Went on a search tonight on infra-red heat and more specifically, wavelengths, and came across this thing called "Ultrasonic Diathermy".
I then found a device that does so:
Quote
Ultrasonic equipment generates high frequency sound waves (1MHz) that are transferred to a specific body area via a round-headed probe. The sound waves travel deep into tissue and create gentle heat. As the probe glides over the skins surface, sound waves penetrate the skins surface causing soft tissues to creating deep heat. In turn, the heat induces vasodilatation: drawing blood into the target tissues. The generated deep heat is found to help relieve pain and reduce muscle spasms.
That is exactly what we want!
I also found similar devices/links on amazon and aol which go more by the name of an "ultrasonic massager" or "ultrasonic therapy".. Same principles apply:
AOL - Lifestyle News, Beauty, Style, Health, Travel & Food - AOL.com
The downside is that it needs to be in contact with the skin. Thought I’d share though.