I don't know what emitters they are exactly. I tried to take it apart enough to see but when I got down to where appeared to be glued I had to stop. Hospital property and all that.
It reduces the time needed for wounds to heal. We combine the blue light from the LEDs with a chromophore gel that creates specific wavelengths of light. Those wavelengths stimulate and deliver energy to exposed skin which results in increased cellular metabolism. It's similar to cold laser therapy but lower overall energy so it doesn't penetrate as far into the body.