Energy contained within an ultrasound beam decreases as it travels through biological tissues. In fact energy decreases because it is absorbed by biological tissues; the ultrasound wave loses energy as it overcomes internal friction that exists in tissues while traveling through them. Energy decreases also because of reflection or scattering of the ultrasound beam when it reaches a reflecting surface (for example, approximately 70% reflection of the beam occurs when ultrasound waves strike bone tissue, because of its elevated acoustical impedance).
The higher the ultrasound frequency, the more rapidly the molecules will move against this friction. The more they move, the more energy is absorbed. Consequently at high ultrasound frequencies (1-3 MHz) the beam will have less energy available to propagate further through biological tissues and will just produce superficial effects.
This is one of the major differences between traditional high frequency 1-3 MHz ultrasound devices and EQultrasound (38 kHz +/-2): since EQultrasound operates at a much lower frequency than traditional high frequency devices, it can reach deeper equine tissues and structures with limited absorption by superficial tissues.
On the other hand the ultrasound emission of high frequency 1-3 MHz devices will affect just superficial tissues, unless the intensity of the applied ultrasound is significantly increased in terms of W/cm2, but this can lead to burns and “hot spots” that might cause severe tissue damage.
EQultrasound low-frequency / longwave treatment modality is able to reach deep targets and to safely produce intense mechanical effects, essential for an effective treatment of several equine musculoskeletal conditions.