ISVR3070 Ocean Acoustics & Biomedical Ultrasound
Sound is a vital tool for exploring and understanding the underwater environment, it also plays a key role in many biomedical applications. This module will describe the underlying physics of sound propagation in liquids and discusses the engineering challenges when designing and assessing underwater acoustic systems. The module will consider the underlying physical principles explaining the phenomena observed in the ocean. It will consider the basic principles underlying how sound propagates and provide an understanding of some of the basics of understanding rudimentary models of sound transmission. It will describe the different types of acoustic systems and will consider how man-made systems can be analysed to make design decisions. These design principles are then applied to understand how marine mammals echolocate in the ocean. The role of acoustic systems in the conservation of these animals is also discussed. Ultrasound is widely used in medicine not only for diagnosis, but also for therapeutic purposes and for treatments. The sound fields employed in such systems typically result in non-linear propagation. This module considers how non-linearity affects sound fields and considers use of ultrasound in a biomedical context.
Aims and Objectives
Aims To introduce the fundamentals associated with the behaviour of sound and applications of acoustics in the underwater environment. The module incorporates proofs of basic relevant physics and describes the range of environments and applications. Though much of the work relates to the ocean environment, sections on non-linear and biomedical ultrasonics are also included. Objectives (teaching) The student should feel comfortable with the underlying physical processes governing sound and ultrasound in liquids, and be able as a consequence to explore similarities between sound in the ocean and ultrasound in the body, and extrapolate to new circumstances through discussion.
Disciplinary Specific Learning Outcomes
Having successfully completed this module you will be able to:
- Read, understand and interpret the literature relating to underwater acoustics and biomedical ultrasonics.
- Describe certain key discoveries and characteristics of underwater acoustics, nonlinear propagation and biomedical ultrasonics.
Propagation of sound in the ocean: Plane wave equation, sound speed dependencies, sound speed profiles in the ocean. Oceanic ray bending Huygen’s principle, reflection of sound waves, transmission loss, bottom reflections Oceanic noise Sources of noise (Knudsen and Wenz spectra), rain, breaking, bubbles. Sonar Equations Classes of sonar systems. Prototypical sonar system. Passive and active sonar equations definition of terms. Reverberation. Propagation modelling Ray tracing models and normal modes. Bioacoustics Sound sensing and production in cetaceans (whales and dolphins). The role of acoustics in conservation of these animals. Analysis of echolocation capabilities of dolphins. Non-linear acoustics The propagation of finite amplitude waveforms; Acoustics streaming; Self-interaction, parametric and stimulated scattering effects in liquids. Biomedical Ultrasound Measurement; Clinical ultrasound (diagnosis and therapy); Mechanisms of biohazard (Hyperthermia, Cavitation).
Learning and Teaching
Teaching and learning methods
Teaching methods include 3 lectures a week. Revision classes which go through past papers. Students join the course with widely varying experience (it not being uncommon to find, in addition to the Master’s students from MSc Sound and Vibration Studies, the audience including MSc Ship Science, undergraduates, and members of biomedical and oceanography departments who sit in for certain lectures. There is also a wide range of language skills, and past experience of learning methods, in the audience. To approach this mix the style of teaching uses much discussion during lectures, with free questioning both ways, between lecturer and audience (though class being invited to think, rather than individuals being asked questions). Learning activities include The lecture style includes much discussion and exploration of ideas, to foster cognitive and reasoning skills, and to develop a logic approach to the topic. Past papers sheets are gone through with students on a tutorial basis in order to practise their analytical skills and these are backed up with interactive tutorial sessions. A lab class will be held and formative feedback will be given on the lab report. Students are encouraged to do past paper questions in their own time which will be marked if completed and feedback given. Students are encouraged to read supporting texts and a booklist is provided.
|Total study time||150|
Resources & Reading list
Resources. The Blackboard site for this course provides pdfs of all lecture notes, plus a number of specific texts and examples for the students to use.
A lab report
Repeat type: Internal & External