Colloid Vibration Potential for Imaging in Engineering and Medicine

Ultrasound Vibration Potential (UVP) is an electric signal generated when ultrasound pulses travel through a colloidal suspension or ionic electrolyte. The electric potential can be measured, providing information useful to characterize the nanoparticles and ionic electrolytes in engineering and particularly, complimentary information to conventional ultrasound imaging in medicine. The main advantage of this method over current conventional ultrasound imaging is that it can measure and further, image differences in ion recipe or physiochemical properties of particles in colloids. The simple approach is to apply external ultrasound pressure wave propagating through a nanoparticle suspension or ionic electrolytes. The nanoparticles begin to vibrate due to the ultrasound pressure, and this results in the generation of electric potential which can be detected by an electrode sensor attached to the body.
This thesis reviews the fundamental physical theory of ultrasound and UVP imaging techniques. The ultrasound vibration potential distribution (UVPD) model based on a static charge dipole field is established and analysed in a numerical method. A new UVP testing phantom made from agar, called the Leeds standard III UVP device for UVP imaging, has been designed, in which electrodes are non-intrusively attached to the body. The measurements using the mock body phantom, containing either ionic or nanoparticle species, are in good quality comparing those measurements obtained from colloidal suspension and consistence with results from the numerical simulation. A method of frequency domain analyse with a number of segmented chirp signal ranges is proposed, which reveals both frequency and phase angle responses are function of particle size. The research also demonstrates how UVP can reveal specific physiochemical structures of colloids or tissue which the conventional ultrasound technique cannot see, with samples of ionic species, silica and titanium dioxide nanoparticles and further the animal (pork) tissue.
The results, along with previous findings, further support the potential of UVP for application in engineering for nanoparticle and ionic electrolyte characterisation and providing new and/or complementary knowledge for medical diagnosis and research.