title: Reusable tissue-mimicking hydrogel phantoms for focused ultrasound ablation.
abstract: The ability of N-isopropylacrylamide (NIPAM)-based hydrogel phantoms to mimic tissues with different acoustic and thermal properties under high-intensity focused ultrasound (HIFU) ablation was investigated. These phantoms were designed to model the formation of thermal lesions in tissues above the threshold temperature of protein denaturation. By adjusting the concentration of acrylic acid (AAc) in the NIPAM-based hydrogel phantoms, the cloud point (i.e., lower critical solution temperature) of the phantoms could be tailored to produce HIFU thermal lesions similar to those formed in different swine tissues in terms of size and shape. Additionally, energy thresholds for inducing transient or permanent bubbles in the phantoms during HIFU ablation were also identified to shed light on the onset of cavitation or material damage. The NIPAM-based hydrogel phantoms developed in this study possess major advantages such as transparent, reusable and tailorable properties, and are practical tools for characterizing an ablative device (or treatment) to determine its efficacy and safety.
authors.affiliation: Department of Physical Medicine and Rehabilitation, National Taiwan University Hospital & College of Medicine, Taipei, Taiwan; Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes, Miaoli, Taiwan.
authors.forename: Ming-Kuan
authors.initials: MK
authors.lastname: Sun
authors.affiliation: Department of Materials Science and Engineering, National Taiwan University, Taipei, Taiwan.
authors.forename: Jay
authors.initials: J
authors.lastname: Shieh
authors.affiliation: Department of Physical Medicine and Rehabilitation, National Taiwan University Hospital & College of Medicine, Taipei, Taiwan.
authors.forename: Chia-Wen
authors.initials: CW
authors.lastname: Lo
authors.affiliation: Department of Civil Engineering, National Taiwan University, Taipei, Taiwan.
authors.forename: Chuin-Shan
authors.initials: CS
authors.lastname: Chen
authors.affiliation: Department of Civil Engineering, Chung Yuan Christian University, Chung Li, Taiwan.
authors.forename: Ben-Ting
authors.initials: BT
authors.lastname: Chen
authors.affiliation: Department of Civil Engineering, Chung Yuan Christian University, Chung Li, Taiwan. Electronic address: cwhuang@cycu.edu.tw.
authors.forename: Chang-Wei
authors.initials: CW
authors.lastname: Huang
authors.affiliation: Department of Physical Medicine and Rehabilitation, National Taiwan University Hospital & College of Medicine, Taipei, Taiwan; Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes, Miaoli, Taiwan. Electronic address: wenshiang@gmail.com.
authors.forename: Wen-Shiang
authors.initials: WS
authors.lastname: Chen
keywords: Cloud point; High-intensity focused ultrasound (HIFU); N-isopropylacrylamide (NIPAM); Phantom; Thermal lesion; Tissue-mimicking