What is the best LED light for medical use?

[BabyDoc]

I recently purchased my fist LED light (Fenix L2D Q5 Premium) to use in my pediatric practice, but have been disappointed when looking at throats that the light alters mucous membrane coloration. It gives a slightly bluish cast to tissues within the mouth that should look pink or red. Throats that appear inflamed with a incadescent light source, look less inflamed with LED light compared to surrounding normal tissues. I am using the L2D on 12 lumens (its lowest level) which could be part of the problem. I wonder if this is really more illumination than is needed, and might be washing out color differences. Or coultd the Q5 Cree LED be the tinting everything. (It is funny but I don't appreciate a particularly blue tint when I shine the light on a white wall. )

Is there perhaps another LED Flashlight that might be better suited for medical use that will enhance color differences rather than decrease them as the Q5 Fenix L2D seems to do? If there any medical people with experience who can provide help with this, I would appreciate it.

 

[mkmckinley]

The rebel 100 Fenix's have a warmer color, but if you're just looking in throats why not just get a few solitaires. That's what I use instead of those craptastic penlights as they're borderline disposable and I can lose and loan them without worrying about them. You don't really need a $50 flashlight to light up a kids mouth.

 

[meuge]

I have repeatedly tried to get away from incadescents for examining mucous membranes, and I cannot. I've tried Cree, Rebel, and even old Luxeon...

Perhaps it's because I learned using incads, but I just cannot use LEDs for this purpose, and wind up using my NiCd otoscope/ophthalmoscope as the source of light.

I suppose that perhaps a penlight using a warm-white LED would do the trick, but I don't believe it's mass-produced.

I might even try to make a mod... but I wouldn't know where to start looking for the warm-white LED emitters... as well as constant-current <50mA drivers

 

[Gunner12]

If you really want to use LED, you might have to use the warm white ones (the normal ones don't have enough red light for this application, unless you are used to the light).

A modder here might be able to swap out the LED for a warm white one.

 

[Manzerick]

I think a lot (aside from the real color differece) is how you were trained. Has an LED been the way you were trained, it would not be as "different". I'm just throwing it out there :lolsign:

Who knows?

 

[Beastmaster]

From my standpoint (working with 19 different Physician practices scattered in the Phoenix area) - LED's wash out the detail. Even the cheapie LED penlights that you get at Lowes (Energizer 2xAAA) wash out things too much.

As much as I love LED's - in this case, stick with Incan. Besides, the cute drug reps tend to have incan penlights as giveaways a lot of times.

-Steve

 

[AvidHiker]

Oh, fantastic BabyDoc - what a coincidence!

I was asked to start this thread just the other day by my girlfriend who is in family practice residency right now in NYC. I can see how the significantly different color spectrum of LEDs might cause problems for those (or should I say, most) who are accustomed to incans.

Agreed, warm white LEDs might offer some improvement, but they seem to seldom find their way into flashlights - I suppose due to their relative inefficiency. Another thing to consider would probably be the color rendering index (CRI) of the LED. Does anyone know how warm white LEDs compare in terms of CRI? Is it significantly improved over cooler emitters?

Guess its time for me to start a CPF search.

 

[BabyDoc]

From my standpoint (working with 19 different Physician practices scattered in the Phoenix area) - LED's wash out the detail. Even the cheapie LED penlights that you get at Lowes (Energizer 2xAAA) wash out things too much.

As much as I love LED's - in this case, stick with Incan. Besides, the cute drug reps tend to have incan penlights as giveaways a lot of times.

-Steve

Do you think the problem with color is a washout of color is due to overillumination? 12 Lumens is a bit much when you are less than a foot away. Would a lower output LED be just as likely to do this? Has anyone tried a NavaTac 85 or 120 P and set it at just a few lumens?

The bottom line is I would love to write one of these nice flashlights off for business purposes. Otherwise, I would just use the cheapie incadescents or the wall otoscope. Besides, the HMO where I work doesn't allow those cute drug reps with giveaways in here any more.

