LED lamps in an MRI room

[woodduder]

I have a customer that wants to upgrade their existing incandescent light fixtures in an MRI room to LED. Dedicated LED fixtures are $400.00+ per fixture, so quite costly. Has anybody used LED lamps to replace the incandescent lamps? Does it work OK? Is there an approved LED lamp for use in an MRI. We would be replacing 65 watt R lamps.

 

[gadfly56]

I have a customer that wants to upgrade their existing incandescent light fixtures in an MRI room to LED. Dedicated LED fixtures are $400.00+ per fixture, so quite costly. Has anybody used LED lamps to replace the incandescent lamps? Does it work OK? Is there an approved LED lamp for use in an MRI. We would be replacing 65 watt R lamps.

The LED's have an electronic ballast in them. I would wonder what the local magnetic fields from the MRI might do to the new lamps.

 

[dkidd]

I have a customer that wants to upgrade their existing incandescent light fixtures in an MRI room to LED. Dedicated LED fixtures are $400.00+ per fixture, so quite costly. Has anybody used LED lamps to replace the incandescent lamps? Does it work OK? Is there an approved LED lamp for use in an MRI. We would be replacing 65 watt R lamps.

They seem to make them.

http://www.kenall.com/Kenall-Files/Product-Files/Literature/Kenall_MRI_PSG.pdf

 

[iwire]

I have a customer that wants to upgrade their existing incandescent light fixtures in an MRI room to LED. Dedicated LED fixtures are $400.00+ per fixture, so quite costly. Has anybody used LED lamps to replace the incandescent lamps? Does it work OK? Is there an approved LED lamp for use in an MRI. We would be replacing 65 watt R lamps.

MRI time costs thousands per hour, I would sell them $400 fixtures all day long.

 

[woodduder]

They seem to make them.

http://www.kenall.com/Kenall-Files/Product-Files/Literature/Kenall_MRI_PSG.pdf

Yes they make dedicated LED fixtures for MRI's, that is a fact, but the driver (which is large enough to run several fixtures) has to remain outside of the magnet room and an RF filter installed. I was hoping for an easy screw in lamp solution.

 

[mgookin]

MRI time costs thousands per hour, I would sell them $400 fixtures all day long.

+1

 

[GoldDigger]

The LED's have an electronic ballast in them. I would wonder what the local magnetic fields from the MRI might do to the new lamps.

That is not a problem.

I would worry much more about what the RF emissions from the LEDs would do to the very sensitive electronics of the MRI equipment.
CT scanners use radiation and electronic radiation detectors to do their imaging. The radiation detectors are not particularly sensitive to RF and can be pretty easily shielded.

MRI machines, OTOH, detect very low intensity RF emitted and absorbed differently by atoms immersed in a strong magnetic field. Any RF emission near the machine, whether from the drivers or from the LEDs themselves cannot be tolerated by the MRI equipment. Think of the MRI machine as combining a radio transmitter and a sensitive radio receiver (with directional antennas) with a strong and variable magnetic field.

That is why the purpose-built LED fixtures for MRI environments use remotely mounted drivers and EMI filters between the drivers and the LEDs to minimize RF emission in the MRI room.
The emissions from standard screw-in replacements vary enormously from brand to brand and model to model. Even if you could find low-emission bulbs that would be acceptable, there is no guarantee that the same identical bulbs with the same RF specifications will be available in the future.

This is a highly specialized area, and I would not recommend relying on shirt pocket engineering by an electrician or even an ordinary lighting designer.

 

[steve66]

That is not a problem.

I would worry much more about what the RF emissions from the LEDs would do to the very sensitive electronics of the MRI equipment.
CT scanners use radiation and electronic radiation detectors to do their imaging. The radiation detectors are not particularly sensitive to RF and can be pretty easily shielded.

MRI machines, OTOH, detect very low intensity RF emitted and absorbed differently by atoms immersed in a strong magnetic field. Any RF emission near the machine, whether from the drivers or from the LEDs themselves cannot be tolerated by the MRI equipment. Think of the MRI machine as combining a radio transmitter and a sensitive radio receiver (with directional antennas) with a strong and variable magnetic field.

That is why the purpose-built LED fixtures for MRI environments use remotely mounted drivers and EMI filters between the drivers and the LEDs to minimize RF emission in the MRI room.
The emissions from standard screw-in replacements vary enormously from brand to brand and model to model. Even if you could find low-emission bulbs that would be acceptable, there is no guarantee that the same identical bulbs with the same RF specifications will be available in the future.

This is a highly specialized area, and I would not recommend relying on shirt pocket engineering by an electrician or even an ordinary lighting designer.

Exactly. If you look at the ones Kennal makes for a MRI room, you will notice they are DC. The DC power can make it through the RF filter as it passes into the room, and it won't interfere with the imaging. Even the older incandescent MRI fixtures are usually supplied with DC power, even if it used a standard AC incandescent lamp.

 

[GoldDigger]

Exactly. If you look at the ones Kennal makes for a MRI room, you will notice they are DC. The DC power can make it through the RF filter as it passes into the room, and it won't interfere with the imaging. Even the older incandescent MRI fixtures are usually supplied with DC power, even if it used a standard AC incandescent lamp.

:thumbsup:
Ordinary incandescent lights will not emit RF, but they can produce a large enough magnetic field from the filament to be a problem IF that field is varying.

