Multi-Site Ultrasound Detection System For Osteoporosis

Osteoporosis (OP) is a serious problem that influencing the human health. The number of OP patients has increased year by year with the aging of the population. OP has been defined as a disease characterized by low bone mass and micro-architectural deterioration of bone tissue, leading to a consequent increase in fracture risk. Quantitative ultrasound bone mineral density measurement is a new method developed in recent years. It has received a wide attention due to its advantages such as radiation free, low cost, convenience and portability.Based on the ultrasound fundamental theory, the system diagnoses the OP by measuring the speed of sound (SOS) when the ultrasound passing through radius and phalange. SOS mainly indicates the material density and the changes of microstructural of bones. The measurement of radius is based on axial transmission, which decects the speed of the first arrival signal (FAS). While the measurement of phalange is based on the passing-through transmission of the ultrasound, the parameter is the Amplitude-dependent Speed of Sound (AD-SOS). Generally the higher the SOS value, the higher the bone mineral density.The features of OP in long bones are the decrease of cortial thickness. According to that feasure, we use the software SimSonic2D to build the simulation experiment to simulate the ultrasound transmission in radius and phalange. We built two types of models with different cortical thicknesse (5mm,4.5mm,4mm,3.5mm,3mm,2.5mm,2mm,1.5mm, lmm). 1.25MHz ultrasonic wave are chosen to do the experiment. The simulation results indicate that the SOS and AD-SOS are sensitive to the cortical thickness and the less the cortical thickness, the lower the speed of sound.The system is based on the simulation results and the theory of ultrasound transmission. The hardware platform uses FPGA chip as a control unit, USB chip as a data transmission bridge. The hardware system controls the ultrasound emition and receiving and the corresponding processes to the data sample. The system uses two types of probe to detect radius and phalange to improve the accuracy of result.The software for PC is developed based on the C++ language. The software can send control orders, receive the sample data and process the data, measure the velocity of SOS and AD-SOS. The system can evaluate the long bones by comparing measure results with the reference value.The system measures the two position of the bone and basically realized the diagnosis of osteoporosis and has the characteristics of small volume, high intelligence and portable. This system has important meanings to the diagnoses of OP.