Design of optoacoustic imaging system for deep penetration medical diagnostics

• Main Author: Xu, Chenyu
• Other Authors: Zheng Yuanjin
• Format: Final Year Project
• Language: English
• Published: 2015
• Subjects: DRNTU::Engineering::Electrical and electronic engineering
• Online Access: http://hdl.handle.net/10356/65673
• Institution: Nanyang Technological University

In recent years, technology has evolved so rapidly that systems are becoming more and more complex, especially, current photoacoustic imaging technique may no longer be able to fulfill the requirements of medical diagnose. This led to increase development in the area of self-temperature regulation system. Photoacoustic imaging is an emerging and fast-developing biomedical imaging technique. It may be developed to examine the condition of animal or human organs, such as breast or brain, with simultaneous good contrast as well as high spatial resolution. Such promising technology can realize imaging of biomedical tissues deep inside tissues. This project presents the photoacoustic based temperature sensing and its subsequent close loop control of the temperature. In this project, a customized visible laser at wavelength of 405 nm was designed to emit laser pulse that irradiates the matter. Photoacoustic effect happened and thus emitting ultrasonic signal. These signals were received by an ultrasonic transducer. The subsequent close loop temperature control is intended as a feasibility study and it could be scaled up for photothermal therapy with the capability of tight temperature control. In order to achieve self-temperature regulation, a proportional-integral-derivative (PID) controller monitors the feedback from frequency domain photoacoustic measurements and controls the strength of the heating; finally stabilize the matter temperature at a preset value. Therefore, for future development of medical diagnosed system can be incorporated with self-temperature regulation system with reduced costs and size for portable applications.