 

[AvidHiker]

oops, double post

 

[AvidHiker]

A quick hit from Google:

http://www.ledsmagazine.com/news/4/11/19

As expected, a fix is in the works to improve the red end of the spectrum. Phosphor technology obviously has a ways to go, but such research should be a priority as high power LEDs continue to rapidly mature.

Also, BabyDoc - 12 lumens sounds like it might be overkill for such short range illumination. I wouldn't be suprised if that contributes to the color wash-out.

 

[BabyDoc]

A quick hit from Google:

http://www.ledsmagazine.com/news/4/11/19

As expected, a fix is in the works to improve the red end of the spectrum. Phosphor technology obviously has a ways to go, but such research should be a priority as high power LEDs continue to rapidly mature.

Also, BabyDoc - 12 lumens sounds like it might be overkill for such short range illumination. I wouldn't be suprised if that contributes to the color wash-out.

Thank you for this link. I guess the problem is with the current LED's. They just can't render accurate reds. But I guess there is hope for the future with these new LED's. This article specifically says they will be better suited for medical/dental purposes.

 

[OceanView]

I was under the impression that even "warm whites" are still deficient in certain color regions, like the red end. Is that true? An incan may look "warm" but at least it has a fairly full spectrum when trying to differentiate colors, while a "warm white" may look similarly "warm" but actually be deficient in certain regions and be unacceptable for this kind of work.

I don't think "getting used to" an LED is really a good answer to this physician's question. The problem is lack of color information, and you can't tell if something isn't red because it really isn't, or just because there's not enough red in the light. Or put another way, the green of my houseplants looks pale in LED light. Can I conclude that my plants are dying and lack chlorophyll, or are they just pale because the LED light lacks enough green?

 

[dougie]

Hi! I'm a UK paramedic and cant remember when I last used anything other than a LED for oral illumination. The primary care practice I work at in the mornings doesn't have LED devices for anything so the majority of the clinical staff are more used to using incandescent equipment:shakehead. However, we have one German surgeon who does use a LED light for throat examinations without issues.

I personally have noticed a marked problem with color rendition when using more powerful LEDs. Perhaps that is your problem?

FWIW I recently bought a Surefire E1B which offers a 5 lumen output on low with a distinct warmish color. My experiments with it over the past few days are extremely positive and if you get a chance I'd try one out?

Even if you find it doesn't work for you I'm sure you'd find a use for it?

Doug:thumbsup:

 

[BabyDoc]

It sounds to me from what other people are saying that color rendition in the red region and green region is a problem with these lights. It is amazing that we spend so much time on this forum talking about lumens, and so little about accurate color rendition. We shine our lights on walls and worry about how pure the white and how even the spread is, rather than worry about how pure the colors of the objects the light is supposed to illuminate. I am surprised this topic doesn't come up here more often. I am a new flashlightaholic and have been rather excited about how bright and efficient these lights are. I love their style, feel, and flexibility in output. However, the fact that these lights don't render colors accurately is somewhat sobering. Sigh!

 

[cv3po]

I don't know about best but I've found the new DS series Nichia 5mm led's to have a nice warm color. These are used in the new Photon II, Freedom and Rex. The latter two are dimmable and might work quite well for you. I have a PII with a single 2032 instead of 2-2016 batt's and it leans to the yellow end of the spectrum. As always YMMV, good luck!

 

[Beastmaster]

Do you think the problem with color is a washout of color is due to overillumination? 12 Lumens is a bit much when you are less than a foot away. Would a lower output LED be just as likely to do this? Has anyone tried a NavaTac 85 or 120 P and set it at just a few lumens?

The bottom line is I would love to write one of these nice flashlights off for business purposes. Otherwise, I would just use the cheapie incadescents or the wall otoscope. Besides, the HMO where I work doesn't allow those cute drug reps with giveaways in here any more.

