2019 Volume 40 Issue 2 Pages 116-126
In this work, we built ultrasonic disc-shaped transducer for targeted neuromodulation with the addition of a solid axicon lens based on a polydimethylsiloxane (PDMS) interface. We made a numerical and experimental characterization of its acoustic field. The motor cortex of CF-1 mice was stimulated, through the skin and skull into the intact brain, with low-intensity pulsed ultrasound. Evoked muscle responses in different body segments were clearly observed, including hindlimb, forelimb, and tail. Axicon lens affixed on the face of the transducer makes possible a targeted modulation of the motor cortex by pulsed ultrasound, inducing muscle contraction in a specific body segment. In this approach, the lateral and axial spatial resolution is comparable to spherical segment ultrasound transducers, but with a shorter focal length. Thus, ultrasound axicon looks attractive to investigate the functional contributions of fine-grained spatial structures in the brain.
