3.) Therapeutic Heat: Part B, Heating with Ultrasound
Therapeutic range is 39.8-43°C (103.6 to 109.4°F). After 45°C you risk cellular death and below isn't going to get you the effect your after. A member at another site (manko007) did some experiments by placing a thermometer in his urethra and measuring common heat applications. US was able to get to those ranges quicker, maintain best and be the most comfortable.
Therapeutic ultrasound has been used for decades for physical therapy. It's using sound waves to heat up tissues deeper into muscle bellies and tendons. There are precautions like you have to keep the transducer moving because it can heat up bone and cause pain, don't go over spine or other major nerve pathways and no organs other than penis (heart, lung, liver, testicles, prostate, etc). It usually is found in 2 frequencies 1 mHz and 3 mHz.
1 mHz can heat deeper than 2.5-5.0 cm and 3 mHz can heat 0-2.5 cm. Theoretically 3 mHz is ideal but in practical terms both would work just fine. Both heat deep and won't cause skin burn with other methods of heat. If I apply it to my dorsal side I'll mainly feel the heat in the center and on other side of penis.
1 mHz option. Delta 1 mHz.
The 3 mHz option, also the one I currently have. Delta 3 mHz
The Science of Ultrasound Dosing
I personally keep my settings on 1.6-2.0 w/ cm^2 for 10 to 20 min. I've found that to be a safe range and still provide sufficient heating in 5 to 10 min.
Ultrasound now known to me to be the best thing for therapeutic heat around. It can be dangerous if abused so research and common sense need to be used. Far infrared heat lamps, heating pads (especially moist version), or other methods could be used as well with great effects. I just know that ultrasound will reach the therapeutic level quickly and consistently and has little risk if used properly. That means not too long, not to intense and only under a tensile load.
More to come stick around and learn with Longstretch.