I agree completely. If you are going to spend $400 per LED you want to do everything you can to protect them. Your approach of gradually increasing the current is right on. Voltage and heat destroy common household light bulbs, excessive current destroys LEDs. And if it doesn't destroy them outright it will greatly lessen their effective life.

I don't think it is clear to everyone how many LEDs you need to build a helmet. The L1070-66-60 LED has output radiant power of 60 mw. Dr. Dougal's invention calls for up tp 15 watts of radiant power output per square cm during a treatment session. If you assume a 20 minute treatment session and a treatment area of 600 square cm, (the hair area of the head plus the forehead), you would need a total of 9000 watts of radiant power or 7.5 watts per second for the 1200 second treatment period. To get 7.5 watts from 60mw LEDs you would need 125 LEDs. At $400 each, that is $50,000. If you used the less expensive L1070-03 which are about $8.00 each you would need 7500 of them since they only emit 1mw of radiant power per second. The cost of the cheap ones would be $60,000 but forget it, you can't put that many on a helmet. Not sure how accurate my head size numbers are but even if they are off by 25% we are still talking big money.