Reusable tissue-mimicking hydrogel phantoms for focused ultrasound ablation

Ming-Kuan Sun; Jay Shieh; Chia-Wen Lo; Chuin-Shan Chen; Ben-Ting Chen; Chang-Wei Huang; Wen-Shiang Chen

doi:10.1016/j.ultsonch.2014.10.008

Reusable tissue-mimicking hydrogel phantoms for focused ultrasound ablation

Ultrason Sonochem. 2015 Mar:23:399-405. doi: 10.1016/j.ultsonch.2014.10.008. Epub 2014 Oct 16.

Authors

Ming-Kuan Sun¹, Jay Shieh², Chia-Wen Lo³, Chuin-Shan Chen⁴, Ben-Ting Chen⁵, Chang-Wei Huang⁶, Wen-Shiang Chen⁷

Affiliations

¹ 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.
² Department of Materials Science and Engineering, National Taiwan University, Taipei, Taiwan.
³ Department of Physical Medicine and Rehabilitation, National Taiwan University Hospital & College of Medicine, Taipei, Taiwan.
⁴ Department of Civil Engineering, National Taiwan University, Taipei, Taiwan.
⁵ Department of Civil Engineering, Chung Yuan Christian University, Chung Li, Taiwan.
⁶ Department of Civil Engineering, Chung Yuan Christian University, Chung Li, Taiwan. Electronic address: cwhuang@cycu.edu.tw.
⁷ 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.

PMID: 25453217
DOI: 10.1016/j.ultsonch.2014.10.008

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.

Keywords: Cloud point; High-intensity focused ultrasound (HIFU); N-isopropylacrylamide (NIPAM); Phantom; Thermal lesion; Tissue-mimicking.

Publication types

Research Support, Non-U.S. Gov't