The Design Of Data Acquisition And Transmission System For The Diagnosis Of Osteoporosis Using Quantitative Ultrasound

Due to the increase of human being's life and formation of gerontal society, the osteoporosis and osteoporotic fracture, as one of the gerontal diseases, cause serious harm to people increasingly. A number of people suffer from pain for a long time. As the increase of patients and the rise in price of health service, families and society are brought about the tremendous in mind and economy. Compared with other diagnosis methods, Ultrasonic bone density instruments estimate the osseous in a completely new method, which is more accurate, well repeatability, no radiation damage and so on.It is practicable to screen out the large group of people's general examination and filtration becausee of the cheaper price.In this research, the way which measures the speed of sound (SOS) within the cortical bone of midtibia by quantitative ultrasound, reflects the quality of bone.In theory, longitudinal wave that probe transmits transforms into transverse wave within the cortical bone of midtibia complying with the theory of wave mode transform. And measurement formula of SOS has been deduced from the measuring instance. The final formula deduced from experimentation avoids the influence of soft tissue. The core in the research is the design of data acquisition that includes the data sample and transmission.As the Sample-chip that is up to 40MHz belongs to the way of high-speed sample, the research chooses CPLD as the center of control unit,whose functions charge the data that store in the SRAM at first and transfer them to the computer with the single-chip within USB interface.So this part of design includes the address generator that provides address to visit the SRAM as well as the read-write control logic unit and the timer, which finishes the aim of data acquisition.In addition, 2-bit accumulator is perfectly used to differentiate two SRAMs to work in this part.The third chapter of paper introduces the design of data sample,data store,data transmission and control unit that coordinates with them .In the design of transmission, as USB technology that is very popular has convenience and high speed, this research selects it to finish the task, that the data transfer to the computer. The fourth chapter of paper shows the design of fireware, driver, and interface step by step so that the USB specification and the process of development become easier. The last two chapters show the analysis and perspective according to the result with the measure of this device.Furthermore, contrasted with the coequal device in a hospital, this device gets the satisfied results. Therefore, this study lays the foundataion of intelligent ultrasonic osteoporcsis diagnosis instrument for the future.