Abstract
Optical holograms can modulate light wavefronts to generate visible images. In the same way, acoustic images can also be synthesized by holograms, shaping the areas where mechanical waves present a high amplitude, and areas where the media is at rest. We present acoustic holograms based on metasurfaces for emerging therapeutic applications of focused ultrasound for the non-invasive treatment of neurological disorders. When targeting acoustic beams into the brain, accurate focusing is mainly limited due to the strong phase aberrations produced by the refraction and attenuation of the skull. Acoustic holograms can overcome these limitations by synthesizing aberration-free ultrasonic fields of complex spatial distribution inside the skull. Our results show that, using low-cost 3D-printed holograms, ultrasonic beams can be focused not only at a single point, but overlapping at one or various target structures simultaneously, e.g., left and right hippocampi. Designs are validated by ex-vivo and in-vivo experiments to produce a bilateral blood-brain barrier opening in mice for drug delivery, and complex thermal patterns for localized hyperthermia. Other complex fields such as vortex beams for trapping small objects can also be synthesized inside the human skull. These results open new paths to spread emerging therapeutic ultrasound applications including blood-brain barrier opening, hyperthermia or neuromodulation using low-cost systems.
BibTeX citation
@inproceedings{JimenezMetamaterials2021Holograms,
author = {Noé Jiménez and Sergio Jiménez-Gambín and Diana Andrés and José M. Benlloch and Francisco Camarena},
booktitle = {METAMATERIALS 2021. 15th International Congress on Artificial Materials for Novel Wave Phenomena. New York, 20 - 25 September},
editor = {Metamorphose},
isbn = {ISSN: 0001-4966},
month = {09},
organization = {The City University of New York},
publisher = {AIP Publishing},
series = {Oral},
title = {Acoustic Holograms for Biomedical Ultrasound Applications},
year = {2021}
}