It is important to understand the nature of infrared energy. The Willow Curve appears to claim that the IR energy radiated penetrates into the skin and deeper - and that claim makes little sense: for IR to have penetrating abilities as they claim it must be generated at very high temperatures (or result in wavelengths just short of the visible light) - such high temperatures (well in excess of 1000 degrees C) would be too dangerous.
…
Before buying I would urge potential buyers to read up on Infrared technology. Good Luck!
Not to wade into the “does it work according to their claims” argument, but LEDs and lasers can create infrared radiation in the 1400 to 750 nm region very effectively without needing the high temperatures you’re associating with thermal-spectrum emission of that kind of radiation.
http://en.wikipedia.org/wiki/Heat_therapy has info on heat therapy and notes that IR-A spectrum is effective and penetrates to several mm. I’ve had occasion to test high power IR LEDs for various purposes, and they penetrate fingers all the way, sufficiently that you can detect your cardiac pulse on the other side. So I can see where an IR beam can be applied and it will penetrate under the skin; the radiation is eventually absorbed by the body and presumably converted to heat. The only thing is that you need to pump out enough IR power that you actually generate some beneficial (?) heating effect. I have no idea what that power level would be, but generating a couple of Watts worth of IR energy with today’s infrared LED technology is not that hard… if you had to pump out let’s say more than 20 Watts then you would have to be more diligent in the design of your device.