Bummer on the drug reps.

Here's my take on it.

As others have mentioned - color rendition has a lot to do with it. Warmer LED's may help, but you're in a position where you have to have accurate color rendition.

Overpowering light also has a lot to do with it too. I know that in my own testing of various flashlights, washout can occur.

As for why people like the whiteness and brightness - I'll have to slip back to my old Police instructor mode again.

When you're on the street - you need the brightest, baddest, and toughest flashlight that either a) the department gives you or b) you buy for your own use.

In order to screw with people's eyes in a low light tactical situation, you need a light that is brighter than the surrounding background lighting (if you're in an urban scenario) and a light that you can turn on and off rapidly while moving.

LED's provide another plus. It's bluish side of the spectrum forces a harsher reaction of the rods/cones/iris and also has a longer lasting negative temporary effect. There's a joke about testing LED effectiveness by how fast your vision returns. There's some truth to it.

The con of all this is that color rendition goes out the tubes. I get far better color rendition with my SureFire A2 Aviator than I do with my 6P LED.

So - LED's in some uses have a huge advantage. In the medical industry - it doesn't.

-Steve

 

[FlashInThePan]

Although there's still some debate on the subject, I think that most people on CPF would agree that LEDs are worse for color rendition, especially in the red end of the spectrum. This problem's most noticable when you're outdoors, or when you're using the light to examine body tissues.

I too would recommend an incan for your purposes. However, if you really want to use an LED, another option is to use a modified light that has a warm tinted LED along with a red LED. Various CPF members have made these kinds of dual-led mods (and my apologies to those who did, for I can't remember your names!). The red LED helps make up for what the standard white LED lacks. I've seen these mods in person; while they still don't offer the color rendition of an incan, they're a definite improvement over a standard white LED alone. If you want, I'm sure that you could post your desires here, and any number of respected CPF modders could help you out!

 

[FrogsInWinter]

. . . It is amazing that we spend so much time on this forum talking about lumens, and so little about accurate color rendition. . .

Actually there have been threads talking about the differences in color rendition between Incans & LEDs. Sometimes the debate gets a little heated too. If I have the time I'll try to find the links to some of those threads. Or maybe some kind soul could post the links to the threads about color rendition differences between LEDs & Incans? It seems like you want to stick with LEDs, but you might have to use incans for oral exams.

If money is not too much of a concern, SureFire's incandescent lights are top quality. I've heard lots of good things about the A2 Aviator in particular. But 50 lumens might be overkill, and you might be less than thrilled with the 50 minute runtime on a set of batteries. Streamlight also has good quality lights.
If you don't like the idea of changing batteries, then I would recommend a rechargeable incandescent light. Again SureFire and Streamlight have good lights that might be able to meet your requiremets.

From SureFire:
- E1e Executive Elite (15 lumens)
- 9AN Commander (This is NOT overkill, the low mode for this light is listed at 20 lumens)

From Streamlight:
- Propolymer 2AA (xenon of course)
- anything from the Twin-Task line

You might want to consider a headlamp as well, its always nice having both hands free. In that case, Pelican, Petzl, Princeton Tec, and Streamlight all make good incandescent headlamps. Good Luck!

 

[kramer5150]

fascinating thread!!!

Periodically I inspect my kids ears for earwax build up. They have a dry-clumpy kind that just falls out as opposed to the wet gooey stuff. So I dust it off with a q-tip.

I prefer the warm-ish tones of my 6P, but 65L is overkill... and furthermore my daughter complains "Too hot Daddy!!, use the green light please". The green light, being a nuwai river rock, which happens to be my most yellow LED. So, whichever incan you choose... keep that in mind.

Good Luck!!

 

[Mercaptan]

The best LED for medical use? The answer is... none. Like what Beastmaster says, the advantages of an LED really aren't pertinent to medicine.

Stick with the crappy Moore Medical penlights, they suck, but they do have decent color definition.