 

[woodduder]

That is not a problem.

I would worry much more about what the RF emissions from the LEDs would do to the very sensitive electronics of the MRI equipment.
CT scanners use radiation and electronic radiation detectors to do their imaging. The radiation detectors are not particularly sensitive to RF and can be pretty easily shielded.

MRI machines, OTOH, detect very low intensity RF emitted and absorbed differently by atoms immersed in a strong magnetic field. Any RF emission near the machine, whether from the drivers or from the LEDs themselves cannot be tolerated by the MRI equipment. Think of the MRI machine as combining a radio transmitter and a sensitive radio receiver (with directional antennas) with a strong and variable magnetic field.

That is why the purpose-built LED fixtures for MRI environments use remotely mounted drivers and EMI filters between the drivers and the LEDs to minimize RF emission in the MRI room.
The emissions from standard screw-in replacements vary enormously from brand to brand and model to model. Even if you could find low-emission bulbs that would be acceptable, there is no guarantee that the same identical bulbs with the same RF specifications will be available in the future.

This is a highly specialized area, and I would not recommend relying on shirt pocket engineering by an electrician or even an ordinary lighting designer.

I think I will have them call the GE rep that sold the MRI so he can discuss with them. I'll let him tell them what they need to have. Thanks for the replies.

 

[jumper]

MRI time costs thousands per hour, I would sell them $400 fixtures all day long.

+1

+2

 

[GoldDigger]

I think I will have them call the GE rep that sold the MRI so he can discuss with them. I'll let him tell them what they need to have. Thanks for the replies.

You are welcome. Sounds like a good way to avoid being in the middle between the two.

MRI manufacturers may well go overboard on some items, based on earlier generation machines (or even contradict the NEC, as with language about independent ground rods), but in general you cannot go wrong by following their instructions, while not asking could lead to major grief.

 

[steve66]

:thumbsup:
Ordinary incandescent lights will not emit RF, but they can produce a large enough magnetic field from the filament to be a problem IF that field is varying.

They will emit RF if they are put on a dimmer, and many MRI rooms are equipped with dimmers. So the MRI dimmers generally always put out DC.

And one problem with providing straight 60 Hz., 120V AC is that the filament won't last long because it will vibrate due to the 60 Hz. being applied in the presence of a strong magnetic field.

 

[shoon]

FWIW,

I went this route in a garage I am building. I was able to get the 4' T8 LED lamps for around $16 CDN per bulb. So for each fixture- $32 for bulbs and $50 for a cheapo fixture puts me under $100 a fixture which is decent for LED.
There are a few options you can go if you decide to go this route. Some of the LED lights have the option of running off the existing ballast (which nullifies the energy efficiency offered by the LED somewhat because of losses in ballast) or you can get LED's that require you to remove the ballast and wire tombstones directly to 120. Some of the LED tubes allow you to rotate the end pins to aim the tubes in certain directions as well.

The market has been flooded with LED products, so depending where you buy from make sure you still have the UL certifications.

 

[GoldDigger]

FWIW,

I went this route in a garage I am building. I was able to get the 4' T8 LED lamps for around $16 CDN per bulb. So for each fixture- $32 for bulbs and $50 for a cheapo fixture puts me under $100 a fixture which is decent for LED.
There are a few options you can go if you decide to go this route. Some of the LED lights have the option of running off the existing ballast (which nullifies the energy efficiency offered by the LED somewhat because of losses in ballast) or you can get LED's that require you to remove the ballast and wire tombstones directly to 120. Some of the LED tubes allow you to rotate the end pins to aim the tubes in certain directions as well.

The market has been flooded with LED products, so depending where you buy from make sure you still have the UL certifications.

And just what does your garage have in common with an MRI room in a medical facility?

 

[iwire]

And just what does your garage have in common with an MRI room in a medical facility?

Hey, maybe he provides MRIs as a hobby.

 

[tshea]

LED in MRI room

LED in MRI room

Last one we did the Architect said NO to LED. He's done about 30 MRI rooms. We installed EFI/RF filters for all the lights. These were 65R30. All were located away from the magnet.
Interesting work if you can get an MRI room.

 

[brantmacga]

MRI time costs thousands per hour, I would sell them $400 fixtures all day long.

No kidding.,..: I had one this year and it was almost $5k for 90 minutes.


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[Electric-Light]

MIL spec, medical grade or laboratory apparatus accessories cost many times more because of lower volume, different sales network and more hands on verification requirement. The high cost of things going wrong means they are way more likely to make factory recommended purchase no questions asked.

It could be a vendor built kit but someone has to pay for research, shopping and testing. If they only sell a handful a year $400 is a fair price.

24v or 12v LED tapes are usually simple. 3 or 6 LEDs in series with a resistor. They should be free of magnetic materials.
They would just wire the same path as the existing incandescent bulbs and terminate to an old school design unsophisticated linear constant current power supply. Some standard PWM dimming LED ballast make the LED strips into an effective RFI emission antenna and don't even pass FCC regulations for home use. Current reduction types spray less interference but if it uses switching power supply, the noise level can be too much. A linear power supply uses analog circuits to operate a transistor like a big rheostat. It's not very efficient but it produces a very clean power.

Standard light fixtures use chassis and fasteners that stick to magnet.

 

[QUANTU]

LED installed in MRI

LED installed in MRI

We had led light installed last year. They works goog so far