Soft Tissue Ultrasonic Scattering Sub-concentration Is Estimated

Soft tissue ultrasound parameters can reflect the physiological and pathological changes and the structure of the organization. Estimating the ultrasonic transmission characteristics have been the research hotspot in the biomedical field. The concentration of the scatterer is estimated in the medical field, which can be used to detect or prevent the occurrence of disease. For non-organic diseases, there is very difficult of detecting the disease such as hepatitis, cirrhosis and so on.which using traditional B-testing. However we can detect its changes in the concentration of organization to prevent disease. At present, it has a number of algorithms in this area with varied effects. This research topic is to seek the best estimation method and improve the accuracy of soft tissue algorithm. It can closely apply to clinical field.From the rule of the ultrasonic transmission and the basic method that is receiving and dealing with signal, this paper researches the method that is gathering and dealing with the ultrasonic scatter signal by researched the mechanism and model of the ultrasonic transmission. In this paper, we will improve the traditional methods which is using estimate the distribution rule of the concentration of the ultrasonic scatterer and make the experiment that simulate the concentration of ultrasound scatterer. The mainly research contents of this paper is as following:(1) From the theoretical model of the soft tissue ultrasound transmission, this paper analysis the suitable for the ultrasonic transmission model estimation for density of ultrasonic scatterer.(2) This paper, through discussing the estimated scattering methods of the density of scattering. By using the traditional use of attenuation ratio of the density of scattering reflect the density of scattering on this basis and introducing the power spectrum of backscatter inversion with scatter concentration. It seeks the relationship between the power spectrum and the density by using curve fitting method. Finally we will compare with the two algorithms.(3) Within the basic spectrum of time domain signal analysis, this algorithm uses the Burg algorithm of AR spectral analysis and improves the accuracy of soft tissue algorithm.(4) We can design the ultrasonic testing system, the lateral resolution of ultrasonic probe relate to its beam width by using ultrasound scanning equipment on the transducer. The width of the probe beam can estimate through this system.(5) This paper designs experimental phantom and estimates the density of distribution. It compares the existing algorithm and improved algorithm. The results of this paper show that:(1) New algorithm that can make high-accuracy to estimate concentration of the scatterer is more ideal than the traditional algorithm that is using attenuation coefficient to reflect the concentration of the scatterer.(2) The experimental result show that using attenuation coefficient method and power spectrum method to estimate the distributing concentration of the water and gelatin phantom shows the concentration of sand distribution that using power spectrum to calculate is closely to the theory values. It shows that the algorithm is feasible. The algorithm perform a high accuracy comparison with traditional attenuation coefficient..(3) The result that estimating the power spectrum of the time domain signal by using Fourier transform and processing Burg. Burg algorithm is more stable and has good-effect. This algorithm has more potential applications in the detection and prevention of non-organic for the medical field by using power spectral density method.