Energy Focused Ultrasound Tumor Therapy System - Image Processing Subsystem

Malignant tumor is one of the most serious illness threatening to people health, how to cure it is always the goal that people make great efforts to. Today, the main methods used in curing tumor are surgery, actinotheraphy, chemotherapy and so on. Surgery is easy in casing malignant cells transfer, and it is impossible to operate in some place of the body, it can also bring great harm to person's body. Actinotheraphy use radiation to treat tumor, at the same time of killing malignant cells, it will also kill the general cells. Chemotherapy use chemical drugs to treat tumor, it also bring harm to person's body. It is a new hotspot that using ultrasonic to treat tumor in the world recently. Focusing ultrasonic on tumor, we can kill the malignant cells using the heat generated by ultrasonic without serious side effect like actinotheraphy or chemotherapy, so, it is new method with great hope. That we make the research of the system of HIFU (high-intensity focused ultrasound) have great practicability and economic benefit.Ultrasound B-scan images processing subsystem is one of the key subsystem of the tumor therapy system with HIFU, playing an important role in the development of the tumor therapy system with HIFU. Medicine 3D-image can give more information than 2D-image, and provide exact data for diagnosis and treatment. The aim of this paper is to reconstruct 3D-image of tumor, and offer 3D-data used by analysis and therapy.In this paper, we study this aspects of Ultrasonics, B-scan imaging, image collecting, Digital Image Processing, and establish the whole frame of image processing. We first use MATLAB to simulate for its feasibility, then write programme and debug it. The whole frame used in this paper is that, First, by using video card, we get a series of B-scan images, then delete the noise in this images. Secondly, draw the outline of interesting object in each image by manual, through clicking mouse on screen. Thirdly, reconstruct 3D-image using 2D contour. Finally, using OpenGL lib, we show the 3D-image on screen.Because of the principle of ultrasonic imaging, removing the speckle noise in the images is the most difficult focus in ultrasonic image processing. In this paper, we present wavelet shrinkage and gray level mapping techniques to remove noise, and get satisfying result by experiment. The method not only removes the speckle noise, but also enhances contrast.Reconstructing 3D-image from 2D contour lines is a very difficult problem, we study the shortest diagonal algorithm that is used for signal contour line, and present enhanced algorithm, by that, we realize the connection between two contour lines.In this paper, we use OpenGL technique in showing 3D-image, improving display effect. It is very easy to realize image scale, image translation, image rotation, and so on.