Physical Field Simulation And Algorithm Optimization Based On Ultrasonic Backscatter Of Cancellous Bone

Many studies have shown that osteoporosis can not only be manifested as a decrease in bone mineral density(BMD),but also in the degeneration of cancellous bone microstructure.At present,the instrument for early detection of osteoporosis in the market is mainly based on the measurement of human bone mineral density(BMD),and less can reflect the changes in the microstructure of the cancellous bone,which is not conducive to the comprehensive diagnosis of osteoporosis.In recent years,with the development of ultrasonic backscatter technology,it has been found that the ultrasonic backscattering method can obtain information about the microstructure of cancellous bone.However,due to the weak backscatter signal of the human cancellous bone,the imperfect signal processing algorithm and the lack of effective simulation and verification environment,the technology is still unable to meet the requirements of clinical application.Based on the finite element analysis and multi physical field simulation technology,This paper construct the acoustic solid coupling model of human calcaneus according to the structure of the human calcaneus,the acoustic characteristics of the human calcaneus and the properties of the mechanics.For the research of ultrasonic backscattering in cancellous bone,it provides a simulation verification environment which is closer to the real scene,reduces the cost of the algorithm and improves the efficiency of the research.On the basis of the above simulation model,this paper takes the important evaluation parameter of the cancellous bone microstructure——the mean space of the bone trabecula(MTBS)as the breakthrough point,and carries out the simulation analysis of the existing MTBS measurement algorithms(matched filter base frequency estimation and quadratic transformation).In view of the quadratic harmonic oversize problems and low frequency leakage in the two algorithms,an optimization scheme for multiplying the two algorithms is proposed in this paper.Through the simulation analysis and the Measured verification,the conclusion is drawn that the proposed scheme can improve the measurement range of the existing algorithms and meet the needs of the human body measurement in the condition of maintaining the measurement precision.Based on the above algorithm,the existing ultrasonic backscatter bone density measurement system is improved,and a large number of physical model verification and human measurement research are carried out on the basis of the improved system.According to the measured results,this paper draws a conclusion that the MTBS parameters measured by the optimized algorithm can reflect the bone condition of the human body to a certain extent,and have no obvious correlation with the results measured by other equipment,which has the certain clinical diagnostic significance and the value of further research.