Methods to design and evaluate transcranial ultrasonic lenses using acoustic holography

[EN] Ultrasonic three-dimensional printed holograms are getting increasing interest for transcranial therapies since they can correct skull aberrations and, simultaneously, adapt the acoustic field to particular brain targets. However, evaluating the targeting performance of these systems requires t...

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Bibliographic Details
Authors: Andrés, Diana, CARRIÓN GARCÍA, ALICIA|||0000-0002-0630-6065, Camarena Femenia, Francisco|||0000-0002-6713-1414, Jimenez, Noe|||0000-0002-6539-670X
Format: article
Publication Date:2023
Country:España
Institution:Universitat Politècnica de València (UPV)
Repository:RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
Language:English
OAI Identifier:oai:riunet.upv.es:10251/212624
Online Access:https://riunet.upv.es/handle/10251/212624
Access Level:Open access
Keyword:Ultrasound
Holograms
Brain therapy
Holography
FISICA APLICADA
Description
Summary:[EN] Ultrasonic three-dimensional printed holograms are getting increasing interest for transcranial therapies since they can correct skull aberrations and, simultaneously, adapt the acoustic field to particular brain targets. However, evaluating the targeting performance of these systems requires the measurement of complex volumetric acoustic fields, which in many practical situations cannot be estimated by direct hydrophone measurements. In this work, we apply single-plane holographic measurement techniques to experimentally calibrate and measure the full volumetric field produced by holographic lenses. Two ex vivo test cases are presented, a four-foci lens and a preclinical case, both targeting through a macaque skull for potential applications in blood¿brain barrier opening (BBBO) studies. Time-reversal and angular spectrum projection methods are compared to direct experimental measurements. Results show that holographic projection methods can reconstruct the complex acoustic images produced by holographic lenses, matching direct measurements in all test cases. However, while direct measurements are restricted to transverse-field cross sections, holographic projection allows estimating the field on the whole targeting volume. In this way, the location and the full three-dimensional shape of all acoustic foci can be obtained. Furthermore, these techniques can provide the field at the surface of the lens to compare it to the design phase distribution. Using this procedure, complex volumetric acoustic fields can be reconstructed, saving significant measurement time and computational resources, and enabling an accurate characterization of phase plates and other holographic lens topologies.