{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,11]],"date-time":"2026-05-11T20:04:59Z","timestamp":1778529899353,"version":"3.51.4"},"reference-count":58,"publisher":"MDPI AG","issue":"24","license":[{"start":{"date-parts":[[2023,12,8]],"date-time":"2023-12-08T00:00:00Z","timestamp":1701993600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Key Research Program of Frontier Sciences, Chinese Academy of Sciences","award":["ZDBS-LY-7023"],"award-info":[{"award-number":["ZDBS-LY-7023"]}]},{"name":"Key Research Program of Frontier Sciences, Chinese Academy of Sciences","award":["12374453"],"award-info":[{"award-number":["12374453"]}]},{"name":"National Natural Science Foundation of China","award":["ZDBS-LY-7023"],"award-info":[{"award-number":["ZDBS-LY-7023"]}]},{"name":"National Natural Science Foundation of China","award":["12374453"],"award-info":[{"award-number":["12374453"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>In this paper, we utilize micro-computed tomography (micro-CT) to obtain micro-CT images with a resolution of 60 \u03bcm and establish a micro-CT model based on the k-wave toolbox, which can visualize the microstructures in trabecular bone, including pores and bone layers. The transcranial ultrasound phased array focusing field characteristics in the micro-CT model are investigated. The ultrasonic waves are multiply scattered in skull and time delays calculations from the transducer to the focusing point are difficult. For this reason, we adopt the pulse compression method and the linear frequency modulation Barker code to compute the time delay and implement phased array focusing in the micro-CT model. It is shown by the simulation results that ultrasonic loss is mainly caused by scattering from the microstructures of the trabecular bone. The ratio of main and side lobes of the cross-correlation calculation is improved by 5.53 dB using the pulse compression method. The focusing quality and the calculation accuracy of time delay are improved. Meanwhile, the beamwidth at the focal point and the sound pressure amplitude decrease with the increase in the signal frequency. Focusing at different depths indicates that the beamwidth broadens with the increase in the focusing depth, and beam deflection focusing maintains good consistency in the focusing effect at a distance of 9 mm from the focal point. This indicates that the phased-array method has good focusing results and focus tunability in deep cranial brain. In addition, the sound pressure at the focal point can be increased by 8.2% through amplitude regulation, thereby enhancing focusing efficiency. The preliminary experiment verification is conducted with an ex vivo skull. It is shown by the experimental results that the phased array focusing method using pulse compression to calculate the time delay can significantly improve the sound field focusing effect and is a very effective transcranial ultrasound focusing method.<\/jats:p>","DOI":"10.3390\/s23249702","type":"journal-article","created":{"date-parts":[[2023,12,8]],"date-time":"2023-12-08T05:47:30Z","timestamp":1702014450000},"page":"9702","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Transcranial Ultrasonic Focusing by a Phased Array Based on Micro-CT Images"],"prefix":"10.3390","volume":"23","author":[{"given":"Yuxin","family":"Yin","sequence":"first","affiliation":[{"name":"Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190, China"},{"name":"University of Chinese Academy of Sciences, Beijing 100049, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Shouguo","family":"Yan","sequence":"additional","affiliation":[{"name":"Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Juan","family":"Huang","sequence":"additional","affiliation":[{"name":"Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Bixing","family":"Zhang","sequence":"additional","affiliation":[{"name":"Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190, China"},{"name":"University of Chinese Academy of Sciences, Beijing 100049, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2023,12,8]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"285","DOI":"10.3109\/02656736.2015.1007398","article-title":"Neurological applications of transcranial high intensity focused ultrasound","volume":"31","author":"Wang","year":"2015","journal-title":"Int. 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