Acoustic Characterisation of Konjac Glucomannan Gel as a Medical Phantom Anis Nazihah MAT DAUD 1,a , Md Supar ROHANI 1,b,* and Rosly JAAFAR 2,c 1 Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, 81310 Skudai, Johor, Malaysia 2 Department of Physics, Faculty of Science and Mathematics, Universiti Pendidikan Sultan Idris, 35900 Tanjong Malim, Perak, Malaysia a anisnmd@yahoo.co.uk, b mdsupar@utm.my, c rosly@fsmt.upsi.edu.my Keywords: acoustic properties, konjac glucomannan gel, medical phantom, ultrasonic insertion technique, temperature Abstract. Acoustic properties are the main criteria to evaluate the compatibility of tested materials as a medical phantom. We determined the acoustic properties of konjac glucomannan (KGM) gel to verify its compatibility as a medical phantom. The acoustic properties measurement employed ultrasonic insertion technique and utilized two identical transducers of 5 MHz center frequencies. One KGM gel block with 5.62 mm thickness was used as sample to determine its longitudinal speed, acoustic impedance and attenuation coefficient at three different water temperatures; (21.5 ± 0.1), (22.5 ± 0.1) and (23.5 ± 0.1) o C. Findings indicated that its longitudinal speed and acoustic impedance increased from (1495 ± 1) to (1499 ± 1) m s -1 and (1.555 ± 0.001) to (1.559 ± 0.001) × 10 6 kg m -2 s -1 as the water temperature increased from (21.5 ± 0.1) to (23.5 ± 0.1) o C. It also indicated that its attenuation coefficient varied around (0.1303 ± 0.0107) to (0.1373 ± 0.0103) dB cm -1 with increasing water temperature. KGM gel is compatible to be a medical phantom since its acoustic properties are comparable to the acoustic properties of human soft tissue. Introduction The acoustic properties of human tissues are different from one another [1]. Thus, the values of acoustic properties are important to determine the compatibility of a tested material as a medical phantom. Medical phantoms are materials that mimic acoustic properties of human tissue [2, 3]. The common materials used as phantom are polyvinyl alcohol (PVA) gel [4, 5], polyacrylamide (PAA) gel [6, 7], gelatin [8, 9] and agar [10–12]. Konjac glucomannan (KGM) is a neutral polysaccharide produced from Amorphophallus konjac tubers. It is normally used as a gelling agent since it has some unique properties, such as high elasticity [13, 14], good ultrasonic characteristics [13] and stable in the presence of acid and salt [14]. Some previous studies mixed carrageenan with KGM to increase the elasticity of carrageenan [14–16]. In 2015, Tomlinson and Taylor investigated the mechanical properties of KGM gel for biomechanics application [17]. However, they did not study its acoustic properties to determine its compatibility as a medical phantom. In this paper, the acoustic properties of KGM gel; longitudinal speed, acoustic impedance and attenuation coefficient are measured using ultrasonic insertion technique at the temperature range of (21.5 ± 0.1) to (23.5 ± 0.1) o C. Measurements are repeated for five times to verify the consistency of results. Then, the results are compared with the acoustic properties values of real human tissue to confirm its compatibility as a medical phantom. Solid State Phenomena Submitted: 2016-10-21 ISSN: 1662-9779, Vol. 268, pp 379-383 Revised: 2017-07-04 doi:10.4028/www.scientific.net/SSP.268.379 Accepted: 2017-07-06 © 2017 Trans Tech Publications, Switzerland Online: 2017-10-17 All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of Trans Tech Publications, www.scientific.net. (#101453171-14/09/17,16:11:44)