Assessment of Biomechanical Properties of Soft Tissues Using Portable Ultrasound Indentation System

  • 高 詩涵

Student thesis: Master's Thesis

Abstract

The definition of soft tissues is any tissues that connect support or surround organs of human It consists of skin fat fiber tendon ligament muscle and fascia Diseases of soft tissues include infection inflammation rupture tumor edema and hematoma The status of soft tissues in the human body is often of interest in clinical diagnosis According to previous studies we know that if soft tissues undergo pathological changes they are usually accompanied by changes in their stiffness and thickness Palpation is often used to clinically detect changes in soft tissues but this method is subjective and unquantifiable; we need a quantitative more accurate system to collocate with palpation Ultrasound is a good choice because advantages of using it are that it is non-invasive quantifiable easy to perform and cheaper than other instruments Hence in this study we developed a portable ultrasound indentation system with a hand-held probe and used chirp-coded excitation with the Tukey window function as the signal trigger Chirp-coded excitation with the Tukey window function is an effective method to increase the echo signal-to-noise ratio (eSNR) and transmitted energy because if eSNR is too low this may affect the output of the signal process and reduce the worth of a technique in clinical diagnosis If the energy of the transmitted ultrasound signals is too low it will affect the penetration depth of the ultrasound system In future studies we could use this system to detect abnormalities not only in the biceps brachii but also in other soft tissues in the human body Therefore we used ultrasound elastography with a 5-MHz single element transducer combined with a load cell which can measure 0–5 N and record the force when compressing the transducer We then integrated the ultrasound signals and force values to process the elastic information of the soft tissues In the in vitro validation we tested the technique on double layer phantoms with different hardness and stiffness as well as on porcine soft tissues In the in vivo validation we tested the biceps brachii in the human body From the information gained on tissue elasticity we found that our system was able to distinguish variations in hardness in a double layer phantom along with different layers in the porcine tissues and biceps brachii of the human body
Date of Award2016 Aug 3
Original languageEnglish
SupervisorTainsong Chen (Supervisor)

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