Develop a photoacoustic sensor for blood pressure measurement

Abstract

Photoacoustic imaging also known as optoacoustic imaging, is defined as a biomedical imaging modality based on the photoacoustic effect. In photoacoustic imaging, non-ionizing laser pulses are penetrated biological tissues (when radio frequency pulses are selected, the technology can be called as thermoacoustic imaging). A substantial amount of received energy will be absorbed and converted into heat energy, which results in transient thermoelastic expansion and hence wideband (i.e. MHz) ultrasonic emission. The generated ultrasonic waves are received by ultrasonic transducers and then analysed to form images. It is known that optical absorption is closely related with physiological properties, such as haemoglobin concentration and oxygen saturation. As a result, the amplitude of the ultrasonic emission (i.e. photoacoustic signal), which is proportional to the local energy deposition, reveals physiologically specific optical absorption contrast. This project will demonstrate on a non-invasive photoacoustic sensor experiment which can be used to measure the blood pressure. Software simulation on MatLab and graph generation have been done to support the theory.