the same thing as the OEM part (these doors are NOT controlled by the building's fire system). Naturally, these are items that are no longer under warranty. I am not trying to save the health system $$$ with the thought that I am making a difference - that's hopeless. For many of us I think it's part of our make-up to find inexpensive solutions where it appears that we might be getting taken advantage of.


A malfunction at the junction
--------------------------------------
Dwayne

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