Reusable Ultrasonic Tissue Mimicking Hydrogels Containing Nonionic Surface-Active Agents for Visualizing Thermal Lesions. - Seong Keun Park; S. R. Anjaneya Reddy Guntur; Kang Il Lee; Dong-Guk Paeng; Min Joo Choi (IEEE Trans. Biomed. Eng., 2010)