Application of focused ultrasound for the stimulation of neural structures.

The feasibility of the use of focused ultrasound for stimulation of the superficial and deep-seated receptor structures of humans and animals are presented in this review article. Applications of this method in physiology, for research into somatosensory and hearing perception, and also in clinical medicine for the diagnosis of neurological, dermatological and hearing disorders involving changes in perception of sensations different from normal, are discussed. It is proposed that the main effective factor of focused ultrasound as a stimulus of neural structures is a mechanical one. Such a mechanical effect could produce a change in membrane potential resulting in the stimulation of neural structures, which is related to the origin of tactile, thermal and hearing sensations. The direct action of sign-altering ultrasonic oscillations during the use of comparatively long ultrasound stimuli could possibly be the main effective factor for the induction of pain sensations and can also change the thresholds of other sensations (thermal, hearing and so forth).