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Shinna Minna Ma 02-10-2020 01:36 PM

Two operating room questions about the lights
Other than brightness, is there anything special about the lights used in operating rooms? And while we're on the subject, I noticed in some pictures that some of the OR lights have multiple lights (or their coverings) in different colors, mostly with a bluish tint. What is the reason for that?

brossa 02-10-2020 10:47 PM

Those multi-bulb fixtures are lensed so as to produce overlapping fields of light, ideally without hot spots or variations from one bulb to the next. Twisting a central handle will cause these spots to converge or diverge, in effect altering the focal point of the fixture. You can thus get a tighter, brighter spot or a wider field of illumination. Sometimes the tightly focused beam is just too bright to be comfortable, or the wide beam gives glare and reflections that you don't want.

Colored lenses would most likely be trying to achieve some particular color temperature of the light. It's certainly more comfortable to be working under something resembling midday sunlight than some sickly fluorescent tint, or something that's missing a bunch of valuable wavelengths.

Anecdote: as a med student I rotated through a brand-new ICU that had clerestory windows with sunlight bouncing off a sky-blue ceiling. Everybody that walked in there looked drowned because of the resulting blue light. Skin looked mottled and bruised. They had to close the unit briefly and repaint it.

ftg 02-12-2020 07:46 AM

One thing that could be done by changing the colors is to make it easier to differentiate tissues. E.g., you play around with the colors to maximize the contrast between normal and damaged/cancerous/whatever tissue and start cutting away the bad stuff.

Note: "could be done". Don't know if this is actually done. Even though dermatologists, for example, do something like this during skin examinations.

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